Clinical Features of Childhood Primary Ciliary Dyskinesia by Genotype and Ultrastructural Phenotype

PubMed Central

Ferkol, Thomas W.; Rosenfeld, Margaret; Lee, Hye-Seung; Dell, Sharon D.; Sagel, Scott D.; Milla, Carlos; Zariwala, Maimoona A.; Pittman, Jessica E.; Shapiro, Adam J.; Carson, Johnny L.; Krischer, Jeffrey P.; Hazucha, Milan J.; Cooper, Matthew L.; Knowles, Michael R.; Leigh, Margaret W.

2015-01-01

Rationale: The relationship between clinical phenotype of childhood primary ciliary dyskinesia (PCD) and ultrastructural defects and genotype is poorly defined. Objectives: To delineate clinical features of childhood PCD and their associations with ultrastructural defects and genotype. Methods: A total of 118 participants younger than 19 years old with PCD were evaluated prospectively at six centers in North America using standardized procedures for diagnostic testing, spirometry, chest computed tomography, respiratory cultures, and clinical phenotyping. Measurements and Main Results: Clinical features included neonatal respiratory distress (82%), chronic cough (99%), and chronic nasal congestion (97%). There were no differences in clinical features or respiratory pathogens in subjects with outer dynein arm (ODA) defects (ODA alone; n = 54) and ODA plus inner dynein arm (IDA) defects (ODA + IDA; n = 18) versus subjects with IDA and central apparatus defects with microtubular disorganization (IDA/CA/MTD; n = 40). Median FEV1 was worse in the IDA/CA/MTD group (72% predicted) versus the combined ODA groups (92% predicted; P = 0.003). Median body mass index was lower in the IDA/CA/MTD group (46th percentile) versus the ODA groups (70th percentile; P = 0.003). For all 118 subjects, median number of lobes with bronchiectasis was three and alveolar consolidation was two. However, the 5- to 11-year-old IDA/CA/MTD group had more lobes of bronchiectasis (median, 5; P = 0.0008) and consolidation (median, 3; P = 0.0001) compared with the ODA groups (median, 3 and 2, respectively). Similar findings were observed when limited to participants with biallelic mutations. Conclusions: Lung disease was heterogeneous across all ultrastructural and genotype groups, but worse in those with IDA/CA/MTD ultrastructural defects, most of whom had biallelic mutations in CCDC39 or CCDC40. PMID:25493340

Microscopic and ultrastructural features in Wolcott-Rallison syndrome, a permanent neonatal diabetes mellitus: about two autopsy cases.

PubMed

Collardeau-Frachon, Sophie; Vasiljevic, Alexandre; Jouvet, Anne; Bouvier, Raymonde; Senée, Valérie; Nicolino, Marc

2015-11-01

Wolcott-Rallison syndrome (WRS) is a rare autosomal recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple bone dysplasia, hepatic dysfunction, and growth retardation. All clinical manifestations result from gene mutations encoding pancreatic endoplasmic reticulum eIF2 α kinase (PERK), an endoplasmic reticulum transmembrane protein that plays a role in the unfolded protein response. Histological and ultrastructural lesions of bone and pancreas have been described in animal models and WRS patients. However, histological and ultrastructural findings of other organs, especially of the liver, are lacking. Autopsy specimens from two pediatric patients with WRS were analyzed. An immunohistochemical study was performed on the pancreas. An ultrastructural study was realized from samples of liver, pancreas, kidney, and myocardium. Our findings were compared with those of the literature and correlated with the molecular data. Hepatocytes and pancreatic exocrine cells exhibited very peculiar features of necrosis suggestive of secondary changes because of endoplasmic reticulum overload. Steatosis occurred in renal tubular cells, hepatocytes, and myocardial fibers. Abnormal mitochondria were noted in renal and myocardial fibers. Pancreas islets were characterized by a marked reduction in the number of insulin-secreting β cells. The histological and ultrastructural features that occur in WRS are directly or indirectly linked to endoplasmic reticulum (ER) dysfunction and can explain the peculiar phenotype of this syndrome. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Rate of dehydration, state of subcellular organisation and nature of cryoprotection are critical factors contributing to the variable success of cryopreservation: studies on recalcitrant zygotic embryos of Haemanthus montanus.

PubMed

Sershen; Berjak, Patricia; Pammenter, N W; Wesley-Smith, James

2012-01-01

Effects of sequential procedures required for cryopreservation of embryos excised from the recalcitrant seeds of Haemanthus montanus were assessed ultrastructurally and in conjunction with respiratory activity and the rate of protein synthesis. Fresh material (water content, 5.05 ± 0.92 g g(-1) dry mass) afforded ultrastructural evidence of considerable metabolic activity, borne out by respiratory rates. Neither exposure to glycerol nor sucrose as penetrating and non-penetrating cryoprotectants, respectively, brought about degradative changes, although increased vacuolation and autophagy accompanied both, while respiratory and protein synthetic activity were not adversely affected. Glycerol-cryoprotected embryos flash dried to water contents >0.4 g g(-1) showed organised ultrastructural features and considerable autophagy consistent with metabolic activity, and although respiratory activity was lower, protein synthesis rate was enhanced relative to fresh material. However, at water contents <0.4 g g(-1), embryo tissue presented a mosaic of cells of variable density and ultrastructural status, but trends in rates of respiration and protein synthesis remained similar. Flash drying after sucrose exposure was accompanied by considerable ultrastructural abnormality particularly at water contents <0.4 g g(-1), lysis of individual and groups of cells and considerable depression of respiration, but not of protein synthesis. Success, assessed as ≥50% axes forming seedlings after cryogen exposure, was obtained only when glycerol-cryoprotected embryos at water contents >0.4 g g(-1)-in which the degree of vacuolation remained moderate-were rapidly cooled. The outcomes of this study are considered particularly in terms of the stresses imposed by prolonged, relatively slow dehydration and ultimate water contents, on embryos showing considerable metabolic activity.

Fine-needle aspiration cytology of malignant hemangiopericytomas with ultrastructural and flow cytometric analyses.

PubMed

Geisinger, K R; Silverman, J F; Cappellari, J O; Dabbs, D J

1990-07-01

A hemangiopericytoma (HPC) is an uncommon soft-tissue neoplasm that may arise in many body sites. The cytologic features of fine-needle aspirates (FNAs) of HPCs have only rarely been described in the literature. We examined FNAs of malignant HPCs from the head and neck region (three) and the retroperitoneum (one) in four adults (aged 38 to 83 years). All four FNAs yielded cellular specimens that consisted of uninuclear tumor cells with high nuclear-cytoplasmic ratios. The cytomorphological spectrum included nuclei that were oval to elongate and had very finely granular, evenly distributed chromatin with one or two small but distinct nucleoli. Hemangiopericytomas yield aspirates that may be considered malignant and may suggest sarcoma. Histologically, all four neoplasms manifested high mitotic activity. The ultrastructural features of all four tumors were supportive of the diagnosis of HPC. Although a specific primary diagnosis of HPC on FNA of a soft-tissue mass is unlikely, cytologic analysis may allow diagnosis of recurrent or metastatic HPC. We were able to perform flow cytometric determinations of tumor DNA content on three of the resected neoplasms. In two, an aneuploid pattern was found, including the neoplasm with the most marked pleomorphism in the FNA. The third was diploid.

Acute erythroblastic leukemia presenting as acute undifferentiated leukemia: a report of two cases with ultrastructural features.

PubMed

Reiffers, J; Bernard, P; Larrue, J; Dachary, D; David, B; Boisseau, M; Broustet, A

1985-01-01

This report describes two elderly patients with acute leukemia in which blast cells were undifferentiated with conventional light microscopy (L.M.) and cytochemistry. Blast cells were identified as belonging to the erythroblastic line by their ultrastructural features: glycogen deposits, lipidic vacuoles, cytoplasmic ferritin molecules and rhopheocytotic invagination. Moreover, blast cells were surrounding a central macrophage. Thus, these two patients had acute erythroblastic leukemia which differs from erythroleukemia (M6 of FAB classification) in which blast cells present myeloblastic characteristics.

Congenital dyserythropoiesis with intererythroblastic chromatin bridges and ultrastructurally-normal erythroblast heterochromatin: a new disorder.

PubMed

Wickramasinghe, S N; Spearing, R L; Hill, G R

1998-12-01

Two non-anaemic subjects, a father and daughter, with a new form of congenital dyserythropoiesis are reported. The features of their disorder are: (1) an abnormal blood film with basophilic stippling of red cells and oval macrocytes, (2) various dysplastic changes in the erythroblasts, including internuclear chromatin bridges, (3) ultrastructurally-normal erythroblast heterochromatin, (4) normal serum thymidine kinase activity, and (5) a probable autosomal dominant inheritance. The last three features distinguish this disorder from CDA type I.

Intracranial suprasellar angiolipoma: ultrastructural and immunohistochemical features.

PubMed

Lach, B; Lesiuk, H

1994-01-01

The authors present ultrastructural and immunohistochemical characteristics of an intracranial suprasellar tumor displaying features of cavernous angioma with islets of adipose tissue. Electron microscopy revealed thin-walled vessels separated by a loose collagenous stroma containing nests of mature adipocytes as well as fibroblasts, myofibroblasts, mast cells, and a few macrophages. Intracytoplasmic lipid droplets were also identified in scattered pericytes and smooth muscle cells of vascular walls and in the transitional cells resembling smooth muscle cells and adipocytes. Many adipose tissue cells were positive for S-100 protein with polyclonal antibodies. Other lipidized tumor cells were immunoreactive for some or all of the following: smooth muscle-specific actin, factor XIIIa, vimentin, and, occasionally, for desmin. Ultrastructure and immunohistochemistry indicate that in addition to typical adipocytes, lipidized cells of another nature contribute to the characteristic appearance of the adipose tissue component of angiolipoma.

Clinical Features and Associated Likelihood of Primary Ciliary Dyskinesia in Children and Adolescents.

PubMed

Leigh, Margaret W; Ferkol, Thomas W; Davis, Stephanie D; Lee, Hye-Seung; Rosenfeld, Margaret; Dell, Sharon D; Sagel, Scott D; Milla, Carlos; Olivier, Kenneth N; Sullivan, Kelli M; Zariwala, Maimoona A; Pittman, Jessica E; Shapiro, Adam J; Carson, Johnny L; Krischer, Jeffrey; Hazucha, Milan J; Knowles, Michael R

2016-08-01

Primary ciliary dyskinesia (PCD), a genetically heterogeneous, recessive disorder of motile cilia, is associated with distinct clinical features. Diagnostic tests, including ultrastructural analysis of cilia, nasal nitric oxide measurements, and molecular testing for mutations in PCD genes, have inherent limitations. To define a statistically valid combination of systematically defined clinical features that strongly associates with PCD in children and adolescents. Investigators at seven North American sites in the Genetic Disorders of Mucociliary Clearance Consortium prospectively and systematically assessed individuals (aged 0-18 yr) referred due to high suspicion for PCD. The investigators defined specific clinical questions for the clinical report form based on expert opinion. Diagnostic testing was performed using standardized protocols and included nasal nitric oxide measurement, ciliary biopsy for ultrastructural analysis of cilia, and molecular genetic testing for PCD-associated genes. Final diagnoses were assigned as "definite PCD" (hallmark ultrastructural defects and/or two mutations in a PCD-associated gene), "probable/possible PCD" (no ultrastructural defect or genetic diagnosis, but compatible clinical features and nasal nitric oxide level in PCD range), and "other diagnosis or undefined." Criteria were developed to define early childhood clinical features on the basis of responses to multiple specific queries. Each defined feature was tested by logistic regression. Sensitivity and specificity analyses were conducted to define the most robust set of clinical features associated with PCD. From 534 participants 18 years of age and younger, 205 were identified as having "definite PCD" (including 164 with two mutations in a PCD-associated gene), 187 were categorized as "other diagnosis or undefined," and 142 were defined as having "probable/possible PCD." Participants with "definite PCD" were compared with the "other diagnosis or undefined" group. Four criteria-defined clinical features were statistically predictive of PCD: laterality defect; unexplained neonatal respiratory distress; early-onset, year-round nasal congestion; and early-onset, year-round wet cough (adjusted odds ratios of 7.7, 6.6, 3.4, and 3.1, respectively). The sensitivity and specificity based on the number of criteria-defined clinical features were four features, 0.21 and 0.99, respectively; three features, 0.50 and 0.96, respectively; and two features, 0.80 and 0.72, respectively. Systematically defined early clinical features could help identify children, including infants, likely to have PCD. Clinical trial registered with ClinicalTrials.gov (NCT00323167).

The morphology and ultrastructure of salivary glands of Zoraptera (Insecta).

PubMed

Dallai, R; Mercati, D; Mashimo, Y; Machida, R; Beutel, R G

2017-07-01

The salivary glands of two species of Zoraptera, Zorotypus caudelli and Zorotypus hubbardi, were examined and documented mainly using transmission electron microscopy (TEM). The results obtained for males and females of the two species are compared and functional aspects related to ultrastructural features are discussed. The salivary glands are divided into two regions: the secretory cell region and the long efferent duct, the latter with its distal end opening in the salivarium below the hypopharyngeal base. The secretory region consists of a complex of secretory cells provided with microvillated cavities connected by short ectodermal ducts to large ones, which are connected with the long efferent duct. The secretory cell cytoplasm contains a large system of rough endoplasmic reticulum and Golgi apparatus producing numerous dense secretions. The cells of the efferent duct, characterized by reduced cytoplasm and the presence of long membrane infoldings associated with mitochondria, are possibly involved in fluid uptaking from the duct lumen. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultrastructural Aspects of the Prenatal Bovine Ovary Differentiation with a Special Focus on the Interstitial Cells.

PubMed

Kenngott, R A-M; Scholz, W; Sinowatz, F

2016-10-01

The aim of this investigation was to study the ultrastructural features during the development of fetal bovine ovaries (crown rump length ranging from 11.4 to 94.0 cm). An interesting observation was the occurrence of big elongated cells containing a variety of electron dense granules and light homogenous vacuoles/bodies. They were located between the stroma cells surrounding the germ cell cord ends, adjacent to the first formed primordial follicles, typically situated near blood vessels. ER alpha and ER beta receptor positive cells could be detected in the same regions by means of immunohistochemistry. Intercellular bridges linked the germ cells nests oogonia. Germ cell cords consisted of centrally located, large, pale oogonia, surrounded by elongated somatic cells with very long cytoplasm extensions. Primordial follicles with flat pale follicular cells could be observed on the inner end of the cords. Extrusions of the outer nuclear membrane could often been recognised in voluminous oocytes. © 2016 Blackwell Verlag GmbH.

A light microscopy and ultrastructural study of the testes of tortoise Testudo graeca (Testudinidae).

PubMed

Ibargüengoytía, N R; Pastor, L M; Pallares, J

1999-04-01

Adult males of Testudo graeca were used to preliminarily study the light microscopic morphology and the ultrastructure of the testes. Spermiogenesis has shown the presence of some interspecific variations among Chelonia, while the general features of the testes and spermatocytes are morphologically similar to other reptilians. The male reproductive state observed in the months analysed has shown spermatogenesis recrudescence in spring, a complete germinal series in autumn and testicular regression in winter. The observation of ultrastructural features, characteristic of steroidogenic activity, suggests a synchrony in tubular and interstitial compartments in T. graeca, with little steroidogenic activity in winter and active synthesis in spring and autumn. In conclusion, the results of this histological study suggest a probable asynchrony between the male and female reproductive cycle in this species and show synchrony in the steroidogenic activity of Sertoli and Leydig cells.

Macroscopic, histologic, and ultrastructural lesions associated with avian keratin disorder in Black-capped Chickadees (Poecile atricapillus)

USGS Publications Warehouse

Van Hemert, C.; Armién, A. G.; Blake, J.E.; Handel, Colleen M.; O'Hara, T. M.

2013-01-01

An epizootic of beak abnormalities (avian keratin disorder) was recently detected among wild birds in Alaska. Here we describe the gross, histologic, and ultrastructural features of the disease in 30 affected adult black-capped chickadees (Poecile atricapillus). Grossly, there was elongation of the rhamphotheca, with varying degrees of lateral deviation, crossing, and gapping between the upper and lower beak. Not uncommonly, the claws were overgrown, and there was alopecia, scaling, and crusting of the skin. The most prominent histopathologic features in the beak included epidermal hyperplasia, hyperkeratosis, and core-like intrusions of necrotic debris. In affected birds, particularly those with moderate to severe beak overgrowth, there was remodeling of premaxillary and mandibular bones and various dermal lesions. Lesions analogous to those found in beaks were present in affected claws, indicating that this disorder may target both of these similar tissues. Mild to moderate hyperkeratosis occurred in other keratinized tissues, including skin, feather follicles, and, occasionally, sinus epithelium, but typically only in the presence of microbes. We did not find consistent evidence of a bacterial, fungal, or viral etiology for the beak lesions. The changes observed in affected birds did not correspond with any known avian diseases, suggesting a potentially novel hyperkeratotic disorder in wild birds.

Pancreatic PEComa: a case report with ultrastructural localization of HMB-45 within melanosomes.

PubMed

Finzi, Giovanna; Micello, Donata; Wizemann, Giorgio; Sessa, Fausto; Capella, Carlo

2012-04-01

PEComas (perivascular epithelioid cell tumors) represent a group of mesenchymal neoplasms showing characteristic morphologic, immunohistochemical, ultrastructural, and genetic features. These neoplasms are usually considered benign, being often well circumscribed by a thin capsule and showing scarce atypia. However, in some cases, they show local invasion and multiple metastases and cause the patient's death. PEComas have been found in many locations, but only 7 cases have been described in the pancreas to date. Here, the authors report an additional case of this rare neoplasm and demonstrate the HMB-45 immunoreactivity of melanosomes or premelanosomes at the ultrastructural level.

Ultrastructural dynamics of human reproduction, from ovulation to fertilization and early embryo development.

PubMed

Familiari, Giuseppe; Heyn, Rosemarie; Relucenti, Michela; Nottola, Stefania A; Sathananthan, A Henry

2006-01-01

This study describes the updated, fine structure of human gametes, the human fertilization process, and human embryos, mainly derived from assisted reproductive technology (ART). As clearly shown, the ultrastructure of human reproduction is a peculiar multistep process, which differs in part from that of other mammalian models, having some unique features. Particular attention has been devoted to the (1) sperm ultrastructure, likely "Tygerberg (Kruger) strict morphology criteria"; (2) mature oocyte, in which the MII spindle is barrel shaped, anastral, and lacking centrioles; (3) three-dimensional microarchitecture of the zona pellucida with its unique supramolecular filamentous organization; (4) sperm-egg interactions with the peculiarity of the sperm centrosome that activates the egg and organizes the sperm aster and mitotic spindles of the embryo; and (5) presence of viable cumulus cells whose metabolic activity is closely related to egg and embryo behavior in in vitro as well as in vivo conditions, in a sort of extraovarian "microfollicular unit." Even if the ultrastructural morphodynamic features of human fertilization are well understood, our knowledge about in vivo fertilization is still very limited and the complex sequence of in vivo biological steps involved in human reproduction is only partially reproduced in current ART procedures.

Tripartite differentiation (squamous, glandular, and melanocytic) of a primary cutaneous neuroendocrine carcinoma. An immunocytochemical and ultrastructural study.

PubMed

Isimbaldi, G; Sironi, M; Taccagni, G; Declich, P; Dell'Antonio, A; Galli, C

1993-06-01

We report a case of primary cutaneous neuroendocrine carcinoma (PCNEC) with squamous, glandular, and melanocytic differentiation and associated Bowen disease. The paranuclear globular positivity of low-molecular-weight cytokeratins agrees with the ultrastructural observations of paranuclear fibrous bodies in the small neuroendocrine cells, while the diffuse cytoplasmic positivity corresponds to the sparse intermediate filaments in large cells with squamous differentiation. "Transitional forms" are characterized by both diffuse and globular cytoplasmic positivity for cytokeratins and by the ultrastructural evidence of neuroendocrine and squamous features. Therefore the ultrastructural demonstration of intracytoplasmic tonofibrils and tonofilaments, intercellular glandular lumina, lined by well-formed microvilli, and immature premelanosomes in the neurosecretory cells supports the proposed tripartite differentiation of neuroendocrine cells of this case of PCNEC.

Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766)

PubMed Central

Ciena, Adriano Polican; Bolina, Cristina de Sousa; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei

2013-01-01

The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae. PMID:23701183

Clinical Features and Associated Likelihood of Primary Ciliary Dyskinesia in Children and Adolescents

PubMed Central

Ferkol, Thomas W.; Davis, Stephanie D.; Lee, Hye-Seung; Rosenfeld, Margaret; Dell, Sharon D.; Sagel, Scott D.; Milla, Carlos; Olivier, Kenneth N.; Sullivan, Kelli M.; Zariwala, Maimoona A.; Pittman, Jessica E.; Shapiro, Adam J.; Carson, Johnny L.; Krischer, Jeffrey; Hazucha, Milan J.

2016-01-01

Rationale: Primary ciliary dyskinesia (PCD), a genetically heterogeneous, recessive disorder of motile cilia, is associated with distinct clinical features. Diagnostic tests, including ultrastructural analysis of cilia, nasal nitric oxide measurements, and molecular testing for mutations in PCD genes, have inherent limitations. Objectives: To define a statistically valid combination of systematically defined clinical features that strongly associates with PCD in children and adolescents. Methods: Investigators at seven North American sites in the Genetic Disorders of Mucociliary Clearance Consortium prospectively and systematically assessed individuals (aged 0–18 yr) referred due to high suspicion for PCD. The investigators defined specific clinical questions for the clinical report form based on expert opinion. Diagnostic testing was performed using standardized protocols and included nasal nitric oxide measurement, ciliary biopsy for ultrastructural analysis of cilia, and molecular genetic testing for PCD-associated genes. Final diagnoses were assigned as “definite PCD” (hallmark ultrastructural defects and/or two mutations in a PCD-associated gene), “probable/possible PCD” (no ultrastructural defect or genetic diagnosis, but compatible clinical features and nasal nitric oxide level in PCD range), and “other diagnosis or undefined.” Criteria were developed to define early childhood clinical features on the basis of responses to multiple specific queries. Each defined feature was tested by logistic regression. Sensitivity and specificity analyses were conducted to define the most robust set of clinical features associated with PCD. Measurements and Main Results: From 534 participants 18 years of age and younger, 205 were identified as having “definite PCD” (including 164 with two mutations in a PCD-associated gene), 187 were categorized as “other diagnosis or undefined,” and 142 were defined as having “probable/possible PCD.” Participants with “definite PCD” were compared with the “other diagnosis or undefined” group. Four criteria-defined clinical features were statistically predictive of PCD: laterality defect; unexplained neonatal respiratory distress; early-onset, year-round nasal congestion; and early-onset, year-round wet cough (adjusted odds ratios of 7.7, 6.6, 3.4, and 3.1, respectively). The sensitivity and specificity based on the number of criteria-defined clinical features were four features, 0.21 and 0.99, respectively; three features, 0.50 and 0.96, respectively; and two features, 0.80 and 0.72, respectively. Conclusions: Systematically defined early clinical features could help identify children, including infants, likely to have PCD. Clinical trial registered with ClinicalTrials.gov (NCT00323167). PMID:27070726

Endocrine cells in human Bartholin's glands. An immunohistochemical and ultrastructural analysis.

PubMed

Fetissof, F; Arbeille, B; Bellet, D; Barre, I; Lansac, J

1989-01-01

Endocrine cells were investigated in human Bartholin's glands by use of histochemical, immunohistochemical and ultrastructural methods. Endocrine cells represent normal constituents of these glands, being mainly distributed throughout the transitional epithelium of the major excretory duct; however, single elements are dispersed among the acinar lobules. Serotonin-, calcitonin-, katacalcin-, bombesin- and alpha-hCG-immunoreactive cells were recognized, with serotonin-immunoreactive cells predominating. Co-expression of calcitonin, katacalcin or alpha-hCG with serotonin was observed in single endocrine cells. At the ultrastructural level, these cells are richly granulated and show typical neuroendocrine features. Bartholin's glands display an endocrine profile quite similar to that of other cloacal-derived tissues.

Somatostatinoma: collision with neurofibroma and ultrastructural features.

PubMed

Varikatt, W; Yong, J L C; Killingsworth, M C

2006-11-01

The clinical presentation, histopathology and immunoelectron microscopic features of two cases of duodenal somatostatinoma are described, one of which is a hitherto unreported example of a collision tumour with a neurofibroma. Ultrastructural morphometric immunoelectron microscopy studies revealed the presence of four types of cells in both tumours, but there was no difference in the proportions of these cells between the collision tumour and the non-collision tumour. Neurosecretory granules ranging in size from 255-815 nm were generally larger than those previously reported for somatostatinomas and somatostatin was identified in granules of all sizes across this range. Neither tumour was associated with the somatostatinoma syndrome comprising associated diabetes mellitis, steatorrhoea and cholelithiasis.

Ultrastructural study of Rift Valley fever virus in the mouse model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, Christopher; Steele, Keith E.; Honko, Anna

Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed inmore » the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.« less

Serous cutaneous glands in new world hylid frogs: an ultrastructural study on skin poisons confirms phylogenetic relationships between Osteopilus septentrionalis and Phrynohyas venulosa.

PubMed

Delfino, Giovanni; Brizzi, Rossana; Nosi, Daniele; Terreni, Alessandro

2002-08-01

Transmission electron microscope investigations of the serous (poison) skin glands in the New World tree frogs Osteopilus septentrionalis and Phrynohyas venulosa revealed that they produce granules with closely similar substructures, namely, a dense cortex and pale medulla. In both species these features, that contrast the complex, sometimes repeating patterns described in other hylid frogs, derive from similar secretory and maturational processes starting from the Golgi phase of poison biosynthesis. Observations on secretory discharge showed that the two species share common release mechanisms, based on bulk discharge (holocrine) processes. Our data provide novel evidence of the extensive ultrastructural polymorphism of serous skin products in Hylidae and agree with phylogenies that regard this family as polyphyletic in origin. Assuming that ultrastructural features of cutaneous poison biosynthesis and maturation are adequate clues for tracking anuran phylogeny, the present findings also support a close relationship between Osteopilus and Phrynohyas taxa as previously suggested by osteological evidence. Copyright 2002 Wiley-Liss, Inc.

Ontogeny of tick hemocytes: a comparative analysis of Ixodes ricinus and Ornithodoros moubata.

PubMed

Borovicková, Barbara; Hypsa, Václav

2005-01-01

Hemocytes of two tick species, Ixodes ricinus and Ornithodoros moubata, were investigated with the aim to determine their ultrastructural characteristics and developmental relationships. Only a limited number of ultrastructural features was shown to be unequivocally homological across all hemocyte types. The two species, representing distant groups of ticks, differ in the composition of their circular cell populations. In I. ricinus, three groups of distinct morphological types of hemocytes could be determined according to well-defined ultrastructural features: a typical non-phagocytic granular cell with electron-dense granula and homogeneous cytoplasm (Gr II), and two different types of phagocytic hemocytes, namely plasmatocytes with a low number of granula and phagocytic granolocytes, designated as Gr I. In contrast, an additional cell type resembling insect spherulocytes was determined in O. moubata. This cell type does not seem to be homologous to any I. ricinus hemocyte and may represent a cell type typical of soft ticks only. Possible ontogenetic lineages of the hemocytes of both tick-species were inferred.

The role of immunohistochemistry, electron microscopy, and ultrastructural cytochemistry in the diagnosis of mixed carcinoma-neuroendocrine neoplasms.

PubMed

Graham, A R; Payne, C M; Nagle, R B; Angel, E

1987-02-01

We studied four mixed carcinoma-neuroendocrine neoplasms from gastrointestinal tract and pancreas by routine light microscopy (LM), immunohistochemistry (IH), electron microscopy (EM), and ultrastructural cytochemistry (UC). By LM, the individual tumors showed fairly pure neuroendocrine (carcinoid) or epithelial (papillary) patterns, mixed neuroendocrine-carcinoma features and poorly-differentiated tumor in sheets and nests which did not lend itself to morphologic characterization. IH demonstrated mixed expression, within different areas of the same neoplasm, of epithelial antigens (keratins and carcinoembryonic antigen [CEA]) and neuroendocrine markers (neuron-specific enolase [NSE], bombesin and neurohormonal peptides). By EM, each tumor showed ultrastructural features of epithelial and neuroendocrine differentiation which varied substantially in terms of number of cells involved and their distribution; two of the neoplasms showed biphasic differentiation within single cells. The nature of the neurosecretory granules was verified with the uranaffin reaction (UR). This study illustrates the value of combining LM, IH, EM and UC for the identification of mixed carcinoma-neuroendocrine lesions.

Congenital renal rhabdoid tumor with placental metastases: immunohistochemistry, cytogenetic, and ultrastructural findings.

PubMed

de Tar, Michael; Sanford Biggerstaff, Julie

2006-01-01

Malignant congenital tumors of fetal origin are rare lesions, the most common type being congenital neuroblastoma. Although prenatal diagnosis is possible in large tumors, occasionally the tumor will be diagnosed first by its metastatic involvement of the placenta. Placental metastases can reflect either maternal or fetal primary sites, and each has relatively specific patterns of placental involvement. We describe the clinical and pathologic features of a widely metastatic congenital renal rhabdoid tumor with its placental and autopsy findings, and include the immunohistochemical, cytogenetic, and ultrastructural features. The pathologic features of the placenta in congenital renal rhabdoid tumor with placental metastasis have not been previously described. The examination of the placenta in this case led to the initial diagnosis and obviated the need for additional diagnostic procedures.

Pseudogynecomastia due to neurofibromatosis--a light microscopic and ultrastructural study.

PubMed

Lipper, S; Willson, C F; Copeland, K C

1981-08-01

A six year old boy with bilateral breast enlargement was found to have a normal endocrine status. Resected tissue revealed the features of pseudogynecomastia due to a proliferation of fibrous tissue traversed by neuroid structures. Multinucleated giant cells were present within the fibrous tissue. Ultrastructural study revealed organized nerve elements in a collagenous stroma. The multinucleated giant cells appeared to be variants of the predominant stromal fibroblasts.

Three-dimensional ultrastructure of the surface of the tongue of the rat snake, Elaphe climacophora.

PubMed

Iwasaki, S; Yoshizawa, H; Kawahara, I

1996-05-01

Many studies have been performed to clarify the relationship between behavioral performance of the tongue and Jacobson's organ. The purpose of the present study was to examine the ultrastructural features of the surface of the tongue of the rat snake, Elaphe climacophora, and to delineate the functional relationship between the tongue and Jacobson's organ from a morphological perspective. The three-dimensional ultrastructure of the surface of the tongue of the rat snake Elaphe climacophora was investigated by scanning electron microscopy. Most of the surface of the bifurcated apex of the tongue was relatively smooth. Dome-shaped, hemispherical bulges or microfacets were compactly arranged on the epithelial cell surface over this entire region. Intercellular borders were clearly recognizable as striations. These features were almost the same as those of the dorsal surface of the transitional area between the bifurcated lingual apex and the anterior part of the lingual body. In the posterior half of the lingual body, no microfacets were seen at all. Both microridges and microvilli were compactly distributed on cell surfaces. No evidence was obtained from our ultrastructural analysis for an important role of the lingual apex in the vomeronasal system. By contrast, the epithelial surface of the body of the tongue appeared suitable for retaining stimulating compounds.

Detection of fibrils associated with Rickettsia rickettsii.

PubMed

Todd, W J; Burgdorfer, W; Wray, G P

1983-09-01

The ultrastructural appearance of the "halozone" formed at the interface between the spotted fever agent Rickettsia rickettsii and the cytoplasm of persistently infected cultured vole cells (Microtus pennsylvanicus) was studied by transmission electron microscopy. In sections of epoxy-embedded specimens stained with uranyl acetate and lead citrate, the halozone appeared clear and devoid of ultrastructural features. However, when unembedded preparations of whole infected cells were examined at 1,000 kV, fine structural features were observed within the halozone. These features, associated with the rickettsial outer membrane, were more clearly detectable when the infected cells were extracted with the detergent Triton X-100 before fixation. Under such conditions, long extensions of the rickettsial outer membrane, microfilament-like structures attached to that membrane, and extensive attachments between adjacent rickettsiae were seen. The fine structural features within the rickettsial halozone were also seen at 75 kV when unembedded sections were prepared from polyethylene glycol-embedded specimens. Thus, epoxy-embedding medium obscures the fine structural features within the halozone surrounding the rickettsiae in infected cells.

Detection of fibrils associated with Rickettsia rickettsii.

PubMed Central

Todd, W J; Burgdorfer, W; Wray, G P

1983-01-01

The ultrastructural appearance of the "halozone" formed at the interface between the spotted fever agent Rickettsia rickettsii and the cytoplasm of persistently infected cultured vole cells (Microtus pennsylvanicus) was studied by transmission electron microscopy. In sections of epoxy-embedded specimens stained with uranyl acetate and lead citrate, the halozone appeared clear and devoid of ultrastructural features. However, when unembedded preparations of whole infected cells were examined at 1,000 kV, fine structural features were observed within the halozone. These features, associated with the rickettsial outer membrane, were more clearly detectable when the infected cells were extracted with the detergent Triton X-100 before fixation. Under such conditions, long extensions of the rickettsial outer membrane, microfilament-like structures attached to that membrane, and extensive attachments between adjacent rickettsiae were seen. The fine structural features within the rickettsial halozone were also seen at 75 kV when unembedded sections were prepared from polyethylene glycol-embedded specimens. Thus, epoxy-embedding medium obscures the fine structural features within the halozone surrounding the rickettsiae in infected cells. Images PMID:6411620

Ultrastructure features of camel cornea--collagen fibril and proteoglycans.

PubMed

Almubrad, Turki; Akhtar, Saeed

2012-01-01

  The uniform distribution of collagen fibrils and proteoglycans maintain the transparency of normal cornea. We describe the ultrastructural features of camel cornea including collagen fibrils and proteoglycans (PGs).   Camel corneas (of 6-, 8-, and 10-month-old animals) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in sodium acetate buffer and processed for electron microscopy. The 'AnalySIS LS Professional' program was used to analyze the collagen fibril diameter.   The camel cornea consists of four layers: the epithelium (227 μm), stroma (388 μm), Descemet's membrane (DM), and endothelium. The epithelium constituted 36% of the camel cornea, whereas corneal stroma constituted 62% of the corneal thickness (629 μm). The PGs in the posterior stroma were significantly larger in number and size compared with the anterior and middle stroma. The collagen fibril diameter was 25 nm and interfibrillar spacing 40 nm. Fibrillar structures are present throughout the DM.   The structure of the camel cornea is very different from human and other animals. The unique structure of the cornea might be an adaptation to help the camel to survive in a hot and dry climate. The camel cornea may also be a good model to study the effect of hot and dry climates on the cornea. © 2011 American College of Veterinary Ophthalmologists.

Genotype-dependent efficiency of endosperm development in culture of selected cereals: histological and ultrastructural studies.

PubMed

Popielarska-Konieczna, Marzena; Kozieradzka-Kiszkurno, Małgorzata; Tuleja, Monika; Ślesak, Halina; Kapusta, Paweł; Marcińska, Izabela; Bohdanowicz, Jerzy

2013-02-01

The paper reports studies, including histological and ultrastructural analyses, of in vitro cell proliferation and development of immature endosperm tissue isolated from caryopses of Triticum aestivum, Triticum durum, and Triticosecale plants. Endosperm isolated at 7-10 days post-anthesis developed well on MS medium supplemented with auxins and/or cytokinins. The efficiency of endosperm response was highly genotype-dependent and best in two winter cultivars of hexaploid species. The pathways of development and proliferation were very similar among the selected species and cultivars. Histological and scanning electron microscope (SEM) analysis revealed that only the part of the endosperm not touching the medium surface continued growth and development, resulting in swelling. The central part of swollen regions was composed mainly of cells containing many large starch grains. The peripheric parts of developed endosperm consisted of highly vacuolated cells and small cells with dense cytoplasm. SEM showed that cells from the swollen region were covered partially with a membraneous structure. Transmission electron microscope studies of cells from the outer part of the developing region showed features typical for cell activity connected with lipid metabolism.

The structure and innervation of the saccopleural membrane of the domestic fowl, Gallus gallus: an ultrastructural and immunohistochemical study.

PubMed Central

Cook, R D; Vaillant, C; King, A S

1987-01-01

Microscopic studies have shown the saccopleural membrane in the respiratory system of the domestic fowl to consist of a sheet of three dense layers of collagen fibres covered dorsally and ventrally by mainly simple squamous epithelium. On the ventral surface, which faces into the caudal thoracic air sac, there are occasional ridges of pseudostratified ciliated epithelium. Many nerve bundles are present throughout the membrane, the larger bundles of myelinated and unmyelinated axons being confined to the lamina propria under the dorsal epithelium (parietal pleura). In addition to axonal profiles with the ultrastructural appearance of cholinergic or adrenergic axons, peptidergic-type axons were identified. Immunofluorescence studies demonstrated VIP-, substance P-, somatostatin- and enkephalin-immunoreactive fibres in the membrane. Although it has been suggested that receptors may be present in this region of the respiratory system, none of the axons have features suggestive of sensory terminals, although many axonal profiles are closely associated with the epithelia where no obvious effector cells are present. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:3654325

Enamel matrix derivative Emdogain as an adjuvant for a laterally-positioned flap in the treatment of gingival recession: an electron microscopic appraisal.

PubMed

Lafzi, A; Farahani, R M; Tubbs, R S; Roushangar, L; Shoja, M M

2007-05-01

Enamel matrix derivative (EMD), such as Emdogain, has been suggested for the improvement of wound healing in periodontal surgical therapy. The present qualitative study seeks to illustrate the ultrastructural changes associated with a human gingival wound at 10 days after the application of EMD as an adjunct to a laterally-positioned flap in a patient with gingival recession. An otherwise healthy patient, who had been suffering from bilateral gingival recession defects on teeth #23 and #26, was studied. One defect was treated with a laterally-positioned flap, while the other was treated with a combination of EMD and a laterally-positioned flap. Ten days after the operation gingival biopsy specimens were obtained from the dentogingival region and examined using a transmission electron microscope. A considerable difference was found in both the cellular and extracellular phases of EMD and non-EMD sites. The fibroblasts of EMD site were more rounded with plump cytoplasms and euchromatic nuclei. A well-developed rough endoplasmic reticulum and numerous mitochondria could be detected. In contrast, the fibroblasts of non-EMD site were of flattened spindle-like morphology. While the signs of apoptosis could rarely be detected at EMD site, apoptotic bodies and ultra-structural evidence of apoptosis (crescent-like heterochromatic nuclei and dilated nuclear envelopes) were consistent features at non-EMD site. The extracellular matrix at EMD site mainly consisted of well-organised collagen fibres, while non-EMD site contained sparse and incompletely-formed collagen fibres. Coccoid bacteria were noted within the extracellular matrix and neutrophils at non-EMD site. It seems that EMD may enhance certain features of gingival wound healing, which may be attributable to its anti-apoptotic, anti-bacterial or anti-inflammatory properties.

[Ultrastructural changes of human dental hard tissues during orthodontic treatment with fixed appliances].

PubMed

Antonova, I N; Goncharov, V D; Bobrova, E A

The aim of the study was to evaluate ultrastructural changes of dental enamel after fixation of orthodontic appliances, initial influence of orthodontic forces and removal of braces. Five intact permanent tooth extracted for orthodontic reasons were included in the experimental study. Scanning probe microscopy was conducted in 4 random enamel points in each tooth (20 points overall) in semi-contact mode with standard 10 nm probes. The study showed ultrastructural enamel changes such as nanofractures up to 1 mm along the braces locks. The changes correlated with surface morphological features and teeth anatomy and may play an important role in dental decay and non-carious lesions occurring in the course of orthodontic treatment.

Colonization of cashew plants by Lasiodiplodia theobromae: Microscopical features

USDA-ARS?s Scientific Manuscript database

Lasiodiplodia theobromae is a phytopathogenic fungus causing gummosis, a threatening disease for cashew plants in Brazil. In an attempt to investigate the ultrastructural features of the pathogen colonization and its response to immunofluorescence labeling, light, confocal and electron microscope st...

Primary cilia in gastric Gastrointestinal Stromal Tumours (GISTs): an ultrastructural study

PubMed Central

Castiella, Tomás; Muñoz, Guillermo; Luesma, María José; Santander, Sonia; Soriano, Mario; Junquera, Concepción

2013-01-01

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal (non-epithelial) neoplasms of the human gastrointestinal (GI) tract. They are thought to derive from interstitial cells of Cajal (ICCs) or an ICC progenitor based on immunophenotypical and ultrastructural similarities. Because ICCs show primary cilium, our hypothesis is based on the possibility that some of these neoplastic cells could also present it. To determine this, an exhaustive ultrastructural study has been developed on four gastric GISTs. Previous studies had demonstrated considerable variability in tumour cells with two dominating phenotypes, spindly and epithelioid. In addition to these two types, we have found another cell type reminiscent of adult ICCs with a voluminous nucleus surrounded by narrow perinuclear cytoplasm with long slender cytoplasmic processes. We have also noted the presence of small undifferentiated cells. In this study, we report for the first time the presence of primary cilia (PCs) in spindle and epithelioid tumour cells, an ultrastructural feature we consider of special interest that has hitherto been ignored in the literature dealing with the ultrastructure of GISTs. We also point out the frequent occurrence of multivesicular bodies (MVBs). The ultrastructural findings described in gastric GISTs in this study appear to be relevant considering the critical roles played by PCs and MVBs recently demonstrated in tumourigenic processes. PMID:23672577

Ultrastructural analysis of testicular tissue and sperm by transmission and scanning electron microscopy.

PubMed

Chemes, Hector E

2013-01-01

Transmission electron microscopy (TEM) studies have provided the basis for an in-depth understanding of the cell biology and normal functioning of the testis and male gametes and have opened the way to characterize the functional role played by specific organelles in spermatogenesis and sperm function. The development of the scanning electron microscope (SEM) extended these boundaries to the recognition of cell and organ surface features and the architectural array of cells and tissues. The merging of immunocytochemical and histochemical approaches with electron microscopy has completed a series of technical improvements that integrate structural and functional features to provide a broad understanding of cell biology in health and disease. With these advances the detailed study of the intricate structural and molecular organization as well as the chemical composition of cellular organelles is now possible. Immunocytochemistry is used to identify proteins or other components and localize them in specific cells or organelles with high specificity and sensitivity, and histochemistry can be used to understand their function (i.e., enzyme activity). When these techniques are used in conjunction with electron microscopy their resolving power is further increased to subcellular levels. In the present chapter we will describe in detail various ultrastructural techniques that are now available for basic or translational research in reproductive biology and reproductive medicine. These include TEM, ultrastructural immunocytochemistry, ultrastructural histochemistry, and SEM.

Generation of a three-dimensional ultrastructural model of human respiratory cilia.

PubMed

Burgoyne, Thomas; Dixon, Mellisa; Luther, Pradeep; Hogg, Claire; Shoemark, Amelia

2012-12-01

The ultrastructures of cilia and flagella are highly similar and well conserved through evolution. Consequently, Chlamydomonas is commonly used as a model organism for the study of human respiratory cilia. Since detailed models of Chlamydomonas axonemes were generated using cryoelectron tomography, disparities among some of the ultrastructural features have become apparent when compared with human cilia. Extrapolating information on human disease from the Chlamydomonas model may lead to discrepancies in translational research. This study aimed to establish the first three-dimensional ultrastructural model of human cilia. Tomograms of transverse sections (n = 6) and longitudinal sections (n = 9) of human nasal respiratory cilia were generated from three healthy volunteers. Key features of the cilium were resolved using subatomic averaging, and were measured. For validation of the method, a model of the well characterized structure of Chlamydomonas reinhardtii was simultaneously generated. Data were combined to create a fully quantified three-dimensional reconstruction of human nasal respiratory cilia. We highlight key differences in the axonemal sheath, microtubular doublets, radial spokes, and dynein arms between the two structures. We show a decreased axial periodicity of the radial spokes, inner dynein arms, and central pair protrusions in the human model. We propose that this first human model will provide a basis for research into the function and structure of human respiratory cilia in health and in disease.

Meibomian gland studies: histologic and ultrastructural investigations.

PubMed

Jester, J V; Nicolaides, N; Smith, R E

1981-04-01

Heightened interest in meibomian gland dysfunction has prompted us to evaluate the normal morphological and ultrastructural characteristics of the meibomian gland. Histologic analysis of human, primate, steer, and rabbit glands revealed evidence of keratinized epithelium extending throughout the meibomian gland duct. Characteristic ultrastructural features of keratinized epithelium identified in primate and rabbit glands included tonofilaments, keratohyaline granules, lamellar bodies, and keratinized squamous cells. Comparison of the meibomian gland duct to the pilosebaceous canal and the sebaceous duct brought out certain dissimilarities such as (1) the lack of a well-developed stratum granulosum and (2) the absence of lipid inclusions within transitional cells from duct to acini. We postulate that abnormalities of the keratinizing process may be responsible for meibomian gland dysfunction states.

Ultrastructure of selected struvite-containing urinary calculi from cats.

PubMed

Neumann, R D; Ruby, A L; Ling, G V; Schiffman, P S; Johnson, D L

1996-01-01

To elucidate the ultrastructural details of struvite-containing urinary calculi from cats. Specimens studied were inclusive of the range of textures visible during preliminary analysis by use of a stereoscopic dissecting microscope. Textural types, which were used to infer crystal growth conditions, were differentiated with regard to crystal habit, crystal size, growth orientation, and primary porosity. Thirty specimens were selected from a collection of approximately 1,600 feline urinary calculi: 20 of these were composed entirely of struvite, and 10 consisted of struvite and calcium phosphate (apatite). Qualitative and quantitative analyses of specimens included use of plain and polarized light microscopy, x-ray diffractometry, scanning electron microscopy with backscattered electron imagery, x-ray fluorescence scans, and electron probe microanalysis. Four textural types were recognized among struvite calculi, whereas 2 textural types of struvite-apatite calculi were described. The presence of minute, well interconnected primary pores in struvite-containing urinary calculi from cats is an important feature, which may promote possible interaction of calculi with changes in urine composition. Primary porosity, which can facilitate interaction between the calculus and changing urine composition, may explain the efficacy of dietary or medicinal manipulations to promote the dissolution of struvite-containing uroliths from this species.

Long-term ultrastructural indices of lead intoxication in pulmonary tissue of the rat.

PubMed

Kaczyńska, Katarzyna; Walski, Michał; Szereda-Przestaszewska, Małgorzata

2013-12-01

In the present research long-term pulmonary toxicity of lead was investigated in rats treated by intraperitoneal administration of lead acetate for three consecutive days (25 mg/kg per day). Five weeks after treatment average lead content in the whole blood was 0.41 μg/dL ± 0.05, in the lung homogenates it measured 3.35 μg/g ± 0.54, as compared to the control values of 0.13 ± 0.07 μg/dL and 1.03 μg/g ± 0.59, respectively. X-ray microanalysis of lung specimens displayed lead localized mainly within type II pneumocytes and macrophages. At the ultrastructural level the effects of lead toxicity were found in lung capillaries, interstitium, epithelial cells, and alveolar lining. Alveolar septa showed intense fibrosis, consisting of collagen, elastin, and fibroblasts. Thinned alveolar septa had emphysematous tissue with some revealing signs of angiogenesis. Type II pneumocytes contained lamellar bodies with features of laminar destruction. Fragments of the surfactant layer were often detached from the alveolar epithelium. These findings indicate that 5 weeks after exposure, lead provokes reconstruction of the alveolar septa including fibrosis and emphysematous changes in the lung tissue.

Differentiation of breast cancer cells in vitro is promoted by the concurrent influence of myoepithelial cells and relaxin.

PubMed Central

Bani, D.; Riva, A.; Bigazzi, M.; Bani Sacchi, T.

1994-01-01

Our previous studies showed that relaxin promotes differentiation of MCF-7 breast adenocarcinoma cells. In the current investigation, we aimed to elucidate whether the effect of the hormone is potentiated when MCF-7 cells are grown together with myoepithelial cells, thus creating a microenvironment reminiscent of the organised tissue architecture of the mammary parenchyma in vivo. The findings obtained reveal that most MCF-7 cells cultured alone have an undifferentiated, blast-like phenotype, only a minority showing a more differentiated phenotype with more organelles and rudimentary intercellular junctions. When co-cultured with myoepithelial cells more MCF-7 cells acquire ultrastructural features consistent with a more differentiated phenotype, such as a rich organellular complement, apical microvilli and intercellular junctions. When relaxin was added to the co-cultures, the ultrastructural signs of differentiation could be observed in even more MCF-7 cells and became more pronounced than in the absence of the hormone, judged by the appearance of a clear-cut polarisation of cytoplasmic organelles, an almost continuous coat of apical microvilli and numerous intracellular pseudolumina. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7947095

Immunotactoid Glomerulopathy and Cryoglobulinemic Nephropathy: Two Entities with Many Similarities. A Unified Conceptual Approach.

PubMed

Herrera, Guillermo A; Ojemakinde, Kunle O; Turbat-Herrera, Elba A; Gu, Xin; Zeng, Xu; Iskandar, Samy S

2015-01-01

Immunotactoid glomerulopathy is a rare disorder that has been characterized at the ultrastructural level. Due to its rarity, there are few comprehensive studies relating to this disorder. Electron microscopy essentially characterizes this disease. The glomerular electron dense deposits which are typical of this condition consist of aggregates of highly organized microtubular structures of various diameters, but generally measuring 30-50 nm in width with a propensity to dispose themselves in parallel bundles intersecting in different planes. This study compares a large series of patients with cryoglobulinemic nephropathy with a series of patients with immunotactoid glomerulopathy to address whether there may be similarities that warrant considering these two entities part of a spectrum. This study reviews the clinicopathologic features of both entities and emphasizes ultrastructural findings that characterize them. Significant immunomorphologic overlap was found when these two disorders were compared in this study. There were also striking similarities in clinical presentation/behavior, laboratory findings and prognosis. Proteomic analysis has also demonstrated similar spectra for both entities. We postulate that immunotactoid glomerulopathy and cryoglobulinemic nephropathy are part of the spectrum of renal manifestations in patients with circulating cryoglobulins and renal disease.

Life-cycle, ultrastructure, and phylogeny of Parvilucifera corolla sp. nov. (Alveolata, Perkinsozoa), a parasitoid of dinoflagellates.

PubMed

Reñé, Albert; Alacid, Elisabet; Figueroa, Rosa Isabel; Rodríguez, Francisco; Garcés, Esther

2017-04-01

Recent studies of marine protists have revealed parasites to be key components of marine communities. Here we describe a new species of the parasitoid genus Parvilucifera that was observed infecting the dinoflagellate Durinskia baltica in salt marshes of the Catalan coast (NW Mediterranean). In parallel, the same species was detected after the incubation of seawater from the Canary Islands (Lanzarote, NE Atlantic). The successful isolation of strains from both localities allowed description of the life cycle, ultrastructure, and phylogeny of the species. Its infection mechanism consists of a free-living zoospore that penetrates a dinoflagellate cell. The resulting trophont gradually degrades the dinoflagellate cytoplasm while growing in size. Once the host is consumed, schizogony of the parasitoid yields a sporocyte. After cytokinesis is complete, the newly formed zoospores are released into the environment and are ready to infect new host cells. A distinguishing feature of the species is the radial arrangement of its zoospores around the central area of the sporocyte during their formation. The species shows a close morphological similarity with other species of the genus, including P. infectans, P. sinerae, and P. rostrata. Copyright © 2016 Elsevier GmbH. All rights reserved.

Sperm ultrastructure of shrimps from the family Penaeidae (Crustacea: Dendrobranchiata) in a phylogenetic context.

PubMed

Camargo, Tavani Rocha; Rossi, Natalia; Castilho, Antonio L; Costa, Rogério C; Mantelatto, Fernando L; Zara, Fernando José

2017-07-01

We describe the sperm ultrastructure of six penaeid species, including at least one member of each tribe (Penaeini, Parapenaeini and Trachypenaeini). Fragments of the vas deferens of the Penaeidae Farfantepenaeus brasiliensis, Farfantepenaeus paulensis, Litopenaeus schmitti, Parapenaeus americanus, Rimapenaeus constrictus and Xiphopenaeus kroyeri were fixed and processed according to the routine for transmission electron microscopy. The morphological results were contextualized in an evolutionary perspective using molecular markers for the phylogenetic reconstruction of this group. A phylogram was proposed by Bayesian inference based on 1007 bp of 33 sequences of the combined genes (16S rDNA and COI mtDNA) from 27 dendrobranchiate specimens. Our findings show that morphological differences in the sperm ultrastructures of members among the tribes of Penaeidae can be used as a baseline to understand their evolutionary relationships. Individuals from the Penaeini tribe show plesiomorphic characteristics in the sperm ultrastructure compared to the Trachypenaeini tribe from which they were derived, such as shrimp from family Sicyoniidae. The morphological complexity of the sperm of the different penaeid members corroborated with the genetic phylogeny, which showed different clades for each tribe and the close relationship with Sicyoniidae. The sperm features of the selected species studied here reflected their evolutionary history. These features confirm the previous phylogenetic hypothesis and question the monophyly of Penaeidae, which should be verified in the future with a more complete set of representative members of each tribe. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pulmonary hyalinosis in dogs.

PubMed

Dagle, G E; Filipy, R E; Adee, R R; Stuart, B O

1976-01-01

Pulmonary hyalinosis occurred in Beagles exposed to radon daughters with uranium ore dust. The lesion was composed of alveolar cells distended with material positive for periodic acid-Schiff (PAS) and oil red O that ultrastructurally consisted of a whorled arrangement of lamellar membranes suggestive of a storage disease. The high incidence in exposed dogs and the ultrastructural appearance suggested the material originated endogenously as a degenerative response to injury.

Mixed pituitary adenoma/craniopharyngioma: clinical, morphological, immunohistochemical and ultrastructural study of a case, review of the literature, and pathogenetic and nosological considerations.

PubMed

Finzi, Giovanna; Cerati, Michele; Marando, Alessandro; Zoia, Cesare; Ferreli, Fabio; Tomei, Giustino; Castelnuovo, Paolo; La Rosa, Stefano; Capella, Carlo

2014-02-01

Mixed pituitary adenoma/craniopharyngiomas are very rare tumors. Their pathogenesis is still unclear and it is not known whether they are collision tumors derived from independent stem cells or whether they originate from a single stem cell undergoing divergent differentiation. The latter hypothesis is supported by the close commixture between the two tumor components with transition areas that has been previously described. However, "hybrid" cells with both pituitary adenoma and craniopharyngioma features have never been described. In this paper we report a case of mixed pituitary adenoma/craniopharyngioma observed in a 75-year-old woman presenting with diplopia and slight increase of serum prolactin, who underwent endoscopic endonasal trans-sphenoidal tumor resection. Histologically, the tumor was composed of a typical pituitary silent subtype 2 ACTH cell adenoma admixed with islands of adamantinomatous craniopharyngioma. Electron microscopy showed that, in addition to distinct silent subtype 2 ACTH and craniopharyngioma cells, there were "hybrid" cells, showing characteristics of both pituitary adenoma and craniopharyngioma, consisting of small dense secretory granules, bundles of cytoplasmic filaments, and desmosomes. This ultrastructural finding was also confirmed by the presence of cells showing nuclear p40 expression and chromogranin A immunoreactivity. The close commixture between the two components and the ultrastructural and immunohistochemical findings demonstrate a common histogenesis of the two components and support the classification of the neoplasm as a mixed tumor. The patient completely recovered and, 10 months after surgery, head MR confirmed the complete resection of the lesion.

A combined morphological, ultrastructural, molecular, and biochemical study of the peculiar family Gomontiellaceae (Oscillatoriales) reveals a new cylindrospermopsin-producing clade of cyanobacteria.

PubMed

Bohunická, Markéta; Mareš, Jan; Hrouzek, Pavel; Urajová, Petra; Lukeš, Martin; Šmarda, Jan; Komárek, Jiří; Gaysina, Lira A; Strunecký, Otakar

2015-12-01

Members of the morphologically unusual cyanobacterial family Gomontiellaceae were studied using a polyphasic approach. Cultured strains of Hormoscilla pringsheimii, Starria zimbabweënsis, Crinalium magnum, and Crinalium epipsammum were thoroughly examined, and the type specimen of the family, Gomontiella subtubulosa, was investigated. The results of morphological observations using both light microscopy and transmission electron microscopy were consistent with previous reports and provided evidence for the unique morphological and ultrastructural traits of this family. Analysis of the 16S rRNA gene confirmed the monophyletic origin of non-marine repre-sentatives of genera traditionally classified into this family. The family was phylogenetically placed among other groups of filamentous cyanobacterial taxa. The presence of cellulose in the cell wall was analyzed and confirmed in all cultured Gomontiellaceae members using Fourier transform infrared spectroscopy and fluorescence microscopy. Evaluation of toxins produced by the studied strains revealed the hepatotoxin cylindrospermopsin (CYN) in available strains of the genus Hormoscilla. Production of this compound in both Hormoscilla strains was detected using high-performance liquid chromatography in tandem with high resolution mass spectrometry and confirmed by positive PCR amplification of the cyrJ gene from the CYN biosynthetic cluster. To our knowledge, this is the first report of CYN production by soil cyanobacteria, establishing a previously unreported CYN-producing lineage. This study indicates that cyanobacteria of the family Gomontiellaceae form a separate but coherent cluster defined by numerous intriguing morphological, ultrastructural, and biochemical features, and exhibiting a toxic potential worthy of further investigation. © 2015 Phycological Society of America.

FLIPPER, a combinatorial probe for correlated live imaging and electron microscopy, allows identification and quantitative analysis of various cells and organelles.

PubMed

Kuipers, Jeroen; van Ham, Tjakko J; Kalicharan, Ruby D; Veenstra-Algra, Anneke; Sjollema, Klaas A; Dijk, Freark; Schnell, Ulrike; Giepmans, Ben N G

2015-04-01

Ultrastructural examination of cells and tissues by electron microscopy (EM) yields detailed information on subcellular structures. However, EM is typically restricted to small fields of view at high magnification; this makes quantifying events in multiple large-area sample sections extremely difficult. Even when combining light microscopy (LM) with EM (correlated LM and EM: CLEM) to find areas of interest, the labeling of molecules is still a challenge. We present a new genetically encoded probe for CLEM, named "FLIPPER", which facilitates quantitative analysis of ultrastructural features in cells. FLIPPER consists of a fluorescent protein (cyan, green, orange, or red) for LM visualization, fused to a peroxidase allowing visualization of targets at the EM level. The use of FLIPPER is straightforward and because the module is completely genetically encoded, cells can be optimally prepared for EM examination. We use FLIPPER to quantify cellular morphology at the EM level in cells expressing a normal and disease-causing point-mutant cell-surface protein called EpCAM (epithelial cell adhesion molecule). The mutant protein is retained in the endoplasmic reticulum (ER) and could therefore alter ER function and morphology. To reveal possible ER alterations, cells were co-transfected with color-coded full-length or mutant EpCAM and a FLIPPER targeted to the ER. CLEM examination of the mixed cell population allowed color-based cell identification, followed by an unbiased quantitative analysis of the ER ultrastructure by EM. Thus, FLIPPER combines bright fluorescent proteins optimized for live imaging with high sensitivity for EM labeling, thereby representing a promising tool for CLEM.

Nasal tumor with widespread cutaneous metastases in a Golden Retriever.

PubMed

Koehler, J W; Weiss, R C; Aubry, O A; Smith, A N; Hathcock, J T; Brawner, W R

2012-09-01

An intact, 8-year-old, male Golden Retriever dog was presented for evaluation of a nasal mass and approximately 30 firm, raised, variably ulcerated dermal and subcutaneous masses. Histopathology of both nasal and multiple skin masses revealed multiple nonencapsulated, infiltrative masses comprising clusters, anastomosing trabeculae, and packets of neoplastic, round to ovoid, hyperchromatic cells with marked nuclear molding. Surrounding the neoplastic cells was a marked stromal response in which many of the spindle-shaped cells expressed muscle-specific actin and had ultrastructural features consistent with myofibroblasts. A literature search indicates that this is the first report in a peer-reviewed journal of cutaneous metastasis of a nasal neuroendocrine tumor in any domestic animal species.

The ultrastructural features of the premalignant oral lesions.

PubMed

Olinici, Doiniţa; Cotrutz, Carmen Elena; Mihali, Ciprian Valentin; Grecu, Vasile Bogdan; Botez, Emanuela Ana; Stoica, Laura; Onofrei, Pavel; Condurache, Oana; Dimitriu, Daniela Cristina

2018-01-01

Premalignant oral lesions are among the most important risk factors for the development of oral squamocellular carcinoma. Recent population studies indicate a significant rise in the prevalence of leukoplakia, erythroplakia/erythroleukoplakia, actinic cheilitis, submucous fibrosis and erosive lichen planus. Since standard histopathological examination has numerous limitations regarding the accurate appreciation of potential malignant transformation, the present study aims to aid these evaluations using the transmission electron microscopy (TEM) technique, which emphasizes ultrastructural changes pertaining to this pathology. Oral mucosa fragments collected from 43 patients that were clinically and histopathologically diagnosed with leukoplakia, erosive actinic cheilitis and erosive lichen planus have been processed through the classic technique for the examination using TEM and were examined using a Philips CM100 transmission electron microscope. The electron microscopy study has confirmed the histopathological diagnosis of the tissue samples examined using photonic microscopy and has furthermore revealed a series of ultrastructural details that on the one hand indicate the tendency for malignant transformation, and on the other reveal characteristic features of tumor development. All the details furnished by TEM complete the overall picture of morphological changes, specific to these lesions, indicating the importance of using these techniques in establishing both a correct diagnosis and prognosis.

Adjuvant potential of virgin coconut oil extract on antiretroviral therapy-induced testicular toxicity: An ultrastructural study.

PubMed

Ogedengbe, O O; Jegede, A I; Onanuga, I O; Offor, U; Peter, A I; Akang, E N; Naidu, E C S; Azu, O O

2018-04-01

The effects of Virgin coconut oil as an adjuvant to highly active antiretroviral therapy (HAART) were investigated on the testicular ultrastructure and biochemical markers in rats. Twenty male Sprague-Dawley rats, weighing 153-169 g were divided into four groups and treated as follows: control A (distilled water), B (HAART), C (HAART+Virgin coconut oil 10 ml/kg) and D (Virgin coconut oil [VCO] 10 ml/kg). Testicular segments were evaluated using transmission electron microscopy. Serum was assayed for testosterone, luteinising hormone, follicle stimulating hormone and testicular tissue for malondialdehyde and glutathione. Ultrastructure of basement membrane (Bm), mitochondria and spermatocytes was normal in the control group. HAART-treated group showed significant increase (p < .01) in Bm thickness with significant decrease in Leydig cell nuclear diameter (p < .05) and volume (p < .01) when compared with control group. Mitochondrial cristae appear collapsed, and Sertoli cells showed cytoplasmic vacuolations. HAART+VCO group showed improved ultrastructural details in Bm, and Sertoli cell and Leydig cells show abundant lipid droplets. Virgin coconut oil-treated group showed thinning of Bm with otherwise normal ultrastructural features of organelles. HAART-treated group showed significant increase (p < .01) in testosterone levels. There was no significant effect on malondialdehyde and glutathione levels. Virgin coconut oil improved testicular morphology and reversed HAART-induced ultrastructural alterations. Further studies on putative mechanism are required. © 2017 Blackwell Verlag GmbH.

Ultrastructural characteristics of the cranial dura mater-arachnoid interface layer.

PubMed

Angelov, D N

1990-01-01

The ultrastructural features of the encephalic dura mater-arachnoid borderline (interface) layer (zone) of rats, rabbits, cats and humans were studied. The rat's interface zone included the electron-lucent epithelium-like arranged fibroblasts of the inner dural layer, the rich in filaments cells of the dural neurothelium, a 20 nm wide intercellular cleft filled with electron-dense material and the dark mitochondria-rich cells of the outer arachnoidal layer; in rabbits and cats, this laminar distinction was less prominent, while in man, it was almost absent.

Histological and ultrastructural features of the rectum in Poecilimon cervus Karabağ, 1950 (Orthoptera: Tettigoniidae).

PubMed

Polat, Irmak; Suludere, Zekiye; Candan, Selami

2017-02-01

The morphology and ultrastructure of the rectum in Poecilimon cervus Karabağ, 1950 (Orthoptera, Tettigoniidae) were analyzed by light microscope, scanning (SEM) and transmission electron microscopes (TEM). The rectum is the final part of the digestive tract that plays an important role in water reabsorption in insects and so provides osmoregulation. In the transverse sections, six rectal pads and columnar epithelium can be distinguished. The cuticular intima lines the lumen at the apical side of the epithelium. In the cytoplasm, there are numerous mitochondria, some endocytic vesicles, secreting vesicles whose sizes differ according to the area in the cell, and a nucleus with globular in shape. With this study, we aimed to demonstrate the ultrastructure of the rectum of P. cervus and differences or similarities of with other species. © 2016 Wiley Periodicals, Inc.

The ultrastructural surface morphology of oral cancer cells and keratinocytes after exposure to chitosan

NASA Astrophysics Data System (ADS)

Fatimah; Sarsito, A. S.; Wimardhani, Y. S.

2017-08-01

Low-molecular-weight chitosan (LMWC) has the same selective cytotoxic effects on oral cancer cells as cisplatin. The cell deaths caused by the anticancer characteristics of chitosan show that apoptosis is not the death pathway of the primary cells involved. The interactions between LMWC and the cells need to be explored. The objective of this study was to compare the ultrastructural morphology of oral Squamous Cell Carcinoma (SCC Ca)-922 and noncancer keratinocyte HaCaT cell lines after exposure to LMWC and cisplatin. The cells were treated with LMWC and cisplatin, and their ultrastructural morphology was analyzed using scanning electron micrographs. Features of early apoptosis, seen as the loss of microvilli, were detected in the LMWC-exposed Ca9-22 cells, and there was a material surrounding the cells. In contrast, the LMWC-exposed HaCaT cells showed no changes related to apoptosis. The results were the opposite when cisplatin was used. This study confirms that there are differences in the ultrastructural surface morphology of LMWC-exposed and cisplatin-exposed oral cancer cells and keratinocytes that could be correlated with their biological activity.

Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare)

USGS Publications Warehouse

Murphy, B.G.; Bradway, D.; Walsh, T.; Sanders, G.E.; Snekvik, K.

2009-01-01

A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

Reproducibility of the NEPTUNE descriptor-based scoring system on whole-slide images and histologic and ultrastructural digital images.

PubMed

Barisoni, Laura; Troost, Jonathan P; Nast, Cynthia; Bagnasco, Serena; Avila-Casado, Carmen; Hodgin, Jeffrey; Palmer, Matthew; Rosenberg, Avi; Gasim, Adil; Liensziewski, Chrysta; Merlino, Lino; Chien, Hui-Ping; Chang, Anthony; Meehan, Shane M; Gaut, Joseph; Song, Peter; Holzman, Lawrence; Gibson, Debbie; Kretzler, Matthias; Gillespie, Brenda W; Hewitt, Stephen M

2016-07-01

The multicenter Nephrotic Syndrome Study Network (NEPTUNE) digital pathology scoring system employs a novel and comprehensive methodology to document pathologic features from whole-slide images, immunofluorescence and ultrastructural digital images. To estimate inter- and intra-reader concordance of this descriptor-based approach, data from 12 pathologists (eight NEPTUNE and four non-NEPTUNE) with experience from training to 30 years were collected. A descriptor reference manual was generated and a webinar-based protocol for consensus/cross-training implemented. Intra-reader concordance for 51 glomerular descriptors was evaluated on jpeg images by seven NEPTUNE pathologists scoring 131 glomeruli three times (Tests I, II, and III), each test following a consensus webinar review. Inter-reader concordance of glomerular descriptors was evaluated in 315 glomeruli by all pathologists; interstitial fibrosis and tubular atrophy (244 cases, whole-slide images) and four ultrastructural podocyte descriptors (178 cases, jpeg images) were evaluated once by six and five pathologists, respectively. Cohen's kappa for inter-reader concordance for 48/51 glomerular descriptors with sufficient observations was moderate (0.40

Ultrastructural changes of goat corpus luteum during the estrous cycle.

PubMed

Jiang, Yi-Fan; Hsu, Meng-Chieh; Cheng, Chiung-Hsiang; Tsui, Kuan-Hao; Chiu, Chih-Hsien

2016-07-01

The present study was designed to study the ultrastructure of goat corpora lutea (CL, n=10) and structural changes as related to steroidogenic functions during the estrous cycle. The reproduction status of goats was estimated by analyzing serum progesterone concentrations. The CL at various stages was surgically collected. To characterize ultrastructural features associated with steroidogenesis, tissue and cellular structures were studied. Blood supplies were examined based on features of the endothelial cells and capillary structures in the CL. Activated endothelial cells and developing vessels were observed in the early stage, whereas mature endothelial cells, accumulating extracellular matrix fibers, and stabilized vessels were observed in the middle and late stages of assessment. In the late stage of assessment, shrunken goat luteal cells scattered around the capillaries were detected and formed circular regression areas. Features of autophagy and luteal cell apoptosis were noted. In large luteal cells, steroidogenic organelles were present, including microvillar channels, endoplasmic reticulum, and mitochondria. Conformational changes in the endoplasmic reticulum and increased mitochondria with tubular cristae were observed in the early-middle CL transitions. In contrast, mitochondria swelled and the cristae transformed to the lamellar type in the late stage, suggesting that organelle plasticity could contribute to steroidogenesis in goat CL. In conclusion, results suggest angiogenesis occurs in early developing CL and programmed cell death occurred in the late stage of CL assessment in the present study. Structures and quantiles of steroidogenic organelles are correlated with the steroidogenic functions in goats. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrastructural analysis of Phytomonas species from Euphorbia pinea reveals trans-cytoplasmic filaments 10 nm in diameter.

PubMed

Page, A M; Lagnado, J R

2000-10-01

Phytomonas sp. derived from Euphorbia pinea are digenetic plant trypanosomes that are transmitted by the squashbug Stenocephalus agilis and exist exclusively as promastigotes. The stable sub-pellicular microtubular array, the flagellar axoneme and the paraflagellar rod represent the major cytoskeletal components common to all trypanosomes. The work described in this paper examines in detail the ultrastructural morphology of the organism and highlights a number of novel structural features, and in particular, the presence of some detergent-resistant proteins which take the form of bundles of trans-cytoplasmic filaments of ca. 10 nm in diameter, seen in cells from both log- and stationary-phase cultures. The ultrastructural morphology and immunological cross-reactivity of these filaments are described, and their relationship to filamentous bundles previously reported in stationary-phase cultures of Crithidia fasciculata and to intermediate filaments of animal cells is discussed.

Ultrastructure of oogenesis in imposex females of Babylonia areolata (Caenogastropoda: Buccinidae)

NASA Astrophysics Data System (ADS)

Muenpo, C.; Suwanjarat, J.; Klepal, W.

2011-09-01

During a tributyltin (TBT)-exposure experiment, the ultrastructural features of oogenesis have been examined in TBT-induced imposex females of Babylonia areolata and compared with those of the normal female. The results obtained from such experiment demonstrates that B. areolata exhibits a low to moderate intensity of imposex because all VDSI values are never higher than 3. Ultrastructures of germ cell development including oogonia, pre-vitellogenic, early vitellogenic, late vitellogenic and mature oocytes show that oogenesis in imposex female is similar to that of normal females except for the presence of numerous lipid droplets in the cytoplasm of the oocytes and the follicle cells in imposex females, indicating the degeneration of their oocytes. Vitellogenesis in B. areolata involves both auto- and heterosynthetic processes that resemble those of the basal gastropods and the pulmonates. In addition, the presence of cortical granules and microvilli are unique structures of this species.

Numerous eosinophilic globules (skeinoid fibers) in a duodenal stromal tumor: an exceptional case showing smooth muscle differentiation.

PubMed

Matsukuma, S; Doi, M; Suzuki, M; Ikegawa, K; Sato, K; Kuwabara, N

1997-11-01

A unique case of duodenal stromal tumor in a 51-year-old man is reported. The tumor histologically showed spindle cell proliferation and numerous eosinophilic globules. Most globules were composed of tangled 45 nm thick fibrils, which were ultrastructurally identical to 'skeinoid fibers'. The presence of glycogen granules in the tumor cells and the immunoreactivity for alpha-smooth muscle actin suggested smooth muscle differentiation. Focal ultrastructural findings also supported the smooth muscle nature of this tumor. There were no immunohistochemical and ultrastructural features indicating neural differentiation. In previous studies, the presence of such 'skeinoid fibers' was suggested to be a histological marker for neural differentiation in gastrointestinal stromal tumor. However, the findings in the present case suggest that numerous 'skeinoid fibers' can be identified in duodenal stromal tumor with smooth muscle differentiation, although this condition may be rare.

Clear cell trichoblastoma: a clinicopathological and ultrastructural study of two cases.

PubMed

Kazakov, Dmitry V; Mentzel, Thomas; Erlandson, Robert A; Mukensnabl, Petr; Michal, Michal

2006-06-01

Clear cell change in basal cell carcinomas is a well-recognized phenomenon, but is obviously rare in trichoblastomas. We present two cases of clear cell trichoblastoma in which clear cell change was very much prominent, and the results of an ultrastructural study intended to explore the basis of that feature. Both our patients were women, aged 56 and 77 years, who presented with solitary, slowly growing nodules that measured 3 to 5 cm in largest dimension and were located on the scalp and the flexor aspect of the lower arm. Microscopically, the tumors in both cases were symmetric, non-ulcerated, and composed of variably sized and shaped (cribriform, racemiform, strands, cords, nodules) aggregations of monomorphous basaloid epithelial cells that were associated with a specific trichogenic stroma. Common to both tumors was clear cell cytoplasm evident in the majority of the epithelial cells in one case and almost in the entire epithelial cell population in the other. In most epithelial aggregations the epithelial cells with clear cytoplasm often appeared columnar and were arranged in a palisade along a recognizable basal membrane, thus indicative of outer sheath differentiation at the bulb. There were other signs of follicular differentiation. Ultrastructurally, variably sized clusters of uniform small basaloid epithelial cells were separated from the stroma by a thin discontinuous basement membrane. In addition to the usual organelles, the cytoplasm contained fairly conspicuous tonofilaments and variably sized vacuoles devoid of a limiting membrane, located between the palisaded nuclei and the outer cell membrane. The majority of vacuoles were empty, although clumps of a finely granular substance were occasionally evident. No distinct lipid droplets or glycogen particles were identified. The basaloid cells were joined by scattered small desmosomes. These findings were consistent with trichilemmal differentiation at the bulb.

[Structure and ultrastructure of the ovary of Cichlasoma urophthalmus (Osteichthyes: Cichlidae)].

PubMed

Viedma, Rubí; Franco, Jonathan; Bedia, Carlos; Guedea Fernández, Guadalupe; Villa Zevallos, Héctor Barrera; Barrera Escorcia, Héctor

2011-06-01

The study of the normal development, differentiation, structure and function of various components of developing follicles in the ovaries of numerous fish species have been a consistent focus of comparative reproduction. The structural and ultrastructural features of gonads from Cichlasoma urophthalmus have received scarce attention. In this work, we realized a descriptive study of female gonads of Cichlasoma urophthalmus. A total of 40 samples were collected in the Veracruz Alvarado Lagoon, Mexico in 2007-2008 period including the windy, dry and rainy seasons. Female gonads were extracted and a portion was fixed in 4% formaldehyde for treatment for routine histology hematoxylin and eosin (HE) and another part was processed for transmission electron microscopy (TEM). The gonads were fixed in 3% glutaraldehyde and 2% osmium tetroxide, followed by dehydrated in ethanol 50%, 70%, 80%, 95% and 100% for inclusion in Epon, thin sections were then prepared and were contrasted with lead citrate and uranyl acetate. The process of oocyte development can be divided into five distinct stages (formation of oocytes from oogonia, primary growth, lipid stage, vitellogenesis and maturation). In this work, we found that the primary growth stage is characterized by intense RNA synthesis and the differentiation of the vitelline envelope. Secondary growth starts with the accumulation of lipid droplets in the oocyte cytoplasm (lipid stage), which is then followed by massive uptake and processing of proteins into yolk platelets (vitellogenic stage). During the maturation stage, the lipid inclusions coalesce into a single oil droplet, and hydrolysis of the yolk platelets leads to the formation of a homogeneous mass of fluid yolk in mature eggs. In conclusion, further studies should elucidate structure and ultrastructural changes in the ovarian follicular components, in C. urophthalmus during different stages of oocyte growth.

The clypeal gland: a new exocrine gland in termite imagoes (Isoptera: Serritermitidae, Rhinotermitidae, Termitidae).

PubMed

Křížková, Barbora; Bourguignon, Thomas; Vytisková, Blahoslava; Sobotník, Jan

2014-11-01

Social insects possess a rich set of exocrine organs producing diverse pheromones and defensive compounds. This is especially true for termite imagoes, which are equipped with several glands producing, among others, sex pheromones and defensive compounds protecting imagoes during the dispersal flight and colony foundation. Here, we describe the clypeal gland, a new termite exocrine organ occurring in the labro-clypeal region of imagoes of most Rhinotermitidae, Serritermitidae and Termitidae species. The clypeal gland of Coptotermes testaceus consists of class 1 (modified epidermal cell) and class 3 (bicellular gland unit) secretory cells. Ultrastructural features suggest that the gland secretes volatile compounds and proteins, probably after starting the reproduction. One peculiar feature of the gland is the presence of multiple secretory canals in a single canal cell, a feature never observed before in other insect glands. Although the function of the gland remains unknown, we hypothesize that it could produce secretion signalling the presence of functional reproductives or their need to be fed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ulcerative colitis: ultrastructure of interstitial cells in myenteric plexus.

PubMed

Rumessen, J J; Vanderwinden, J-M; Horn, T

2010-10-01

Interstitial cells of Cajal (ICC) are key regulatory cells in the gut. In the colon of patients with severe ulcerative colitis (UC), myenteric ICC had myoid ultrastructural features and were in close contact with nerve terminals. In all patients as opposed to controls, some ICC profiles showed degenerative changes, such as lipid droplets and irregular vacuoles. Nerve terminals often appeared swollen and empty. Glial cells, muscle cells, and fibroblast-like cells (FLC) showed no alterations. FLC enclosed macrophages (MLC), which were in close contact with naked axon terminals. The organization and cytological changes may be of pathophysiological significance in patients with UC.

Salivary duct carcinoma with rhabdoid features: Report of 2 cases with immunohistochemical and ultrastructural analyses

PubMed Central

Kusafuka, Kimihide; Onitsuka, Tetsuro; Muramatsu, Koji; Miki, Tomoko; Murai, Chika; Suda, Toshihito; Fuke, Tomohito; Kamijo, Tomoyuki; Iida, Yoshiyuki; Nakajima, Takashi

2014-01-01

Background Salivary duct carcinoma with rhabdoid features is extremely rare. Methods We report 2 cases of salivary duct carcinoma with rhabdoid features treated at our institution. Results Case 1 was a 44-year-old Japanese man who had swelling in the left parotid region. This tumor consisted of residual pleomorphic adenoma and widely invasive carcinoma, which showed a diffuse growth pattern by atypical rhabdoid cells. Case 2 was a 66-year-old Japanese man who had swelling of the right cervical region. This submandibular tumor was also composed of both residual pleomorphic adenoma region and invasive adenocarcinoma components, whereas some metastatic lesions were purely composed of rhabdoid cells. Such cells were strongly and diffusely positive for cytokeratins (CKs), gross cystic disease fluid protein-15 (GCDFP), and androgen receptor (AR). Case 1 was also positive for Her-2 and p53. Conclusion Both patients were diagnosed with carcinoma ex pleomorphic adenoma and their carcinomatous components were composed of salivary duct carcinoma with rhabdoid features, which is a highly aggressive tumor, similar to salivary duct carcinoma. © 2013 The Authors. Head & Neck published by Wiley Periodicals, Inc. Head Neck 36: E28–E35, 2014 PMID:24038506

Cells resembling intraventricular macrophages are present in the subretinal space of human foetal eyes.

PubMed

McMenamin, P G; Loeffler, K U

1990-06-01

The subretinal spaces (SRS) in 17 human foetal eyes were investigated by light microscopy and scanning and transmission electron microscopy. A hitherto undocumented group of pleomorphic cells was detected on the apical surface of the retinal pigment epithelium (RPE) and on the undersurface of the neural retina. These cells formed a regularly spaced array in the peripheral SRS, particularly in the most anterior portion nearest the ciliary body anlage. The morphology of the SRS cells ranged from a small round or ovoid form with a few short basal pseudopodia to an extremely flattened dendritic form. Ultrastructural features, such as large melanophagolysosomes, consistent with a phagocytic function, were observed in some cells. These SRS cells bore remarkable resemblance to epiplexus and supraependymal cells, considered to be the resident population of macrophages on the ventricular surfaces of the brain. This morphological parallelism, together with the anatomically homologous location, is strong evidence that SRS cells represent a normal population of macrophages in the developing human eye. No features consistent with an RPE or neuronal origin were observed. The possible role of these cells as transient phagocytes in the SRS with a possible destiny as retinal microglia is discussed.

Ultrastructure of the labrum and foregut of Derocheilocaris remanei (Crustacea, Mystacocarida).

PubMed

Herrera-Alvarez, Letizia; Fernández, Isabel; Benito, Jesús; Pardos, Fernando

1996-11-01

The cuticle-lined foregut of Derocheilocaris remanei consists of the mouth with its associated labrum, and an undifferentiated esophagus. It is separated from the midgut by an esophageal valve. The labrum is a conspicuous structure moved by five pairs of muscles (four dorsoventral and one longitudinal). Four pairs of subcuticular glands open to its inner face forming two longitudinal, lateral rows of cuticular pores. Each secretory unit is composed of a glandular component (with one or two secretory cells), a neck cell, and a duct cell. In addition, a single gland cell opens mesially into the buccal cavity. The ventrally located mouth is a complex structure characterized by a filter-like system, a sensory organ, and epithelial cells with highly developed microvilli. The esophagus is a simple tube with a characteristic curvature following the mouth. It has a rounded cross section and a triradiate lumen. A layer of circular musculature surrounds this region. The end of the esophagus protrudes into the midgut lumen forming the so-called esophageal valve. The ultrastructural features of the foregut, with the presence of a mucus-trapping mechanism, a relatively well-developed filter system and associated structures and an esophagus lacking glands confirm the microphagic feeding habits of mystacocarids. © 1996 Wiley-Liss, Inc. Copyright © 1996 Wiley-Liss, Inc.

The Placenta in Monoclea forsteri Hook. and Treubia lacunosa (Col.) Prosk: Insights into Placental Evolution in Liverworts

PubMed Central

CARAFA, A.; DUCKETT, J. G.; LIGRONE, R.

2003-01-01

Placental morphology is remarkably diverse between major bryophyte groups, especially with regard to the presence and distribution of transfer cells in the sporophyte and gametophyte. In contrast, with the exception of metzgerialean liverworts, placental morphology is highly conserved within major bryophyte groups. Here we examine the ultrastructure of the placenta in Monoclea forsteri and Treubia lacunosa, basal members of the marchantialean and metzgerialean liverwort lineages, respectively. In both species several layers of transfer cells are found on both sides of the placenta, with sporophytic transfer cells exhibiting prominent wall labyrinths. Consistent with previous reports of a similar placenta in other putatively basal and isolated liverwort genera such as Fossombronia, Haplomitrium, Blasia and Sphaerocarpos, this finding suggests that this type of placenta represents the plesiomorphic (primitive) condition in liverworts. Distinctive ultrastructural features of placental cells in Monoclea include branched plasmodesmata in the sporophyte and prominent arrays of smooth endoplasmic reticulum, seemingly active in secretion in the gametophyte. These arrays contain a core of narrow tubules interconnected by electron‐opaque rods, structures with no precedent in plants. Analysis of the distribution of different types of placenta in major bryophyte groups provides valuable insights into their inter‐relationships and possible phylogeny. PMID:12876192

A functional thyrotropin- and growth hormone-secreting pituitary adenoma with a ultrastructurally monomorphic feature: a case study.

PubMed

Ozawa, Y; Kameya, T; Kasuga, A; Naritaka, H; Kanda, N; Maruyama, H; Saruta, T

1998-04-01

A 38-yr-old female with a TSH- and GH-secreting pituitary adenoma is described, who had both overt symptoms, hyperthyroidism and acromegaly. Her serum TSH was not suppressed despite high concentrations of free T3 and free T4, and her alpha-subunit/TSH molar ratio was high. Her serum GH was consistently high, and was not suppressed by an oral glucose tolerance test. Preoperative testing revealed that, although the TSH response was impaired, TSH, alpha-subunit and GH were increased by TRH injection, and that these hormones were reduced by bromocriptine or somatostatin analog. Although she did not have hyperprolactinemia, the in vitro culture and immunohistochemical studies revealed that the adenoma cells produced and released PRL, in addition to TSH, alpha-subunit and GH. Immunohistochemical studies showed the presence of GH in the cytoplasm of many adenoma cells. TSH beta-positive adenoma cells were less frequently seen than GH-positive adenoma cells. No cells showed the coexistence of GH and TSH beta, and a few cells were positive for PRL. By electron microscopy, the adenoma was found to be composed of a single cell type resembling thyrotrophs, and did not have any characteristics of somatotrophs. This case was considered to be of interest, because the adenoma was ultrastructurally monomorphous, but immunohistochemically polymorphous.

Overexpression of the lamina proteins Lamin and Kugelkern induces specific ultrastructural alterations in the morphology of the nuclear envelope of intestinal stem cells and enterocytes.

PubMed

Petrovsky, Roman; Krohne, Georg; Großhans, Jörg

2018-03-01

The nuclear envelope has a stereotypic morphology consisting of a flat double layer of the inner and outer nuclear membrane, with interspersed nuclear pores. Underlying and tightly linked to the inner nuclear membrane is the nuclear lamina, a proteinous layer of intermediate filament proteins and associated proteins. Physiological, experimental or pathological alterations in the constitution of the lamina lead to changes in nuclear morphology, such as blebs and lobulations. It has so far remained unclear whether the morphological changes depend on the differentiation state and the specific lamina protein. Here we analysed the ultrastructural morphology of the nuclear envelope in intestinal stem cells and differentiated enterocytes in adult Drosophila flies, in which the proteins Lam, Kugelkern or a farnesylated variant of LamC were overexpressed. Surprisingly, we detected distinct morphological features specific for the respective protein. Lam induced envelopes with multiple layers of membrane and lamina, surrounding the whole nucleus whereas farnesylated LamC induced the formation of a thick fibrillary lamina. In contrast, Kugelkern induced single-layered and double-layered intranuclear membrane structures, which are likely be derived from infoldings of the inner nuclear membrane or of the double layer of the envelope. Copyright © 2018 Elsevier GmbH. All rights reserved.

Chronic cigarette smoke causes oxidative damage and apoptosis to retinal pigmented epithelial cells in mice.

PubMed

Fujihara, Masashi; Nagai, Norihiro; Sussan, Thomas E; Biswal, Shyam; Handa, James T

2008-09-01

The purpose of this study was to determine whether mice exposed to chronic cigarette smoke develop features of early age-related macular degeneration (AMD). Two month old C57Bl6 mice were exposed to either filtered air or cigarette smoke in a smoking chamber for 5 h/day, 5 days/week for 6 months. Eyes were fixed in 2.5% glutaraldehyde/2% paraformaldehyde and examined for ultrastructural changes by transmission electron microscopy. The contralateral eye was fixed in 2% paraformaldehyde and examined for oxidative injury to the retinal pigmented epithelium (RPE) by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OHdG) immunolabeling and apoptosis by TUNEL labeling. Mice exposed to cigarette smoke had immunolabeling for 8-OHdG in 85+/-3.7% of RPE cells counted compared to 9.5+/-3.9% in controls (p<0.00001). Bruch membrane was thicker in mice exposed to smoke (1086+/-332 nm) than those raised in air (543+/-132 nm; p = 0.0069). The two most pronounced ultrastructural changes (severity grading scale from 0-3) seen were a loss of basal infoldings (mean difference in grade = 1.98; p<0.0001), and an increase in intracellular vacuoles (mean difference in grade = 1.7; p<0.0001). Ultrastructural changes to Bruch membrane in cigarette-smoke exposed mice were smaller in magnitude but consistently demonstrated significantly higher grade injury in cigarette-exposed mice, including basal laminar deposits (mean difference in grade = 0.54; p<0.0001), increased outer collagenous layer deposits (mean difference in grade = 0.59; p = 0.002), and increased basal laminar deposit continuity (mean difference in grade = 0.4; p<0.0001). TUNEL assay showed a higher percentage of apoptotic RPE from mice exposed to cigarette smoke (average 8.0+/-1.1%) than room air (average 0+/-0%; p = 0.043). Mice exposed to chronic cigarette smoke develop evidence of oxidative damage with ultrastructural degeneration to the RPE and Bruch membrane, and RPE cell apoptosis. This model could be useful for studying the mechanism of smoke induced changes during early AMD.

Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis).

PubMed

Miller, M A; Barr, B C; Nordhausen, R; James, E R; Magargal, S L; Murray, M; Conrad, P A; Toy-Choutka, S; Jessup, D A; Grigg, M E

2009-10-01

In 2004, three wild sea otters were diagnosed with putative Sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. Schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. Tissue cysts walls from sea otter 1 (SO1) stained positively using anti-S. neurona polyclonal antiserum. However, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. Two immature tissue cysts in the brain of SO1 were examined using transmission electron microscopy. Ultrastructural features included cyst walls with thin villous projections up to 1 microm long with tapered ends and a distinctive, electron-dense outer lining layer composed of linearly-arranged, semi-circular structures with a "hobnailed" surface contour. Small numbers of microtubules extended down through the villi into the underlying granular layer. Metrocytes were short and plump with an anterior apical complex, 22 sub-pellicular microtubules, numerous free ribosomes and no rhoptries. Some metrocytes appeared to be dividing, with two adjacent nuclear profiles. Collectively these ultrastructural features were compatible with developing protozoal cysts and were similar to prior descriptions of S. neurona tissue cysts. Panspecific 18S rDNA primers were utilized to identify protozoa infecting the brains of these otters and DNA amplification and additional sequencing at the ITS1 locus confirmed that all three otters were infected with S. neurona. No other Sarcocystis spp. were detected in the brains or skeletal muscles of these animals by immunohistochemistry or PCR. We believe this is the first ultrastructural and molecular confirmation of the development of S. neurona tissue cysts in the CNS of any animal.

Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis)

PubMed Central

Miller, M.A.; Barr, B.C.; Nordhausen, R.; James, E.R.; Magargal, S.L.; Murray, M.; Conrad, P.A.; Toy-Choutka, S.; Jessup, D.A.; Grigg, M.E.

2009-01-01

In 2004, three wild sea otters were diagnosed with putative Sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. Schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. Tissue cysts from sea otter 1 (SO1) stained positively using anti-S. neurona polyclonal antiserum. However, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. Two immature tissue cysts in the brain of SO1 were examined using transmission electron microscopy. Ultrastructural features included cyst walls with thin villous projections up to 1 μm long with tapered ends and a distinctive, electron-dense outer lining layer composed of linearly-arranged, semi-circular structures with a “hobnailed” surface contour. Small numbers of microtubules extended down through the villi into the underlying granular layer. Metrocytes were short and plump with an anterior apical complex, 22 subpellicular microtubules, numerous free ribosomes and no rhoptries. Some metrocytes appeared to be dividing, with two adjacent nuclear profiles. Collectively these ultrastructural features were compatible with developing protozoal cysts and were similar to prior descriptions of S. neurona tissue cysts. Panspecific 18S rDNA primers were utilized to identify protozoa infecting the brains of these otters and DNA amplification and additional sequencing at the ITS1 locus confirmed that all three otters were infected with S. neurona. No other Sarcocystis spp. were detected in the brains or skeletal muscles of these animals by immunohistochemistry or PCR. We believe this is the first ultrastructural and molecular confirmation of the development of S. neurona tissue cysts in the CNS of any animal. PMID:19527725

Humoral hypercalcemia of malignancy in nude mouse model of a canine adenocarcinoma derived from apocrine glands of the anal sac. Biochemical, histomorphometric, and ultrastructural studies.

PubMed

Rosol, T J; Capen, C C; Weisbrode, S E; Horst, R L

1986-06-01

A serially transplantable tumor line, designated CAC-8, has been developed in nude mice from a spontaneously occurring adenocarcinoma of the anal sac from a hypercalcemic dog. Nude mice with transplanted CAC-8 developed hypercalcemia (mean 16.3 +/- 0.6 mg/dl) and moderate hypophosphatemia without bone metastasis. Urinary excretion of calcium and hydroxyproline were increased 6- and 2.3-fold, respectively. Urinary excretion of cAMP was moderately increased but phosphorus excretion was not significantly altered. Serum 1,25-dihydroxycholecalciferol was increased significantly in tumor-bearing nude mice in proportion to the magnitude of tumor-induced hypercalcemia. Histomorphometric evaluation of lumbar vertebrae from nude mice with CAC-8 revealed decreased total and cortical bone volume, a 3.3-fold increase in bone resorption rate and a 2.5-fold increase in bone formation rate at the tissue level. The transplanted CAC-8 has maintained the histologic pattern of the original carcinoma up to the present sixth passage. Ultrastructural evaluation of transplanted tumor cells revealed 150-250-nm secretory-like granules. The granules did not stain by using an ultrastructural cytochemical (uranaffin) stain specific for neuroendocrine secretory granules. Ultrastructurally, the parathyroid glands of nude mice with CAC-8 appeared inactive with large intracytoplasmic whorl of agranular membranes. These data suggest the transplanted carcinoma secreted a humoral factor which resulted in hypercalcemia. The tumor line (CAC-8) propagated in nude mice represents an animal model of humoral hypercalcemia of malignancy that shares many features with the syndrome described in human patients. Unique features of this transplanted carcinoma associated with hypercalcemia include increased serum dihydroxycholecalciferol, increased rate of bone formation as well as bone resorption, an absence of bone metastases, and evidence of parathyroid gland suppression.

Aerodynamics and pollen ultrastructure in Ephedra.

PubMed

Bolinder, Kristina; Niklas, Karl J; Rydin, Catarina

2015-03-01

• Pollen dispersal is affected by the terminal settling velocity (Ut) of the grains, which is determined by their size, bulk density, and by atmospheric conditions. The likelihood that wind-dispersed pollen is captured by ovulate organs is influenced by the aerodynamic environment created around and by ovulate organs. We investigated pollen ultrastructure and Ut of Ephedra foeminea (purported to be entomophilous), and simulated the capture efficiency of its ovules. Results were compared with those from previously studied anemophilous Ephedra species.• Ut was determined using stroboscopic photography of pollen in free fall. The acceleration field around an "average" ovule was calculated, and inflight behavior of pollen grains was predicted using computer simulations. Pollen morphology and ultrastructure were investigated using SEM and STEM.• Pollen wall ultrastructure was correlated with Ut in Ephedra. The relative proportion and amount of granules in the infratectum determine pollen bulk densities, and (together with overall size) determine Ut and thus dispersal capability. Computer simulations failed to reveal any functional traits favoring anemophilous pollen capture in E. foeminea.• The fast Ut and dense ultrastructure of E. foeminea pollen are consistent with functional traits that distinguish entomophilous species from anemophilous species. In anemophilous Ephedra species, ovulate organs create an aerodynamic microenvironment that directs airborne pollen to the pollination drops. In E. foeminea, no such microenvironment is created. Ephedroid palynomorphs from the Cretaceous share the ultrastructural characteristics of E. foeminea, and at least some may, therefore, have been produced by insect-pollinated plants. © 2015 Botanical Society of America, Inc.

Retinal Ultrastructure of Murine Models of Dry Age-related Macular Degeneration (AMD)

PubMed Central

Ramkumar, Hema L.; Zhang, Jun; Chan, Chi-Chao

2010-01-01

Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness worldwide in the elderly population. The pathology of dry AMD consists of degeneration of photoreceptors and the RPE, lipofuscin (A2E) accumulation, and drusen formation. Mice have been widely used for generating models that simulate human AMD features for investigating the pathogenesis, treatment and prevention of the disease. Although the mouse has no macula, focal atrophy of photorecptors and RPE, lipofuscin accumulation, and increased A2E can develop in aged mouse eyes. However, drusen are rarely seen in mice because of their simpler Bruch’s membrane and different process of lipofuscin extrusion compared with humans. Thus, analyzing basal deposits at the ultrastructural level and understanding the ultrastructural pathologic differences between various mouse AMD models are critical to comprehending the significance of research findings and response to possible therapeutic options for dry AMD. Based on the multifactorial pathogenesis of AMD, murine dry AMD models can be classified into three groups. First, genetically engineered mice that target genes related to juvenile macular dystrophies are the most common models, and they include abcr−/− (Stargardt disease), transgenic ELOVL4 (Stargardt-3 dominant inheritary disease), Efemp1R345W/R345W (Doyne honeycomb retinal dystrophy), and Timp3S156C/S156C (Sorsby fundus dystrophy) mice. Other murine models target genes relevant to AMD, including inflammatory genes such as Cfh−/−, Ccl2−/−, Ccr2−/−, Cx3cr1−/−, and Ccl2−/−/cx3cr1−/−, oxidative stress associated genes such as Sod1−/− and Sod2 knockdown, metabolic pathway genes such as neprilysin −/− (amyloid β), transgenic mcd/mcd (cathepsin D), Cp−/−/Heph−/Y (ferroxidase ceruloplasmin/hepaestin, iron metabolism), and transgenic ApoE4 on high fat and high cholesterol diet (lipid metabolism). Second, mice have also been immunologically manipulated by immunization with carboxyethylpyrrole (CEP), an oxidative fragment of DHA found in drusen, and found to present with dry AMD features. Third, natural mouse strains such as arrd2/arrd2 (Mdm gene mutation) and the senescence accelerated mice (SAM) spontaneously develop features of dry AMD like photoreceptor atrophy and thickening of Bruch’s membrane. All the aforementioned models develop retinal lesions with various features that simulate dry AMD lesions: focal photoreceptor degeneration, abnormal RPE with increased lipofuscin, basal infolding, decreased melanosomes and degeneration. However, Bruch’s membrane changes are less common. Most mice develop retinal lesions at an older age (6–24 months, depending on the models), while the Ccl2−/−/cx3cr1−/− mice develop lesions by 4–6 weeks. Although murine models present various degrees of retinal and/or RPE degeneration, classical drusen is extremely rare. Using electron microscopy, small drusenoid deposits are found between RPE and Bruch’s membrane in a few models including Efemp1 R345W/R345W, Ccl2−/−/cx3cr1−/−, neprilysin −/−, transgenic mcd/mcd, and ApoE4 transgenic mice on a high fat diet. High A2E levels are measured in the retinas of abcr−/−, transgenic ELOVL4, and Ccl2−/−/cx3cr1−/− mice. In summary, murine models provide useful tools for studying AMD pathogenesis and evaluating novel therapies for this disease. This review compares the major dry AMD murine models and discusses retinal pathology at the ultrastructural level. PMID:20206286

Effect of different blood-guided conditioning programmes on skeletal muscle ultrastructure and histochemistry of sport horses.

PubMed

Lindner, A; Dag Erginsoy, S; Kissenbeck, S; Mosen, H; Hetzel, U; Drommer, W; Chamizo, V E; Rivero, J L L

2013-04-01

The effects of three different blood-guided conditioning programmes on ultrastructural and histochemical features of the gluteus medius muscle of 2-year-old sport horses were examined. Six non-trained Haflinger horses performed three consecutive conditioning programmes of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 1.5 (v1.5 ), 2.5 (v2.5 ) and 4 (v4 ) mm respectively] and durations (25 and 45 min). Each conditioning programme lasted 6 weeks and was followed by a 5-week resting period. Pre-, post- and deconditioning muscle biopsies were analysed. Although training and detraining adaptations were similar in nature, they varied significantly in magnitude among the three different conditioning programmes. Overall, the adaptations consisted in significant increases in size of mitochondria and myofibrils, as well as a hypertrophy of myofibrillar ATPase type IIA muscle fibres and a reduction in number of type IIx low-oxidative fibres. Together, these changes are compatible with a significant improvement in both muscle aerobic capacity and muscle strength. The use of v1.5 and v2.5 as the exercise intensities for 45 min elicited more significant adaptations in muscle, whereas conditioning horses at v4 for 25 min evoked minimal changes. Most of these muscular adaptations returned towards the pre-conditioning status after 5 weeks of inactivity. It is concluded that exercises of low or moderate intensities (in the range between v1.5 and v2.5 ) and long duration (45 min) are more effective for improving muscle features associated with stamina and power in sport horses than exercises of higher intensity (equivalent to v4 ) and shorter duration (25 min). © 2012 Blackwell Verlag GmbH.

Prototheca zopfii Induced Ultrastructural Features Associated with Apoptosis in Bovine Mammary Epithelial Cells

PubMed Central

Shahid, Muhammad; Wang, Jianfang; Gu, Xiaolong; Chen, Wei; Ali, Tariq; Gao, Jian; Han, Dandan; Yang, Rui; Fanning, Séamus; Han, Bo

2017-01-01

Prototheca zopfii infections are becoming global concerns in humans and animals. Bovine protothecal mastitis is characterized by deteriorating milk quality and quantity, thus imparting huge economic losses to dairy industry. Previous published studies mostly focused on the prevalence and characterization of P. zopfii from mastitis. However, the ultrastructural pathomorphological changes associated with apoptosis in bovine mammary epithelial cells (bMECs) are not studied yet. Therefore, in this study we aimed to evaluate the in vitro comparative apoptotic potential of P. zopfii genotype-I and -II on bMECs using flow cytometry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed fast growth rate and higher adhesion capability of genotype-II in bMECs as compared with genotype-I. The viability of bMECs infected with P. zopfii genotype-II was significantly decreased after 12 h (p < 0.05) and 24 h (p < 0.01) in comparison with control cells. Contrary, genotype-I couldn't show any significant effects on cell viability. Moreover, after infection of bMECs with genotype-II, the apoptosis increased significantly at 12 h (p < 0.05) and 24 h (p < 0.01) as compared with control group. Genotype-I couldn't display any significant effects on cell apoptosis. The host specificity of P. zopfii was also tested in mouse osteoblast cells, and the results suggest that genotype-I and -II could not cause any significant apoptosis in these cell lines. SEM interpreted the pathomorphological alterations in bMECs after infection. Adhesion of P. zopfii with cells and further disruption of cytomembrane validated the apoptosis caused by genotype-II under SEM. While genotype-1 couldn't cause any significant apoptosis in bMECs. Furthermore, genotype-II induced apoptotic manifested specific ultrastructure features, like cytoplasmic cavitation, swollen mitochondria, pyknosis, cytomembrane disruption, and appearance of apoptotic bodies under TEM. The findings of the current study revealed that genotype-II has the capability to invade and survive within the bMECs, thus imparting significant damages to the mammary cells which result in apoptosis. This study represents the first insights into the pathomorphological and ultrastructure features of apoptosis in bMECs induced by P. zopfii genotype-II. PMID:28752077

Henneguya melini n. sp. (Myxosporea: Myxobolidae), a parasite of Corydoras melini (Teleostei: Siluriformes) in the Amazon region: morphological and ultrastructural aspects.

PubMed

Mathews, Patrick D; Maia, Antônio A M; Adriano, Edson A

2016-09-01

A new species of myxozoan, Henneguya melini sp. n. (Myxosporea: Myxobolidae), was described based on morphologic and ultrastructural features. This is a parasite of the ornamental freshwater fish C. melini from the Rio Negro, and it was found in five of 30 (16.7 %) C. melini examined. The parasite was found in the gill filaments, and the plasmodia had form of round to ellipsoid, with mature and immature spores inside them. The average spore body was 15.5 ± 0.2 μm in length, 4.7 ± 0.1 μm in width, and the tail measured 25.3 ± 0.1 μm in length. The spores showed typical features of the genus Henneguya, with two valves of equal size and two symmetrical polar capsules of 4.8 ± 0.7 μm in length and 1.7 ± 0.3 μm in width. Each polar capsule had a polar filament with five to six turns. Based on morphology (morphologic and ultrastructural data) of the plasmodia and spores and the fact that this is the first report of a Henneguya species in a fish species of the genus Corydoras, it was considered a new myxozoan species.

Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method

PubMed Central

Novaleski, Carolyn K.; Mizuta, Masanobu; Rousseau, Bernard

2016-01-01

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described two methodological procedures for evaluating cell death in the epithelium of immobilized, approximated, and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling. Results revealed that ultrastructural characteristics of apoptotic cell death, specifically condensed chromatin and apoptotic bodies, were observed after vocal fold vibration and approximation. Although episodes of necrotic cell death were rare, few enlarged cell nuclei were present after vibration and approximation. The vocal fold expresses an immunohistochemical marker for apoptosis along the apical surface of the epithelium. This study provides a solid foundation for future investigations regarding the role of cell death in vocal fold health and disease. PMID:27537846

Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method.

PubMed

Novaleski, Carolyn K; Mizuta, Masanobu; Rousseau, Bernard

2016-01-01

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described 2 methodological procedures for evaluating cell death in the epithelium of immobilized, approximated and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, the terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling. Results revealed that ultrastructural characteristics of apoptotic cell death, specifically condensed chromatin and apoptotic bodies, were observed after vocal fold vibration and approximation. Although episodes of necrosis were rare, few enlarged cell nuclei were present after vibration and approximation. The vocal fold expresses an immunohistochemical marker for apoptosis along the apical surface of the epithelium. This study provides a solid foundation for future investigations regarding the role of cell death in vocal fold health and disease. © 2016 S. Karger AG, Basel.

Hypoxic pretreatment protects against neuronal damage of the rat hippocampus induced by severe hypoxia.

PubMed

Gorgias, N; Maidatsi, P; Tsolaki, M; Alvanou, A; Kiriazis, G; Kaidoglou, K; Giala, M

1996-04-01

The present study investigates whether under conditions of successive hypoxic exposures pretreatment with mild (15% O(2)) or moderate (10% O(2)) hypoxia, protects hippocampal neurones against damage induced by severe (3% O(2)) hypoxia. The ultrastructural findings were also correlated with regional superoxide dismutase (SOD) activity changes. In unpretreated rats severe hypoxia induced ultrastructural changes consistent with the aspects of delayed neuronal death (DND). However, in preexposed animals hippocampal damage was attenuated in an inversely proportional way with the severity of the hypoxic pretreatment. The ultrastructural hypoxic tolerance findings were also closely related to increased regional SOD activity levels. Thus the activation of the endogenous antioxidant defense by hypoxic preconditioning, protects against hippocampal damage induced by severe hypoxia. The eventual contribution of increased endogenous adenosine and/or reduced excitotoxicity to induce hypoxic tolerance is discussed.

Fructose-Drinking Water Induced Nonalcoholic Fatty Liver Disease and Ultrastructural Alteration of Hepatocyte Mitochondria in Male Wistar Rat

PubMed Central

Thent, Zar Chi; Haji Suhaimi, Farihah

2015-01-01

Background. Nonalcoholic fatty liver disease (NAFLD) is one of the complications of the metabolic syndrome. It encompasses a wide range of disease spectrum from simple steatosis to liver cirrhosis. Structural alteration of hepatic mitochondria might be involved in the pathogenesis of NAFLD. Aims. In the present study, we used a newly established model of fructose-induced metabolic syndrome in male Wistar rats in order to investigate the ultrastructural changes in hepatic mitochondria that occur with fructose consumption and their association with NAFLD pathogenesis. Methods. The concentration of fructose-drinking water (FDW) used in this study was 20%. Six male Wistar rats were supplemented with FDW 20% for eight weeks. Body composition and metabolic parameters were measured before and after 8 weeks of FDW 20%. Histomorphology of the liver was evaluated and ultrastructural changes of mitochondria were assessed with transmission electron micrograph. Results. After 8 weeks of fructose consumption, the animals developed several features of the metabolic syndrome. Moreover, fructose consumption led to the development of macrovesicular hepatic steatosis and mitochondrial ultrastructural changes, such as increase in mitochondrial size, disruption of the cristae, and reduction of matrix density. Conclusion. We conclude that in male Wistar rat 8-week consumption of FDW 20% leads to NAFLD likely via mitochondrial structural alteration. PMID:26273656

Phloem ultrastructure and pressure flow: Sieve-Element-Occlusion-Related agglomerations do not affect translocation.

PubMed

Froelich, Daniel R; Mullendore, Daniel L; Jensen, Kåre H; Ross-Elliott, Tim J; Anstead, James A; Thompson, Gary A; Pélissier, Hélène C; Knoblauch, Michael

2011-12-01

Since the first ultrastructural investigations of sieve tubes in the early 1960s, their structure has been a matter of debate. Because sieve tube structure defines frictional interactions in the tube system, the presence of P protein obstructions shown in many transmission electron micrographs led to a discussion about the mode of phloem transport. At present, it is generally agreed that P protein agglomerations are preparation artifacts due to injury, the lumen of sieve tubes is free of obstructions, and phloem flow is driven by an osmotically generated pressure differential according to Münch's classical hypothesis. Here, we show that the phloem contains a distinctive network of protein filaments. Stable transgenic lines expressing Arabidopsis thaliana Sieve-Element-Occlusion-Related1 (SEOR1)-yellow fluorescent protein fusions show that At SEOR1 meshworks at the margins and clots in the lumen are a general feature of living sieve tubes. Live imaging of phloem flow and flow velocity measurements in individual tubes indicate that At SEOR1 agglomerations do not markedly affect or alter flow. A transmission electron microscopy preparation protocol has been generated showing sieve tube ultrastructure of unprecedented quality. A reconstruction of sieve tube ultrastructure served as basis for tube resistance calculations. The impact of agglomerations on phloem flow is discussed.

Ultrastructure of poison glands of South American frogs: a comparison between Physalaemus albonotatus and Leptodactylus chaquensis (Anura: Leptodactylidae).

PubMed

Alvarez, Blanca Beatriz; Delfino, Giovanni; Nosi, Daniele; Terreni, Alessandro

2005-02-01

Serous (poison) cutaneous glands of the leptodactylid species Physalaemus albonotatus and Leptodactylus chaquensis were compared using light and transmission electron microscopy. Glands in the two species share structural traits common in anurans, including the peripheral contractile sheath (myoepithelium) and the syncytial secretory unit that produces, stores, and modifies the poison. At the ultrastructural level, early steps of poison production are also similar and fit the usual path of proteosynthesis, involving rough endoplasmic reticulum (RER) and Golgi stacks (dictyosomes) in the peripheral syncytial cytoplasm. However, several differences are obvious during the maturational processes that lead post-Golgian products to their ultimate ultrastructural traits. In P. albonotatus, the dense product released from the dictyosomes acquires a thick repeating substructure, which, however, becomes looser in the inner portion of the syncytium. In L. chaquensis, serous maturation involves gradual condensation, and opaque, somewhat "vacuolized" granules are formed. These different maturational paths expressed during poison manufacturing in the two species agree with the polyphyletic origin of the family Leptodactylidae. On the other hand, data collected for P. albonotatus fit previous findings from P. biligonigerus and stress the view that poisons produced by congeneric species share similar (or identical) ultrastructural features. Copyright 2004 Wiley-Liss, Inc.

Pigmented Cells in the Pineal Gland of Female Viscacha (Lagostomus maximus maximus): A Histochemical and Ultrastructural Study

PubMed Central

Busolini, Fabricio Ivan; Rodríguez, Graciela Beatriz; Filippa, Verónica Palmira

2017-01-01

The presence of pigment has been demonstrated in different nervous structures such as those of retina, substantia nigra, and locus coeruleus. These pigments have also been described in the pineal gland of different mammal species. Histochemical and ultrastructural studies of the pineal gland of female viscacha (Lagostomus maximus maximus) were performed to analyze the presence of pigmented cells under natural conditions and to evaluate a probable relation between pigment content and glandular activity during pregnancy. The following techniques were applied: hematoxylin-eosin, phosphotungstic acid-hematoxylin, Masson-Fontana silver, DOPA histochemistry, Schmorl's reaction and toluidine blue. Estradiol and progesterone serum levels were determined by RIA. The ultrastructural features of the pineal pigment granules were also analyzed. Pigment granules were observed in a random distribution, but the pigmented cells were frequently found near blood vessels. The pineal pigment was histochemically identified as melanin. Differences in the amount of pigmented cells were found between pregnant and nonpregnant viscachas. The ultrastructural analysis revealed the presence of premelanosomes and melanosomes. Estradiol and progesterone levels vary during pregnancy. In conclusion, the changes in the amount of pigment content and hormone levels may indicate that the pineal gland of female viscacha is susceptible to endocrine variations during pregnancy. PMID:29391866

Phloem Ultrastructure and Pressure Flow: Sieve-Element-Occlusion-Related Agglomerations Do Not Affect Translocation[W

PubMed Central

Froelich, Daniel R.; Mullendore, Daniel L.; Jensen, Kåre H.; Ross-Elliott, Tim J.; Anstead, James A.; Thompson, Gary A.; Pélissier, Hélène C.; Knoblauch, Michael

2011-01-01

Since the first ultrastructural investigations of sieve tubes in the early 1960s, their structure has been a matter of debate. Because sieve tube structure defines frictional interactions in the tube system, the presence of P protein obstructions shown in many transmission electron micrographs led to a discussion about the mode of phloem transport. At present, it is generally agreed that P protein agglomerations are preparation artifacts due to injury, the lumen of sieve tubes is free of obstructions, and phloem flow is driven by an osmotically generated pressure differential according to Münch’s classical hypothesis. Here, we show that the phloem contains a distinctive network of protein filaments. Stable transgenic lines expressing Arabidopsis thaliana Sieve-Element-Occlusion-Related1 (SEOR1)–yellow fluorescent protein fusions show that At SEOR1 meshworks at the margins and clots in the lumen are a general feature of living sieve tubes. Live imaging of phloem flow and flow velocity measurements in individual tubes indicate that At SEOR1 agglomerations do not markedly affect or alter flow. A transmission electron microscopy preparation protocol has been generated showing sieve tube ultrastructure of unprecedented quality. A reconstruction of sieve tube ultrastructure served as basis for tube resistance calculations. The impact of agglomerations on phloem flow is discussed. PMID:22198148

3D X-ray ultra-microscopy of bone tissue.

PubMed

Langer, M; Peyrin, F

2016-02-01

We review the current X-ray techniques with 3D imaging capability at the nano-scale: transmission X-ray microscopy, ptychography and in-line phase nano-tomography. We further review the different ultra-structural features that have so far been resolved: the lacuno-canalicular network, collagen orientation, nano-scale mineralization and their use as basis for mechanical simulations. X-ray computed tomography at the micro-metric scale is increasingly considered as the reference technique in imaging of bone micro-structure. The trend has been to push towards increasingly higher resolution. Due to the difficulty of realizing optics in the hard X-ray regime, the magnification has mainly been due to the use of visible light optics and indirect detection of the X-rays, which limits the attainable resolution with respect to the wavelength of the visible light used in detection. Recent developments in X-ray optics and instrumentation have allowed to implement several types of methods that achieve imaging that is limited in resolution by the X-ray wavelength, thus enabling computed tomography at the nano-scale. We review here the X-ray techniques with 3D imaging capability at the nano-scale: transmission X-ray microscopy, ptychography and in-line phase nano-tomography. Further, we review the different ultra-structural features that have so far been resolved and the applications that have been reported: imaging of the lacuno-canalicular network, direct analysis of collagen orientation, analysis of mineralization on the nano-scale and use of 3D images at the nano-scale to drive mechanical simulations. Finally, we discuss the issue of going beyond qualitative description to quantification of ultra-structural features.

Canine Clitoral Carcinoma: A Clinical, Cytologic, Histopathologic, Immunohistochemical, and Ultrastructural Study.

PubMed

Verin, Ranieri; Cian, Francesco; Stewart, Jennifer; Binanti, Diana; MacNeill, Amy L; Piviani, Martina; Monti, Paola; Baroni, Gianna; Le Calvez, Sophie; Scase, Timothy J; Finotello, Riccardo

2018-01-01

Vaginal and vulvar tumors are uncommon in dogs. Knowledge of canine primary clitoral neoplasia is restricted to a few case reports, and only carcinomas have been reported. Cytologic and histologic features reported in the literature seem to overlap with those of canine apocrine gland anal sac adenocarcinoma (AGASA). Clinical features also recall those of canine AGASA, such as locoregional metastases and hypercalcemia of malignancy (HM). In this study, 6 cases of primary canine clitoral carcinomas (CCCs), with and without HM, were investigated by means of cytology, histopathology, electron microscopy, and immunohistochemistry for neuroendocrine markers including chromogranin A (CGA), synaptophysin (SYN), neuron-specific enolase (NSE), and S-100. In all 6 tumors, cytologic findings were consistent with malignant epithelial neoplasia of apocrine gland origin. The tumors examined were classified into 3 different histological patterns representing different degrees of differentiation: tubular, solid, and rosette type. Both CGA and SYN were mildly expressed in 2 of 6 tumors, while NSE was consistently expressed in all 6 cases. None of the tumors were S-100 positive. Transmission electron microscopy revealed electron-dense cytoplasmic granules compatible with neuroendocrine granules in all 6 cases. CCCs presented clinicopathologic features resembling AGASAs with neuroendocrine characteristics, and 2 of 6 neoplasms were considered as carcinomas with neuroendocrine differentiation and were positive for 3 neuroendocrine markers. CCCs can often present with HM, and long-term outcome is likely poor. Our study concludes that CCC seems to be a rare tumor, but it might be underestimated because of the overlapping features with AGASA. Further studies should aim to define the true incidence of this disease.

Postirradiation malignant fibrous histiocytoma of the lung. Demonstration of alpha 1-antitrypsin-like material in neoplastic cells.

PubMed

Chowdhury, L N; Swerdlow, M A; Jao, W; Kathpalia, S; Desser, R K

1980-12-01

A metastasizing fibrous histiocytoma arising in the lung of a patient who received radiation therapy and long-term chemotherapy for malignant lymphoma is presented. Ultrastructural studies revealed fibroblast-like and histiocyte-like cells, cells of intermediate type showing ultrastructural features of both fibroblast-like and histiocyte-like cells, primitive mesenchymal cells, multinucleate tumor cells, and xanthomatous cells. The neoplastic cells showed dilated rough endoplasmic reticula with intracisternal accumulation of electron-dense material forming lattice-like structures. Direct immunofluorescence staining of the neoplastic cells using antihuman alpha 1-antitrypsin showed specific activity, with fluorescent deposits exhibiting interlacing globular formations. These findings and their implications are discussed.

[The limitation of glucose catabolism as a factor in protection during hypoxia].

PubMed

Burbello, A T; Vishvtseva, V V; Denisenko, P P; Safonova, A F; Dobrokhotova, E G

1995-01-01

Violuric acid was first shown to have antihypoxic and antioxidative properties, to exert protective action in sodium nitrite-induced hemic hypoxia. Hepatic glucose and glucogen levels increased, the activity of glucose-6- phosphodihydrogenase enhanced, while that of lactate dehydrogenase and alkaline phosphatase decreased, the content of cAMP restored, whereas cGMP and 2,3-diphosphoglycerate levels decreased to a greater extent. The action of violuric acid was especially evident at the ultrastructural level-the ultrastructure of brush receptor elements in anoxia in the presence of violuric acid's action retained all the features characteristic for intact animals, which was accompanied by a significant accumulation of glycogen in the neuroplasm.

Real space flight travel is associated with ultrastructural changes, cytoskeletal disruption and premature senescence of HUVEC.

PubMed

Kapitonova, M Y; Muid, S; Froemming, G R A; Yusoff, W N W; Othman, S; Ali, A M; Nawawi, H M

2012-12-01

Microgravity, hypergravity, vibration, ionizing radiation and temperature fluctuations are major factors of outer space flight affecting human organs and tissues. There are several reports on the effect of space flight on different human cell types of mesenchymal origin while information regarding changes to vascular endothelial cells is scarce. Ultrastructural and cytophysiological features of macrovascular endothelial cells in outer space flight and their persistence during subsequent culturing were demonstrated in the present investigation. At the end of the space flight, endothelial cells displayed profound changes indicating cytoskeletal lesions and increased cell membrane permeability. Readapted cells of subsequent passages exhibited persisting cytoskeletal changes, decreased metabolism and cell growth indicating cellular senescence.

Polypoid dermal hemangiopericytoma: a case report.

PubMed

Pollock, A M; Sweeney, E C

1998-10-01

A polypoid dermal lesion with histologic, immunohistochemical, and ultrastructural features of hemangiopericytoma is described. Such tumors, arising in the dermis, are exceptionally rare, and whereas the tumor bears some resemblance to meningioma-like tumors of the skin and the well-recognized animal counterpart, canine hemangiopericytoma, it is histologically distinct.

Avian Follicular and Interdigitating Dendritic Cells: Isolation and Morphologic, Phenotypic, and Functional Analyses

USDA-ARS?s Scientific Manuscript database

An antiserum against Eimeria tenella sporozoites was used to localize and isolate Ag-binding cells in intestinal cecal tonsils of parasite-infected chickens. Based on their tissue localization, ultrastructural features, and expression of surface markers, two subpopulations of cells were isolated, C...

Ultrastructural markers of lymph nodes in patients with acquired immune deficiency syndrome and in homosexual males with unexplained persistent lymphadenopathy. A quantitative study.

PubMed

Onerheim, R M; Wang, N S; Gilmore, N; Jothy, S

1984-09-01

To determine if vesicular rosettes (VR), tubuloreticular structures (TRS), and "test-tube and ring-shaped forms" (TRF) are characteristic ultrastructural features of the syndromes of acquired immune deficiency (AIDS) or of unexplained persistent lymphadenopathy (PLS), the authors studied lymph nodes from nine patients with PLS, two patients with AIDS, and seven controls by electron microscopy. An average of 122 lymphocytes per case were photographed. VR were present in only 0.37% of lymphocytes in 4 of 11 index cases and were mimicked by grouped vesicles and degenerating multivesicular bodies (MVB). TRS were found in 10 of 11 index cases, compared with only one of seven controls (P less than 0.01). In the index cases, they were more frequent in AIDS (mean 21%) than in PLS lymphocytes (mean 4%) (P less than 0.05). MVB were found in all index cases and five of seven controls and were more frequent in index lymphocytes (mean 19%) than in controls (mean 5%) (P less than 0.01). TRF were found in one Haitian male with AIDS, where they were present in 4% of lymphocytes. VR are infrequent and indistinct. MVB probably reflect the reactivity of the lymphocytes. TRF is not a feature of PLS. The authors conclude that there are no pathognomonic ultrastructural markers of AIDS or PLS but that TRS are characteristic of both syndromes and occur frequently enough to be supportive to the diagnosis of AIDS and PLS.

Polarized Ends of Human Macula Densa Cells: Ultrastructural Investigation and Morphofunctional Correlations.

PubMed

Cangiotti, Angela Maria; Lorenzi, Teresa; Zingaretti, Maria Cristina; Fabri, Mara; Morroni, Manrico

2018-05-01

The morphology of the kidney macula densa (MD) has extensively been investigated in animals, whereas human studies are scanty. We studied the fine structure of human MD cells focusing on their apical and basal ends and correlating structure and function. The MD region was examined by transmission electron microscopy in six renal biopsies from patients with kidney disease. Ultrastructural analysis of MD cells was performed on serial sections. MD cells show two polarized ends. The apical portion is characterized by a single, immotile cilium associated with microvilli; apically, cells are joined by adhering junctions. In the basal portion, the cytoplasm contains small, dense granules and numerous, irregular cytoplasmic projections extending to the adjacent extraglomerular mesangium. The projections often contain small, dense granules. A reticulated basement membrane around MD cells separates them from the extraglomerular mesangium. Although the fact that tissue specimens came from patients with kidney disease mandates extreme caution, ultrastructural examination confirmed that MD cells have sensory features due to the presence of the primary cilium, that they are connected by apical adhering junctions forming a barrier that separates the tubular flow from the interstitium, and that they present numerous basal interdigitations surrounded by a reticulated basement membrane. Conceivably, the latter two features are related to the functional activity of the MD. The small, dense granules in the basal cytoplasm and in cytoplasmic projections are likely related to the paracrine function of MD cells. Anat Rec, 301:922-931, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Ab interno trabeculectomy: ultrastructural evidence and early tissue response in a human eye.

PubMed

Ferrari, Ettore; Ortolani, Fulvia; Petrelli, Lucia; Contin, Magali; Pognuz, Derri Roman; Marchini, Maurizio; Bandello, Francesco

2007-10-01

To report the results of ultrastructural analysis of the postoperative effects of ab interno trabeculectomy in a human eye. Department of Ophthalmology, Palmanova Hospital, Palmanova, Udine, Italy. A 60-year-old woman with cataract and glaucoma had enucleation for a choroidal melanoma 10 days after ab interno trabeculectomy combined with phacoemulsification. A second ab interno trabeculectomy was performed after enucleation to evaluate the outcomes of the previous trabeculectomy. Light and transmission electron microscopy analyses were performed on samples excised from areas (1) not subjected to a procedure (control samples), (2) that had ab interno trabeculectomy before enucleation, and (3) that had ab interno trabeculectomy immediately after enucleation. Control samples showed normal trabecular features. Semithin sections of all ab interno trabeculectomy samples showed full-thickness removal of trabeculum segments, with Schlemm's canal lumen opening into the anterior chamber and apparent preservation of the adjacent structures. On ultrathin sections of samples that had ab interno trabeculectomy before enucleation, the endothelium lining the outer wall of Schlemm's canal and other angle components showed intact ultrastructural features. In trabecular beams that were not removed, the extracellular matrix appeared to have maintained its fine texture and was free of activated fibroblasts or leucocyte infiltrates. Observations confirm that ab interno trabeculectomy causes direct communication between Schlemm's canal lumen and the anterior chamber in vivo and immediately after enucleation during the early postoperative period. The absence of an evident inflammatory reaction in the examined case should be considered with caution because of possible tumor-induced immune suppression.

Fine structure and morphogenesis of spironolactone bodies in the zona glomerulosa of the human adrenal cortex

PubMed Central

Kovacs, K.; Horvath, E.; Singer, W.

1973-01-01

Numerous spironolactone bodies have been detected in the zona glomerulosa cells of the adrenal cortex of a 36-year-old spironolactone-treated woman whose non-tumorous right adrenal gland was removed surgically because of primary hyperaldosteronism. Electron microscopy revealed spherical laminated whorls which consisted of a central core composed of an amorphous electron-dense material surrounded by numerous smooth-walled concentric membranes. Continuous with and deriving from the endoplasmic reticulum, they were present in viable cells and were not associated with ultrastructural features indicating cellular injury. Cytoplasmic inclusions similar to spironolactone bodies can be detected in other organs after the administration of various compounds. Thus, they can be regarded as neither specific to spironolactone treatment nor exclusively inducible in the zona glomerulosa of the adrenal cortex. Images PMID:4131694

Juxtaglomerular cell tumor of the kidney: report of two cases with a papillary pattern.

PubMed

Têtu, B; Vaillancourt, L; Camilleri, J P; Bruneval, P; Bernier, L; Tourigny, R

1993-11-01

We report the clinicopathologic, immunohistochemical, and electron microscopic study of two cases of juxtaglomerular cell tumor of the kidney with a hitherto unreported dominant papillary pattern. Both tumors were associated with high blood pressure that did not respond to medical therapy, but that returned to normal after removal of the kidney. They were well delineated, tan, and had no necrosis. The cores of the papillary structures consisted of polygonal cells found to express renin by immunohistochemistry and to contain renin protogranules by electron microscopy. The papillary fronds were covered by one layer of cuboidal epithelial cells that did not stain for renin and had ultrastructural features reminiscent of the collecting duct epithelium. These tumors must be differentiated from malignant papillary tumors of the kidney, such as papillary clear cell carcinoma, transitional cell carcinoma, and collecting duct carcinoma.

The ultra-structural organization of the elastic network in the intra- and inter-lamellar matrix of the intervertebral disc.

PubMed

Tavakoli, J; Elliott, D M; Costi, J J

2017-08-01

The inter-lamellar matrix (ILM)-located between adjacent lamellae of the annulus fibrosus-consists of a complex structure of elastic fibers, while elastic fibers of the intra-lamellar region are aligned predominantly parallel to the collagen fibers. The organization of elastic fibers under low magnification, in both inter- and intra-lamellar regions, was studied by light microscopic analysis of histologically prepared samples; however, little is known about their ultrastructure. An ultrastructural visualization of elastic fibers in the inter-lamellar matrix is crucial for describing their contribution to structural integrity, as well as mechanical properties of the annulus fibrosus. The aims of this study were twofold: first, to present an ultrastructural analysis of the elastic fiber network in the ILM and intra-lamellar region, including cross section (CS) and in-plane (IP) lamellae, of the AF using Scanning Electron Microscopy (SEM) and second, to -compare the elastic fiber orientation between the ILM and intra-lamellar region. Four samples (lumbar sheep discs) from adjacent sections (30μm thickness) of anterior annulus were partially digested by a developed NaOH-sonication method for visualization of elastic fibers by SEM. Elastic fiber orientation and distribution were quantified relative to the tangential to circumferential reference axis. Visualization of the ILM under high magnification revealed a dense network of elastic fibers that has not been previously described. Within the ILM, elastic fibers form a complex network, consisting of different size and shape fibers, which differed to those located in the intra-lamellar region. For both regions, the majority of fibers were oriented near 0° with respect to tangential to circumferential (TCD) direction and two minor symmetrical orientations of approximately±45°. Statistically, the orientation of elastic fibers between the ILM and intra-lamellar region was not different (p=0.171). The present study used extracellular matrix partial digestion to address significant gaps in understanding of disc microstructure and will contribute to multidisciplinary ultrastructure-function studies. Visualization of the intra-lamellar matrix under high magnification revealed a dense network of elastic fibers that has not been previously described. The present study used extracellular matrix partial digestion to address significant gaps in understanding of disc microstructure and will contribute to multidisciplinary ultrastructure-function studies. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

An ultrastructural study of spermiogenesis in three species of Physalaemus (Anura, Leptodactylidae).

PubMed

Amaral, M J; Fernandes, A P; Báo, S N; Recco-Pimentel, S M

1999-12-01

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9 + 2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod were observed in these Physalaemus species.

Ultrastructural findings in lung biopsy material from children with congenital heart defects.

PubMed Central

Meyrick, B.; Reid, L.

1980-01-01

The ultrastructural features of pulmonary arteries are described in lung biopsy material from 6 children with congenital heart defects. Right ventricular hypertrophy was found in all 6 children and increased pulmonary artery pressure in all but one. The presence of muscle in smaller and more peripheral arteries than expected for the age of the child was detected in all cases. Ultrastructural examination of the peripheral arteries revealed, for the first time, in the nonmuscular regions of human arterial walls, pericytes and intermediate cells (previously shown to be precursor smooth-muscle cells); in addition, new arterial muscle was found in the normally nonmuscular region. In the 4 cases where medial thickness of the normally muscular arteries was increased, the smooth-muscle cells were hypertrophied and the extracellular connective tissue increased. In all cases, junctions between endothelial cells and smooth-muscle cells, intermediate cells, or pericytes were found. These changes are similar to those described in the rat with hypoxia-induced pulmonary hypertension. In addition, in 2 of the 6 cases, bundles of nerve axons in Schwann cell sheaths were found in adventitial layer of small, intraacinar muscular arteries (not previously demonstrated ultrastructurally at this site in the human lung); varicosities with agranular and granular vesicles, probably adrenergic, were also identified. Images Figure 4 Figure 5 Figure 1 Figure 2 Figure 3 PMID:7446706

Antennal multiporous sensilla: their gustatory features for host recognition in female parasitic wasps (insecta, Hymenoptera: Platygastroidea).

PubMed

Isidoro, N; Romani, R; Bin, F

2001-12-01

In parasitic wasps, various kinds of antennal plates have been interpreted as olfactory organs due to the presence of numerous pores. However, on the basis of ultrastructural investigations, some of these multiporous plates were revealed as being release sites of exocrine glands while others were postulated to have a gustatory function. Such sensilla, present only on female antennae, show unique features, found exclusively in Platygastroidea, with some differences between Scelionidae and Platygastridae. The cuticular apparatus consists of a short basiconic shaft with an apical multiporous area, the pores of which are covered by movable structures. The cellular components are made up of a remarkable number of sensory neurons, from 200 to 220, and an undefined number of sheath cells. These multiporous sensilla have tubular accessory glands that release their secretion through the socket sensillum only in scelionids. These morphological characters, combined with behavioral observations, strongly suggest a gustatory function, although electrophysiological studies are still needed to confirm this. A new terminology for antennal multiporous plates is discussed in relation to their different functions. Copyright 2001 Wiley-Liss, Inc.

Ultrastructure and immunolocalization of digestive enzymes in the midgut of Podisus nigrispinus (Heteroptera: Pentatomidae).

PubMed

Fialho, Maria do Carmo Q; Terra, Walter R; Moreira, Nathália R; Zanuncio, José C; Serrão, Jose Eduardo

2013-07-01

The predatory stinkbug Podisus nigrispinus has been utilized in biological control programs. Its midgut is anatomically divided into anterior, middle and posterior regions, which play different roles in the digestive process. We describe the midgut ultrastructure and the secretion of digestive enzymes in the midgut of P. nigrispinus. Midguts were analyzed with transmission electron microscopy and the digestive enzymes amylase, cathepsin L, aminopeptidase and α-glucosidase were immunolocalized. The ultrastructural features of the digestive cells in the anterior, middle and posterior midgut regions suggest that they play a role in digestive enzyme synthesis, ion and nutrient absorption, storage and excretion. The digestive enzymes have different distribution along the midgut regions of the predator P. nigrispinus. Amylase, aminopeptidase and α-glucosidase occur in three midgut regions, whereas cathepsin L occurs in the middle and posterior midgut regions. The anterior midgut region of P. nigrispinus seems to play a role in water absorption, the middle midgut may be involved in nutrient absorption and the posterior midgut region is responsible for water transport to the midgut lumen. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ultrastructural and clinical evidence of subretinal debris accumulation in type 2 macular telangiectasia.

PubMed

Cherepanoff, Svetlana; Killingsworth, Murray C; Zhu, Meidong; Nolan, Timothy; Hunyor, Alex P; Young, Stephanie H; Hageman, Gregory S; Gillies, Mark C

2012-11-01

To describe subretinal debris found on ultrastructural examination in an eye with macular telangiectasia (MacTel) type 2 and on optical coherence tomography (OCT) in a subset of patients with MacTel type 2. Blocks from the mid-periphery and temporal perifovea of an eye with clinically documented MacTel type 2 were examined with electron microscopy (EM). Cases came from the Sydney centre of the MacTel project and the practices of the authors. On EM examination, subretinal debris was found in the perifovea with accumulation of degenerate photoreceptor elements in the subretinal space. Despite the substantial subretinal debris, there was minimal retinal pigment epithelial (RPE) reaction. Focal defects were seen in the inner limiting membrane in the perifovea. Of the 65 Sydney MacTel project participants, three (5%) had prominent yellow material at the fovea. OCT revealed smooth mounds between the RPE and the ellipsoid region. The material was hyperautofluorescent. This study suggests that subretinal accumulation of photoreceptor debris may be a feature of MacTel type 2. Ultrastructural and OCT evidence of disease beyond the vasculature, involving photoreceptors and Muller cells, is presented.

Cytological and ultrastructural studies on root tissues

NASA Technical Reports Server (NTRS)

Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

1984-01-01

The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

Myopathic Alterations in Extraocular Muscle of Rats Subchronically Fed Pyridostigmine Bromide

DTIC Science & Technology

1990-01-01

myasthenia gravis and could be used by U.S. mil- sis. Ultrastructurally, in muscles such as diaphragm, itary personnel and their allies as part of a...cleft were common features. This last feature has changes at the NMJ of diaphragm and soleus mus- been reported in human myasthenia gravis in the cles...greater sensitivity to PB, VA (1976). The motor end plate in myasthenia gravis as severe morphologic alterations are still present and in experimental

Ultrastructural characteristics of carcinogen-induced nondysplastic changes in tracheal epithelium.

PubMed Central

Klein-Szanto, A. J.; Topping, D. C.; Heckman, C. A.; Nettesheim, P.

1980-01-01

Nondysplastic hypotrophic and metaplastic epithelial alterations induced by dimethylbenz(a)anthracene in isogenic tracheal transplants were studied by light and electron microscopy 3--24 months after cessation of a 4-week carcinogen exposure. Hypotrophic epithelium observed at all time points was characterized by the presence of nonciliated cells that adopted either cuboidal or squamous shapes, forming simple or bistratified epithelia. Most of these cells, as well as some metaplastic cells, exhibited features of mucin-secreting cells. The metaplastic epithelia showed nonkeratinizing squamous metaplasia, closely related to transitional metaplasia, and keratinizing squamous metaplasia, which presented either an atrophic or an acanthotic epithelium. Although many of these epithelia showed morphologic features of normal stratified epithelia, several nonkeratinizing squamous metaplasias and acanthotic keratinizing squamous metaplasias exhibited some irregularities, probably representing very early atypical ultrastructural features (ie, perinuclear concentration of tonofilament bundles, the presence of dark and clear basal epithelial cells, interruptions and alterations of the basal lamina). These features were not observed in a group of early squamous metaplasias studied for comparative purposes 2 weeks after cessation of dimethylbenz(a)anthracene exposure, which were characterized by a combination of degenerative phenomena and increased cell proliferation. Images Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 14 Figure 15 Figure 6 Figure 7 PMID:6766047

Low Night Temperature Affects the Phloem Ultrastructure of Lateral Branches and Raffinose Family Oligosaccharide (RFO) Accumulation in RFO-Transporting Plant Melon (Cucumismelo L.) during Fruit Expansion

PubMed Central

Hao, Jinghong; Gu, Fengying; Zhu, Jie; Lu, Shaowei; Liu, Yifei; Li, Yunfei; Chen, Weizhi; Wang, Liping; Fan, Shuangxi; Xian, Cory J.

2016-01-01

Due to the importance and complexity of photo assimilate transport in raffinose family oligosaccharide (RFO)-transporting plants such as melon, it is important to study the features of the transport structure (phloem) particularly of the lateral branches connecting the source leaves and the sink fruits, and its responses to environmental challenges. Currently, it is unclear to what extents the cold environmental temperature stress would alter the phloem ultrastructure and RFO accumulation in RFO-transporting plants. In this study, we firstly utilized electron microscopy to investigate the changes in the phloem ultrastructure of lateral branches and RFO accumulation in melons after being subjected to low night temperatures (12°C and 9°C). The results demonstrated that exposure to 9°C and 12°C altered the ultrastructure of the phloem, with the effect of 9°C being more obvious. The most obvious change was the appearance of plasma membrane invaginations in 99% companion cells and intermediary cells. In addition, phloem parenchyma cells contained chloroplasts with increased amounts of starch grains, sparse cytoplasm and reduced numbers of mitochondria. In the intermediary cells, the volume of cytoplasm was reduced by 50%, and the central vacuole was present. Moreover, the treatment at 9°C during the night led to RFO accumulation in the vascular bundles of the lateral branches and fruit carpopodiums. These ultrastructural changes of the transport structure (phloem) following the treatment at 9°C represented adaptive responses of melons to low temperature stresses. Future studies are required to examine whether these responses may affect phloem transport. PMID:27501301

Low Night Temperature Affects the Phloem Ultrastructure of Lateral Branches and Raffinose Family Oligosaccharide (RFO) Accumulation in RFO-Transporting Plant Melon (Cucumismelo L.) during Fruit Expansion.

PubMed

Hao, Jinghong; Gu, Fengying; Zhu, Jie; Lu, Shaowei; Liu, Yifei; Li, Yunfei; Chen, Weizhi; Wang, Liping; Fan, Shuangxi; Xian, Cory J

2016-01-01

Due to the importance and complexity of photo assimilate transport in raffinose family oligosaccharide (RFO)-transporting plants such as melon, it is important to study the features of the transport structure (phloem) particularly of the lateral branches connecting the source leaves and the sink fruits, and its responses to environmental challenges. Currently, it is unclear to what extents the cold environmental temperature stress would alter the phloem ultrastructure and RFO accumulation in RFO-transporting plants. In this study, we firstly utilized electron microscopy to investigate the changes in the phloem ultrastructure of lateral branches and RFO accumulation in melons after being subjected to low night temperatures (12°C and 9°C). The results demonstrated that exposure to 9°C and 12°C altered the ultrastructure of the phloem, with the effect of 9°C being more obvious. The most obvious change was the appearance of plasma membrane invaginations in 99% companion cells and intermediary cells. In addition, phloem parenchyma cells contained chloroplasts with increased amounts of starch grains, sparse cytoplasm and reduced numbers of mitochondria. In the intermediary cells, the volume of cytoplasm was reduced by 50%, and the central vacuole was present. Moreover, the treatment at 9°C during the night led to RFO accumulation in the vascular bundles of the lateral branches and fruit carpopodiums. These ultrastructural changes of the transport structure (phloem) following the treatment at 9°C represented adaptive responses of melons to low temperature stresses. Future studies are required to examine whether these responses may affect phloem transport.

Ultrastructural study of the human neurohypophysis. III. Vascular and perivascular structures.

PubMed

Seyama, S; Pearl, G S; Takei, Y

1980-01-01

The vascular and perivascular regions of the human neurohypophysis were studied electron microscopically. The abluminal basement membrane, perivascular space, luminal basement membrane and endothelium are interposed between the neural parenchyma and the blood stream. The capillaries are fenestrated, with pores measuring 30 to 50 nm in diameter. The perivascular and intercellular spaces form prominent networks that penetrate between rows of neurohypophysial parenchymal cells. The perivascular space contains pericytes, histiocytes, fibroblasts and mast cells, with ultrastructural features typical of each cell type. No transitional forms between histiocytes and pericytes were observed. A schema for the extracellular flow of neurohypophysial hormones through the sinusoidal and perivascular spaces is proposed, suggesting an important role for the pituicytes and their intercellular junctions in the control of hormone release.

Reconstruction of the feeding apparatus in Postgaardi mariagerensis provides evidence for character evolution within the Symbiontida (Euglenozoa).

PubMed

Yubuki, Naoji; Simpson, Alastair G B; Leander, Brian S

2013-01-01

Microbial eukaryotes living in low oxygen environments often have novel physiological and morphological features that facilitate symbiotic relationships with bacteria and other means for acquiring nutrients. Comparative studies of these features provide evidence for phylogenetic relationships and evolutionary history. Postgaardi mariagerensis, for instance, is a euglenozoan that lives in low oxygen environments and is enveloped by episymbiotic bacteria. The general ultrastructure of P. mariagerensis was described more than a decade ago and no further studies have been carried out since, mainly because these cells are difficult to obtain. Postgaardi lacks the diagnostic features found in other major euglenozoan lineages (e.g., pellicle strips and kinetoplast-like mitochondrial inclusions) and no molecular data are available, so the phylogenetic position of this genus within the Euglenozoa remains unclear. We re-examined and reconstructed the ultrastructural organization of the feeding apparatus in Postgaardi by serial sectioning an existing block of resin-embedded cells. Postgaardi possesses distinctive finger-like projections within the feeding apparatus; this system has only been found in one other highly distinctive flagellate, namely the symbiontid Calkinsia. Detailed comparisons of the cytoskeleton in Postgaardi and in two symbiontids, Calkinsia and Bihospites, provided new evidence for phylogenetic relationships and character evolution in all three genera. Copyright © 2012 Elsevier GmbH. All rights reserved.

Three-dimensional Super Resolution Microscopy of F-actin Filaments by Interferometric PhotoActivated Localization Microscopy (iPALM).

PubMed

Wang, Yilin; Kanchanawong, Pakorn

2016-12-01

Fluorescence microscopy enables direct visualization of specific biomolecules within cells. However, for conventional fluorescence microscopy, the spatial resolution is restricted by diffraction to ~ 200 nm within the image plane and > 500 nm along the optical axis. As a result, fluorescence microscopy has long been severely limited in the observation of ultrastructural features within cells. The recent development of super resolution microscopy methods has overcome this limitation. In particular, the advent of photoswitchable fluorophores enables localization-based super resolution microscopy, which provides resolving power approaching the molecular-length scale. Here, we describe the application of a three-dimensional super resolution microscopy method based on single-molecule localization microscopy and multiphase interferometry, called interferometric PhotoActivated Localization Microscopy (iPALM). This method provides nearly isotropic resolution on the order of 20 nm in all three dimensions. Protocols for visualizing the filamentous actin cytoskeleton, including specimen preparation and operation of the iPALM instrument, are described here. These protocols are also readily adaptable and instructive for the study of other ultrastructural features in cells.

Histopathological changes associated with high intensity focused ultrasound (HIFU) treatment for localised adenocarcinoma of the prostate

PubMed Central

Van Leenders, G J L H; Beerlage, H; Ruijter, E; de la Rosette, J J M C H; van de Kaa, C A

2000-01-01

Aims—Investigation of the histopathological changes in prostatectomy specimens of patients with prostate cancer after high intensity focused ultrasound (HIFU) and identification of immunohistochemical markers for tissue damage after HIFU treatment. Methods—Nine patients diagnosed with adenocarcinoma of the prostate underwent unilateral HIFU treatment seven to 12 days before radical prostatectomy. The prostatectomy specimens were analysed histologically. Immunohistochemical staining and electron microscopy were performed to characterise more subtle phenotypic changes. Results—All prostatectomy specimens revealed well circumscribed HIFU lesions at the dorsal side of the prostate lobe treated. Most epithelial glands in the centre of the HIFU lesions revealed signs of necrosis. Glands without apparently necrotic features were also situated in the HIFU lesions, raising the question of whether lethal destruction had occurred. This epithelium reacted with antibodies to pancytokeratin, prostate specific antigen (PSA), and Ki67, but did not express cytokeratin 8, which is indicative of severe cellular damage. Ultrastructural examination revealed disintegration of cellular membranes and cytoplasmic organelles consistent with cell necrosis. HIFU treatment was incomplete at the ventral, lateral, and dorsal sides of the prostate lobe treated. Conclusions—HIFU treatment induces a spectrum of morphological changes ranging from apparent light microscopic necrosis to more subtle ultrastructural cell damage. All HIFU lesions are marked by loss of cytokeratin 8. HIFU does not affect the whole area treated, leaving vital tissue at the ventral, lateral, and dorsal sides of the prostate. Key Words: prostate cancer • high intensity focused ultrasound treatment PMID:10889823

Ultrastructural studies on the boundary tissue of the seminiferous tubules of different mammals.

PubMed

Cieciura, L; Jaszczuk-Jarosz, B; Pietrzkowska, K

1988-01-01

The aims of our studies were to compare the ultrastructure of the boundary tissue of seminiferous tubules of various mammals (rat, mouse, hamster, guinea pig, rabbit, ram, bull and man). Visual analysis of electron micrographs revealed the similarity of structure of all layers at investigated animals. The boundary tissue consists of 4 layers: 1) amorphous inner lamina, 2) cellular inner lamina, 3) amorphous outer lamina, 4) cellular outer lamina. The outer lamina of boundary tissue of rat, mouse and hamster revealed in histochemical reactions meshes resembling honey-combs. The wall of seminiferous canalicules of bull and ram consists of more bigger and different structure than one at the other laboratory animals. The most different structure of boundary tissue in man was observed. The capillary vessels penetrate in the myofibroblastic layer, when comparted to that found in other mammals on the surface of the wall.

Keratolysis exfoliativa (dyshidrosis lamellosa sicca): a distinct peeling entity.

PubMed

Chang, Y Y; van der Velden, J; van der Wier, G; Kramer, D; Diercks, G F H; van Geel, M; Coenraads, P J; Zeeuwen, P L J M; Jonkman, M F

2012-11-01

Keratolysis exfoliativa (KE), also known as dyshidrosis lamellosa sicca, is a palmoplantar dermatosis characterized by air-filled blisters and collarette desquamation. It has been regarded as a subtype of dyshidrotic eczema, a fungal infection or a dermatophytid reaction. KE may also resemble acral peeling skin syndrome and localized epidermolysis bullosa simplex. Although KE is a common disorder, it is a rarely reported and is an under-recognized dermatosis. To delineate the characteristic features of KE. We investigated the clinical, immunohistopathological, ultrastructural and molecular features of KE. Patients were included from the clinical records. Additional diagnostic research consisted of mutation analysis of the candidate genes TGM5, KRT5, KRT14, FLG, SPINK6 and SPINK9. A total of 24 patients with KE were identified, six with familial and 18 with sporadic KE. Lesions consisted of air-filled blisters only on palmoplantar skin, followed by collarette and lamellar peeling. Both light microscopy and electron microscopy showed cleavage and partially degraded corneodesmosomes within the stratum corneum, whereas immunofluorescence microscopy showed normal expression of corneodesmosomal components. No mutations were found in TGM5, KRT5/14 and SPINK6/9. There was no clear link with atopy or with FLG mutations. Our study suggests premature corneodesmolysis as the main pathological mechanism of this palmoplantar skin disorder. We conclude that KE appears to be a distinct peeling entity. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

Heterogeneity in macular corneal dystrophy.

PubMed

Edward, D P; Yue, B Y; Sugar, J; Thonar, E J; SunderRaj, N; Stock, E L; Tso, M O

1988-11-01

Macular corneal dystrophy is an autosomal recessive disorder in which abnormal deposits in the corneal stroma have been identified. We examined the corneal buttons of 12 patients, who had clinical features of macular dystrophy, by histochemical staining, transmission electron microscopy, and immunohistochemical techniques. All corneas exhibited positive staining with Muller Mowry's colloidal iron. Using monoclonal antibodies 1/20/5-D-4, J-10, J-19, and J-36 that recognize specific sites on the sulfated keratan sulfate molecule, we stained corneal sections by an avidin-biotin-peroxidase complex method and identified two groups of macular corneal dystrophy. One group consisting of four corneas reacted positively with all four antibodies, and the other group consisting of eight corneas did not react with any of the antibodies used. These results confirmed those recently presented by Yang et al that there may be subgroups of macular dystrophy that can be identified by immunohistochemical methods. Also, serum levels of sulfated keratan sulfate were determined in seven patients. One patient who displayed a normal level of serum keratan sulfate had positive corneal immunoreactivity. Of the six patients who lacked serum keratan sulfate, four showed negative and two had positive corneal immunostaining, suggesting at least three subgroups in the disease. An attempt was made to correlate the clinical features, histochemical-staining characteristics, and ultrastructural morphology with the immunoreactivity to keratan sulfate antibodies, but no correlations could be made.

Transmission electron microscopy, fluorescence microscopy, and confocal raman microscopic analysis of ultrastructural and compositional heterogeneity of Cornus alba L. wood cell wall.

PubMed

Ma, Jianfeng; Ji, Zhe; Zhou, Xia; Zhang, Zhiheng; Xu, Feng

2013-02-01

Transmission electron microscopy (TEM), fluorescence microscopy, and confocal Raman microscopy can be used to characterize ultrastructural and compositional heterogeneity of plant cell walls. In this study, TEM observations revealed the ultrastructural characterization of Cornus alba L. fiber, vessel, axial parenchyma, ray parenchyma, and pit membrane between cells, notably with the ray parenchyma consisting of two well-defined layers. Fluorescence microscopy evidenced that cell corner middle lamella was more lignified than adjacent compound middle lamella and secondary wall with variation in lignification level from cell to cell. In situ Raman images showed that the inhomogeneity in cell wall components (cellulose and lignin) among different cells and within morphologically distinct cell wall layers. As the significant precursors of lignin biosynthesis, the pattern of coniferyl alcohol and aldehyde (joint abbreviation Lignin-CAA for both structures) distribution in fiber cell wall was also identified by Raman images, with higher concentration occurring in the fiber secondary wall where there was the highest cellulose concentration. Moreover, noteworthy was the observation that higher concentration of lignin and very minor amounts of cellulose were visualized in the pit membrane areas. These complementary microanalytical methods provide more accurate and complete information with regard to ultrastructural and compositional characterization of plant cell walls.

Quantitative Assessment of Ultrastructure and Light Scatter in Mouse Corneal Debridement Wounds

PubMed Central

Boote, Craig; Du, Yiqin; Morgan, Sian; Harris, Jonathan; Kamma-Lorger, Christina S.; Hayes, Sally; Lathrop, Kira L.; Roh, Danny S.; Burrow, Michael K.; Hiller, Jennifer; Terrill, Nicholas J.; Funderburgh, James L.; Meek, Keith M.

2012-01-01

Purpose. The mouse has become an important wound healing model with which to study corneal fibrosis, a frequent complication of refractive surgery. The aim of the current study was to quantify changes in stromal ultrastructure and light scatter that characterize fibrosis in mouse corneal debridement wounds. Methods. Epithelial debridement wounds, with and without removal of basement membrane, were produced in C57BL/6 mice. Corneal opacity was measured using optical coherence tomography, and collagen diameter and matrix order were quantified by x-ray scattering. Electron microscopy was used to visualize proteoglycans. Quantitative PCR (Q-PCR) measured mRNA transcript levels for several quiescent and fibrotic markers. Results. Epithelial debridement without basement membrane disruption produced a significant increase in matrix disorder at 8 weeks, but minimal corneal opacity. In contrast, basement membrane penetration led to increases in light scatter, matrix disorder, and collagen diameter, accompanied by the appearance of abnormally large proteoglycans in the subepithelial stroma. This group also demonstrated upregulation of several quiescent and fibrotic markers 2 to 4 weeks after wounding. Conclusions. Fibrotic corneal wound healing in mice involves extensive changes to collagen and proteoglycan ultrastructure, consistent with deposition of opaque scar tissue. Epithelial basement membrane penetration is a deciding factor determining the degree of ultrastructural changes and resulting opacity. PMID:22467580

Ultrastructure and molecular phylogenetic position of a novel phagotrophic stramenopile from low oxygen environments: Rictus lutensis gen. et sp. nov. (Bicosoecida, incertae sedis).

PubMed

Yubuki, Naoji; Leander, Brian S; Silberman, Jeffrey D

2010-04-01

A novel free free-living phagotrophic flagellate, Rictus lutensis gen. et sp. nov., with two heterodynamic flagella, a permanent cytostome and a cytopharynx was isolated from muddy, low oxygen coastal sediments in Cape Cod, MA, USA. We cultivated and characterized this flagellate with transmission electron microscopy, scanning electron microscopy and molecular phylogenetic analyses inferred from small subunit (SSU) rDNA sequences. These data demonstrated that this organism has the key ultrastructural characters of the Bicosoecida, including similar transitional zones and a similar overall flagellar apparatus consisting of an x fiber and an L-shape microtubular root 2 involved in food capture. Although the molecular phylogenetic analyses were concordant with the ultrastructural data in placing R. lutensis with the bicosoecid clade, the internal position of this relatively divergent sequence within the clade was not resolved. Therefore, we interpret R. lutensis gen. et sp. nov. as a novel bicosoecid incertae sedis. Copyright 2009 Elsevier GmbH. All rights reserved.

Ultrastructure of antennal sensilla of the peach aphid Myzus persicae Sulzer, 1776.

PubMed

Ban, Li-Ping; Sun, Yin-Peng; Wang, Ying; Tu, Xiong-Bing; Zhang, Shan-Gan; Zhang, Yun-Ting; Wu, Yun-Sheng; Zhang, Ze-Hua

2015-02-01

The antennal sensilla of alate Myzus persicae were mapped using transmission electron microscopy and the ultrastructure of sensilla trichoidea, coeloconica, and placoidea are described. Trichoid sensilla, located on the tip of the antennae, are innervated by 2-4 neurons, with some outer dendrites reaching the distal end of the hair. Coeloconic sensilla in primary rhinaria are of two morphological types, both equipped with two dendrites. Dendrites of Type II coeloconic sensilla are enveloped in the dendrite sheath, containing the sensillum lymph. In sensilla coeloconica of Type I, instead, dendrites are enclosed by an electron opaque solid cuticle, with no space left for the sensillum lymph. The ultrastructure of big placoid sensillum reveals the presence of three groups of neurons, with 2-3 dendrites in each neuron group, while both small placoid sensilla are equipped with a single group of neurons, consisting of three dendrites. Both large and small placoid sensilla bear multiple pores on the outer cuticle. The function of these sensilla is also discussed. © 2014 Wiley Periodicals, Inc.

Systemic rhabdomyosarcoma presenting as leukemia: case report with ultrastructural study and reviews.

PubMed

Huntrakoon, M; Callaway, L A; Vergara, G G

1987-08-01

A 20-year-old white male was initially suspected clinically and pathologically of having an acute lymphoblastic leukemic process because of fatigue, severe anemia, thrombocytopenia, a leuko-erythroblastic peripheral blood picture, and a diffusely infiltrated bone marrow. Subsequent review of the bone marrow material indicated cytologic features consistent with either an embryonal, undifferentiated small cell mesenchymal malignancy or reticulo-endothelial malignancy. Ultimately, the electron microscopic (EM) study of the tumor proved to be diagnostic of rhabdomyosarcoma. An extensive search for a primary site of rhabdomyosarcoma did not show any lesion, although the genitourinary region was clinically suspected. The clinical course was a rapidly downhill one with extensive bone and CNS involvement. The patient died 5 months later. An autopsy permit was not obtained. This case emphasizes the occasional tendency of rhabdomyosarcoma to masquerade as a hematopoietic malignancy at the time of presentation and the usefulness of EM study in confirming a diagnosis.

[An electron microscopic study on the RNA component of synaptonemal complexes in spermatocytes of Mus musculus].

PubMed

Xing, M; Jing, D Z; Hao, S

1991-01-01

The ultrastructural and cytochemical features of synaptonemal complexes (SC) in sections of spermatocytes of Mus musculus were studied under electron microscope. In specimens stained with uranyl acetate and lead citrate the SC was found consisting of three main elements. the lateral element (LE), the central element (CE) and the transverse filament (L-C filament). When stained with the Bernhard's technique, the SC was recognized as a contrasted, tripartite structure which was usually located in the bleached area occupied by the condensed chromatin and composed of highly electron-dense LEs and medium electron-dense CE and L-C filaments. The SC and the LE, stained either by uranyl acetate-lead citrate or by the Bernhard's technique, always showed diameters of about 210 nm and 60 nm, respectively. The results suggest that RNA may be an important component of the SC.

Blue nevi of the Müllerian tract: case series and review of the literature.

PubMed

Craddock, Kenneth J; Bandarchi, Bizhan; Khalifa, Mahmoud A

2007-10-01

Blue nevi are rare in the cervix and vagina. Melanocytes are not normally found in these sites and have been hypothesized to arise either from the Schwann cells of stromal nerves or from melanocytic precursors which have aberrantly migrated from the neural crest to rest in the Müllerian stroma. Because of their rarity (3 previous cases in the literature), vaginal blue nevi have not previously been studied with immunohistochemical and ultrastructural analysis. We describe 3 cases of blue nevus occurring in the Müllerian tract, 1 in the vagina and 2 in the endocervix. The vaginal lesion was seen during routine examination of a 40-year-old woman. The endocervical blue nevi were incidental findings in hysterectomies performed for leiomyomata and endometrial serous carcinoma in women aged 44 and 57 years, respectively. All 3 cases showed loose aggregates of cytologically benign, pigmented, dendritic spindle cells in the superficial stroma. They were immunoreactive for S100 and melan-A, but not HMB45. Ultrastructural analysis revealed numerous melanosomes, with no Schwannian features identified. Compared with the endocervical lesions, the vaginal nevus cells were more heavily pigmented, and on electron microscopy, a greater proportion of stage IV melanosomes were seen. We provide the first immunohistochemical and ultrastructural findings in a vaginal blue nevus, which confirm that it is of a similar nature to the endocervical blue nevi. Ultrastructurally, our results support a melanocytic rather than Schwannian origin for Müllerian blue nevi.

Ultrastructural characteristics of three undifferentiated mouse embryonic stem cell lines and their differentiated three-dimensional derivatives: a comparative study.

PubMed

Alharbi, Suzan; Elsafadi, Mona; Mobarak, Mohammed; Alrwili, Ali; Vishnubalaji, Radhakrishnan; Manikandan, Muthurangan; Al-Qudsi, Fatma; Karim, Saleh; Al-Nabaheen, May; Aldahmash, Abdullah; Mahmood, Amer

2014-04-01

The fine structures of mouse embryonic stem cells (mESCs) grown as colonies and differentiated in three-dimensional (3D) culture as embryoid bodies (EBs) were analyzed by transmission electron microscopy. Undifferentiated mESCs expressed markers that proved their pluripotency. Differentiated EBs expressed different differentiation marker proteins from the three germ layers. The ultrastructure of mESCs revealed the presence of microvilli on the cell surfaces, large and deep infolded nuclei, low cytoplasm-to-nuclear ratios, frequent lipid droplets, nonprominent Golgi apparatus, and smooth endoplasmic reticulum. In addition, we found prominent juvenile mitochondria and free ribosomes-rich cytoplasm in mESCs. Ultrastructure of the differentiated mESCs as EBs showed different cell arrangements, which indicate the different stages of EB development and differentiation. The morphologies of BALB/c and 129 W9.5 EBs were very similar at day 4, whereas C57BL/6 EBs were distinct from the others at day 4. This finding suggested that differentiation of EBs from different cell lines occurs in the same pattern but not at the same rate. Conversely, the ultrastructure results of BALB/c and 129 W9.5 ESCs revealed differentiating features, such as the dilated profile of a rough endoplasmic reticulum. In addition, we found low expression levels of undifferentiated markers on the outer cells of BALB/c and 129 W9.5 mESC colonies, which suggests a faster differentiation potential.

Nematodes ultrastructure: complex systems and processes.

PubMed

Basyoni, Maha M A; Rizk, Enas M A

2016-12-01

Nematode worms are among the most ubiquitous organisms on earth. They include free-living forms as well as parasites of plants, insects, humans and other animals. Recently, there has been an explosion of interest in nematode biology, including the area of nematode ultrastructure. Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm. It appears that the cuticle is a very complex and evolutionarily plastic feature with important functions involving protection, body movement and maintaining shape. They only have longitudinal muscles so; they seem to thrash back and forth. While nematodes have digestive, reproductive, nervous and excretory systems, they do not have discrete circulatory or respiratory systems. Nematodes use chemosensory and mechanosensory neurons embedded in the cuticle to orient and respond to a wide range of environmental stimuli. Adults are made up of roughly 1000 somatic cells and hundreds of those cells are typically associated with the reproductive systems. Nematodes ultrastructure seeks to provide studies which enable their use as models for diverse biological processes including; human diseases, immunity, host-parasitic interactions and the expression of phylogenomics. The latter has, however, not been brought into a single inclusive entity. Consequently, in the current review we tried to provide a comprehensive approach to the current knowledge available for nematodes ultrastructures.

Ultrastructural basis for the efficiency of an ileal orthotopic neobladder 27 years after surgery.

PubMed

Orlandini, G; Guizzardi, S; Ferretti, S; Simonazzi, M; Bucci, G; Gatti, R

2002-01-01

The morphological and functional basis of the excellent clinical outcome of ileal orthotopic neobladders are largely unknown. Only long-term follow-up studies will provide an adequate answer to this unsettled question. We have studied a patient who underwent this type of surgery over 27 years ago. Besides an important secretive adaptation we have found, at the ultrastructural level, that the monolayered epithelium does not show signs of true metaplasia and that changes had occurred in the intercellular junctions, namely that desmosomes are significantly increased. Although limited to a single case, these features, if confirmed by further observations, suggest a working hypothesis for the understanding of the definitive phenotypic adaptation of the ileal epithelium to the new aggressive environment. Copyright 2002 S. Karger AG, Basel

Reissner's membrane and the spiral ligament in normal rats and those treated with ethacrynic acid

NASA Technical Reports Server (NTRS)

Ross, M. D.

1981-01-01

A description is presented of recent ultrastructural findings in Reissner's membrane and the spiral ligament in rats treated daily with ethacrynic acid during the 2nd and 3rd weeks of postnatal life, a period of final maturation of the inner ear and its fluids. A distension of Reissner's membrane in every cochlear turn, indicative of mild endolymphatic hydrops, was found to occur in animals that received a higher dose of ethacrynic acid. Ultrastructurally, the cytoplasm of the epithelial cells of Reissner's membrane showed increased electron density after treatment with ethacrynic acid. This increase was most pronounced in animals treated with a greater quantity of the drug. The epithelial cells had similar ultracellular features throughout except that the cells were much thinner in the region of maximal distension.

Central granular cell odontogenic tumor: immunohistochemistry and ultrastructure.

PubMed

Meer, Shabnum; Altini, Mario; Coleman, Hedley; Daya, Nilesh

2004-01-01

Central granular cell odontogenic tumors are rare, with only 30 cases having been reported. The tumors usually occur in the mandibular molar area and are seen as localized painless swellings in patients older than 40 years. We report an additional case that occurred in the posterior mandible of an elderly black woman. All reported cases of this tumor are benign, and cure is effected by localized surgical excision. Ultrastructurally, the cells contain numerous lysosomes and phagocytic vacuoles. Immunohistochemically, the granular cells were positive for vimentin, CD68, muramidase, carcinogenic embryonic antigen, and bcl-2. These features support a mesenchymal origin with a possible histiocytic lineage for the granular cells. Awareness of the occurrence of this neoplasm is important to promote detection and differentiation from other intraoral granular cell lesions.

Ultrastructural analysis of oocytes of Rhipicephalus (Boophilus) annulatus during postengorgement period as a tool to evaluate the cytotoxic effects of amitraz and deltamethrin on the germinative cells.

PubMed

Sreelekha, Kanapadinchareveetil; Chandrasekhar, Leena; Kartha, Harikumar S; Ravindran, Reghu; Juliet, Sanis; Ajithkumar, Karapparambu G; Nair, Suresh N; Ghosh, Srikanta

2017-11-30

The present study utilizes the ultrastructural analysis of the fully engorged female Rhipicephalus (Boophilus) annulatus ticks, as a tool to evaluate the cytotoxic potential of deltamethrin and amitraz on the germinative cells. The ultrastructural analysis of the ovary of the normal (untreated) R (B.) annulatus revealed, oocytes in different stages of development, attached to the ovary wall by pedicel cells. The attachment site of oocyte to the pedicel cell was characterized by indentations of the plasma membrane. The oocyte was bound by three cell membranes viz., plasma membrane, chorion and basal lamina. The stages of oocytes were differentiated ultrastructurally based on the features of their outer membrane and the number and size of lipid and yolk droplets. Detailed day wise analysis of ultrastructural changes in the ovary during the post-engorgement period revealed the occurrence of the degenerative changes from day five onwards. These appeared first in the oocytes followed by the germinal epithelium. The ovary of ticks treated with methanol (control), revealed similar topographies as that of a normal ovary except for the presence of very few oocytes with ring shaped nucleoli. Ultrastructurally, treatment with deltamethrin produced more prominent and extensive morphological alterations when compared to amitraz. In the case of ticks treated with amitraz, the oocytes of stage IV and V showed wavy and disrupted outer boundaries along with the loss of integrity of the yolk droplets. Uneven nuclear membranes of stage II oocytes and cristolysis of mitochondria of mature oocytes were the other changes noticed. Ticks treated with deltamethrin revealed prominent modifications such as, detachment of the basal lamina, wrinkled boundary, inconsistent nuclear membrane, ring shaped nucleoli and chromatin clumping in the case of the early stage oocytes (I and II), whereas swelling and cristolysis of mitochondria were seen in mature oocytes. The study further indicated that, in addition to the previous proven neurotoxic effects, these compounds act directly on the ovary of tick. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrastructural analysis of cell component distribution in the apical cell of Ceratodon protonemata

NASA Technical Reports Server (NTRS)

Walker, L. M.; Sack, F. D.

1995-01-01

A distinctive feature of tip-growing plant cells is that cell components are distributed differentially along the length of the cell, although most ultrastructural analyses have been qualitative. The longtitudinal distribution of cell components was studied both qualitatively and quantitatively in the apical cell of dark-grown protonemata of the moss Ceratodon. The first 35 micrometers of the apical cell was analyzed stereologically using transmission electron microscopy. There were four types of distributions along the cell's axis, three of them differential: (1) tubular endoplasmic reticulum was evenly distributed, (2) cisternal endoplasmic reticulum and Golgi vesicles were distributed in a tip-to-base gradient, (3) plastids, vacuoles, and Golgi stacks were enriched in specific areas, although the locations of the enrichments varied, and (4) mitochondria were excluded in the tip-most 5 micrometers and evenly distributed throughout the remaining 30 micrometers. This study provides one of the most comprehensive quantitative, ultrastructural analyses of the distribution of cell components in the apex of any tip-growing plant cell. The finding that almost every component had its own spatial arrangement demonstrates the complexity of the organization and regulation of the distribution of components in tip-growing cells.

Immunohistochemical and ultrastructural changes in rat fat tissue related to the local hCG injection.

PubMed

Tunç, E; Erdogan, D; Calgüner, E; Göktas, G; Elmas, Ç; Gözil, R; Bahçelioglu, M; Öktem, H

2013-11-01

Recently, it has been observed that weight loss is accelerated by human chorionic gonadotropin (hCG) hormone preparation used for hypothalamic dysfunction in obesity treatment in both sexes. hCG is also used for in vitro fertilization and in treatment of hypogonadotropic hypogonadism. Our aim was to observe the ultrastructural changes caused by local injections of hCG made for purpose of weight loss and to present them to inform those receiving such therapy. In our study, 10 obese female, 10 male obese, 10 non-obese female and 10 non-obese male rats were used. In each group, single dose of subcutaneous hCG injection has been applied to 7 rats for 5 weeks in 5 days of the week, and placebo has been applied to the remaining 3 rats. Following the injection, the tissues were evaluated morphologically, immunohistochemically and ultrastructurally. Leptin immunoreactivity was similar in all groups. When the adipose tissue samples were examined under electron microscope, they were observed to exhibit normal structure with organelles located around the nuclei and nucleoli, and no distinctive features were found among the groups. Administering hCG in addition to diet had no advantage on weight reduction in rats.

Effects of growth hormone on the ultrastructure of bovine preimplantation embryos.

PubMed

Kölle, Sabine; Stojkovic, Miodrag; Reese, Sven; Reichenbach, Horst-Dieter; Wolf, Eckhard; Sinowatz, Fred

2004-07-01

Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos. The aim of our study was therefore to analyze the effects of GH on the morphology and ultrastructure of the cells of bovine preimplantation embryos produced by in vitro fertilization (IVF). In order to determine the physiologically optimal morphology of blastocysts, ex vivo embryos obtained by uterine flushing were also included in the study. As shown by transmission electron microscopy, treatment with GH induced the elimination of glycogen storage in cells of the inner cell mass of 7-day-old embryos. GH also stimulated the exocytosis of lipid vesicles in the inner cell mass and trophectoderm cells of these embryos. Quantitative analysis of micrographs demonstrated a higher volume density of embryonic mitochondria in 7-day-old embryos cultured with GH than in control embryos. Treatment with GH regularly resulted in an improvement of the ultrastructural features of embryos produced in vitro, thus resembling the morphology of ex vivo embryos. Scanning electron-microscopy studies demonstrated that GH altered the structure and the pore size of the zona pellucida of blastocysts. Our studies imply that GH can modulate carbohydrate, lipid, and energy metabolism and influence transportation processes in the early IVF embryo.

A comparative ultrastructural study of pit membranes with plasmodesmata associated thickenings in four angiosperm species.

PubMed

Rabaey, David; Lens, Frederic; Huysmans, Suzy; Smets, Erik; Jansen, Steven

2008-11-01

Recent micromorphological observations of angiosperm pit membranes have extended the number and range of taxa with pseudo-tori in tracheary elements. This study investigates at ultrastructural level (TEM) the development of pseudo-tori in the unrelated Malus yunnanensis, Ligustrum vulgare, Pittosporum tenuifolium, and Vaccinium myrtillus in order to determine whether these plasmodesmata associated thickenings have a similar developmental pattern across flowering plants. At early ontogenetic stages, the formation of a primary thickening was observed, resulting from swelling of the pit membrane in fibre-tracheids and vessel elements. Since plasmodesmata appear to be frequently, but not always, associated with these primary pit membrane thickenings, it remains unclear which ultrastructural characteristics control the formation of pseudo-tori. At a very late stage during xylem differentiation, a secondary thickening is deposited on the primary pit membrane thickening. Plasmodesmata are always associated with pseudo-tori at these final developmental stages. After autolysis, the secondary thickening becomes electron-dense and persistent, while the primary thickening turns transparent and partially or entirely dissolves. The developmental patterns observed in the species studied are similar and agree with former ontogenetic studies in Rosaceae, suggesting that pseudo-tori might be homologous features across angiosperms.

Ultrastructural evaluation of gingival connective tissue in hereditary gingival fibromatosis.

PubMed

Pêgo, Sabina Pena B; de Faria, Paulo Rogério; Santos, Luis Antônio N; Coletta, Ricardo D; de Aquino, Sibele Nascimento; Martelli-Júnior, Hercílio

2016-07-01

To describe the ultrastructural features of hereditary gingival fibromatosis (HGF) in affected family members and compare microscopic findings with normal gingival (NG) tissue. Gingival tissue samples from nine patients with HGF from five unrelated families were evaluated by transmission electron microscopy. Nine NG tissue samples were used for comparison. Areas containing collagen fibrils forming loops and folds were observed in both groups, whereas oxytalan fibers were frequently identified in the HGF group. The diameter of collagen fibrils and the interfibrillar space among them were more uniform in the NG group than in the HGF group. Fibroblasts were the most common cells found in both the HGF and NG groups and exhibited enlarged, rough endoplasmic reticulum, mitochondria with well-preserved crests, conspicuous nucleoli, and euchromatic chromatin. Other cells, such as mast cells, plasma cells, and macrophages, were also observed. HGF tissues had ultrastructural characteristics that were very similar to those of NG tissues. Oxytalan fibers were observed more frequently in the HGF samples than in the NG samples. Other studies of HGF in patients from different families should be performed to better understand the pathogenesis of this hereditary condition. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular and ultrastructural studies of a fibrillar collagen from octocoral (Cnidaria).

PubMed

Orgel, Joseph P R O; Sella, Ido; Madhurapantula, Rama S; Antipova, Olga; Mandelberg, Yael; Kashman, Yoel; Benayahu, Dafna; Benayahu, Yehuda

2017-09-15

We report here the biochemical, molecular and ultrastructural features of a unique organization of fibrillar collagen extracted from the octocoral Sarcophyton ehrenbergi Collagen, the most abundant protein in the animal kingdom, is often defined as a structural component of extracellular matrices in metazoans. In the present study, collagen fibers were extracted from the mesenteries of S. ehrenbergi polyps. These fibers are organized as filaments and further compacted as coiled fibers. The fibers are uniquely long, reaching an unprecedented length of tens of centimeters. The diameter of these fibers is 9±0.37 μm. The amino acid content of these fibers was identified using chromatography and revealed close similarity in content to mammalian type I and II collagens. The ultrastructural organization of the fibers was characterized by means of high-resolution microscopy and X-ray diffraction. The fibers are composed of fibrils and fibril bundles in the range of 15 to 35 nm. These data indicate a fibrillar collagen possessing structural aspects of both types I and II collagen, a highly interesting and newly described form of fibrillar collagen organization. © 2017. Published by The Company of Biologists Ltd.

Ultrastructural characters of the spermatozoa in Digeneans of the genus Lecithochirium Lühe, 1901 (Digenea, Hemiuridae), parasites of fishes: comparative study of L. microstomum and L. musculus

PubMed Central

Ndiaye, Papa Ibnou; Quilichini, Yann; Sène, Aminata; Tkach, Vasyl V.; Bâ, Cheikh Tidiane; Marchand, Bernard

2014-01-01

This study provides the first ultrastructural data of spermatozoa in the genus Lecithochirium. The spermatozoa of L. microstomum (from Trichiurus lepturus in Senegal) and L. musculus (from Anguilla anguilla in Corsica) exhibit the general pattern described in the great majority of the Digenea, namely two axonemes with the 9 + “1” pattern typical of the Trepaxonemata, one mitochondrion, a nucleus, parallel cortical microtubules and external ornamentation of the plasma membrane. Spermatozoa of L. microstomum and L. musculus have some specific features such as the presence of a reduced number of cortical microtubules arranged on only one side of the spermatozoon, the lack of spine-like bodies and expansion of the plasma membrane. The external ornamentation of the plasma membrane entirely covers the anterior extremity of the spermatozoa. The ultrastructure of the posterior extremity of the spermatozoa corresponds to the pattern previously described in the Hemiuridae, characterized by only singlets of the second axoneme. A particularity of these spermatozoa is the organization of the microtubule doublets of the second axoneme around the nucleus in the posterior part of the spermatozoon. PMID:25275216

Ultrastructural and histological findings on examination of skin in osteogenesis imperfecta: a novel study.

PubMed

Balasubramanian, Meena; Wagner, Bart E; Peres, Luiz C; Sobey, Glenda J; Parker, Michael J; Dalton, Ann; Arundel, Paul; Bishop, Nicholas J

2015-04-01

Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of bone formation, resulting in low bone mass and an increased propensity for fractures. It is a variable condition with a range of clinical severities. The histological and ultrastructural findings in the skin of patients with OI have not been described in detail in the previously published literature. Although protein analysis of cultured fibroblasts has historically been used in the diagnostic work-up of OI patients, other aspects of skin examination are not routinely performed as part of the diagnostic pathway in patients with OI. The aims of this study were to perform histological and ultrastructural examination of skin biopsies in patients with OI. This was to identify common and distinguishing features in the numerous genetically distinct subtypes of OI and compare the findings with those in patients who did not present with fractures, and to enable the use of the results thus obtained to aid in the diagnostic work-up of patients with OI. As part of a larger research study set-up to identify clinical features and natural history in patients with atypical features of OI, skin biopsy and examination (histology and electron microscopy) were undertaken. Genetic analysis and ancillary investigations were also performed to identify similarities within this group and to differentiate this group from the 'normal' population. At the end of this study, we were able to demonstrate that the histological and electron microscopic findings on a skin biopsy may be an indicator of the likelihood of identifying a pathogenic mutation in type 1 collagen genes. This is because patients with specific findings on examination, such as elastic fibre area fraction (on histological analysis), collagen fibril diameter variability, deviation from the expected mean and collagen flowers (on electron microscopy), are more likely to be positive on genetic analyses. This has, in turn, provided more insight into the pathways to direct gene testing and has reinforced the need for accurate phenotyping before undertaking further genetic investigations. The morphometric assessment of elastic fibre area fraction and ultrastructural findings from this study have provided us with a better understanding of OI and insights into the possible mechanism of these changes in the skin. Correlation of skin findings with the clinical phenotype as well as genetic testing has enabled understanding of the molecular pathogenesis and translation of changes at the genomic level to clinical phenotype.

Ultrastructural evaluation of explanted opacified Hydroview (H60M) intraocular lenses

PubMed Central

Cartwright, Nathaniel E Knox; Mayer, Eric J; McDonald, Brendan M; Skinner, Andrew; Salter, Chris J; Tole, Derek M; Sparrow, John M; Dick, Andrew D; Group, The Bristol IOL Study; Ferguson, David J P

2007-01-01

Aim To describe the ultrastructural appearance of explanted opacified Hydroview H60M intraocular lenses. Methods 14 explanted lenses were examined by scanning electron microscopy, and their appearance compared with a non‐implanted H60M lens from the same time period. Wavelength‐dispersive x ray spectroscopy (WDX) was performed on two opacified lenses. Results Subsurface deposits were seen in all explanted opacified lenses. These deposits broke only onto the surface of more densely opacified lenses. WDX confirmed that the deposits contained both calcium and phosphorous, consistent with their being calcium apatite. Conclusion These findings challenge the widely accepted opinion that H60M intraocular lens opacification begins on the surface of the optic. PMID:16987894

Ultrastructural blood-brain barrier alterations and edema formation in acute spinal cord trauma.

PubMed

Goodman, J H; Bingham, W G; Hunt, W E

1976-04-01

Endothelial changes leading to edema formation are examined in the primate spinal cord (Macaca mulatta) following a lesion created by a 20-gm weight falling 15 cm onto the exposed dura. Intravascular perfusion of a paraformaldehydeglutaraldehyde solution followed by carbon black provides adequate fixation of vascular structures and glial elements. Myelin is poorly preserved. Ultrastructural alterations of the blood-brain barrier consist of loss of integrity of the endothelial tight junctions. Edema caused by vascular disruption and parenchymatous extravasation of intravascular contents is observed along with glial swelling. Interglial gap junctions persist in areas of marked cellular seperation and do not impede the migration of edema fluid.

Ultrastructure Processing of Ordered Polymers

DTIC Science & Technology

1990-01-18

from regenerated cellulose , then from synthetic polymer consisting of chemical raw materials derived from oils and coal. Since then, some scientists have...ordered crystal- line material, crystallite, throughout the fiber, which is composed of microfibrils and fibrils. The small crystallites are regularly...these flat ribbons appears to consist of smaller " microfibrils " of lateral dimension varying from 50-80 A, as described before(Figs. 15 and 16). These

Anaplastic ependymoma simulating glioblastoma in the cerebrum of an adult.

PubMed

Shintaku, Masayuki; Hashimoto, Kenji

2012-01-01

A case of anaplastic ependymoma of the cerebral hemisphere in which the histopathological features closely simulated those of glioblastoma is reported. The patient was a 72-year-old woman with a large, well-demarcated tumor in the left temporal lobe. The tumor was totally extirpated, but recurred 18 months later, and the patient died after 4 months. The extirpated tumor was well circumscribed from the surrounding brain tissue and consisted of a sheet-like, dense proliferation of atypical, short spindle or polygonal cells. Extensive geographic necrosis with nuclear pseudopalisading was seen. Although perivascular pseudorosettes were observed in many areas, true ependymal rosettes were absent. Immunohistochemistry for glial fibrillary acidic protein and epithelial membrane antigen and ultrastructural study confirmed the ependymal nature of tumor cells. The histopathological spectrum of anaplastic ependymoma is very wide and reflects the basically dual characteristics of ependymal cells: epithelial and glial phenotypes. The present case indicates that some anaplastic ependymomas strongly express the glial phenotype and also show remarkable anaplastic cytological features, thus closely simulating glioblastoma. The diagnostic criteria for anaplastic ependymoma, and the nosological position of highly anaplastic ependymoma and its possible clinical implications, are briefly discussed.

Ultrastructural alteration of mouse lung by prolonged exposure to mixtures of helium and oxygen

NASA Technical Reports Server (NTRS)

Harrison, G. A.; Solomon, J. D.

1975-01-01

Observed changes consist mainly of blebbing of capillary endothelium and alveolar epithelium, which is quite possibly indicative of cellular edema; also, there can be observed highly-convoluted basement membrane, alveolar debris, and increased numbers of platelets.

Basement membrane of mouse bone marrow sinusoids shows distinctive structure and proteoglycan composition: a high resolution ultrastructural study.

PubMed

Inoue, S; Osmond, D G

2001-11-01

Venous sinusoids in bone marrow are the site of a large-scale traffic of cells between the extravascular hemopoietic compartment and the blood stream. The wall of the sinusoids consists solely of a basement membrane interposed between a layer of endothelial cells and an incomplete covering of adventitial cells. To examine its possible structural specialization, the basement membrane of bone marrow sinusoids has now been examined by high resolution electron microscopy of perfusion-fixed mouse bone marrow. The basement membrane layer was discontinuous, consisting of irregular masses of amorphous material within a uniform 60-nm-wide space between apposing endothelial cells and adventitial cell processes. At maximal magnifications, the material was resolved as a random arrangement of components lacking the "cord network" formation seen in basement membranes elsewhere. Individual components exhibited distinctive ultrastructural features whose molecular identity has previously been established. By these morphological criteria, the basement membrane contained unusually abundant chondroitin sulfate proteoglycan (CSPG) revealed by 3-nm-wide "double tracks," and moderate amounts of both laminin as dense irregular coils and type IV collagen as 1-1.5-nm-wide filaments, together with less conspicuous amounts of amyloid P forming pentagonal frames. In contrast, 4.5-5-nm-wide "double tracks" characteristic of heparan sulfate proteoglycan (HSPG) were absent. The findings demonstrate that, in comparison with "typical" basement membranes in other tissues, the bone marrow sinusoidal basement membrane is uniquely specialized in several respects. Its discontinuous nature, lack of network organization, and absence of HSPG, a molecule that normally helps to maintain membrane integrity, may facilitate disassembly and reassembly of basement membrane material in concert with movements of adventitial cell processes as maturing hemopoietic cells pass through the sinusoidal wall: the exceptionally large quantity of CSPG may represent a reservoir of CD44 receptor for use in hemopoiesis. Copyright 2001 Wiley-Liss, Inc.

Where are the sensory organs of Nybelinia surmenicola (Trypanorhyncha)? A comparative analysis with Parachristianella sp. and other trypanorhynchean cestodes.

PubMed

Biserova, Natalia M; Gordeev, Ilya I; Korneva, Janetta V

2016-01-01

The sensory organs in tegument of two trypanorhynchean species--Nybelinia surmenicola (plerocercoid) and adult Parachristianella sp. (Cestoda, Trypanorhyncha)--were studied with the aim of ultrastructural description and a comparative analysis. The Nybelinia surmenicola plerocercoid lacks papillae with sensory cilia on the bothria adhesive surface. We found an unciliated sensory organ within the median bothria fold. This unciliated free nerve ending contains the central electron-dense disc, three dense supporting rings, and broad root. The nerve ending locates in the basal matrix under the tegument. The tegument of N. surmenicola has a number of ultrastructural features which make it significantly different from other Trypanorhyncha: (i) the tegumental cytoplasm has a plicated constitution in a form of high apical and deep basal folds, (ii) numerous layers of the basal matrix are presented in the subtegument, and (iii) the squamiform and bristlelike microtriches N. surmenicola lack the base and the basal plate. In contrast, numerous ciliated and unciliated receptors were found in Parachristianella sp.: six types on the bothria and one type in the strobila tegument. Ultrastructural constitution of sensory organs in the form of ciliated free nerve endings as well as unciliated basal nerve endings of Parachristianella sp. has many common features inside Eucestoda. In comparison with other Trypanorhyncha, all Nybelinia species studied have less quantity of the bothrial sensory organs. This fact may reflect behavioral patterns of Nybelinia as well as phylogenetic position into Trypanorhyncha. Our observations of living animals conventionally demonstrate the ability of N. surmenicola plerocercoids to locomote in forward direction on the Petri dish surface. The participation of the bothrial microtriches in a parasite movement has been discussed.

The cytochemical and ultrastructural characteristics of phagocytes in the Pacific oyster Crassostrea gigas.

PubMed

Jiang, Shuai; Jia, Zhihao; Xin, Lusheng; Sun, Ying; Zhang, Ran; Wang, Weilin; Wang, Lingling; Song, Linsheng

2016-08-01

Phagocytes have been proved to play vital roles in the innate immune response. However, the cellular characteristics of phagocytes in invertebrates, especially in molluscs, remain largely unknown. In the present study, fluorescence activated cell sorting (FACS) was employed to sort the phagocytes from the non-phagocytic haemocytes of the Pacific oyster Crassostrea gigas. The cytochemical staining analysis revealed that phagocytes were positive staining for α-naphthyl acetate esterase and myeloperoxidase, while negative staining for toluidine blue and periodic acid-Schiff. The non-phagocytic haemocytes exhibited positive staining for periodic acid-Schiff, weak positive staining for toluidine blue, but negative staining for α-naphthyl acetate esterase and myeloperoxidase. In addition, phagocytes exhibited ultrastructural cellular features similar to those of macrophages, with large cell diameter, rough cell membrane and extended pseudopodia revealed by the scanning electron microscopy, while the non-phagocytic haemocytes exhibited small cell diameter, smooth cell surface and round spherical shape. Transmission electron microscopy further demonstrated that phagocytes were abundant of cytoplasmic bodies and mitochondria, while non-phagocytic haemocytes were characterized as the comparatively large cell nucleus with contorted and condensed heterochromatin adherent to the nuclear envelope. Moreover, compared with non-phagocytic haemocytes, phagocytes exhibited significantly higher levels of intracellular cytokines, including tumor necrosis factor, interferon-like protein and interleukin-17, and significantly higher abundance of lysosome and reactive oxygen species, which were of great importance to the activation of immune response and pathogen clearance. Taken together, these findings revealed the different cytochemical and ultrastructural features between phagocytes and non-phagocytic haemocytes in C. gigas, which would provide an important clue to investigate the mechanism of phagocytosis underlying the innate immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of the changes in the basal cell region of oral lichen planus: An ultrastructural study

PubMed Central

Paul, Mayura; Shetty, Devi Charan

2013-01-01

Context: Oral lichen planus (OLP) affects 0.5-1% of the total world's population. The histological features of oral lichen planus were first described by Dubreuill in 1906. Despite the advent of various techniques, the etiology of lichen planus remains obscure, although many theories for the etiology have been proposed. Aims: By studying OLP electron microscopically, we shall be emphasizing on the cells and its interactions in specific/altered surroundings which would help us in hypothesizing the effects of its specific cell-to-cell interactions. Materials and Methods: A total of 20 cases of oral lichen planus were selected and categorized into erosive and nonerosive forms based upon clinical pattern and confirmed as lichen planus by histopathological analysis. Tissue specimens thus obtained were cut into two halves and fixed in appropriate fixatives, i.e., neutral buffered formalin for paraffin-embedded hematoxylin and eosin stained sections and 2.5% glutaraldehyde and 2% paraformaldehyde for electron microscopic purpose respectively. Results: Ultrastructural comparison among the two forms showed significant differences between them. The basal layer showed cytoplasmic processes, intercellular spaces, desmosomes, nuclei, and signs of degeneration. The erosive form showed elongated, narrow or irregular cytoplasmic projections whereas the nonerosive showed short and broad based projections. Conclusions: The present study confirms the ultrastructural findings of basal cells in OLP with previous authors findings. Besides this, the categorization of the ultrastructural differences between erosive and nonerosive has raised the question of difference in the probable cellular and molecular mechanism between erosive and nonerosive forms. PMID:23798823

Ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea).

PubMed

Poddubnaya, Larisa G; Kuchta, Roman; Bristow, Glenn A; Scholz, Tomas

2015-05-22

Using scanning and transmission electron microscopy, ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea) from ratfish, Chimaera monstrosa (Holocephali), was studied for the first time. The proper anterior organ is localised at a short distance (about 170 µm) from an apical pore surrounded by a receptor field, whereas its distal end is marked by a muscular sphincter. The tegumental surface of this organ is covered with short filitriches of irregular length; large area of muscle layers traverse beneath the tegumental layer. The funnel-shaped canal of G. urna (2.5-3.0 mm long) is a specialised, muscular part of the posterior attachment organ; it opens on the rounded elevation on the dorsal body surface. The tegumental layer bears conical sclerite-like structures (up to 1.5 µm long). It produces electron-dense bodies that are transported into a canal lumen and surrounded thick muscle area mixed with numerous nerve fibres. The present ultrastructural study of G. urna indicates that gyrocotylideans share some ultrastructural characters of the anterior organ with spathebothriidean cestodes with a single anterior attachment sucker-like organ. In contrast, the unique posterior rosette attachment organ with funnel-shaped canal of the Gyrocotylidea resembles the haptor of polyopisthocotylean monogeneans in its position at the posterior end of the body and presumed origin. The above-mentioned features add more clarity to support the basal position of the Gyrocotylidea Poche, 1926 among cestodes. In addition, they also indicate a possible relationship of gyrocotylidean ancestors with monogeneans.

Ultrastructure Features and Three-Dimensional Transmission Electron Tomography of Dhub Lizard (Uromastyx Aegyptia) Cornea and Its Adaptation to a Desert Environment.

PubMed

Akhtar, Saeed; Alkhalaf, Mousa; Khan, Adnan A; Almubrad, Turki M

2016-08-01

We report ultrastructural features and transmission electron tomography of the dhub lizard (Uromastyx aegyptia) cornea and its adaptation to hot and dry environments. Six corneas of dhub lizards were fixed in 2.5% glutaraldehyde and processed for electron microscopy and tomography. The ultrathin sections were observed with a JEOL 1400 transmission electron microscope. The cornea of the dhub lizard is very thin (~28-30 µm). The epithelium constitutes ~14% of the cornea, whereas the stroma constitutes 80% of the cornea. The middle stromal lamellae are significantly thicker than anterior and posterior stromal lamellae. Collagen fibril (CF) diameters in the anterior stroma are variable in size (25-75 nm). Proteoglycans (PGs) are very large in the middle and posterior stroma, whereas they are small in the anterior stroma. Three-dimensional electron tomography was carried out to understand the structure and arrangement of the PG and CFs. The presence of large PGs in the posterior and middle stroma might help the animal retain a large amount of water to protect it from dryness. The dhub corneal structure is equipped to adapt to the dry and hot desert environment.

Black hair follicular dysplasia in Large Münsterländer dogs: clinical, histological and ultrastructural features

PubMed Central

von Bomhard, Wolf; Mauldin, Elizabeth A.; Schmutz, Sheila M.; Leeb, Tosso; Casal, Margret L.

2012-01-01

Four Large Münsterländer cross-bred dogs affected with black hair follicular dysplasia (BHFD) and one unaffected control littermate were observed, and skin was sampled weekly over the first 19 weeks of life. Affected dogs were born with silvery grey hair, a consequence of melanin clumping in the hair shafts. Hair bulb melanocytes were densely pigmented, and contained abundant stage IV melanosomes but adjacent matrix keratinocytes lacked melanosomes. Melanin clumping was not prominent in epidermal melanocytes in the haired skin but occurred in the foot pads. Follicular changes progressed from bulbar clumping, clumping in the isthmus/ infundibulum and finally to dysplastic hair shafts. Alopecia developed progressively in pigmented areas. Silver-grey hair, melanin clumping, accumulation of stage IV melanosomes within melanocytes and insufficient melanin transfer to adjacent keratinocytes are also classic features of human Griscelli syndrome. The underlying cause in Griscelli syndrome is a defect of melanocytic intracellular transport proteins leading to inadequate and disorganized melanosome transfer to keratinocytes with resultant melanin clumping. In view of the correlation in the phenotype, histology and ultrastructure between both disorders, a defect in intracellular melanosome transport is postulated as the pathogenic mechanism in BHFD. PMID:16674733

Microvesicating effects of sulfur mustard on an in vitro human skin model.

PubMed

Hayden, Patrick J; Petrali, John P; Stolper, Gina; Hamilton, Tracey A; Jackson, George R; Wertz, Philip W; Ito, Susumu; Smith, William J; Klausner, Mitchell

2009-10-01

Bis-(beta-chloroethyl) sulfide (SM) is a potent skin vesicant previously used for chemical warfare. Progress in determination of the mechanistic basis of SM pathology, and development of prophylactic and/or therapeutic countermeasures to SM exposure has been hampered by lack of physiologically relevant models of human skin. The current work evaluated a newly developed tissue engineered full-thickness human skin model in a completely in vitro approach to investigation of SM-induced dermal pathology. The model was first characterized with regard to overall morphology, lipid composition, basement membrane (BM) composition and ultrastructural features that are important targets of SM pathologic activity. Well-developed BM ultrastructural features were observed at the dermal-epidermal junction (DEJ), thus demonstrating successful resolution of a primary deficiency of models previously evaluated for SM studies. Studies were then conducted to evaluate histopathological effects of SM on the model. Good replication of in vivo effects was observed, including apoptosis of basal keratinocytes (KC) and microblister formation at the DEJ. Tissue engineered skin models with well-developed basement membrane structures thus appear to be useful tools for in vitro mechanistic studies of SM vesicant activity and development of preventive/therapeutic approaches for SM pathology.

Micromorphology and ultrastructure of the floral nectaries of Polemonium caeruleum L. (Polemoniaceae).

PubMed

Chwil, Mirosława; Chwil, Stanisław

2012-10-01

The Polemoniaceae family forms flowers diverse in the terms of pollination methods and nectar types. The micromorphology of the nectary surface and the tissue structures as well as the ultrastructure of the cells of the floral nectaries in Polemonium caeruleum L. were examined using light, scanning and transmission electron microscopy. A bowl-shaped nectary, detached from the ovary, grows at its base. Its contour shows folds with depressions in the places where the stamens grow, forming five-lobed disc (synapomorphic character). Nectar is secreted through modified anomocytic stomata, which are formed in the epidermis covering the tip and the lateral wall of the projection located between the staminal filaments. The undulate nectary consists of a single-layered epidermis and three to nine layers of parenchymal cells. The cells of the nectary contain a dense cytoplasm, numerous plastids with an osmophilic stroma and starch grains, well-developed endoplasmic reticulum, as well as a large number of mitochondria interacting with the Golgi bodies. The ultrastructure of nectary cells indicates the granulocrine secretion mechanism and diversified transport of nectar.

Ultrastructural and molecular characterization of Glugea serranus n. sp., a microsporidian infecting the blacktail comber, Serranus atricauda (Teleostei: Serranidae), in the Madeira Archipelago (Portugal).

PubMed

Casal, Graça; Rocha, Sónia; Costa, Graça; Al-Quraishy, Saleh; Azevedo, Carlos

2016-10-01

A new microsporidian infecting the connective tissue of the coelomic cavity of the blacktail comber Serranus atricauda, in the Madeira Archipelago (Portugal), is described on the basis of morphological, ultrastructural, and molecular features. The microsporidian formed large whitish xenomas adhering to the peritoneal visceral organs of the host. Each xenoma consisted of a single hypertrophic cell, in the cytoplasm of which mature spores proliferated within parasitophorous vacuoles surrounded by numerous collagen fibers. Mature spores were ellipsoidal and uninucleated, measuring an average of 6.5 ± 0.5 μm in length and 3.4 ± 0.6 μm in width. The anchoring disk of the polar filament was subterminal, laterally shifted from the anterior pole of the spore. The isofilar polar filament coiled in 18-19 turns, forming two rows that surrounded the posterior vacuole. The latter occupied about one third of the spore length. The polaroplast surrounding the apical and uncoiled portion of the polar filament displayed two distinct regions: a lamellar region and an electron-dense globule. Molecular analysis of the rRNA genes, including the internal transcribed spacer region, and phylogenetic analysis using maximum likelihood and neighbor joining demonstrated that this microsporidian parasite clustered with some Glugea species. Based on the differences found both at the morphological and molecular levels, to other members of the genus Glugea, the microsporidian infecting the blacktail comber is considered a new species, thus named Glugea serranus n. sp.

An introduction to loricifera, cycliophora, and micrognathozoa.

PubMed

Kristensen, Reinhardt Møbjerg

2002-07-01

Loriciferans, cycliophorans and micrognathozoans are amongst the latest groups of animals to be discovered. Other than all being microscopic, they have very different body plans and are not closely related. Loriciferans were originally assigned to the Aschelminthes. However, both new molecular and ultrastructural researches have shown that Aschelminthes consist of two unrelated groups, Cycloneuralia and Gnathifera. Cycloneuralia may be included in the Ecdysozoa, including all molting invertebrates, and Gnathifera are more closely related to Platyhelminthes. The phylum Loricifera shares many apomorphic characters (e.g., scalids on the introvert) with both Priapulida and Kinorhyncha, and can be included in the taxon Scalidophora, a subgroup of Cycloneuralia. Cycliophora was originally allied to the Entoprocta and Ectoprocta (Bryozoa) based on ultrastructual research. Subsequent molecular data show they may be related to Rotifera and Acanthocephala, within the taxon Gnathifera. The phylogenetic position of Cycliophora is therefore not settled, and more ultrastructural and molecular data are needed. Micrognathozoa is the most recent major group of animals to be described. They show strong affinities with both Rotifera and Gnathostomulida (within the taxon Gnathifera), especially in the fine structure of the pharyngeal apparatus, where the jaw elements have cuticular rods with osmiophilic cores. Furthermore the micrognathozoans have two rows of multiciliated cells that form a locomotory organ, similar to that seen in some gastrotrichs and interstitial annelids. This character is never seen in Rotifera or in the monociliated Gnathostomulida. Rotifera and Acanthocephala always have a syncytial epidermis (Syndermata). Micrognathozoa lack this characteristic feature. Therefore, they are postulated to be placed basally in the Gnathifera, either as a sister-group to Gnathostomulida or as a sister-group to Rotifera + Acanthocephala.

Electron microscopic changes of detrusor in benign enlargement of prostate and its clinical correlation.

PubMed

Yadav, Sher Singh; Bhattar, Rohit; Sharma, Lokesh; Banga, Gautam; Sadasukhi, Trilok Chandra

2017-01-01

To study the ultra structural changes in bladder musculature in cases of BPE and their clinical relevance. In this descriptive longitudinal, controlled, observational study patients were enrolled into three groups, group 1, group 2A and group 2B. Control group (group-1) consisted of age matched normal male patients, who underwent surveillance or diagnostic cystoscopy for microscopic hematuria or irritative symptoms. Case group (group-2) comprised of patients with BPE, undergoing TURP. Case group (group-2) was further classified into: Category 2A (patients not on catheter) and cat-egory 2B (patients on catheter). All relevant clinical parameters like IPSS, prostate size, Qmax, PVR were recorded. Cystoscopy and bladder biopsy were performed in all patients. Various ultrastructural parameters like myocytes, fascicular pattern, interstitial tissue, nerve hypertrophy and cell junction pattern were analyzed under electron microscope and they were clinically correlated using appropriate statistical tests. Control group had significant difference as compared to case group in terms of baseline parameters like IPSS, flow rate and prostate size, both preoperatively and postoperatively, except for PVR, which was seen only preoperatively. There was statistically significant difference in ultrastructural patterns between case and control group in all five electron microscopic patterns. However, no significant difference was found between the subcategories of case groups. BPE is responsible for ultra structural changes in detrusor muscle and these changes remain persistent even after TURP. Nerve hypertrophy, which was not thoroughly discussed in previous studies, is also one of the salient feature of this study. Copyright® by the International Brazilian Journal of Urology.

Spermatodesm reorganization in the spermatophore and in the spermatheca of the bushcricket Tylopsis liliifolia (Fabricius) (Orthoptera, Tettigoniidae).

PubMed

Viscuso, Renata; Vitale, Danilo G M

2015-05-01

Spermatozoa of Tettigoniidae are usually transferred to the female by means of a spermatophore which is also the site of feather-shaped spermatodesm formation. These spermatodesms are then transferred to a spermatheca, composed of a spermathecal duct and of a seminal receptacle, involved in storing spermatozoa. In order to extend the knowledge about sperm transfer and spermatodesms reorganization in the Tettigoniidae, a morpho-structural investigation was carried out on spermatophore and spermatheca of Tylopsis liliifolia and on the reorganization of the gametes from the spermatophore. Our results show that the spermatodesms undergo disorganization in the spermatophore; unlike other Tettigoniidae, however, feather-shaped spermatodesms are never found. The epithelium of the spermatheca consists of two cell types, the cuticle-forming and the gland cells, with secretory features. The gland cells, absent in the distal tract of the seminal receptacle, release their secretion in a "reservoir" where an efferent duct opens. In the distal tract of the spermathecal duct, adjacent epithelial cells show diversified ultrastructural characteristics whose probable role is discussed. A particular feature of T. liliifolia is the genesis of the feather-shaped spermatodesms in the seminal receptacle. This feature and the peculiar organization of the feather-shaped spermatodesm are a possible autapomorphy of T. liliifolia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Proterozoic microfossils revealing the time of algal divergences

NASA Astrophysics Data System (ADS)

Moczydlowska-Vidal, Malgorzata

2010-05-01

Proterozoic microfossils revealing the time of algal divergences Małgorzata Moczydłowska-Vidal Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, SE 752 36 Uppsala, Sweden (malgo.vidal@pal.uu.se) Morphological and reproductive features and cell wall ultrastructure and biochemistry of Proterozoic acritarchs are used to determine their affinity to modern algae. The first appearance datum of these microbiota is traced to infer a minimum age of the divergence of the algal classes to which they may belong. The chronological appearance of microfossils that represent phycoma-like and zygotic cysts and vegetative cells and/or aplanospores, respectively interpreted as prasinophyceaen and chlorophyceaen microalgae, is related to the Viridiplantae phylogeny. These divergence times differ from molecular clock estimates, and the palaeontological evidence suggests that they are older. The best examples of unicellular, organic-walled microfossils (acritarchs) from the Mesoproterozoic to Early Ordovician are reviewed to demonstrate features, which are indicative of their affinity to photosynthetic microalgae. The first indication that a microfossil may be algal is a decay- and acid-resistant cell wall, which reflects its biochemistry and ultrastructure, and probably indicates the ability to protect a resting/reproductive cyst. The biopolymers synthesized in the cell walls of algae and in land plants ("plant cells"), such as sporopollenin/algaenan, are diagnostic for photosynthetic taxa and were inherited from early unicellular ancestors. These preservable cell walls are resistant to acetolysis, hydrolysis and acids, and show diagnostic ultrastructures such as the trilaminar sheath structure (TLS). "Plant cell" walls differ in terms of chemical compounds, which give high preservation potential, from fungal and animal cell walls. Fungal and animal cells are fossilized only by syngenetic permineralization, whereas "plant cells" are fossilized as body fossils more ubiquitously and without mineralization. Microalgae radiated quickly in the Cambrian and Ordovician; however, several morphotypes with features related to the reproductive cycle occur in the Proterozoic, although they are not always recognized as such. The assignment of Proterozoic unicellular microfossils with resistant cell walls to specific eukaryotic groups is tentative. However, we argue that the new interpretations of their functional morphology, combined with cell wall ultrastructure and biochemistry, allow their assignment to microalgal classes. Microfossils with advanced ornamentation and ontogenetically formed excystment structures or endocysts, which prove that they are cysts in a complex life cycle with sexual reproduction, are related to the basal lineage of the Chlorophytes and the class Chlorophyceae. A cell wall ultrastructure with a TLS supports the affinity of some spheroidal taxa to the Chlorophytes. The phylogeny of the Chlorophytes shows a sequence of branching nodes from a stem-group of the Viridiplantae that leads to the classes Prasinophyceae and Chlorophyceae, and then the Ulvophyceae. Based on a modern interpretation of the record, the timing of these nodes is deduced to be prior to c. 1650 Ma for the Prasinophyceae, c. 1450 Ma for the Chlorophyceae, and c. 950 Ma for the Ulvophyceae. The origin of the Chlorophytes, and in general the Viridiplantae, predates 1.8 Ga. These ages, based on microfossils, are earlier than the estimates based on molecular clocks.

Differential protein partitioning within the herpesvirus tegument and envelope underlies a complex and variable virion architecture

PubMed Central

Bohannon, Kevin Patrick; Jun, Yonggun; Gross, Steven P.; Smith, Gregory Allan

2013-01-01

The herpesvirus virion is a multilayered structure consisting of a DNA-filled capsid, tegument, and envelope. Detailed reconstructions of the capsid are possible based on its icosahedral symmetry, but the surrounding tegument and envelope layers lack regular architecture. To circumvent limitations of symmetry-based ultrastructural reconstruction methods, a fluorescence approach was developed using single-particle imaging combined with displacement measurements at nanoscale resolution. An analysis of 11 tegument and envelope proteins defined the composition and plasticity of symmetric and asymmetric elements of the virion architecture. The resulting virion protein map ascribes molecular composition to density profiles previously acquired by traditional ultrastructural methods, and provides a way forward to examine the dynamics of the virion architecture during infection. PMID:23569236

[Ultrastructure of the digestive system in Dermatophagoides farinae (Acariformes:Pyroglyphidae)].

PubMed

Wang, Yue-Ming; Liu, Xiao-Yu; Jiang, Cong-Li; Huang, Li-Nian; Sun, Xin; Liu, Zhi-Gang

2013-12-01

Fifty living mites (Dermatophagoides farinae) were fixed in 2.5% glutaraldehyde, postfixed in 1% osmium tetroxide, dehydrated in a graded ethanol series, embedded in embedding medium. The ultrastructure of the digestive tract in D. farinae was observed by serial ultrathin sections with a transmission electron microscope. The alimentary canal of D. farinae consists of the cuticle-lined foregut and hindgut separated by a microvilli-lined midgut (anterior midgut, posterior midgut). There are different types of epithelial cells in the anterior midgut The microvilli of epithelial cells in posterior midgut are longer than that of the anterior midgut In posterior midgut, the food bolus is surrounded by the peritrophic membrane. The midgut is the main site of digestion and absorption.

Differential protein partitioning within the herpesvirus tegument and envelope underlies a complex and variable virion architecture.

PubMed

Bohannon, Kevin Patrick; Jun, Yonggun; Gross, Steven P; Smith, Gregory Allan

2013-04-23

The herpesvirus virion is a multilayered structure consisting of a DNA-filled capsid, tegument, and envelope. Detailed reconstructions of the capsid are possible based on its icosahedral symmetry, but the surrounding tegument and envelope layers lack regular architecture. To circumvent limitations of symmetry-based ultrastructural reconstruction methods, a fluorescence approach was developed using single-particle imaging combined with displacement measurements at nanoscale resolution. An analysis of 11 tegument and envelope proteins defined the composition and plasticity of symmetric and asymmetric elements of the virion architecture. The resulting virion protein map ascribes molecular composition to density profiles previously acquired by traditional ultrastructural methods, and provides a way forward to examine the dynamics of the virion architecture during infection.

[The ultrastructure of Leydig cells under the influence of drinking mineral water and electromagnetic radiation under the stress conditions in the rats].

PubMed

Geniatulina, M S; Korolev, Yu N; Nikulina, L A

The objective of the present study was elucidate the peculiar features of low-intensity electromagnetic radiation (LI EMR) and mineral water (MW) on the ultrastructure of rat Leydig cells under conditions of immobilization stress. The experiments were carried out on outbred male rats with the use of electron microscopy. It has been demonstrated that the prophylactic consumption of drinking sulfate-containing mineral water and the application low-intensity electromagnetic radiation (with the flow power density of 1 mcW/cm2 and frequency around 1,000 Hz) or the combination of these two modalities under conditions of immobilization stress reduced the degree of ultrastructural derangement in the rat Leydig cells and stimulated the development of regenerative processes. In the cases of the single-factor impact, drinking mineral water exerted more pronounced action than low-intensity electromagnetic radiation on mitochondrial regeneration. In case of the simultaneous application of the two factors their protective action on the Leydig cells was much more conspicuous than that of either of them applied alone. It is concluded that drinking sulfate-containing mineral water in combination with the application of low-intensity electromagnetic radiation enhances resistance of the rat Leydig cells to stress.

Ochronosis-like condition in a cat.

PubMed

Bryan, Laura K; Weeks, Brad R; Payne, Harold Ross; Thompson, Lori A; Mansell, Joanne L

2016-08-01

Endogenous ochronosis is caused by a defect in the enzyme homogentisate 1,2-dioxygenase (HGD), which results in abnormal pigment deposition in the skin and urine abnormalities. Ochronosis previously has not been described histologically or ultrastructurally in a domestic animal species. To describe the clinical, histopathological and ultrastructural findings in a case of aberrant pigmentation in a cat with features that resemble ochronosis. A 5-year-old, spayed female Domestic short hair cat presented with multiple black cutaneous plaques on the face and progressive lethargy. The cat's urine turned brown when exposed to air. The familial history of the cat was unknown. Clinical examination; histopathology, electron microscopy and mass/energy dispersive X-ray spectroscopy of tissues. Septic peritonitis and additional pigment in the spleen, intestine and lymph node were found at postmortem examination. The pigment was determined to be an organic compound and had a similar histological appearance, staining properties, ultrastructure and composition to ochronotic pigment. No mutations were found in exons 3, 6, 8 and 13 of the HGD gene in the cat. To the best of the authors' knowledge, this is the first report of a condition resembling ochronosis in a domestic animal species that has been evaluated with histopathology and advanced imaging techniques. It provides an additional differential in cases of aberrant pigmentation in cats. © 2016 ESVD and ACVD.

[An ultrastructural study of oogenesis in the planarian Schmidtea mediterranea (Platyhelminthe, Paludicola)].

PubMed

Harrath, Abdul Halim; Alwasal, Saleh H; Alhazza, Ibrahim; Zghal, Fathia; Tekaya, Saida

2011-07-01

The ovary of the freshwater planarian Schmidtea mediterranea has been studied for the first time using both light and electron microscopy methods. The ultrastructure of the ovary revealed two types of cells: accessory cells and germinal cells at various stages of differentiation, distributed along a maturation axis. Initially, oogonia underwent cytoplasm growth due to the development of organelles, such as endoplasmic reticulum, Golgi complex, and mitochondria, which are all involved in the production of cytoplasmic inclusions or yolk globules. It is shown that the chromatoid body and fibrogranular aggregates may participate in the synthesis of vitelline inclusions. When completely mature, the oocytes have become larger, due to the accumulation of nutritive inclusions, which are round in shape and have a paracrystalline structure. These inclusions are interpreted as being yolk globules and may represent a kind of nutritive material for the developing embryo. These ultrastructural features of the ovary agree with the available phylogenetic tree, based on morphological and karyological characters that considers Schmidtea group as a genus and not a subgenus. The presence of sperm between the oocytes suggests that fertilization may occur within the ovary, representing an uncommon condition within the Triclads, in which fertilization usually takes places outside of the ovaries. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Syncytial Hepatitis of Tilapia ( Oreochromis niloticus L.) is Associated With Orthomyxovirus-Like Virions in Hepatocytes.

PubMed

Del-Pozo, J; Mishra, N; Kabuusu, R; Cheetham, S; Eldar, A; Bacharach, E; Lipkin, W I; Ferguson, H W

2017-01-01

Using transmission electron microscopy (TEM), the presented work expands on the ultrastructural findings of an earlier report on "syncytial hepatitis," a novel disease of tilapia (SHT). Briefly, TEM confirmed the presence of an orthomyxovirus-like virus within the diseased hepatocytes but not within the endothelium. This was supported by observing extracellular and intracellular (mostly intraendosomal), 60-100 nm round virions with a trilaminar capsid containing up to 7 electron-dense aggregates. Other patterns noted included enveloped or filamentous virions and virion-containing cytoplasmic membrane folds, suggestive of endocytosis. Patterns atypical for orthymyxovirus included the formation of syncytia and the presence of virions within the perinuclear cisternae (suspected to be the Golgi apparatus). The ultrastructural morphology of SHT-associated virions is similar to that previously reported for tilapia lake virus (TiLV). A genetic homology was investigated using the available reverse transcriptase polymerase chain reaction (RT-PCR) probes for TiLV and comparing clinically sick with clinically normal fish and negative controls. By RT-PCR analysis, viral nucleic acid was detected only in diseased fish. Taken together, these findings strongly suggest that a virus is causally associated with SHT, that this virus shares ultrastructural features with orthomyxoviruses, and it presents with partial genetic homology with TiLV (190 nucleotides).

Morphological and ultrastructural evaluation of the golden retriever muscular dystrophy trachea, lungs, and diaphragm muscle.

PubMed

Lessa, Thais Borges; de Abreu, Dilayla Kelly; Rodrigues, Márcio Nogueira; Brólio, Marina Pandolphi; Miglino, Maria Angélica; Ambrósio, Carlos Eduardo

2014-11-01

Duchenne muscular dystrophy (DMD) is a genetic disease, characterized by atrophy and muscle weakness. The respiratory failure is a common cause of early death in patients with DMD. Golden retriever muscular dystrophy (GRMD) is a canine model which has been extensively used for many advances in therapeutics applications. As the patients with DMD, the GRMD frequently died from cardiac and respiratory failure. Observing the respiratory failure in DMD is one of the major causes of mortality we aimed to describe the morphological and ultrastructural data of trachea, lungs (conductive and respiratory portion of the system), and diaphragm muscle using histological and ultrastructural analysis. The diaphragm muscle showed discontinuous fibers architecture, with different diameter; a robust perimysium inflammatory infiltrate and some muscle cells displayed central nuclei. GRMD trachea and lungs presented collagen fibers and in addition, the GRMD lungs showed higher of levels collagen fibers that could limit the alveolar ducts and alveoli distension. Therefore, the most features observed were the collagen areas and fibrosis. We suggested in this study that the collagen remodeling in the trachea, lungs, and diaphragm muscle may increase fibrosis and affect the trachea, lungs, and diaphragm muscle function that can be a major cause of respiratory failure that occur in patients with DMD. © 2014 Wiley Periodicals, Inc.

Salivary gland oncocytes in African hedgehogs (Atelerix albiventris) mimicking cytomegalic inclusion disease.

PubMed

Brunnert, S R; Hensley, G T; Citino, S B; Herron, A J; Altman, N H

1991-07-01

The salivary glands from three African hedgehogs contained multiple foci of cytomegalic cells, which occasionally had a mild to moderate infiltrate of lymphocytes at the periphery. The cytomegalic cells were 35 to 40 microns in diameter with abundant acidophilic granular to hyalin cytoplasm. The nuclei were enlarged with clumped marginalized chromatin and a large, (6 to 8 microns in diameter) central, brightly eosinophilic nucleolus that had the appearance of an inclusion body by light microscopy. Histochemically most of the cytomegalic cells contained cytoplasmic metachromatic granules with Feyrter's thionine inclusion stain. Scattered cells at the periphery of the cytomegalic foci contained periodic acid-Schiff-positive cytoplasmic granules. Ultrastructurally the cytomegalic cells contained numerous tightly-packed, often bizarre, enlarged mitochondria that completely filled the cytoplasm. The nucleus consisted of a dense central core of chromatin associated with the nucleolus and the remaining chromatin was clumped and marginalized. Nuclear and cytoplasmic virions consistent with cytomegalovirus were not present. Histochemical stains of the nucleus for heavy metals were negative. The ultrastructural and histochemical findings of the cytomegalic cells were consistent with oncocytes. Previous reports in the literature of similar cells in the salivary glands of insectivores appear to have been erroneously described as cytomegalovirus infections.

Melatonin and roentgen irradiation-induced acute radiation enteritis in Albino rats: an animal model.

PubMed

Hussein, Mahmoud R; Abu-Dief, Eman E; Kamel, Esam; Abou El-Ghait, Amal T; Abdulwahed, Saad Rezk; Ahmad, Mohamed H

2008-11-01

Roentgen irradiation can affect normal cells, especially the rapidly growing ones such as the mucosal epithelial cells of the small intestine. The small intestine is the most radiosensitive gastrointestinal organ and patients receiving radiotherapy directed to the abdomen or pelvis may develop radiation enteritis. Although roentgen rays are widely used for both imaging and therapeutic purposes, our knowledge about the morphological changes associated with radiation enteritis is lacking. This study tries to tests the hypothesis that "the intake of melatonin can minimize the morphological features of cell damage associated with radiation enteritis". We performed this investigation to test our hypothesis and to examine the possible radioprotective effects of melatonin in acute radiation enteritis. To achieve these goals, an animal model consisting of 60 Albino rats was established. The animals were divided into five groups: Group 1, non-irradiated; Group 2, X-ray irradiated (X-ray irradiation, 8 Grays); Group 3, X-ray irradiated-pretreated with solvent (ethanol and phosphate buffered saline); Group 4, non-irradiated-group treated with melatonin, and Group 5, X-ray irradiated-pretreated with melatonin. The small intestines were evaluated for gross (macroscopic), histological, morphometric (light microscopy), and ultrastructural changes (transmission electron microscopy). We found morphological variations among the non-irradiated-group, X-ray irradiated-group and X-ray irradiated-intestines of the animals pretreated with melatonin. The development of acute radiation enteritis in X-ray irradiated-group (Groups 2 and 3) was associated with symptoms of enteritis (diarrhea and abdominal distention) and histological features of mucosal injury (mucosal ulceration, necrosis of the epithelial cells). There was a significant reduction of the morphometric parameters (villous count, villous height, crypt height and villous/crypt height ratio). Moreover, the ultrastructural features of cell damage were evident including: apoptosis, lack of parallel arrangement of the microvilli, loss of the covering glycocalyx, desquamation of the microvilli, vacuolation of the apical parts of the cells, dilatation of the rough endoplasmic reticulum, and damage of the mitochondrial cristae. In the non-irradiated-group and in X-ray irradiated-intestines of the animals pretreated with melatonin (Group 5), these changes were absent and the intestinal mucosal structure was preserved. Administration of melatonin prior to irradiation can protect the intestine against X-rays destructive effects, i.e. radiation enteritis. The clinical applications of these observations await further studies.

Ultrastructural diversity between centrioles of eukaryotes.

PubMed

Gupta, Akshari; Kitagawa, Daiju

2018-02-16

Several decades of centriole research have revealed the beautiful symmetry present in these microtubule-based organelles, which are required to form centrosomes, cilia, and flagella in many eukaryotes. Centriole architecture is largely conserved across most organisms, however, individual centriolar features such as the central cartwheel or microtubule walls exhibit considerable variability when examined with finer resolution. Here, we review the ultrastructural characteristics of centrioles in commonly studied organisms, highlighting the subtle and not-so-subtle differences between specific structural components of these centrioles. Additionally, we survey some non-canonical centriole structures that have been discovered in various species, from the coaxial bicentrioles of protists and lower land plants to the giant irregular centrioles of the fungus gnat Sciara. Finally, we speculate on the functional significance of these differences between centrioles, and the contribution of individual structural elements such as the cartwheel or microtubules towards the stability of centrioles.Centriole structure, cartwheel, triplet microtubules, SAS-6, centrosome.

Inclusion dynamics in PC12 is comparable between amphetamines and MPTP.

PubMed

Gesi, Marco; Lazzeri, Gloria; Ferrucci, Michela; Pellegrini, Antonio; Lenzi, Paola; Ruggieri, Stefano; Fornai, Francesco; Paparelli, Antonio

2006-08-01

In previous studies it was demonstrated that amphetamine derivatives and 1-methyl article-4-phenylpyridinium produce neuronal cell bodies. In the present work, we compared the fine ultrastructure of the intracellular inclusions induced by these different neurotoxic treatments. In particular, we compared the dynamical changes occurring when a mild toxic stimulus acts for different time intervals. For this purpose, we exposed catecholamine-synthesizing PC12 cells to different amphetamine derivatives (methamphetamine and 3,4-methylenedioxymethamphetamine), or 1-methyl-4-phenylpyridinium ion, which represents the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,3,4,6-tetrahydropyridine. Despite inclusions that are elicited by different mechanisms depending on the specific neurotoxin, their ultrastructural features are similar and there is a high parallelism in their temporal evolution. This suggests that formation of inclusions is a multi-step process that might be elicited by different stimuli and, once triggered, leads to the same final effect.

Phylogeny of the order Choreotrichida (Ciliophora, Spirotricha, Oligotrichea) as inferred from morphology, ultrastructure, ontogenesis, and SSrRNA gene sequences

PubMed Central

Agatha, Sabine; Strüder-Kypke, Michaela C.

2010-01-01

The phylogeny within the order Choreotrichida is reconstructed using (i) morphologic, ontogenetic, and ultrastructural evidence for the cladistic approach and (ii) the small subunit ribosomal RNA (SSrRNA) gene sequences, including the new sequence of Rimostrombidium lacustris. The morphologic cladograms and the gene trees converge rather well for the Choreotrichida, demonstrating that hyaline and agglutinated loricae do not characterize distinct lineages, i.e., both lorica types can be associated with the most highly developed ciliary pattern. The position of Rimostrombidium lacustris within the family Strobilidiidae is corroborated by the genealogical analyses. The diagnosis of the genus Tintinnidium is improved, adding cytological features, and the genus is divided into two subgenera based on the structure of the somatic kineties. The diagnosis of the family Lohmanniellidae and the genus Lohmanniella are improved, and Rimostrombidium glacicolum​ Petz, Song and Wilbert, 1995 is affiliated. PMID:17166704

Ultra-structural study of insulin granules in pancreatic β-cells of db/db mouse by scanning transmission electron microscopy tomography.

PubMed

Xue, Yanhong; Zhao, Wei; Du, Wen; Zhang, Xiang; Ji, Gang; Ying, Wang; Xu, Tao

2012-07-01

Insulin granule trafficking is a key step in the secretion of glucose-stimulated insulin from pancreatic β-cells. The main feature of type 2 diabetes (T2D) is the failure of pancreatic β-cells to secrete sufficient amounts of insulin to maintain normal blood glucose levels. In this work, we developed and applied tomography based on scanning transmission electron microscopy (STEM) to image intact insulin granules in the β-cells of mouse pancreatic islets. Using three-dimensional (3D) reconstruction, we found decreases in both the number and the grey level of insulin granules in db/db mouse pancreatic β-cells. Moreover, insulin granules were closer to the plasma membrane in diabetic β-cells than in control cells. Thus, 3D ultra-structural tomography may provide new insights into the pathology of insulin secretion in T2D.

Ultrastructural characterisation of the olfactory mucosa of the armadillo Dasypus hybridus (Dasypodidae, Xenarthra)

PubMed Central

FERRARI, C. C.; CARMANCHAHI, P. D.; ALDANA MARCOS, H. J.; AFFANNI, J. M.

2000-01-01

The ultrastructure of the olfactory mucosa of the armadillo Dasypus hybridus was studied. A comparison with the olfactory mucosa of another armadillo (Chaetophractus villosus) was made. The olfactory mucosa of D. hybridus shows many features which are similar to those of other mammals. Interestingly, it differs from the olfactory mucosa of the armadillo C. villosus. A suggestion is made that these differences may be due to differences in the digging habits of these species. In Dasypus, the supporting cells (SCs) showed dense vacuoles, multivesicular bodies and lysosome-like bodies probably related with the endocytotic system. The SCs show a dense network of SER presumably associated with xenobiotic mechanisms. The olfactory receptor neurons exhibit lysosome-like bodies and multivesicular bodies in their perikarya. These organelles suggest the presence of an endocytotic system. Duct cells of Bowman's glands exhibit secretory activities. Bowman's glands are compound-branched tubulo-acinar mixed glands with merocrine secretory mechanisms. PMID:10739023

Evolution of complexity in the zebrafish synapse proteome

PubMed Central

Bayés, Àlex; Collins, Mark O.; Reig-Viader, Rita; Gou, Gemma; Goulding, David; Izquierdo, Abril; Choudhary, Jyoti S.; Emes, Richard D.; Grant, Seth G. N.

2017-01-01

The proteome of human brain synapses is highly complex and is mutated in over 130 diseases. This complexity arose from two whole-genome duplications early in the vertebrate lineage. Zebrafish are used in modelling human diseases; however, its synapse proteome is uncharacterized, and whether the teleost-specific genome duplication (TSGD) influenced complexity is unknown. We report the characterization of the proteomes and ultrastructure of central synapses in zebrafish and analyse the importance of the TSGD. While the TSGD increases overall synapse proteome complexity, the postsynaptic density (PSD) proteome of zebrafish has lower complexity than mammals. A highly conserved set of ∼1,000 proteins is shared across vertebrates. PSD ultrastructural features are also conserved. Lineage-specific proteome differences indicate that vertebrate species evolved distinct synapse types and functions. The data sets are a resource for a wide range of studies and have important implications for the use of zebrafish in modelling human synaptic diseases. PMID:28252024

Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution

NASA Astrophysics Data System (ADS)

Joens, Matthew S.; Huynh, Chuong; Kasuboski, James M.; Ferranti, David; Sigal, Yury J.; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J.; Curran, Kevin P.; Chalasani, Sreekanth H.; Stern, Lewis A.; Goetze, Bernhard; Fitzpatrick, James A. J.

2013-12-01

Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution.

PubMed

Joens, Matthew S; Huynh, Chuong; Kasuboski, James M; Ferranti, David; Sigal, Yury J; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J; Curran, Kevin P; Chalasani, Sreekanth H; Stern, Lewis A; Goetze, Bernhard; Fitzpatrick, James A J

2013-12-17

Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

Ultrastructural Complexity of Nuclear Components During Early Apoptotic Phases in Breast Cancer Cells

PubMed Central

Castelli, Christian; Losa, Gabriele A.

2001-01-01

Fractal morphometry was used to investigate the ultrastructural features of the plasma membrane, perinuclear membrane and nuclear chromatin in SK‐BR‐3 human breast cancer cells undergoing apoptosis. Cells were incubated with 1 μM calcimycin (A23187) for 24 h. Cells in the early stage of apoptosis had fractal dimension (FD) values indicating that their plasma membranes were less rough (lower FD) than those of control cells, while their perinuclear membranes were unaffected. Changes of the chromatin texture within the entire nucleus and in selected nuclear domains were more pronounced in treated cells. This confirms that the morphological reorganization imputable to a loss of structural complexity (reduced FD) occurs in the early stage of apoptosis, is accompanied by the inhibition of distinct enzymatic events and precedes the onset of conventional cellular markers, which can only be detected during the active phases of the apoptotic process. PMID:11790854

Midbody Accumulation in Breast Cancer Stem Cells

DTIC Science & Technology

2011-08-01

transit amplifying or differentiating cells. These results suggest that MBds are in almost exclusively in stem cells and putative breast cancer stem...confer tumor-like properties to these cells. We were unable to establish GFP-MKLP1 breast cancer cell lines for this analysis for some reason that we...and nonpolarized cells (Fig. 1c, d). Immuno- electron microscopy confirmed this localization and revealed ultrastructural features characteristic of

Structure and Ultrastructure of the Endodermal Region of the Alimentary Tract in the Freshwater Shrimp Neocaridina heteropoda (Crustacea, Malacostraca)

PubMed Central

Sonakowska, Lidia; Włodarczyk, Agnieszka; Poprawa, Izabela; Binkowski, Marcin; Śróbka, Joanna; Kamińska, Karolina; Kszuk-Jendrysik, Michalina; Chajec, Łukasz; Zajusz, Bartłomiej; Rost-Roszkowska, Magdalena Maria

2015-01-01

The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones – proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished – D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas – F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea. PMID:25996951

Retinal adaptation to dim light vision in spectacled caimans (Caiman crocodilus fuscus): Analysis of retinal ultrastructure.

PubMed

Karl, Anett; Agte, Silke; Zayas-Santiago, Astrid; Makarov, Felix N; Rivera, Yomarie; Benedikt, Jan; Francke, Mike; Reichenbach, Andreas; Skatchkov, Serguei N; Bringmann, Andreas

2018-05-19

It has been shown that mammalian retinal glial (Müller) cells act as living optical fibers that guide the light through the retinal tissue to the photoreceptor cells (Agte et al., 2011; Franze et al., 2007). However, for nonmammalian species it is unclear whether Müller cells also improve the transretinal light transmission. Furthermore, for nonmammalian species there is a lack of ultrastructural data of the retinal cells, which, in general, delivers fundamental information of the retinal function, i.e. the vision of the species. A detailed study of the cellular ultrastructure provides a basic approach of the research. Thus, the aim of the present study was to investigate the retina of the spectacled caimans at electron and light microscopical levels to describe the structural features. For electron microscopy, we used a superfast microwave fixation procedure in order to achieve more precise ultrastructural information than common fixation techniques. As result, our detailed ultrastructural study of all retinal parts shows structural features which strongly indicate that the caiman retina is adapted to dim light and night vision. Various structural characteristics of Müller cells suppose that the Müller cell may increase the light intensity along the path of light through the neuroretina and, thus, increase the sensitivity of the scotopic vision of spectacled caimans. Müller cells traverse the whole thickness of the neuroretina and thus may guide the light from the inner retinal surface to the photoreceptor cell perikarya and the Müller cell microvilli between the photoreceptor segments. Thick Müller cell trunks/processes traverse the layers which contain light-scattering structures, i.e., nerve fibers and synapses. Large Müller cell somata run through the inner nuclear layer and contain flattened, elongated Müller cell nuclei which are arranged along the light path and, thus, may reduce the loss of the light intensity along the retinal light path. The oblique arrangement of many Müller cell trunks/processes in the inner plexiform layer and the large Müller cell somata in the inner nuclear layer may suggest that light guidance through Müller cells increases the visual sensitivity. Furthermore, an adaptation of the caiman retina to low light levels is strongly supported by detailed ultrastructural data of other retinal parts, e.g. by (i) the presence of a guanine-based retinal tapetum, (ii) the rod dominance of the retina, (iii) the presence of photoreceptor cell nuclei, which penetrate the outer limiting membrane, (iv) the relatively low densities of photoreceptor and neuronal cells which is compensated by (v) the presence of rods with long and thick outer segments, that may increase the probability of photon absorption. According to a cell number analysis, the central and temporal areas of the dorsal tapetal retina, which supports downward prey detection in darker water, are the sites of the highest diurnal contrast/color vision, i.e. cone vision and of the highest retinal light sensitivity, i.e. rod vision. Copyright © 2018 Elsevier Ltd. All rights reserved.

Animal models for treatment of unresectable liver tumours: a histopathologic and ultra-structural study of cellular toxic changes after electrochemical treatment in rat and dog liver.

PubMed

von Euler, Henrik; Olsson, Jerker M; Hultenby, Kjell; Thörne, Anders; Lagerstedt, Anne-Sofie

2003-04-01

Electrochemical treatment (EChT) has been taken under serious consideration as being one of several techniques for local treatment of malignancies. The advantage of EChT is the minimal invasive approach and the absence of serious side effects. Macroscopic, histopathological and ultra-structural findings in liver following a four-electrode configuration (dog) and a two-electrode EChT design (dog and rat) were studied. 30 female Sprague-Dawley rats and four female beagle dogs were studied with EChT using Platinum:Iridium electrodes and the delivered dose was 5, 10 or 90 C (As). After EChT, the animals were euthanized. The distribution of the lesions was predictable, irrespective of dose and electrode configuration. Destruction volumes were found to fit into a logarithmic curve (dose-response). Histopathological examination confirmed a spherical (rat) and cylindrical/ellipsoidal (dog) lesion. The type of necrosis differed due to electrode polarity. Ultra-structural analysis showed distinct features of cell damage depending on the distance from the electrode. Histopathological and ultra-structural examination demonstrated that the liver tissue close to the border of the lesion displayed a normal morphology. The in vivo dose-planning model is reliable, even in species with larger tissue mass such as dogs. A multi-electrode EChT-design could obtain predictable lesions. The cellular toxicity following EChT is clearly identified and varies with the distance from the electrode and polarity. The distinct border between the lesion and normal tissue suggests that EChT in a clinical setting for the treatment of liver tumours can give a reliable destruction margin.

Myofibroblasts in interstitial lung diseases show diverse electron microscopic and invasive features.

PubMed

Karvonen, Henna M; Lehtonen, Siri T; Sormunen, Raija T; Harju, Terttu H; Lappi-Blanco, Elisa; Bloigu, Risto S; Kaarteenaho, Riitta L

2012-09-01

The characteristic features of myofibroblasts in various lung disorders are poorly understood. We have evaluated the ultrastructure and invasive capacities of myofibroblasts cultured from small volumes of diagnostic bronchoalveolar lavage (BAL) fluid samples from patients with different types of lung diseases. Cells were cultured from samples of BAL fluid collected from 51 patients that had undergone bronchoscopy and BAL for diagnostic purposes. The cells were visualized by transmission electron microscopy and immunoelectron microscopy to achieve ultrastructural localization of alpha-smooth muscle actin (α-SMA) and fibronectin. The levels of α-SMA protein and mRNA and fibronectin mRNA were measured by western blot and quantitative real-time reverse transcriptase polymerase chain reaction. The invasive capacities of the cells were evaluated. The cultured cells were either fibroblasts or myofibroblasts. The structure of the fibronexus, and the amounts of intracellular actin, extracellular fibronectin and cell junctions of myofibroblasts varied in different diseases. In electron and immunoelectron microscopy, cells cultured from interstitial lung diseases (ILDs) expressed more actin filaments and α-SMA than normal lung. The invasive capacity of the cells obtained from patients with idiopathic pulmonary fibrosis was higher than that from patients with other type of ILDs. Cells expressing more actin filaments had a higher invasion capacity. It is concluded that electron and immunoelectron microscopic studies of myofibroblasts can reveal differential features in various diseases. An analysis of myofibroblasts cultured from diagnostic BAL fluid samples may represent a new kind of tool for diagnostics and research into lung diseases.

Numerical simulation of colloidal self-assembly of super-hydrophobic arachnid cerotegument structures.

PubMed

Filippov, Alexander É; Wolff, Jonas O; Seiter, Michael; Gorb, Stanislav N

2017-10-07

Certain arachnids exhibit complex coatings of their exoskeleton, consisting of globular structures with complex surface features. This, so-called, cerotegument is formed by a multi-component colloidal secretion that self-assembles and cures on the body surface, and leads to high water repellency. Previous ultrastructural studies revealed the involvement of different glandular cells that contribute different components to the secretion mixture, but the overall process of self-assembly into the complex regular structures observed remained highly unclear. Here we study this process from a theoretical point of view, starting from the so-called Tammes-problem. We show that slight changes of simple parameters lead to a variety of morphologies that are highly similar to the ones observed in the species specific cerotegument structures of whip-spiders. These results are not only important for our understanding of the formation of globular hierarchical structures in nature, but also for the fabrication of novel surface coatings by colloidal lithography. Copyright © 2017 Elsevier Ltd. All rights reserved.

The fine structure of the rectal pads of Zorotypus caudelli Karny (Zoraptera, Insecta).

PubMed

Dallai, R; Mercati, D; Mashimo, Y; Machida, R; Beutel, R G

2016-07-01

The rectal pads of a species of the controversial polyneopteran order Zoraptera were examined using histological sections and TEM micrographs. Six pads are present along the thin rectal epithelium. Each pad consists of a few large principal cells surrounded by flattened junctional cells, which extend also beneath the principal cells. The cells are lined by a thin apical cuticle. No basal cells and no cavity have been observed beneath the pad. Principal cells have a regular layer of apical microvilli and are joined by intercellular septate junctions, which are interrupted by short dilatations of the intercellular space. At these levels the two adjacent plasma membranes are joined by short zonulae adhaerentes. In the cytoplasm, a rich system of strict associations between lateral plasma membranes and mitochondria forms scalariform junctions. Rectal pads share ultrastructural features with similar excretory organs of several neopteran groups, in particular with Blattodea (roaches and termites) and Thysanoptera, and are involved in fluid reabsorption and ion regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The frontal gland in workers of Neotropical soldierless termites

NASA Astrophysics Data System (ADS)

Šobotník, Jan; Sillam-Dussès, David; Weyda, František; Dejean, Alain; Roisin, Yves; Hanus, Robert; Bourguignon, Thomas

2010-05-01

The presence of the frontal gland is well established in termite soldiers of Rhinotermitidae, Serritermitidae, and Termitidae. It is one of their main defensive adaptations or even an exclusive weapon. The gland was also occasionally reported in alate imagoes, but never in the worker caste. Here, we report the first observation of a frontal gland in workers of several Neotropical and one African species of Apicotermitinae. The ultrastructure of Aparatermes cingulatus and Anoplotermes nr. subterraneus is described in detail. In these two species, the gland is well-developed, functional and consists of class 1 secretory cells. The presence of envelope cells, wrapping the gland, is an unusual feature, as well as the presence of several zonulae adherens, connecting neighbouring glandular cells. The frontal gland of workers is homologous to this organ in soldiers and imagoes, as evidenced by the same position in the head and its connection to the same muscle. However, the defensive role of the frontal gland in workers remains to be confirmed.

Two ultrastructurally distinct tubulin paracrystals induced in sea-urchin eggs by vinblastine sulphate.

PubMed

Starling, D

1976-01-01

Two types of ultrastructurally distinct tubulin paracrystals have been induced in sea-urchin eggs with vinblastine sulphate (VLB) under different sets of conditions. One type of paracrystal appears to consist of hexagonally-close packed microtubules and closely resembles paracrystals present in mammalian cells treated with vinblastine or vincristine sulphate, but not previously reported in sea-urchin eggs. The other type is also made up of tubulin subunits, but these do not seem to have polymerized into microtubules. Both types of paracrystal are induced in sea-urchin eggs in the presence of VLB at a time when tubulin subunits would not normally polymerize. Possible mechanisms for tubulin activation and the induction of paracrystal formation are discussed in respect to the available information on the binding sites of the tubulin subunits.

Ultrastructural Changes in Livers of Two Patients with Hypervitaminosis A

PubMed Central

Hruban, Zdenek; Russell, Robert M.; Boyer, James L.; Glagov, Seymour; Bagheri, Saeed A.

1974-01-01

The principal distinctive ultrastructural changes observed in the livers of 2 patients with chronic hypervitaminosis A were perisinusoidal fibrosis and massive accumulation of lipid-storing cells (Ito cells). The fibrosis consisted of a network of basement membranes with numerous bundles of collagen and reticulum fibrils. This network contained numerous Ito cells, and moderate numbers of lymphocytes, macrophoges and other mesenchymal cells. Impairment of blood flow by perisinusoidal fibrosis probably resulted in the secondary alterations in hepatocytes which included cellular atrophy and formation of cytoplasmic bullae. ImagesFig 4Fig 5Fig 6Fig 16Fig 17Fig 18Fig 19Fig 7Fig 8Fig 9Fig 10Fig 11Fig 1Fig 2Fig 3Fig 12Fig 13Fig 14Fig 15 PMID:4416771

Reproductive biology in Anophelinae mosquitoes (Diptera, Culicidae): Fine structure of the female accessory gland.

PubMed

Laghezza Masci, Valentina; Di Luca, Marco; Gambellini, Gabriella; Taddei, Anna Rita; Belardinelli, Maria Cristina; Guerra, Laura; Mazzini, Massimo; Fausto, Anna Maria

2015-07-01

The morphology and ultrastructure of female accessory reproductive glands of Anopheles maculipennis s.s., Anopheles labranchiae and Anopheles stephensi were investigated by light and electron microscopy. The reproductive system in these species is characterized by two ovaries, two lateral oviducts, a single spermatheca and a single accessory gland. The gland is globular and has a thin duct which empties into the vagina, near the opening of the spermathecal duct. Significant growth of the accessory reproductive gland is observed immediately after blood meal, but not at subsequent digestion steps. At ultrastructural level, the gland consists of functional glandular units belonging to type 3 ectodermal glands. The secretory cells are elongated and goblet shaped, with most of their cytoplasm and large nucleus in the basal part, close to the basement lamella. Finely fibrous electron-transparent material occupies the secretory cavity that is in contact with the end of a short efferent duct (ductule) emerging from the gland duct. The present study is the first detailed description of female accessory gland ultrastructure in Anophelinae and provides insights into the gland's functional role in the reproductive biology of these insects. Copyright © 2015 Elsevier Ltd. All rights reserved.

[The effect of 18β-glycyrrhetinic acid on tight junctions of the nasal mucosa epithelial cells in rat models with allergic rhinitis].

PubMed

Ma, Yi; Gui, Yan; Wang, Youhu; Xi, Kehu; Chen, Xiaowan; Zhang, Fuhong; Ma, Chunxia; Hong, Hao; Liu, Xiangyi; Jiang, Ying; Dong, Ming; Yang, Guijun; Zhang, Xiaobing

2014-10-01

To observe 18β-glycyrrhetinic acid (GA) impact on ultrastructure of tight junctions (TJs) of nasal mucosa epithelial cells in rats models of allergic rhinitis (AR). Ninety-six Wistar rats were randomly divided into control group, model group, loratadine group, and 18β-glycyrrhetinic acid group, and each group had 24 rats. Ovalbumin was used to establish a rat AR model. The behavioral changes and the tight junctions of nasal epithelial were observed and compared in different groups after 2,4,6 and 10 weeks intervention. The length of TJs in allergic rhinitis model became shorter, electron-high-density plasma membrane became thicker, number of the integration loci reduced and gap of TJs widened or even ruptured. With the consistent effect of allergens,the changes of TJs in the model group aggravated gradually,and the changes of ultrastructure of TJs in 18β-glycyrrhetinic acid group was relieved apparently compared to model group and even were close to the control model with time. 18β-glycyrrhetinic acid can recover the ultrastructure of the tight junctions of AR rat nasal epithelial cells.

Renal pathophysiologic role of cortical tubular inclusion bodies.

PubMed

Radi, Zaher A; Stewart, Zachary S; Grzemski, Felicity A; Bobrowski, Walter F

2013-01-01

Renal tubular inclusion bodies are rarely associated with drug administration. The authors describe the finding of renal cortical tubular intranuclear and intracytoplasmic inclusion bodies associated with the oral administration of a norepinephrine/serotonin reuptake inhibitor (NSRI) test article in Sprague-Dawley (SD) rats. Rats were given an NSRI daily for 4 weeks, and kidney histopathologic, ultrastructural pathology, and immunohistochemical examinations were performed. Round eosinophilic intranuclear inclusion bodies were observed histologically in the tubular epithelial cells of the renal cortex in male and female SD rats given the NSRI compound. No evidence of degeneration or necrosis was noted in the inclusion-containing renal cells. By ultrastructural pathology, inclusion bodies consisted of finely granular, amorphous, and uniformly stained nonmembrane-bound material. By immunohistochemistry, inclusion bodies stained positive for d-amino acid oxidase (DAO) protein. In addition, similar inclusion bodies were noted in the cytoplasmic tubular epithelial compartment by ultrastructural and immunohistochemical examination.  This is the first description of these renal inclusion bodies after an NSRI test article administration in SD rats. Such drug-induced renal inclusion bodies are rat-specific, do not represent an expression of nephrotoxicity, represent altered metabolism of d-amino acids, and are not relevant to human safety risk assessment.

Dietary adaptions in the ultrastructure of dinosaur dentine.

PubMed

Brink, Kirstin S; Chen, Yu-Cheng; Wu, Ya-Na; Liu, Wei-Min; Shieh, Dar-Bin; Huang, Timothy D; Sun, Chi-Kuang; Reisz, Robert R

2016-12-01

Teeth are key to understanding the feeding ecology of both extant and extinct vertebrates. Recent studies have highlighted the previously unrecognized complexity of dinosaur dentitions and how specific tooth tissues and tooth shapes differ between taxa with different diets. However, it is unknown how the ultrastructure of these tooth tissues contributes to the differences in feeding style between taxa. In this study, we use third harmonic generation microscopy and scanning electron microscopy to examine the ultrastructure of the dentine in herbivorous and carnivorous dinosaurs to understand how the structure of this tissue contributes to the overall utility of the tooth. Morphometric analyses of dentinal tubule diameter, density and branching rates reveal a strong signal for dietary preferences, with herbivorous saurischian and ornithischian dinosaurs consistently having higher dentinal tubule density than their carnivorous relatives. We hypothesize that this relates to the hardness of the dentine, where herbivorous taxa have dentine that is more resistant to breakage and wear at the dentine-enamel junction than carnivorous taxa. This study advocates the detailed study of dentine and the use of advanced microscopy techniques to understand the evolution of dentition and feeding ecology in extinct vertebrates. © 2016 The Author(s).

Subconjunctival mitomycin C before pterygium excision: an ultrastructural study.

PubMed

Chang, Yi-Sheng; Chen, Wen-Chung; Tseng, Sung-Huei; Sze, Chun-I; Wu, Chao-Liang

2008-05-01

Subconjunctival injection of mitomycin C (MMC) before pterygium excision is a new adjunctive therapy to decrease pterygium recurrence. This study aimed to investigate the ultrastructural changes in pterygium after subconjunctival injection of MMC. Four patients underwent subconjunctival injection of 0.1 mL of 0.15 mg/mL MMC 1 month before pterygium excision, and 2 patients served as controls without preoperative MMC injection. The excised specimens of pterygium were examined under transmission electron microscopy. Epithelial cells of the treated pterygium remained unchanged. However, stromal fibroblasts were decreased in number, were oval rather than spindle-shaped, and had shrunken cytoplasmic processes; some were degenerating or apoptotic. Collagen and elastic fibers were decreased in density, disorganized, and degenerated. Capillary endothelial cells were thickened and swollen, with narrow or obliterated lumens. Axonal swelling and demyelination were observed. Subconjunctival injection of MMC inhibits fibrovascular activity in the pterygial stroma, leading to degeneration of the extracellular matrix and nerve axons. These ultrastructural changes are consistent with the clinical observation of reduced vascularity in the pterygium after MMC injection and verify the effectiveness of subconjunctival MMC injection 1 month before pterygium excision in decreasing the risk of pterygium recurrence.

Morphologic characterization of specific granules in Greyhound eosinophils.

PubMed

Iazbik, M C; Couto, C G

2005-06-01

"Vacuolated" eosinophils (ie, eosinophils with empty, nonstaining granules) have been described previously in normal Greyhounds. However, to our knowledge, detailed studies of granules in vacuolated and normal eosinophils in this breed have not been performed. The objective of this prospective study was to characterize some of the morphologic, ultrastructural, and cytochemical staining features of specific (primary) granules in both normal and vacuolated eosinophils in Greyhound blood. Morphologic features of eosinophils in Wright's- and Diff-Quik-stained peripheral blood smears from 49 Greyhounds were compared with 200 blood smears from non-Greyhound dogs. Transmission electron microscopy was done on blood from 3 Greyhounds with vacuolated eosinophils and 3 with normal eosinophil granules. Blood smears from 4 of these dogs also were stained cytochemically with alkaline phosphatase (AP), chloracetate esterase (CAE), and alpha naphthyl butyrate esterase (ANBE). The morphologic features and tinctorial properties of vacuolated and normal eosinophils were compared. Twenty-six Greyhounds (53%) had vacuolated eosinophils and 23 (47%) had normal granulated eosinophils in smears stained with Wright's stain. Only 1% of eosinophils were vacuolated in non-Greyhound dogs. Twenty of the 23 (85%) Greyhounds with normal granulated eosinophils on Wright's-stained smears had vacuolated eosinophils in smears stained with Diff-Quik. Ultrastructurally, no morphologic differences were observed between granules of vacuolated and normal eosinophils. Both vacuolated and normal eosinophils in Greyhounds were positive for AP and negative for CAE and ANBE, as expected for normal dogs. Vacuolated eosinophils in Greyhounds likely reflect, at least in part, differential staining properties of the specific granules with different hematologic stains. Ultrastuctural and cytochemical features of eosinophil granules were similar in normal and vacuolated eosinophils from Greyhounds.

A Combination Histochemical and Autoradiographic Method for Analysis of Enzymatic and Proliferative Responses to Immunoreactive Osteoinducer

DTIC Science & Technology

1988-01-15

DNA replication and alkaline phosphate activity in the responding cells was shown to result in effective differential labeling of these features in mildly fixed tissue sections. Application of this method with monoclonal antibodies specific for induction-associated determinants and with modifications to permit ultrastructural analyses may provide important information relevant to the mechanism of matrix-induced bone formation. Keywords: Osteogenic implants; Immunohistochemistry;

Improved Serial Sectioning Techniques for Correlative Light-Electron Microscopy Mapping of Human Langerhans Islets

PubMed Central

Saitoh, Sei; Ohno, Nobuhiko; Saitoh, Yurika; Terada, Nobuo; Shimo, Satoshi; Aida, Kaoru; Fujii, Hideki; Kobayashi, Tetsuro; Ohno, Shinichi

2018-01-01

Combined analysis of immunostaining for various biological molecules coupled with investigations of ultrastructural features of individual cells is a powerful approach for studies of cellular functions in normal and pathological conditions. However, weak antigenicity of tissues fixed by conventional methods poses a problem for immunoassays. This study introduces a method of correlative light and electron microscopy imaging of the same endocrine cells of compact and diffuse islets from human pancreatic tissue specimens. The method utilizes serial sections obtained from Epon-embedded specimens fixed with glutaraldehyde and osmium tetroxide. Double-immunofluorescence staining of thick Epon sections for endocrine hormones (insulin and glucagon) and regenerating islet-derived gene 1 α (REG1α) was performed following the removal of Epoxy resin with sodium ethoxide, antigen retrieval by autoclaving, and de-osmification treatment with hydrogen peroxide. The immunofluorescence images of endocrine cells were superimposed with the electron microscopy images of the same cells obtained from serial ultrathin sections. Immunofluorescence images showed well-preserved secretory granules in endocrine cells, whereas electron microscopy observations demonstrated corresponding secretory granules and intracellular organelles in the same cells. In conclusion, the correlative imaging approach developed by us may be useful for examining ultrastructural features in combination with immunolocalisation of endocrine hormones in the same human pancreatic islets. PMID:29622846

Ultrastructural aspects of spermatogenesis, testes, and vas deferens in the parthenogenetic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), a carp parasite from Slovakia.

PubMed

Bruňanská, Magdaléna; Nebesářová, Jana; Oros, Mikuláš

2011-01-01

Spermatogenesis, testes, and vas deferens in the parthenogenetic monozoic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea) from Slovakia, parasitizing the carp Cyprinus carpio L., have been investigated by means of transmission electron microscopy for the first time. The present results show that helminths with parthenogenetic and normal reproduction may share some common spermatology features, e.g., dense cytoplasm of the peripherally localized spermatogonia or a rosette type of spermatogenesis. In contrast to tapeworms with normal reproduction, the most prominent ultrastructural characteristic of the spermatocytes of A. huronensis is fragmentation of their nuclei. This clear feature of cell degeneration might be a consequence of the aberrant first meiotic division. Peripheral cortical microtubules and a single centriole, indicators of the ongoing spermiogenesis, were observed only very rarely in the early spermatids. Characteristics of normal spermiogenesis, i.e., apical dense material in the zone of differentiation in early stages of spermiogenesis, flagellar rotation, and proximo-distal fusion, were never found in the present study. The testes follicles are surrounded by a thin cytoplasmic sheath underlined by a basal lamina. Vas deferens is lined by flat epithelium with numerous surface lamellae and cilia. Mature, functional spermatozoa were not observed in the vas deferens of A. huronensis from Slovakia.

Ultrastructure of spermatogenesis in the sea star, Asterina minor.

PubMed

Yamagata, A

1988-02-01

The ultrastructural features of spermatogenesis were investigated in the hermaphroditic sea star Asterina minor. The primordial germ cells in the genital rachis contain small clusters of electron-dense material (nuage material) and a stack of annulate lamellae. They also have a flagellum and basal body complex situated close to the Golgi complex. After the development of the genital rachis into the ovotestis, spermatogenic cells increase in number and differentiation begins. Nuage material is observed in spermatogonia, but it gradually disappears in spermatocytes. The annulate lamellae do not exist beyond the early spermatogonial stage. By contrast, a flagellum and basal body complex are found throughout spermatogenesis. The Golgi-derived proacrosomal vesicles appear in the spermatocyte and coalesce to form an acrosomal vesicle in the early spermatid. The process of acrosome formation is as follows: (1) a lamella of endoplasmic reticulum (ER) continuous with the outer nuclear membrane encloses the posterior portion of the acrosomal vesicle; (2) the vesicle attaches to the cell membrane with its anterior portion; (3) periacrosomal material accumulates in the space between the acrosomal vesicle and the ER; (4) the nucleus proper changes its features to surround the acrosome; (5) amorphous, electron-dense material is deposited under the electron-dense disk; and (6) the nucleus forms a hollow opposite the electron-dense material.

Studies on the cellular and subcellular reactions in epidermis at irritant and allergic dermatitis.

PubMed

Lindberg, M

1982-01-01

To determine the cellular and subcellular reactions of keratinocytes at contact dermatitis, transmission electron microscopy was used in combination with energy dispersive X-ray microanalysis. Stereology and optical diffraction were used as complements to electron microscopy for studies of the effects of variations in the preparation technique on the ultrastructure of epidermis. The morphological effects of an increased hydration of epidermis were assessed by the use of occlusive patch tests. It was found that the relative volume of the epidermal intercellular space and the ultrastructure of the epidermal cells (keratinocytes and Langerhans' cells) were directly dependent on the osmolality of the fixative vehicle if glutaraldehyde was used as fixative. Cellular volume and morphology did also depend on the fixative used. Variations in the volume of the intercellular space were also detected when the water transport through epidermis was impaired by occlusive treatment. In normal epidermis prolonged fixation times (4 weeks) did not affect the morphology of the keratinocytes. However, if the structure and function of the keratinocytes were affected by the application of a irritant substance (DNCB), a loss of electron dense material from the cells was detected within 3 weeks. The ultrastructural changes in the keratinocytes at the irritant chromate and DNCB reactions were of a non-specific nature and are in accordance with the changes described for other irritant agents in the literature. A few cells with the features of apoptosis were recorded. The allergic chromate reaction was found to be a combination of the irritant reaction and a marked inflammatory response. To correlate the ultrastructural alterations in the keratinocytes with the functional state of the cells, X-ray microanalysis was used to determine the elemental redistribution occurring at the irritant DNCB reaction. The results of the X-ray microanalysis showed a good correlation between dose and time dependent effects and with the ultrastructural changes. Cell injury in the keratinocytes lead to decreases in the cellular content of phosphorous, potassium and magnesium and an increase of cellular calcium. Sodium, chloride, and sulphur were only moderately changed. A stimulation of the basal keratinocytes was detectable when a weak DNCB dose was applied to the skin.

Formation of the hindgut cuticular lining during embryonic development of Porcellio scaber (Crustacea, Isopoda)

PubMed Central

Mrak, Polona; Bogataj, Urban; Štrus, Jasna; Žnidaršič, Nada

2015-01-01

Abstract The hindgut and foregut in terrestrial isopod crustaceans are ectodermal parts of the digestive system and are lined by cuticle, an apical extracellular matrix secreted by epithelial cells. Morphogenesis of the digestive system was reported in previous studies, but differentiation of the gut cuticle was not followed in detail. This study is focused on ultrastructural analyses of hindgut apical matrices and cuticle in selected intramarsupial developmental stages of the terrestrial isopod Porcellio scaber in comparison to adult animals to obtain data on the hindgut cuticular lining differentiation. Our results show that in late embryos of stages 16 and 18 the apical matrix in the hindgut consists of loose material overlaid by a thin intensely ruffled electron dense lamina facing the lumen. The ultrastructural resemblance to the embryonic epidermal matrices described in several arthropods suggests a common principle in chitinous matrix differentiation. The hindgut matrix in the prehatching embryo of stage 19 shows characteristics of the hindgut cuticle, specifically alignment to the apical epithelial surface and a prominent electron dense layer of epicuticle. In the preceding embryonic stage – stage 18 – an electron dense lamina, closely apposed to the apical cell membrane, is evident and is considered as the first epicuticle formation. In marsupial mancae the advanced features of the hindgut cuticle and epithelium are evident: a more prominent epicuticular layer, formation of cuticular spines and an extensive apical labyrinth. In comparison to the hindgut cuticle of adults, the hindgut cuticle of marsupial manca and in particular the electron dense epicuticular layer are much thinner and the difference between cuticle architecture in the anterior chamber and in the papillate region is not yet distinguishable. Differences from the hindgut cuticle in adults imply not fully developed structure and function of the hindgut cuticle in marsupial manca, possibly related also to different environments, as mancae develop in marsupial fluid. Bacteria, evenly distributed within the homogenous electron dense material in the hindgut lumen, were observed only in one specimen of early marsupial manca. The morphological features of gut cuticle renewal are evident in the late marsupial mancae, and are similar to those observed in the exoskeleton. PMID:26261443

Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography.

PubMed

McBride, E L; Rao, A; Zhang, G; Hoyne, J D; Calco, G N; Kuo, B C; He, Q; Prince, A A; Pokrovskaya, I D; Storrie, B; Sousa, A A; Aronova, M A; Leapman, R D

2018-06-01

Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach. Copyright © 2018. Published by Elsevier Inc.

Neuronal nitric oxide synthase immunopositive neurons in cat claustrum--a light and electron microscopic study.

PubMed

Hinova-Palova, Dimka; Edelstein, Lawrence; Paloff, Adrian; Hristov, Stanislav; Papantchev, Vassil; Ovtscharoff, Wladimir

2008-08-01

Nitric oxide is a unique neurotransmitter, which participates in many physiological and pathological processes in the organism. Nevertheless there are little data about the neuronal Nitric Oxide Synthase immunoreactive (nNOS-ir) neurons and fibers in the dorsal claustrum (DC) of a cat. In this respect the aims of this study were: (1) to demonstrate nNOS-ir in the neurons and fibers of the DC; (2) to describe their light microscopic morphology and distribution; (3) to investigate and analyze the ultrastructure of the nNOS-ir neurons, fibers and synaptic terminals; (4) to verify whether the nNOS-ir neurons consist a specific subpopulation of claustral neurons; (5) to verify whether the nNOS-ir neurons have a specific pattern of organization throughout the DC. For demonstration of the nNOS-ir the Avidin-Biotin-Peroxidase Complex method was applied. Immunopositive for nNOS neurons and fibers were present in all parts of DC. On the light microscope level nNOS-ir neurons were different in shape and size. According to the latter they were divided into three groups-small (with diameter under 15 microm), medium-sized (with diameter from 16 to 20 microm) and large (with diameter over 21 microm). Some of nNOS-ir neurons were lightly-stained while others were darkly-stained. On the electron microscope level the immunoproduct was observed in neurons, dendrites and terminal boutons. Different types of nNOS-ir neurons differ according to their ultrastructural features. Three types of nNOS-ir synaptic boutons were found. As a conclusion we hope that the present study will contribute to a better understanding of the functioning of the DC in cat and that some of the data presented could be extrapolated to other mammals, including human.

Müller glial cells of the primate foveola: An electron microscopical study.

PubMed

Syrbe, Steffen; Kuhrt, Heidrun; Gärtner, Ulrich; Habermann, Gunnar; Wiedemann, Peter; Bringmann, Andreas; Reichenbach, Andreas

2018-02-01

Previous studies on the ultrastructure of the primate foveola suggested the presence of an inverted cone-like structure which is formed by 25-35 specialized Müller cells overlying the area of high photoreceptor density. We investigated the ultrastructure of the Müller cells in the foveola of a human and macaque retina. Sections through the posterior poles of an eye of a 40 years-old human donor and an eye of an adult cynomolgus monkey (Macaca fascicularis) were investigated with transmission electron microscopy. The foveola consisted of an inner layer (thickness, 5.5-12 μm) which mainly contained somata (including nuclei) and inner processes of Müller cells; this layer overlaid the central Henle fibers and outer nuclear layer. The inner layer contained numerous watery cysts and thin lamelliform and tubular Müller cell processes which spread along the inner limiting membrane (ILM). The cytoplasm of the outer Müller cell processes became increasingly dispersed and electron-lucent in the course towards the outer limiting membrane. The ILM of the foveola was formed by a very thin basal lamina (thickness, <40 nm) while the basal lamina of the parafovea was thick (0.9-1 μm). The data show that there are various conspicuous features of foveolar Müller cells. The numerous thin Müller cell processes below the ILM may smooth the inner surface of the foveola (to minimize image distortion resulting from varying light refraction angles at an uneven retinal surface), create additional barriers to the vitreous cavity (compensating the thinness of the ILM), and provide mechanical stability to the tissue. The decreasing density of the outer process cytoplasm may support the optical function of the foveola. Copyright © 2017. Published by Elsevier Ltd.

New data about the suspensor of succulent angiosperms: Ultrastructure and cytochemical study of the embryo-suspensor of Sempervivum arachnoideum L. and Jovibarba sobolifera (Sims) Opiz.

PubMed

Kozieradzka-Kiszkurno, Małgorzata; Płachno, Bartosz Jan; Bohdanowicz, Jerzy

2012-07-01

The development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells. The basal cell produces haustorial branched invading ovular tissues. The walls of the haustorium and the micropylar part of the basal cell form the wall ingrowths typical for a transfer cells. The ingrowths also partially cover the lateral wall and the chalazal wall separating the basal cell from the other embryo cells. The dense cytoplasm filling the basal cell is rich in: numerous polysomes lying free or covering rough endoplasmic reticulum (RER), active dictyosomes, microtubules, bundles of microfilaments, microbodies, mitochondria, plastids and lipid droplets. Cytochemical tests (including proteins, insoluble polysaccharides and lipids are distributed in the suspensor during different stages of embryo development) showed the presence of high amounts of macromolecules in the suspensor cells, particularly during the globular and heart-shaped phases of embryo development. The protein bodies and lipid droplets are the main storage products in the cells of the embryo-proper. The results of Auramine 0 indicate that a cuticular material is present only on the surface walls of the embryo-proper, but is absent from the suspensor cell wall. The ultrastructural features and cytochemical tests indicate that in the two species - S. arachnoideum and J. sobolifera - the embryo-suspensor is mainly involved in the absorption and transport of metabolites from the ovular tissues to the developing embryo-proper.

Ultrastructure Organization of Human Trabeculae Assessed by 3D sSAXS and Relation to Bone Microarchitecture

PubMed Central

Guizar-Sicairos, Manuel; Gschwend, Oliver; Hangartner, Peter; Bunk, Oliver; Müller, Ralph; Schneider, Philipp

2016-01-01

Although the organization of bone ultrastructure, i.e. the orientation and arrangement of the mineralized collagen fibrils, has been in the focus of research for many years for cortical bone, and many models on the osteonal arrangement have been proposed, limited attention has been paid to trabecular bone ultrastructure. This is surprising because trabeculae play a crucial role for the mechanical strength of several bone sites, including the vertebrae and the femoral head. On this account, we first validated a recently developed method (3D sSAXS or 3D scanning small-angle X-ray scattering) for investigating bone ultrastructure in a quantitative and spatially resolved way, using conventional linearly polarized light microscopy as a gold standard. While both methods are used to analyze thin tissue sections, in contrast to polarized light microscopy, 3D sSAXS has the important advantage that it provides 3D information on the orientation and arrangement of bone ultrastructure. In this first study of its kind, we used 3D sSAXS to investigate the ultrastructural organization of 22 vertebral trabeculae of different alignment, types and sizes, obtained from 4 subjects of different ages. Maps of ultrastructure orientation and arrangement of the trabeculae were retrieved by stacking information from consecutive 20-μm-thick bone sections. The organization of the ultrastructure was analyzed in relation to trabecular microarchitecture obtained from computed tomography and to relevant parameters such as distance to trabecular surface, local curvature or local bone mineralization. We found that (i) ultrastructure organization is similar for all investigated trabeculae independent of their particular characteristics, (ii) bone ultrastructure exhibiting a high degree of orientation was arranged in domains, (iii) highly oriented ultrastructural areas were located closer to the bone surface, (iv) the ultrastructure of the human trabecular bone specimens followed the microarchitecture, being oriented mostly parallel to bone surface, and (v) local surface curvature seems to have an effect on the ultrastructure organization. Further studies that investigate bone ultrastructure orientation and arrangement are needed in order to understand its organization and consequently its relation to bone biology and mechanics. PMID:27547973

Ultrastructural findings in noncompaction prevail with neuromuscular disorders.

PubMed

Finsterer, Josef; Stöllberger, Claudia

2013-01-01

Little is known about the ultrastructural abnormalities of left ventricular hypertrabeculation/noncompaction (LVHT). This literature review aimed to summarize and discuss ultrastructural abnormalities described in LVHT so far. The literature search was conducted via MEDLINE using the search terms 'non-compaction', 'noncompaction', 'left ventricular hypertrabeculation', 'spongy myocardium' in combination with the terms 'ultra-structural', or 'electron microscopy'. Altogether, 11 studies reporting ultrastructural investigations of LVHT were retrieved. In these 11 studies, data on 13 patients with LVHT were presented. Ultrastructural abnormalities found in these study patients were generally nonspecific and included an increase in the number of mitochondria (n = 3), abnormally shaped mitochondria (n = 2), distorted cristae (n = 3), sarcomeric derangement (n = 3), immature cardiomyocytes (n = 1), lipid-like inclusions (n = 1), enlarged interstitial spaces (n = 1), increased interstitial collagen (n = 1), or increased glycogen (n = 1). The morphological abnormalities were most prominent in patients with a neuromuscular disorder like Barth syndrome or mitochondrial myopathy. Only in few patients with LVHT, ultrastructural investigations have been performed so far. Ultrastructural abnormalities in LVHT are nonspecific and most prominent in patients with a neuromuscular disorder. There is a strong need to carry out thorough ultrastructural investigations of LVHT to contribute to the understanding of this still unexplained myocardial abnormality.

Bioabsorption of cadmium, copper and lead by the red macroalga Gelidium floridanum: physiological responses and ultrastructure features.

PubMed

dos Santos, Rodrigo W; Schmidt, Éder C; de L Felix, Marthiellen R; Polo, Luz K; Kreusch, Marianne; Pereira, Debora T; Costa, Giulia B; Simioni, Carmen; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

2014-07-01

Heavy metals, such as lead, copper, cadmium, zinc, and nickel, are among the most common pollutants found in both industrial and urban effluents. High concentrations of these metals cause severe toxic effects, especially to organisms living in the aquatic ecosystem. Cadmium (Cd), lead (Pb) and copper (Cu) are the heavy metals most frequently implicated as environmental contaminants, and they have been shown to affect development, growth, photosynthesis and respiration, and morphological cell organization in seaweeds. This paper aimed to evaluate the effects of 50μM and 100μM of Cd, Pb and Cu on growth rates, photosynthetic pigments, biochemical parameters and ultrastructure in Gelidium floridanum. To accomplish this, apical segments of G. floridanum were individually exposed to the respective heavy metals over a period of 7 days. Plants exposed to Cd, Cu and Pb showed discoloration of thallus pigmentation, chloroplast alteration, especially degeneration of thylakoids, and decrease in photosynthetic pigments, such as chlorophyll a and phycobiliproteins, in samples treated with Cd and Cu. Moreover, cell wall thickness and the volume of plastoglobuli increased. X-ray microanalysis detected Cd, Cu and Pb absorption in the cell wall. The results indicate that Cd, Pb and Cu negatively affect metabolic performance and cell ultrastructure in G. floridanum and that Cu was more toxic than either Pb or Cd. Copyright © 2014 Elsevier Inc. All rights reserved.

Histopathology of Middle East respiratory syndrome coronovirus (MERS-CoV) infection - clinicopathological and ultrastructural study.

PubMed

Alsaad, Khaled O; Hajeer, Ali H; Al Balwi, Mohammed; Al Moaiqel, Mohammed; Al Oudah, Nourah; Al Ajlan, Abdulaziz; AlJohani, Sameera; Alsolamy, Sami; Gmati, Giamal E; Balkhy, Hanan; Al-Jahdali, Hamdan H; Baharoon, Salim A; Arabi, Yaseen M

2018-02-01

The pathogenesis, viral localization and histopathological features of Middle East respiratory syndrome - coronavirus (MERS-CoV) in humans are not described sufficiently. The aims of this study were to explore and define the spectrum of histological and ultrastructural pathological changes affecting various organs in a patient with MERS-CoV infection and represent a base of MERS-CoV histopathology. We analysed the post-mortem histopathological findings and investigated localisation of viral particles in the pulmonary and extrapulmonary tissue by transmission electron microscopic examination in a 33-year-old male patient of T cell lymphoma, who acquired MERS-CoV infection. Tissue needle biopsies were obtained from brain, heart, lung, liver, kidney and skeletal muscle. All samples were collected within 45 min from death to reduce tissue decomposition and artefact. Histopathological examination showed necrotising pneumonia, pulmonary diffuse alveolar damage, acute kidney injury, portal and lobular hepatitis and myositis with muscle atrophic changes. The brain and heart were histologically unremarkable. Ultrastructurally, viral particles were localised in the pneumocytes, pulmonary macrophages, renal proximal tubular epithelial cells and macrophages infiltrating the skeletal muscles. The results highlight the pulmonary and extrapulmonary pathological changes of MERS-CoV infection and provide the first evidence of the viral presence in human renal tissue, which suggests tissue trophism for MERS-CoV in kidney. © 2017 John Wiley & Sons Ltd.

Developmental and Ultrastructural Characterization and Phylogenetic Analysis of Trypanosoma herthameyeri n. sp. of Brazilian Leptodactilydae Frogs.

PubMed

Attias, Márcia; Sato, Lyslaine H; Ferreira, Robson C; Takata, Carmen S A; Campaner, Marta; Camargo, Erney P; Teixeira, Marta M G; de Souza, Wanderley

2016-09-01

We described the phylogenetic affiliation, development in cultures and ultrastructural features of a trypanosome of Leptodacylus chaquensis from the Pantanal biome of Brazil. In the inferred phylogeny, this trypanosome nested into the Anura clade of the basal Aquatic clade of Trypanosoma, but was separate from all known species within this clade. This finding enabled us to describe it as Trypanosoma herthameyeri n. sp., which also infects other Leptodacylus species from the Pantanal and Caatinga biomes. Trypanosoma herthameyeri multiplies as small rounded forms clumped together and evolving into multiple-fission forms and rosettes of epimastigotes released as long forms with long flagella; scarce trypomastigotes and glove-like forms are common in stationary-phase cultures. For the first time, a trypanosome from an amphibian was observed by field emission scanning electron microscopy, revealing a cytostome opening, well-developed flagellar lamella, and many grooves in pumpkin-like forms. Transmission electron microscopy showed highly developed Golgi complexes, relaxed catenation of KDNA, and a rich set of spongiome tubules in a regular parallel arrangement to the flagellar pocket as confirmed by electron tomography. Considering the basal position in the phylogenetic tree, developmental and ultrastructural data of T. herthameyeri are valuable for evolutionary studies of trypanosome architecture and cell biology. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Ultrastructural effects of AAL-toxin TA from the fungus Alternaria alternata on black nightshade (Solanum nigrum L.) leaf discs and correlation with biochemical measures of toxicity.

PubMed

Abbas, H K; Paul, R N; Riley, R T; Tanaka, T; Shier, W T

1998-12-01

Ultrastructural effects of AAL-toxin TA from Alternaria alternata on black nightshade (Solanum, nigrum L.) leaf discs and correlation with biochemical measures of toxicity. In black nightshade (Solanum nigrum L.) leaf discs floating in solutions of AAL-toxin TA (0.01-200 microM) under continuous light at 25 degrees C, electrolyte leakage, chlorophyll loss, autolysis, and photobleaching were observed within 24 h. Electrolyte leakage, measured by the conductivity increase in the culture medium, began after 12 h with 200 microM AAL-toxin T(A), but was observed after 24 h with 0.01 to 50 microM AAL-toxin T(A), when it ranged from 25%) to 63% of total releasable electrolytes, respectively. After 48 h incubation, leakage ranged from 39% to 79% of total for 0.01 to 200 microM AAL-toxin T(A), respectively, while chlorophyll loss ranged from 5% to 32% of total, respectively. Ultrastructural examination of black night-shade leaf discs floating in 10 microM AAL-toxin TA under continuous light at 25 degrees C revealed cytological damage beginning at 30 h, consistent with the time electrolyte leakage and chlorophyll reduction were observed. After 30 h incubation chloroplast starch grains were enlarged in control leaf discs, but not in AAL-toxin T(A)-treated discs, and the thylakoids of treated tissue contained structural abnormalities. After 36-48 h incubation with 10 microM AAL-toxin T(A), all tissues were destroyed with only cell walls, starch grains, and thylakoid fragments remaining. Toxicity was light-dependent, because leaf discs incubated with AAL-toxin T(A) in darkness for up to 72 h showed little phytotoxic damage. Within 6 h of exposure to > or =0.5 microM toxin, phytosphingosine and sphinganine in black nightshade leaf discs increased markedly, and continued to increase up to 24 h exposure. Thus, phy siological and ultrastructural changes occurred in parallel with disruption of sphingolipid synthesis, consistent with the hypothesis that AAL-toxin T(A) causes phytotoxicity by interrupting sphingolipid biosynthesis, thereby damaging cellular membranes.

Light and Electron Microscopy of the European Beaver (Castor fiber) Stomach Reveal Unique Morphological Features with Possible General Biological Significance

PubMed Central

Petryński, Wojciech; Palkowska, Katarzyna; Prusik, Magdalena; Targońska, Krystyna; Giżejewski, Zygmunt; Przybylska-Gornowicz, Barbara

2014-01-01

Anatomical, histological, and ultrastructural studies of the European beaver stomach revealed several unique morphological features. The prominent attribute of its gross morphology was the cardiogastric gland (CGG), located near the oesophageal entrance. Light microscopy showed that the CGG was formed by invaginations of the mucosa into the submucosa, which contained densely packed proper gastric glands comprised primarily of parietal and chief cells. Mucous neck cells represented <0.1% of cells in the CGG gastric glands and 22–32% of cells in the proper gastric glands of the mucosa lining the stomach lumen. These data suggest that chief cells in the CGG develop from undifferentiated cells that migrate through the gastric gland neck rather than from mucous neck cells. Classical chief cell formation (i.e., arising from mucous neck cells) occurred in the mucosa lining the stomach lumen, however. The muscularis around the CGG consisted primarily of skeletal muscle tissue. The cardiac region was rudimentary while the fundus/corpus and pyloric regions were equally developed. Another unusual feature of the beaver stomach was the presence of specific mucus with a thickness up to 950 µm (in frozen, unfixed sections) that coated the mucosa. Our observations suggest that the formation of this mucus is complex and includes the secretory granule accumulation in the cytoplasm of pit cells, the granule aggregation inside cells, and the incorporation of degenerating cells into the mucus. PMID:24727802

Features of natural and gonadotropin-releasing hormone antagonist-induced corpus luteum regression and effects of in vivo human chorionic gonadotropin.

PubMed

Del Canto, Felipe; Sierralta, Walter; Kohen, Paulina; Muñoz, Alex; Strauss, Jerome F; Devoto, Luigi

2007-11-01

The natural process of luteolysis and luteal regression is induced by withdrawal of gonadotropin support. The objectives of this study were: 1) to compare the functional changes and apoptotic features of natural human luteal regression and induced luteal regression; 2) to define the ultrastructural characteristics of the corpus luteum at the time of natural luteal regression and induced luteal regression; and 3) to examine the effect of human chorionic gonadotropin (hCG) on the steroidogenic response and apoptotic markers within the regressing corpus luteum. Twenty-three women with normal menstrual cycles undergoing tubal ligation donated corpus luteum at specific stages in the luteal phase. Some women received a GnRH antagonist prior to collection of corpus luteum, others received an injection of hCG with or without prior treatment with a GnRH antagonist. Main outcome measures were plasma hormone levels and analysis of excised luteal tissue for markers of apoptosis, histology, and ultrastructure. The progesterone and estradiol levels, corpus luteum DNA, and protein contents in induced luteal regression resembled those of natural luteal regression. hCG treatment raised progesterone and estradiol in both natural luteal regression and induced luteal regression. The increase in apoptosis detected in induced luteal regression by cytochrome c in the cytosol, activated caspase-3, and nuclear DNA fragmentation, was similar to that observed in natural luteal regression. The antiapoptotic protein Bcl-2 was significantly lower during natural luteal regression. The proapoptotic proteins Bax and Bak were at a constant level. Apoptotic and nonapoptotic death of luteal cells was observed in natural luteal regression and induced luteal regression at the ultrastructural level. hCG prevented apoptotic cell death, but not autophagy. The low number of apoptotic cells disclosed and the frequent autophagocytic suggest that multiple mechanisms are involved in cell death at luteal regression. hCG restores steroidogenic function and restrains the apoptotic process, but not autophagy.

Differential Structural Plasticity of Corticostriatal and Thalamostriatal Axo-Spinous Synapses in MPTP-Treated Parkinsonian Monkeys

PubMed Central

Villalba, Rosa M.; Smith, Yoland

2011-01-01

Striatal spine loss is a key pathological feature of Parkinson's disease (PD). Knowing that striatal glutamatergic afferents target dendritic spines, these data appear difficult to reconcile with evidence for an increased expression of the vesicular glutamate transporter 1 (vGluT1) in the striatum of PD patients and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys, as well as in some electrophysiological studies showing overactivity of the corticostriatal glutamatergic system in models of parkinsonism. To address the possibility that structural changes in glutamatergic afferents may underlie these discrepancies, we undertook an ultrastructural analysis of vGluT1-positive (i.e., corticostriatal) and vGluT2-positive (i.e., mostly thalamostriatal) axo-spinous glutamatergic synapses using a 3D electron microscopic approach in normal and MPTP-treated monkeys. Three main conclusions can be drawn: 1) spines contacted by vGluT1-containing terminals have larger volume and harbor significantly larger postsynaptic densities (PSDs) than those contacted by vGluT2-immunoreactive boutons; 2) a subset of vGluT2-, but not vGluT1-immunoreactive, terminals display a pattern of multisynaptic connectivity in normal and MPTP-treated monkeys; and 3) VGluT1- and vGluT2-positive axo-spinous synapses undergo ultrastructural changes (larger spine volume, larger PSDs, increased PSD perforations, larger presynaptic terminal) indicative of increased synaptic activity in parkinsonian animals. Furthermore, spines contacted by cortical terminals display an increased volume of their spine apparatus in MPTP-treated monkeys, suggesting an increased protein synthesis at corticostriatal synapses. These findings demonstrate that corticostriatal and thalamostriatal glutamatergic axo-spinous synapses display significantly different ultrastructural features, and that both systems undergo complex morphological changes that could underlie the pathophysiology of corticostriatal and thalamostriatal systems in PD. PMID:21280048

Ultrastructure of preimaginal stages of Piophila megastigmata McAlpine, 1978 (Diptera, Piophilidae): a fly of forensic importance.

PubMed

Paños, A; Arnaldos, M I; García, M D; Ubero-Pascal, N

2013-11-01

Piophila Fallén, 1810 is a genus of small flies composed of two species: Piophila casei (P. casei ) (Linnaeus, 1758), worldwide distributed, and Piophila megastigmata (P. megastigmata ) McAlpine, 1978, recently referred in the Palaearctic Region, from the Iberian Peninsula. Both species share ecological niche and are very interesting for forensic purposes, since they are present in carrion in advance stages of decay and have been found to be related to human corpses. The immature stages of P. megastigmata have ever been described, so this paper gives the ultrastructural morphologies of all preimaginal stages of P. megastigmata studied by light microscopy and scanning electron microscopy (SEM). Particular attention is given to pseudocephalon features—antenna, maxillary palps, facial mask, etc.—cephalopharyngeal skeleton, anterior and posterior spiracles, tegumentary sculpturing, and anal division among others. A comparative analysis of the main distinguishing features is made in order to understand how those features evolve along the developmental process, while larvae II and III are morphologically similar to each other, the larva I shows particular features. Larvae of all stages and pupae are easily distinguishable from other Diptera of forensic importance just based on the presence of trichoid sensilla associated to respiratory slits, instead of peristigmatig tufts, as well as on thewell-known disposition of anal papillae. The shapes of both dorsal edge at the basal part of mouthhook and dorsal bridge of cephalopharyngeal skeleton, and the tegumental ornamentationmay be considered as good features to distinguish the Piophila species, especially for P. megastigmata and P. casei . At the SEM level, shape, number, and arrangement of oral combs, oral ridges, sensilla of maxillary palpus, papillae of anterior spiracle, scales of spiracular field, and posterior spiracles represent good features to distinguish P. megastigmata from P. casei, but further studies will be necessary in West-Paleartic specimens of latter species. The key for identifying third instar larvae of forensically important Piophilidae in the Iberian Peninsula has been updated to include P. megastigmata.

Response of endometrioid ovarian carcinoma in nude mice to the combination of vincristine sulphate and cyclophosphamide.

PubMed

Bjondahl, K; Grönroos, M; Klemi, P; Möttönen, M

1980-01-01

The effect of a combination treatment with vincristine sulphate and cyclophosphamide to endometrioid ovarian carcinoma grown in nude mice hosts was studied by histopathological, ultrastructural and biochemical methods. The first course of treatment had little or no effect. After the second and third courses, however, the growth of the tumors was suppressed as evidenced by increased necrosis and decreased weight of tumors. The total volume of the mitochondria decreased but there was no change in the nucleo-cytoplasmic ratio and other ultrastructural features. In the DNA and RNA contents a decreasing trend was found. No complete remission was observed during the treatment. However, in two treated animals, kept for a longer observation period, the tumors regressed completely and no new tumor growths were found. In the control animals, the tumors grew progressively and the histology was identical to that in the patient. However, the frequency of mitoses was slightly higher in the transplanted tumor than in the primary tumor.

Electron microscopy of vesicular-arbuscular mycorrhizae of yellow poplar. III Host-endophyte interactions during arbuscular development.

PubMed

Kinden, D A; Brown, M F

1975-12-01

Scanning- and transmission-electron microscopy were used to examine developing and mature functional arbuscules in mycorrhizal roots of yellow poplar. Arbuscules developed from intracellular hyphae which branched repeatedly upon penetration into the host cells. Intermediate and late stages of developemnt were characterized by the production of numerous, short, bifurcate hyphae throughout the arbuscule. Mature arbuscules exhibited a coralloid morphology which resulted in a considerable increase in the surface area of the endophyte exposed within the host cells. Distinctive ultrastructural features of arbuscular hyphae included osmiophilic walls, nuclei, abundant cytoplasm, glycogen, and numerous small vacuoles. All arbuscular components were enclosed by host wall material and cytoplasm during development and at maturity. In infected cells, host nuclei were enlarged and the cytoplasm associated with the arbuscular branches typically contained abundant mitochondria, endoplasmic reticulum, and proplastids. Ultrastructural observations suggested that nutrient transfer may be predominantly directed toward the fungal endophyte during arbuscular development and while mature arbuscules remain functional.

The structure and organization of lanceolate mechanosensory complexes at mouse hair follicles

PubMed Central

Li, Lishi; Ginty, David D

2014-01-01

In mouse hairy skin, lanceolate complexes associated with three types of hair follicles, guard, awl/auchene and zigzag, serve as mechanosensory end organs. These structures are formed by unique combinations of low-threshold mechanoreceptors (LTMRs), Aβ RA-LTMRs, Aδ-LTMRs, and C-LTMRs, and their associated terminal Schwann cells (TSCs). In this study, we investigated the organization, ultrastructure, and maintenance of longitudinal lanceolate complexes at each hair follicle subtype. We found that TSC processes at hair follicles are tiled and that individual TSCs host axonal endings of more than one LTMR subtype. Electron microscopic analyses revealed unique ultrastructural features of lanceolate complexes that are proposed to underlie mechanotransduction. Moreover, Schwann cell ablation leads to loss of LTMR terminals at hair follicles while, in contrast, TSCs remain associated with hair follicles following skin denervation in adult mice and, remarkably, become re-associated with newly formed axons, indicating a TSC-dependence of lanceolate complex maintenance and regeneration in adults. DOI: http://dx.doi.org/10.7554/eLife.01901.001 PMID:24569481

Critical Structure for Telescopic Movement of Honey bee (Insecta: Apidae) Abdomen: Folded Intersegmental Membrane

PubMed Central

Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

2016-01-01

The folded intersegmental membrane is a structure that interconnects two adjacent abdominal segments; this structure is distributed in the segments of the honey bee abdomen. The morphology of the folded intersegmental membrane has already been documented. However, the ultrastructure of the intersegmental membrane and its assistive role in the telescopic movements of the honey bee abdomen are poorly understood. To explore the morphology and ultrastructure of the folded intersegmental membrane in the honey bee abdomen, frozen sections were analyzed under a scanning electron microscope. The intersegmental membrane between two adjacent terga has a Z–S configuration that greatly influences the daily physical activities of the honey bee abdomen. The dorsal intersegmental membrane is 2 times thicker than the ventral one, leading to asymmetric abdominal motion. Honey bee abdominal movements were recorded using a high-speed camera and through phase-contrast computed tomography. These movements conformed to the structural features of the folded intersegmental membrane. PMID:27456912

The structure and organization of lanceolate mechanosensory complexes at mouse hair follicles.

PubMed

Li, Lishi; Ginty, David D

2014-02-25

In mouse hairy skin, lanceolate complexes associated with three types of hair follicles, guard, awl/auchene and zigzag, serve as mechanosensory end organs. These structures are formed by unique combinations of low-threshold mechanoreceptors (LTMRs), Aβ RA-LTMRs, Aδ-LTMRs, and C-LTMRs, and their associated terminal Schwann cells (TSCs). In this study, we investigated the organization, ultrastructure, and maintenance of longitudinal lanceolate complexes at each hair follicle subtype. We found that TSC processes at hair follicles are tiled and that individual TSCs host axonal endings of more than one LTMR subtype. Electron microscopic analyses revealed unique ultrastructural features of lanceolate complexes that are proposed to underlie mechanotransduction. Moreover, Schwann cell ablation leads to loss of LTMR terminals at hair follicles while, in contrast, TSCs remain associated with hair follicles following skin denervation in adult mice and, remarkably, become re-associated with newly formed axons, indicating a TSC-dependence of lanceolate complex maintenance and regeneration in adults. DOI: http://dx.doi.org/10.7554/eLife.01901.001.

Ultrastructural observation of the acid-base resistant zone of all-in-one adhesives using three different acid-base challenges.

PubMed

Tsujimoto, Miho; Nikaido, Toru; Inoue, Go; Sadr, Alireza; Tagami, Junji

2010-11-01

The aim of this study was to analyze the ultrastructure of the dentin-adhesive interface using two all-in-one adhesive systems (Clearfil Tri-S Bond, TB; Tokuyama Bond Force, BF) after different acid-base challenges. Three solutions were used as acidic solutions for the acid-base challenges: a demineralizing solution (DS), a phosphoric acid solution (PA), and a hydrochloric acid solution (HCl). After the acid-base challenges, the bonded interfaces were examined by scanning electron microscopy. Thickness of the acid-base resistant zone (ABRZ) created in PA and HCl was thinner than in DS for both adhesive systems. For BF adhesive, an eroded area was observed beneath the ABRZ after immersion in PA and HCl, but not in DS. Conversely for TB adhesive, the eroded area was observed only after immersion in PA. In conclusion, although the ABRZ was observed for both all-in-one adhesive systems, its morphological features were influenced by the ingredients of both the adhesive material and acidic solution.

Ultrastructural study on dynamics of lipid bodies and plastids during ripening of chili pepper fruits.

PubMed

Liu, Lin

2013-03-01

Dynamics of lipid bodies and plastids in chili pepper fruits during ripening were investigated by means of transmission electron microscopy. Mesocarp of chili pepper fruits consists of collenchyma, normal parenchyma, and huge celled parenchyma. In mature green fruits, plastids contain numerous thylakoids that are well organized into grana in collenchyma, a strikingly huge amount of starch and irregularly organized thylakoids in normal parenchyma, and simple tubes rather than thylakoids in huge celled parenchyma. These morphological features suggest that plastids are chloroplasts in collenchyma, chloroamyloplasts in normal parenchyma, proplastids in huge celled parenchyma. As fruits ripen to red, plastids in all cell types convert to chromoplasts and, concomitantly, lipid bodies accumulate in both cytoplasm and chromoplasts. Cytosolic lipid bodies are lined up in a regular layer adjacent to plasma membrane. The cytosolic lipid body consists of a core surrounded by a membrane. The core is comprised of a more electron-dense central part enclosed by a slightly less electron-dense peripheral layer. Plastidial lipid bodies in collenchyma, normal parenchyma, and endodermis initiate as plastoglobuli, which in turn convert to rod-like structures. Therefore, plastidial lipid bodies are more dynamic than cytosolic lipid bodies. Both cytosolic and plastidial lipid bodies contain rich unsaturated lipids. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ultrastructural and Molecular Characterisation of an Heterosporis-Like Microsporidian in Australian Sea Snakes (Hydrophiinae).

PubMed

Gillett, Amber K; Ploeg, Richard; O'Donoghue, Peter J; Chapman, Phoebe A; Webb, Richard I; Flint, Mark; Mills, Paul C

2016-01-01

Four sea snakes (two Hydrophis major, one Hydrophis platurus, one Hydrophis elegans) were found washed ashore on different beaches in the Sunshine Coast region and Fraser Island in Queensland, Australia between 2007-2013. Each snake had multiple granulomas and locally extensive regions of pallor evident in the hypaxial and intercostal musculature along the body. Lesions in two individuals were also associated with vertebral and rib fractures. Histological examination revealed granulomas scattered throughout skeletal muscle, subcutaneous adipose tissue and fractured bone. These were composed of dense aggregates of microsporidian spores surrounded by a mantle of macrophages. Sequences (ssrRNA) were obtained from lesions in three sea snakes and all revealed 99% similarity with Heterosporis anguillarum from the Japanese eel (Anguillarum japonica). However, ultrastructural characteristics of the organism were not consistent with those of previous descriptions. Electron microscopic examination of skeletal muscle revealed large cysts (not xenomas) bound by walls of fibrillar material (Heterosporis-like sporophorocyst walls were not detected). The cysts contained numerous mature microsporidian spores arranged in small clusters, sometimes apparently within sporophorous vesicles. The microspores were monomorphic, oval and measured 2.5-3.0 μm by 1.6-1.8 μm. They contained isofilar polar filaments with 11 (infrequently 9-12) coils arranged in two ranks. This is the first published report of a microsporidian infection in hydrophiid sea snakes. This discovery shows microsporidia with molecular affinities to Heterosporis anguillarum but ultrastructural characters most consistent with the genus Pleistophora (but no hitherto described species). Further studies are required to determine whether the microsporidian presented here belongs to the genus Heterosporis, or to a polymorphic species group as suggested by the recognition of a robust Pleistophora/Heterosporis clade by molecular studies. The gross and histological pathology associated with these infections are described.

Subcutaneous soft tissue sarcoma with rhabdoid features in a dog.

PubMed

Sayama, Ayako; Okado, Keiko; Imaoka, Masako; Yokouchi, Yusuke; Jindo, Toshimasa; Takasaki, Wataru

2014-07-01

A nine-year-old male beagle dog had a white spherical mass in the subcutis of the left lumbar region. Microscopically, spindle to oval cells diffusely proliferated in the fibrous and myxoid stroma. Many neoplastic cells showed rhabdoid features or vacuolated cytoplasm. Immunohistochemically, the neoplastic cells were positive for vimentin and S100 and partly positive for neuron-specific enolase and glial fibrillary acidic protein but were negative for von Willebrand factor, desmin and α-smooth muscle actin. Ultrastructurally, the neoplastic cells had abundant cytoplasmic processes and desmosome-like structures. Cytoplasmic inclusions of rhabdoid-featured cells in HE sections were composed of aggregates of intermediate filaments, and cytoplasmic vacuoles were identified as an invagination of cytoplasm. Although malignant peripheral nerve sheath tumor was suggested according to these results, the present case was diagnosed as a soft tissue sarcoma with rhabdoid features due to a lack of identification of the basal lamina under electron microscopy.

Subcutaneous Soft Tissue Sarcoma with Rhabdoid Features in a Dog

PubMed Central

Sayama, Ayako; Okado, Keiko; Imaoka, Masako; Yokouchi, Yusuke; Jindo, Toshimasa; Takasaki, Wataru

2014-01-01

A nine-year-old male beagle dog had a white spherical mass in the subcutis of the left lumbar region. Microscopically, spindle to oval cells diffusely proliferated in the fibrous and myxoid stroma. Many neoplastic cells showed rhabdoid features or vacuolated cytoplasm. Immunohistochemically, the neoplastic cells were positive for vimentin and S100 and partly positive for neuron-specific enolase and glial fibrillary acidic protein but were negative for von Willebrand factor, desmin and α-smooth muscle actin. Ultrastructurally, the neoplastic cells had abundant cytoplasmic processes and desmosome-like structures. Cytoplasmic inclusions of rhabdoid-featured cells in HE sections were composed of aggregates of intermediate filaments, and cytoplasmic vacuoles were identified as an invagination of cytoplasm. Although malignant peripheral nerve sheath tumor was suggested according to these results, the present case was diagnosed as a soft tissue sarcoma with rhabdoid features due to a lack of identification of the basal lamina under electron microscopy. PMID:25352714

In Vivo Effect of Calcium Hydroxide and Resin-modified Glass Ionomer Cement on Carious Dentin in Young Permanent Molars: An Ultrastructural and Macroscopic Study.

PubMed

Opal, Shireen; Garg, Shalini; Sharma, Deepak; Dhindsa, Abhishek; Jatana, Isha

2017-01-15

The purpose of this study was to evaluate macroscopically and ultrastructurally the effect of calcium hydroxide cement (CH) and resin-modified glass ionomer cement (RMGIC) compared with gutta percha (control) as a lining material on carious dentin after partial caries removal and sealing. Twenty-seven permanent molars with deep carious lesions underwent partial caries removal with the application of CH, RMGIC, or gutta percha (control) and were then sealed for three months. After a partial caries removal and sealing period, the dentin was macroscopically assessed (for color, consistency, and humidity) and further analyzed by scanning electron microscope to assess the ultrastructural changes in dentin (lumen size, mineralization of tubules, occlusion of tubules by cements, and bacterial ingress). The effect of treatment in each group was statistically analyzed. Dentin darkening and hardening were observed after the sealing period in all groups. However, there was no difference in the color after treatment among the three groups. It was observed that RMGIC showed a significant reduction in the size of the lumen compared to CH and the control. Partial caries removal and sealing resulted in dentin hardening, darkening, and dentin remineralization, irrespective of the dentin protection used.

Action of the chemical agent fipronil on the reproductive process of semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae). Ultrastructural evaluation of ovary cells.

PubMed

Oliveira, Patrícia Rosa de; Bechara, Gervásio Henrique; Morales, Maria Aparecida Marin; Mathias, Maria Izabel Camargo

2009-06-01

The ovary of the tick Rhipicephalus sanguineus consists of a wall of epithelial cells and a large number of oocytes in five different developmental stages (I-V), which are attached to the wall by a pedicel. The present study provides ultrastructural information on the effects (dose-response) of the acaricide fipronil (Frontline) on ovaries of semi-engorged females of R. sanguineus, as well as it demonstrates some possible defense mechanisms used by oocytes to protect themselves against this chemical agent. Individuals were divided into four groups. Group I was used as control while groups II, III and IV were treated with fipronil at the concentrations of 1, 5 and 10 ppm, respectively. Fipronil at the concentration of 10 ppm had the strongest effect on the development of oocytes. At this concentration, even oocytes that reached the final developmental stage exhibited damaged cell structures. Moreover, the observation in fipronil-treated R. sanguineus ticks of damaged cellular components such as plasmic membrane, mitochondria and protein granules (due to alteration in the protein synthesis), and cellular defense mechanisms such as increase in the amount of cytoplasmic microtubules and large amounts of digestive vacuoles and myelin figures, were only possible by means of ultrastructure.

Apigenin induced apoptosis in esophageal carcinoma cells by destruction membrane structures.

PubMed

Zhu, Haiyan; Jin, Hua; Pi, Jiang; Bai, Haihua; Yang, Fen; Wu, Chaomin; Jiang, Jinhuan; Cai, Jiye

2016-07-01

Apigenin has shown to have killing effects on some kinds of solid tumor cells. However, the changes in cell membrane induced by apigenin on subcellular- or nanometer-level were still unclear. In this work, human esophageal cancer cells (EC9706 and KYSE150 cells) were employed as cell model to detect the cytotoxicity of apigenin, including cell growth inhibition, apoptosis induction, membrane toxicity, etc. MTT assay showed that apigenin could remarkably inhibit the growth and proliferation in both types of cells. Annexin V/PI-based flow cytometry analysis showed that the cytotoxic effects of apigenin in KYSE150 cells were mainly through early apoptosis induction, while in EC9706 cells, necrosis, and apoptosis were both involved in cell death. The morphological and ultrastructural properties induced by apigenin were investigated at single cellular- or nanometer-level using atomic force microscopy (AFM). Additionally, lactate dehydrogenase (LDH) leakage was measured to assess the changes in membrane permeability. The results indicated that apigenin increased the membrane permeability and caused leakage of LDH, which was consistent with damages on membrane ultrastructure detected by AFM. Therefore, membrane toxicity, including membrane ultrastructure damages and enhanced membrane permeability, played vital roles in apigenin induced human esophageal cancer cell apoptosis. SCANNING 38:322-328, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Ultrastructural Characterization of the Glomerulopathy in Alport Mice by Helium Ion Scanning Microscopy (HIM).

PubMed

Tsuji, Kenji; Suleiman, Hani; Miner, Jeffrey H; Daley, James M; Capen, Diane E; Păunescu, Teodor G; Lu, Hua A Jenny

2017-09-15

The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases. Here we report the application of newly developed helium ion scanning microscopy (HIM) to examine the glomerulopathy in a Col4a3 mutant/Alport syndrome mouse model. Our study revealed unprecedented details of glomerular abnormalities in Col4a3 mutants including distorted podocyte cell bodies and disorganized primary processes. Strikingly, we observed abundant filamentous microprojections arising from podocyte cell bodies and processes, and presence of unique bridging processes that connect the primary processes and foot processes in Alport mice. Furthermore, we detected an altered glomerular endothelium with disrupted sub-endothelial integrity. More importantly, we were able to clearly visualize the complex, three-dimensional podocyte and endothelial interface by HIM. Our study demonstrates that HIM provides nanometer resolution to uncover and rediscover critical ultrastructural characteristics of the glomerulopathy in Col4a3 mutant mice.

Evolutionary Relationship of the Scale-Bearing Kraken (incertae sedis, Monadofilosa, Cercozoa, Rhizaria): Combining Ultrastructure Data and a Two-Gene Phylogeny.

PubMed

Dumack, Kenneth; Mylnikov, Alexander P; Bonkowski, Michael

2017-07-01

The genus Kraken represents a distinct lineage of filose amoebae within the Cercozoa. Currently a single species, Kraken carinae, has been described. SSU rDNA phylogeny showed an affiliation to the Cercomonadida, branching with weak support at its base, close to Paracercomonas, Metabolomonas, and Brevimastigomonas. Light microscopical analyses showed several unique features of the genus Kraken, but ultrastructure data were lacking. In this study, K. carinae has been studied by electron microscopy, these data conjoined with a two-gene phylogeny were used to give more insight into the evolutionary relationship of the genus Kraken within Cercozoa. The data confirmed the absence of flagella, but also showed novel characteristics, such as the presence of extrusomes, osmiophilic bodies, and mitochondria with flat cristae. Surprising was the presence of single-tier scales which are carried by cell outgrowths, much of what is expected of the last common ancestor of the class Imbricatea. The phylogenetic analyses however confirmed previous results, indicating Kraken as a sister group to Paracercomonas in Sarcomonadea with an increased but still low support of 0.98 PP/63 BP. Based on the unique features of Kraken we establish the Krakenidae fam. nov. that we, due to contradictory results in morphology and phylogeny, assign incertae sedis, Monadofilosa. Copyright © 2017 Elsevier GmbH. All rights reserved.

Senescence-associated ultrastructural features of long-term cultures of induced pluripotent stem cells (iPSCs)

PubMed Central

Colasuonno, Fiorella; Borghi, Rossella; Niceforo, Alessia; Muzzi, Maurizio; Bertini, Enrico; Di Giulio, Andrea

2017-01-01

Induced pluripotent stem cells (iPSCs) hold great promise for developing personalized regenerative medicine, however characterization of their biological features is still incomplete. Moreover, changes occurring in long-term cultured iPSCs have been reported, suggesting these as a model of cellular aging. For this reason, we addressed the ultrastructural characterization of iPSCs, with a focus on possible time-dependent changes, involving specific cell compartments. To this aim, we comparatively analysed cultures at different timepoints, by an innovative electron microscopic technology (FIB/SEM). We observed progressive loss of cell-to-cell contacts, associated with increased occurrence of exosomes. Mitochondria gradually increased, while acquiring an elongated shape, with well-developed cristae. Such mitochondrial maturation was accompanied by their turnover, as assessed by the presence of autophagomes (undetectable in young iPSCs), some containing recognizable mitochondria. This finding was especially frequent in middle-aged iPSCs, while being occasional in aged cells, suggesting early autophagic activation followed by a decreased efficiency of the process with culturing time. Accordingly, confocal microscopy showed age-dependent alterations to the expression and distribution of autophagic markers. Interestingly, responsivity to rapamycin, highest in young iPSCs, was almost lost in aged cells. Overall, our results strongly support long-term cultured iPSCs as a model for studying relevant aspects of cellular senescence, involving intercellular communication, energy metabolism, and autophagy. PMID:29064821

CCDC65 Mutation Causes Primary Ciliary Dyskinesia with Normal Ultrastructure and Hyperkinetic Cilia

PubMed Central

Horani, Amjad; Brody, Steven L.; Ferkol, Thomas W.; Shoseyov, David; Wasserman, Mollie G.; Ta-shma, Asaf; Wilson, Kate S.; Bayly, Philip V.; Amirav, Israel; Cohen-Cymberknoh, Malena; Dutcher, Susan K.; Elpeleg, Orly; Kerem, Eitan

2013-01-01

Background Primary ciliary dyskinesia (PCD) is a genetic disorder characterized by impaired ciliary function, leading to chronic sinopulmonary disease. The genetic causes of PCD are still evolving, while the diagnosis is often dependent on finding a ciliary ultrastructural abnormality and immotile cilia. Here we report a novel gene associated with PCD but without ciliary ultrastructural abnormalities evident by transmission electron microscopy, but with dyskinetic cilia beating. Methods Genetic linkage analysis was performed in a family with a PCD subject. Gene expression was studied in Chlamydomonas reinhardtii and human airway epithelial cells, using RNA assays and immunostaining. The phenotypic effects of candidate gene mutations were determined in primary culture human tracheobronchial epithelial cells transduced with gene targeted shRNA sequences. Video-microscopy was used to evaluate cilia motion. Results A single novel mutation in CCDC65, which created a termination codon at position 293, was identified in a subject with typical clinical features of PCD. CCDC65, an orthologue of the Chlamydomonas nexin-dynein regulatory complex protein DRC2, was localized to the cilia of normal nasal epithelial cells but was absent in those from the proband. CCDC65 expression was up-regulated during ciliogenesis in cultured airway epithelial cells, as was DRC2 in C. reinhardtii following deflagellation. Nasal epithelial cells from the affected individual and CCDC65-specific shRNA transduced normal airway epithelial cells had stiff and dyskinetic cilia beating patterns compared to control cells. Moreover, Gas8, a nexin-dynein regulatory complex component previously identified to associate with CCDC65, was absent in airway cells from the PCD subject and CCDC65-silenced cells. Conclusion Mutation in CCDC65, a nexin-dynein regulatory complex member, resulted in a frameshift mutation and PCD. The affected individual had altered cilia beating patterns, and no detectable ultrastructural defects of the ciliary axoneme, emphasizing the role of the nexin-dynein regulatory complex and the limitations of certain methods for PCD diagnosis. PMID:23991085

Long-term sulphur starvation of Arabidopsis thaliana modifies mitochondrial ultrastructure and activity and changes tissue energy and redox status.

PubMed

Ostaszewska, Monika; Juszczuk, Izabela M; Kołodziejek, Izabella; Rychter, Anna M

2014-04-15

Sulphur, as a constituent of amino acids (cysteine and methionine), iron-sulphur clusters, proteins, membrane sulpholipids, glutathione, glucosinolates, coenzymes, and auxin precursors, is essential for plant growth and development. Absence or low sulphur concentration in the soil results in severe growth retardation. Arabidopsis thaliana plants grown hydroponically for nine weeks on Knop nutrient medium without sulphur showed morphological symptoms of sulphur deficiency. The purpose of our study was to investigate changes that mitochondria undergo and the role of the highly branched respiratory chain in survival during sulphur deficiency stress. Ultrastructure analysis of leaf mesophyll cells of sulphur-deficient Arabidopsis showed heterogeneity of mitochondria; some of them were not altered, but the majority had swollen morphology. Dilated mitochondria displayed a lower matrix density and fewer cristae compared to control mitochondria. Disintegration of the inner and outer membranes of some mitochondria from the leaves of sulphur-deficient plants was observed. On the contrary, chloroplast ultrastructure was not affected. Sulphur deficiency changed the respiratory activity of tissues and isolated mitochondria; Complex I and IV capacities and phosphorylation rates were lower, but external NAD(P)H dehydrogenase activity increased. Higher external NAD(P)H dehydrogenase activity corresponded to increased cell redox level with doubled NADH/NAD ratio in the leaf and root tissues. Sulphur deficiency modified energy status in the tissues of Arabidopsis plants. The total concentration of adenylates (expressed as ATP+ADP), measured in the light, was lower in the leaves and roots of sulphur-deficient plants than in the controls, which was mainly due to the severely decreased ATP levels. We show that the changes in mitochondrial ultrastructure are compensated by the modifications in respiratory chain activity. Although mitochondria of Arabidopsis tissues are affected by sulphur deficiency, their metabolic and structural features, which readily reach new homeostasis, make these organelles crucial for adaptation of plants to survive sulphur deficiency. Copyright © 2013 Elsevier GmbH. All rights reserved.

Iris ultrastructure in patients with synechiae as revealed by in vivo laser scanning confocal microscopy : In vivo iris ultrastructure in patients with Synechiae by Laser Scanning Confocal Microscopy.

PubMed

Li, Ming; Cheng, Hongbo; Guo, Ping; Zhang, Chun; Tang, Song; Wang, Shusheng

2016-04-26

Iris plays important roles in ocular physiology and disease pathogenesis. Currently it is technically challenging to noninvasively examine the human iris ultrastructure in vivo. The purpose of the current study is to reveal human iris ultrastructure in patients with synechiae by using noninvasive in vivo laser scanning confocal microscopy (LSCM). The ultrastructure of iris in thirty one patients, each with synechiae but transparent cornea, was examined by in vivo LSCM. Five characteristic iris ultrastructures was revealed in patients with synechiae by in vivo LSCM, which include: 1. tree trunk-like structure; 2. tree branch/bush-like structure; 3. Fruit-like structure; 4. Epithelioid-like structure; 5. deep structure. Pigment granules can be observed as a loose structure on the top of the arborization structure. In iris-associated diseases with Tyndall's Phenomenon and keratic precipitates, the pigment particles are more likely to fall off from the arborization structure. The ultrastructure of iris in patients with synechiae has been visualized using in vivo LSCM. Five iris ultrastructures can be clearly observed, with some of the structures maybe disease-associated. The fall-off of the pigment particles may cause the Tyndall's Phenomenon positive. In vivo LSCM provides a non-invasive approach to observe the human iris ultrastructure under certain eye disease conditions, which sets up a foundation to visualize certain iris-associated diseases in the future.

Detection of ultrastructural changes in genetically altered and exercised skeletal muscle using PS-OCT

NASA Astrophysics Data System (ADS)

Pasquesi, James J.; Schlachter, Simon C.; Boppart, Marni D.; Chaney, Eric; Kaufman, Stephen J.; Boppart, Stephen A.

2006-02-01

Birefringence of skeletal muscle has been associated with the ultrastructure of individual sarcomeres, specifically the arrangement of A-bands corresponding to the thick myosin filaments. Murine skeletal muscle (gastrocnemius) was imaged with a fiber-based PS-OCT imaging system to determine the level of birefringence present in the tissue under various conditions. In addition to muscle controls from wild-type mice, muscle from abnormal mice included: genetically-modified (mdx) mice which model human muscular dystrophy, transgenic mice exhibiting an overexpression of integrin (α7β1), and transgenic integrin (α7β1)knockout mice. Comparisons were also made between rested and exercised muscles to determine the effects of exercise on muscle birefringence for each of these normal and abnormal conditions. The PS-OCT images revealed that the presence of birefringence was similar in the rested muscle with dystrophy-like features (i.e., lacking the structural protein dystrophin - mdx) and in the integrin (α7β1)knockout muscle when compared to the normal (wild-type) control. However, exercising these abnormal muscle tissues drastically reduced the presence of birefringence detected by the PS-OCT system. The muscle exhibiting an overexpression of integrin (α7β1) remained heavily birefringent before and after exercise, similar to the normal (wild-type) muscle. These results suggest that there is a distinct relationship between the degree of birefringence detected using PS-OCT and the sarcomeric ultrastructure present within skeletal muscle.

Electron microscopic features of nasal mucosa treated with topical and circumostial injection of mitomycin C: implications in dacryocystorhinostomy.

PubMed

Ali, Mohammad Javed; Baig, Farhana; Lakshman, Mekala; Naik, Milind N

2015-01-01

To evaluate the ultrastructural effects of topical and circumostial injection of mitomycin C (COS-MMC) on nasal mucosa and compare them with the controls. The study also aimed at classifying the subcellular effects in detail. The nasal mucosa of 6 patients were subjected to 0.02% of mitomycin C for 3 minutes (3 patients) and 0.02% COS-MMC (3 patients) as per standard protocol, during endoscopic dacryocystorhinostomy. Normal nasal mucosa from untreated areas (2 each from topical and COS-MMC groups) were taken as controls after harvesting the treated areas. Full thickness tissues (5 mm × 5 mm) were collected for transmission electron microscopy, and ultrastructural effects were evaluated. Both topical and COS-MMC showed significant and distinct ultrastructural changes involving the epithelial, glandular, vascular, and fibrocollagenous tissues compared with the controls. There were profound changes within fibroblasts with intracellular edema, pleomorphic and vesicular mitochondria, dilated smooth and rough endoplasmic reticulum, and chromatin condensation. In addition, COS-MMC samples showed subepithelial hypocellularity with limited disorganization of structure. The changes in both the MMC groups were restricted to treated areas only. Both topical and COS-MMC show profound changes in nasal mucosa with more marked changes in COS-MMC group. These changes being limited in nature may help in enhancing the success of dacryocystorhinostomy by preventing cicatricial changes of the ostium, especially in high-risk cases such as revision and post-traumatic dacryocystorhinostomy.

Immunocytochemical and ultrastructural identification of pituitary cell types in the protogynous Thalassoma duperrey during adult sexual ontogeny

USGS Publications Warehouse

Parhar, I.S.; Nagahama, Y.; Grau, E.G.; Ross, R.M.

1998-01-01

Protogynous wrasses (Thalassoma duperrey): females (F), primary males (PM) along with a few terminal-phase males (TM) and sex-changed males (SM), were used to characterize the topographical organization of the pituitary. In general, immunocytochemical and ultrastructural features of the adenohypophyseal cell types of the saddleback wrasse pituitary resemble those of other teleosts. In the rostral pars distalis (RPD), corticotropic cells were found bordering the neurohypophysis (NH) and surrounding the centroventrally located prolactin cells. Thyrotropic cells formed a small group in the anteriodorsal part of the rostral and proximal pars distalis (PPD). The somatotropic cells were distributed in large clusters, mostly organized in cell cords around the interdigitations of the NH of the dorsal PPD. Cells containing gonadotropin I?? subunit were localized in the dorsal parts of the PPD, in close association with somatotropic cells and gonadotropin II?? subunit containing cells were seen in the centroventral parts of the PPD and along the periphery of the pars intermedia (PI). The pars intermedia was composed of melanotropic cells and somatolactin cells that lined the neurohypohysis. Distinct ultrastructural differences in corticotropic and somatotropic cells were not observed between the four groups. In all groups, prolactin cells in the ventral-most RPD could be immature cells or actively secreting prolactin. Gonadotropic II cells of PM and F had relatively higher incidence of "nuclear budding" and cell organelles compared to TM and SM. Besides gonadotropic, the active melanotropic and somatolactin cells might be associated with some aspect(s) of reproduction.

Finite element modeling of hyper-viscoelasticity of peripheral nerve ultrastructures.

PubMed

Chang, Cheng-Tao; Chen, Yu-Hsing; Lin, Chou-Ching K; Ju, Ming-Shaung

2015-07-16

The mechanical characteristics of ultrastructures of rat sciatic nerves were investigated through animal experiments and finite element analyses. A custom-designed dynamic testing apparatus was used to conduct in vitro transverse compression experiments on the nerves. The optical coherence tomography (OCT) was utilized to record the cross-sectional images of nerve during the dynamic testing. Two-dimensional finite element models of the nerves were built based on their OCT images. A hyper-viscoelastic model was employed to describe the elastic and stress relaxation response of each ultrastructure of the nerve, namely the endoneurium, the perineurium and the epineurium. The first-order Ogden model was employed to describe the elasticity of each ultrastructure and a generalized Maxwell model for the relaxation. The inverse finite element analysis was used to estimate the material parameters of the ultrastructures. The results show the instantaneous shear modulus of the ultrastructures in decreasing order is perineurium, endoneurium, and epineurium. The FE model combined with the first-order Ogden model and the second-order Prony series is good enough for describing the compress-and-hold response of the nerve ultrastructures. The integration of OCT and the nonlinear finite element modeling may be applicable to study the viscoelasticity of peripheral nerve down to the ultrastructural level. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lafora's-like disease in a fennec fox (Vulpes zerda).

PubMed

Honnold, Shelley P; Schulman, F Yvonne; Bauman, Karen; Nelson, Kevin

2010-09-01

A 6-yr-old captive-born female fennec fox (Vulpes zerda) had a history of multiple seizures and was treated with diazepam and phenobarbital therapy. Despite medical treatment, the seizures continued. They were intermittent and progressive, resulting in neurologic deficits and death of the animal within 6 mo of onset of the clinical signs. At necropsy, the animal was in good nutritional condition, and no gross lesions were noted in the brain. Histologically, amphophilic to basophilic, periodic acid-Schiff (PAS) positive, diastase-resistant inclusions were present in the brain, heart, and liver. Ultrastructurally, the inclusions were variably electron dense, fibrillary to occasionally granular, and non-membrane bound. The clinical, histologic, and ultrastructural findings were consistent with Lafora's disease, which in humans is a rare, fatal, autosomal recessive hereditary neurometabolic disorder characterized by progressive myoclonic epilepsy. This is the first report of Lafora's-like disease in a fennec fox.

Ultrastructure of the synovial membrane in seronegative inflammatory arthropathies.

PubMed Central

Morris, C J; Farr, M; Hollywell, C A; Hawkins, C F; Scott, D L; Walton, K W

1983-01-01

The ultrastructure of the synovial membrane has been studied in 6 patients with seronegative inflammatory arthropathies: Reiter's (2), Crohn's (2), Whipple's (1) and Behçet's disease (1). The most striking changes were found in the synovial B cells, many containing abnormally large mitochondria with altered cristae surrounded by fibrillar material. Similar material was present in dilated endoplasmic reticulum which was the probable source of groups of extracellular fibrillar spheroidal bodies. The B cells also contained electron dense granular lysosomes of very variable size which, in common with the abnormal mitochondria, were often associated with bundles of orientated microfilaments and large golgi complexes. Light microscopy of the synovial membrane was consistent with an inflammatory arthritis, as were the high white cell counts in the synovial fluid. Systemic activity in the patients was indicated by raised ESR and C-reactive protein (CRP). Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. A Figure 5. B PMID:6186810

Echinobothrium chisholmae n. sp. (Cestoda, Diphyllidea) from the giant shovel-nose ray Rhinobatos typus from Australia, with observations on the ultrastructure of its scolex musculature and peduncular spines.

PubMed

Jones, M K; Beveridge, I

2001-09-01

Echinobothrium chisholmae n. sp. is described from Rhinobatos typus Bennett (Rhinobatidae), collected from Heron Island, Great Barrier Reef, Australia. E. chisholmae differs from all congeners in possessing 11 hooks in each dorsal and ventral group on the rostellum and groups of 3-6 hooklets on either side of the hooks. A single metacestode of E. chisholmae was collected from the decapod crustacean Penaeus longistylus Kubo. Yellow pigmentation of the cephalic peduncle in immature adults is caused by the accumulation of large vesicles in the distal cytoplasm of the tegument. The vesicles probably provide materials for spine formation. Ultrastructural examination of the rostellar musculature revealed that the muscles are stratified (striated-like), consisting of a periodic repetition of sarcomeres separated by perforated Z-like lines that are oblique to the long axes of the myofilaments.

Ultrastructure of the post-corpus of Zeldia punctata (Cephalobina) for analysis of the evolutionary framework of nematodes related to Caenorhabditis elegans (Rhabditina).

PubMed Central

Zhang, Y C; Baldwin, J G

2000-01-01

The ultrastructure of the post-corpus of Zeldia punctata (Cephalobina) was compared with previous observations of Caenorhabditis elegans (Rhabditina) and Diplenteron sp. (Diplogastrina) with the goal of interpreting the morphological evolution of the feeding structures in the Secernentea. The post-corpus of Z. punctata consists of six marginal, 13 muscle, five gland and seven nerve cells. The most anterior of four layers of muscle cells consists of six mononucleate cells in Z. punctata. The homologous layer in C. elegans and Diplenteron consists of three binucleate cells, suggesting a unique derived character (synapomorphy) shared between the Rhabditina and Diplogastrina. Contrary to Diplenteron sp. where we observed three oesophageal glands, Z. punctata and C. elegans have five oesophageal glands. We question this shared character as reflecting a common evolution between the Cephalobina and Rhabditina, because there are strong arguments for functional (adaptive) convergence of the five glands in these bacterial feeders. Convergence is further suggested by the mosaic distribution of three versus five glands throughout the Nemata; this distribution creates difficulties in establishing character polarity. Although morphological data are often laborious to recover and interpret, we nevertheless view 'reciprocal illumination' between molecular and morphological characters as the most promising and robust process for reconstructing the evolution of the Secernentea and its feeding structures. PMID:10902689

Studies on proinsulin and proglucagon biosynthesis and conversion at the subcellular level: I. Fractionation procedure and characterization of the subcellular fractions

PubMed Central

Noe, BD; Baste, CA; Bauer, GE

1977-01-01

Anglerfish islets were homogenized in 0.25 M sucrose and separated into seven separate subcellular fractions by differential and discontinuous density gradient centrifugation. The objective was to isolate microsomes and secretory granules in a highly purified state. The fractions were characterized by electron microscopy and chemical analyses. Each fraction was assayed for its content of protein, RNA, DNA, immunoreactive insulin (IRI), and immunoreactive glucagon (IRG). Ultrastructural examination showed that two of the seven subcellular fractions contain primarily mitochondria, and that two others consist almost exclusively of secretory granules. A fifth fraction contains rough and smooth microsomal vesicles. The remaining two fractions are the cell supernate and the nuclei and cell debris. The content of DNA and RNA in all fractions is consistent with the observed ultrastructure. More than 82 percent of the total cellular IRI and 89(percent) of the total cellular IRG are found in the fractions of secretory granules. The combined fractions of secretory granules and microsomes consistently yield >93 percent of the total IRG. These results indicate that the fractionation procedure employed yields fractions of microsomes and secretory granules that contain nearly all the immunoassayable insulin and glucagons found in whole islet tissue. These fractions are thus considered suitable for study of proinsulin and proglucagon biosynthesis and their metabolic conversion at the subcellular level. PMID:328517

Automatic Segmentation and Quantification of Filamentous Structures in Electron Tomography

PubMed Central

Loss, Leandro A.; Bebis, George; Chang, Hang; Auer, Manfred; Sarkar, Purbasha; Parvin, Bahram

2016-01-01

Electron tomography is a promising technology for imaging ultrastructures at nanoscale resolutions. However, image and quantitative analyses are often hindered by high levels of noise, staining heterogeneity, and material damage either as a result of the electron beam or sample preparation. We have developed and built a framework that allows for automatic segmentation and quantification of filamentous objects in 3D electron tomography. Our approach consists of three steps: (i) local enhancement of filaments by Hessian filtering; (ii) detection and completion (e.g., gap filling) of filamentous structures through tensor voting; and (iii) delineation of the filamentous networks. Our approach allows for quantification of filamentous networks in terms of their compositional and morphological features. We first validate our approach using a set of specifically designed synthetic data. We then apply our segmentation framework to tomograms of plant cell walls that have undergone different chemical treatments for polysaccharide extraction. The subsequent compositional and morphological analyses of the plant cell walls reveal their organizational characteristics and the effects of the different chemical protocols on specific polysaccharides. PMID:28090597

Automatic Segmentation and Quantification of Filamentous Structures in Electron Tomography.

PubMed

Loss, Leandro A; Bebis, George; Chang, Hang; Auer, Manfred; Sarkar, Purbasha; Parvin, Bahram

2012-10-01

Electron tomography is a promising technology for imaging ultrastructures at nanoscale resolutions. However, image and quantitative analyses are often hindered by high levels of noise, staining heterogeneity, and material damage either as a result of the electron beam or sample preparation. We have developed and built a framework that allows for automatic segmentation and quantification of filamentous objects in 3D electron tomography. Our approach consists of three steps: (i) local enhancement of filaments by Hessian filtering; (ii) detection and completion (e.g., gap filling) of filamentous structures through tensor voting; and (iii) delineation of the filamentous networks. Our approach allows for quantification of filamentous networks in terms of their compositional and morphological features. We first validate our approach using a set of specifically designed synthetic data. We then apply our segmentation framework to tomograms of plant cell walls that have undergone different chemical treatments for polysaccharide extraction. The subsequent compositional and morphological analyses of the plant cell walls reveal their organizational characteristics and the effects of the different chemical protocols on specific polysaccharides.

Experimental giardiasis in goat kids.

PubMed

Koudela, B; Vítovec, J

1998-01-15

The clinical, pathological and parasitological features of giardiasis resulting from experimental inoculation with 3 x 10(6) Giardia cysts were studied in goat kids. All experimentally inoculated goat kids given Giardia cysts became infected. Three of the eight inoculated kids had decreased appetite, formless feces and become slightly depressed beginning 7 or 8 days post inoculation. The mean duration of the appearance of abnormal feces was 6 days. Irregular and intermitted cysts shedding started after prepatent periods of 6-10 days and lasted throughout this study (10 weeks). The evidence of high infectivity and fast transmission of Giardia were observed under standard zoohygienic conditions. The characteristics of intestinal lesions were similar to those found in other hosts infected with Giardia. The most severe lesions were seen in the duodenum and proximal jejunum, and consisted of moderate villus atrophy, villus blunting, crypt hyperplasia and inflammatory infiltration in the lamina propria. Scanning electron microscopy revealed ultrastructural alterations in the microvillus border of enterocytes. Mucosal smears and histological sections of the gall bladder displayed Giardia trophozoites and gall bladder epithelium hyperplasia together with bile ductular proliferation in the liver tissue in two kids.

Pulmonary lipomatous hemangiopericytoma: report of a rare tumor and comparison with solitary fibrous tumor.

PubMed

Yamazaki, Kazuto; Eyden, Brian P

2007-01-01

Lipomatous hemangiopericytoma is a rare mesenchymal tumor showing areas of lipid-containing cells admixed with a spindle-cell component. Like other hemangiopericytomas, it shows a similar vascular pattern to solitary fibrous tumor and, partly for this reason, it and other hemangiopericytomas have been subsumed into solitary fibrous tumor. The present study provides a comprehensive documentation of a single case of pulmonary lipomatous hemangiopericytoma of the lung, the first to be described at this site, and compares it with solitary fibrous tumor, in terms of clinical, histological, immunohistochemical, ultrastructural, and cytogenetic findings. Apart from the lipid-laden-cell component, pulmonary lipomatous hemangiopericytoma and solitary fibrous tumor were similar histologically. Bcl-2 was positive in both. CD34 was minimally expressed in pulmonary lipomatous hemangiopericytoma, which possessed some non-descriptive intercellular junctions, a feature shared by solitary fibrous tumor, which was CD34 positive. However, one of the latter was rich in gap junctions, a feature consistent with strong connexin (Cx) 43 staining and the existence, hitherto unappreciated, of a CD34/Cx43-positive tumor cell network. In pulmonary lipomatous hemangiopericytoma, chromosomal deletions of 43-44, X, -Y were found. In solitary fibrous tumor, 46, XY, del(13)(q?) abnormalities and abnormalities involving chromosome 10 were frequently observed. These similarities and differences are discussed in the context of the currently favored diagnostic fusion of hemangiopericytoma and solitary fibrous tumor.

Maturation experiments reveal bias in the fossil record of feathers

NASA Astrophysics Data System (ADS)

McNamara, Maria; Field, Daniel

2016-04-01

The evolutionary history of birds and feathers is a major focus in palaeobiology and evolutionary biology. Diverse exceptionally preserved birds and feathered dinosaurs from Jurassic and Cretaceous biotas in China have provided pivotal evidence of early feathers and feather-like integumentary features, but the true nature of many of these fossil soft tissues is still debated. Interpretations of feathers at intermediate developmental stages (i.e. Stages II, III and IV) and of simple quill-like (Stage I) feathers are particularly controversial. This reflects key uncertainties relating to the preservation potential of feathers at different evolutionary-developmental stages, and to the relative preservation potential of diagnostic features of Stage I feathers and hair. To resolve these issues, we used high pressure-high temperature autoclave experiments to simulate the effects of burial on modern feathers from the Black Coucal (Centropus grilii) and Common Starling (Sturnus vulgaris), and on human hair. Our results reveal profound differences in the recalcitrance of feathers of different types during maturation: Stage I and Stage V feathers retain diagnostic morphological and ultrastructural details following maturation, whereas other feather types do not. Further, the morphology and arrangement of certain ultrastructural features diagnostic of Stages III and IV, e.g. barbules, are preferentially lost during maturation. These results indicate a pervasive bias in the fossil record of feathers, whereby preservation of feathers at Stages I and V is favored. Critical stages in the evolution of feathers, i.e. Stages II, III and IV, are less likely to be preserved and more likely to be misinterpreted as feathers at earlier developmental stages. Our discovery has major implications for our understanding of the fidelity of the fossil record of feathers and provides a framework for testing the significance of putative examples of fossil feathers at different developmental stages.

LM and TEM study of the orthokeratinized and parakeratinized epithelium of the tongue in the domestic duck (Anas platyrhynchos f. domestica).

PubMed

Skieresz-Szewczyk, Kinga; Jackowiak, Hanna; Ratajczak, Marlena

2014-12-01

The previous histological studies of the lingual mucosa in birds characterized two types of keratinized epithelium, i.e. orthokeratinized and parakeratinized. These epithelia are composed of three layers: basal, intermediate and keratinized. The present study showed detailed ultrastructural features of cells in particular layers of two types of keratinized epithelia on the tongue in the domestic duck and defined structural differences. TEM observations showed a gradual reduction in cell organelles in the following layers, at increasing amounts of keratin fibers. The characteristic feature of the ortho- and parakeratinized epithelium is the presence of sub-layers in the intermediate layer, i.e. the upper and lower part, which results from the different shape of cell nuclei and dye affinity of the cytoplasm. The keratinized layer of ortho- and parakeratinized epithelium is built of two types of cells such as electron dark and light cells, which undergo exfoliation. The basic difference between the keratinized epithelia is the presence of flattened cell nuclei in the keratinized layer of the parakeratinized epithelium. The differentiating feature is also an arrangement of keratin fibers in the cell cytoplasm of the keratinized layer. The analysis of the thickness of the epithelium and the keratinized layer, indicated differences between keratinized epithelia, which result from two variants of performing protective functions, either through a thick keratinized layer or by a higher epithelium. Differences in the ultrastructure of the ortho- and parakeratinized epithelium are associated with mechanical functions of the epithelium resulting from different forces acting on the tongue during feeding activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Apoptosis: a basic pathological reaction of injured neonatal muscle.

PubMed

Fidziańska, A; Kamińska, A

1991-01-01

A light and electron microscopic study of immature muscle cell degeneration induced by bupivacaine (BPVC) was performed. The pattern of muscle cell death is related to muscle maturity; in newborn rats, cell death has the morphology of apoptosis, whereas in the older animals muscle cell death resembles cell necrosis and the ultrastructural feature of these changes are essentially the same as those described in adult muscle. The ability to undergo apoptosis in response to a pathological stimulus is a common effector mechanism of immature muscle.

Adrenoleukodystrophy. Electron microscopic findings.

PubMed

Powell, H; Tindall, R; Schultz, P; Paa, D; O'Brien, J; Lampert, P

1975-04-01

Ultrastructural and neurochemical studies were done on three male patients with adrenoleukodystrophy. In each case, the affected white matter contained enlarged glial cells filled with pathognomic intracytoplasmic inclusions consisting of electron-lucent spicules bounded by 25-Angstrom wide membranes. Similar inclusions were present in adrenocortical cells. These findings and a review of 47 reported cases indicate that adrenoleukodystrophy is a storage disorder caused by a sex-linked recessive error of metabolism.

Histology and surface ultrastructure during early healing after gingival augmentation with a three-dimensional collagen matrix: A report of six cases.

PubMed

Rusu, Darian; Stratul, Stefan-Ioan; Festila, Dana; Surlin, Petra; Kasaj, Adrian; Baderca, Flavia; Boariu, Marius; Jentsch, Holger; Locovei, Cosmin; Calenic, Bogdan

2017-01-01

The objective of the present case series is to describe the histology and surface ultrastructure of augmented keratinized gingival mucosa in humans during the early healing phase after surgical placement of a xenogeneic collagen matrix. Six patients underwent surgical augmentation of keratinized tissue by placement of a three-dimensional (3D) xenogeneic collagen matrix. Full-depth mucosal biopsies including original attached gingiva, augmented gingiva, and the separation zone were performed at baseline and at postoperative days 7 and 14. The specimens were stained with hematoxylin-eosin, Masson-trichrome, picrosirius red, and Papanicolaou's trichrome. Low-vacuum scanning electron microscopy (SEM) surface analysis was correlated with histology. The separation zone was clearly visible upon histologic and SEM examination at 7 days. The portions of augmented mucosa consisted of well-structured, immature gingival tissue with characteristics of per secundam healing underlying a completely detached amorphous collagenous membrane-like structure of approximately 100 μm thick. At 14 days, histologic and ultrastructural examinations showed an almost complete maturation process. There were no detectable remnants of the collagen matrix within the newly formed tissues at either time point. Within their limits the results suggest that the 3D collagen matrix appears to play an indirect role during the early phase of wound healing by protecting the newly formed underlying tissue and guiding the epithelialization process.

Ultrastructural Characteristics of the Testis, Spermatogenesis and Taxonomic Values of Sperm Morphology in Male Ruditapes philippinarum in Western Korea.

PubMed

Kim, Jin Hee; Chung, Jae Seung; Lee, Ki-Young

2013-06-01

Ultrastructural characteristics of the germ cells and accessory cells in testis during spermatogenesis and taxonomic values of mature sperm morphology of Ruditapes philippinarum were investigated by the transmission electron microscope and scanning electron microscope observations. The testis is the diffuse organ that consists of branching acini containing developing germ cells and accessory cells associated with spermatogenesis. The morphology of the spermatozoon is of the primitive type and is somewhat different to those of other bivalves. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylinderical type and a modified cone shape, respectively. As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part, while the apex part of the acrosome shows electron lucent part. These characteristics of sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part. In particular, a cylinder-like nucleus of the sperm is curved. The spermatozoon is approximately 48-51 μm in length, including a long acrosome (about 2.40 μm in length), a curved sperm nucleus (about 3.40 μm in length), and a tail flagellum. The axoneme of the sperm tail shows a 9+2 structure.

In situ X-ray scattering evaluation of heat-induced ultrastructural changes in dental tissues and synthetic hydroxyapatite

PubMed Central

Sui, Tan; Sandholzer, Michael A.; Lunt, Alexander J. G.; Baimpas, Nikolaos; Smith, Andrew; Landini, Gabriel; Korsunsky, Alexander M.

2014-01-01

Human dental tissues consist of inorganic constituents (mainly crystallites of hydroxyapatite, HAp) and organic matrix. In addition, synthetic HAp powders are frequently used in medical and chemical applications. Insights into the ultrastructural alterations of skeletal hard tissues exposed to thermal treatment are crucial for the estimation of temperature of exposure in forensic and archaeological studies. However, at present, only limited data exist on the heat-induced structural alterations of human dental tissues. In this paper, advanced non-destructive small- and wide angle X-ray scattering (SAXS/WAXS) synchrotron techniques were used to investigate the in situ ultrastructural alterations in thermally treated human dental tissues and synthetic HAp powders. The crystallographic properties were probed by WAXS, whereas HAp grain size distribution changes were evaluated by SAXS. The results demonstrate the important role of the organic matrix that binds together the HAp crystallites in responding to heat exposure. This is highlighted by the difference in the thermal behaviour between human dental tissues and synthetic HAp powders. The X-ray analysis results are supported by thermogravimetric analysis. The results concerning the HAp crystalline architecture in natural and synthetic HAp powders provide a reliable basis for deducing the heating history for dental tissues in the forensic and archaeological context, and the foundation for further development and optimization of biomimetic material design. PMID:24718447

Hydrophilic acrylic intraocular lens optic and haptics opacification in a diabetic patient: bilateral case report and clinicopathologic correlation.

PubMed

Pandey, Suresh K; Werner, Liliana; Apple, David J; Kaskaloglu, Mahmut

2002-11-01

To report clinicopathologic and ultrastructural features of two opacified single-piece hydrophilic acrylic intraocular lenses (IOLs) explanted from a diabetic patient. Interventional case report with clinicopathologic correlation. A 64-year-old white female underwent phacoemulsification and implantation of a single-piece hydrophilic acrylic lens (SC60B-OUV; Medical Developmental Research, Inc., Clear Water, FL) in October 1998 in the left eye and in July 1999 in the right eye. The best-corrected visual acuity after surgery was 20/60 in the left eye and 20/50 in the right eye. The patient had a marked decrease in visual acuity in June 2000 as a result of a milky, white opalescence of both lenses. Intraocular lens explantation and exchange was performed in both eyes and the explanted IOLs were submitted to our center for detailed pathologic, histochemical, and ultrastructural evaluation. They were stained with alizarin red and the von Kossa method for calcium, and also underwent scanning electron microscopy and energy dispersive radiograph spectroscopy to ascertain the nature of the deposits leading to opacification. Documentation of calcium deposits confirmed by histochemical stains and surface analyses. Opacification of the IOL was found to be the cause of decreased visual acuity. The opacification involved both the IOL optic and the haptics in the left eye and was confined to the IOL optic in the right eye. Histochemical and ultrastructural analyses revealed that the opacity was caused by deposition of calcium and phosphate within the lens optic and haptics. There are two features that distinguish this case from those reported earlier. This is the first clinicopathologic report of lens opacification that has involved completely the lens optic and the haptics. Second, these two explanted IOLs document the first bilateral case. This process of intraoptic and haptic opacification represents dystrophic calcification of unknown cause. Diabetic patients appear to be more severely and more often affected by lens opacification. Long-term follow-up of diabetic patients implanted with this IOL design should be maintained by surgeons and manufacturers.

Nocardia cyriacigeogica from Bovine Mastitis Induced In vitro Apoptosis of Bovine Mammary Epithelial Cells via Activation of Mitochondrial-Caspase Pathway.

PubMed

Chen, Wei; Liu, Yongxia; Zhang, Limei; Gu, Xiaolong; Liu, Gang; Shahid, Muhammad; Gao, Jian; Ali, Tariq; Han, Bo

2017-01-01

Nocardia is one of the causing agents of bovine mastitis and increasing prevalence of nocardial mastitis in shape of serious outbreaks has been reported from many countries. However, the mechanisms by which this pathogen damages the bovine mammary epithelial cells (bMECs) is not yet studied. Therefore, this study was designed with the aim to evaluate the apoptotic effects elicited by Nocardia and to investigate the pathway by which the Nocardia induce apoptosis in bMECs. Clinical Nocardia cyriacigeorgica strain from bovine mastitis was used to infect the bMECs for different time intervals, viz . 1, 3, 6, 12, and 18 h, and then the induced effects on bMECs were studied using adhesion and invasion assays, release of lactate dehydrogenase (LDH), apoptosis analysis by annexin V and propidium iodide (PI) double staining, morphological, and ultrastructural observations under scanning electron microscope (SEM) and transmission electron microscope (TEM), mitochondrial transmembrane potential (ΔΨm) assay using flow cytometry, and the protein quantification of mitochondrial cytochrome c and caspase-9 and caspase-3 by western blotting. The results of this study showed that N. cyriacigeorgica possessed the abilities of adhesion and invasion to bMECs. N. cyriacigeorgica was found to collapse mitochondrial transmembrane potential, significantly ( p < 0.05) release mitochondrial cytochrome c and ultimately induce cell apoptosis. Additionally, it promoted casepase-9 ( p < 0.01) and casepase-3 ( p < 0.05) levels, significantly ( p < 0.01) increased the release of LDH and promoted DNA fragmentation which further confirmed the apoptosis. Furthermore, N. cyriacigeorgica induced apoptosis/necrosis manifested specific ultrastructure features under TEM, such as swollen endoplasmic reticulum, cristae degeneration, and swelling of mitochondria, vesicle formation on the cell surface, rupturing of cell membrane and nuclear membrane, clumping, fragmentation, and margination of chromatin. The present study is the first comprehensive insight into patho-morphological ultrastructural features of apoptosis/necrosis induced by N. cyriacigeorgica , which concluded that the clinical N. cyriacigeorgica induced apoptotic changes in the bMECs through mitochondrial-caspase dependent apoptotic pathway.

Comparative effectiveness of a clinostat and a slow-turning lateral vessel at mimicking the ultrastructural effects of microgravity in plant cells

NASA Technical Reports Server (NTRS)

Moore, R.

1990-01-01

The object of this research was to determine how effectively the actions of a clinostat and a fluid-filled, slow-turning lateral vessel (STLV) mimic the ultrastructural effects of microgravity in plant cells. We accomplished this by qualitatively and quantitatively comparing the ultrastructures of cells grown on clinostats and in an STLV with those of cells grown at 1 g and in microgravity aboard the Space Shuttle Columbia. Columella cells of Brassica perviridis seedlings grown in microgravity and in an STLV have similar structures. Both contain significantly more lipid bodies, less starch, and fewer dictyosomes than columella cells of seedlings grown at 1 g. Cells of seedlings grown on clinostats have significantly different ultrastructures from those grown in microgravity or in an STLV, indicating that clinostats do not mimic microgravity at the ultrastructural level. The similar structures of columella cells of seedlings grown in an STLV and in microgravity suggest that an STLV effectively mimics microgravity at the ultrastructural level.

Porosity and test ultrastructure of costate and non-costate Bulimina species

NASA Astrophysics Data System (ADS)

Grunert, Patrick; Piller, Werner E.

2017-04-01

SEM-based investigations of porosity and test wall ultrastructure of Recent costate and non-costate Bulimina species reveal significant differences in pore diameter, pore density and ultrastructural architecture between these two groups. Costate tests of B. inflata and B. mexicana display low pore density, a large pore diameter, and test walls built by a single type of columnar ultrastructural elements. In contrast, non-costate tests of B. aculeata and B. marginata are characterized by significantly higher pore density, smaller pore diameter, and an additional type of ultrastructural elements formed by oblique, tabular crystallite units which encase the pore channels. We interpret the observed combination of traits in B. aculeata and B. marginata as a set of adaptations to poorly oxygenated, intermediate to deep infaunal microhabitats which they typically occupy today. The evolutionary trend towards increased pore density in this group seemingly involved a major modification of the biomineralisation process resulting in the lining of pore channels with a specific type of ultrastructural element to ensure stability of the densely perforated test.

Effects of a sublethal concentration of sodium lauryl sulphate on the morphology and Na+/K+ ATPase activity in the gill of the ornate wrasse (Thalassoma pavo).

PubMed

Brunelli, Elvira; Talarico, Erminia; Corapi, Barbara; Perrotta, Ida; Tripepi, Sandro

2008-10-01

We analysed the morphology and ultrastructure of the gill apparatus of the ornate wrasse, Thalassoma pavo, under normal conditions and after exposure to a sublethal concentration of sodium lauryl sulphate (3.5 mg/l, which is one-third of the 96LC99 value). To identify the biochemical mechanisms affected by this pollutant, we evaluated and compared the localisation of Na(+)/K(+) ATPase in normal and experimental conditions. Immunocytochemical analysis revealed that this enzyme was active in the chloride cells (CCs), which were distributed in clusters in the interlamellar region of the filament. Ultrastructural analysis revealed conspicuous alterations on the epithelium after 96 and 192 h of exposure to sodium lauryl sulphate: structural features of the surface cells were lost, the appearance of intercellular lacunae changed, and cellular degeneration occurred. Statistical analysis comparing the number and dimensions of CCs in normal conditions and after 96 h of exposure showed that the CC area decreased after exposure to the detergent.

Use of electron microscopy to classify canine perivascular wall tumors.

PubMed

Palmieri, C; Avallone, G; Cimini, M; Roccabianca, P; Stefanello, D; Della Salda, L

2013-03-01

The histologic classification of canine perivascular wall tumors (PWTs) is controversial. Many PWTs are still classified as hemangiopericytomas (HEPs), and the distinction from peripheral nerve sheath tumors (PNSTs) is still under debate. A recent histologic classification of canine soft tissue sarcomas included most histologic types of PWT but omitted those that were termed undifferentiated. Twelve cases of undifferentiated canine PWTs were evaluated by transmission electron microscopy. The ultrastructural findings supported a perivascular wall origin for all cases with 4 categories of differentiation: myopericytic (n = 4), myofibroblastic (n = 1), fibroblastic (n = 2), and undifferentiated (n = 5). A PNST was considered unlikely in each case based on immunohistochemical expression of desmin and/or the lack of typical ultrastructural features, such as basal lamina. Electron microscopy was pivotal for the subclassification of canine PWTs, and the results support the hypothesis that canine PWTs represent a continuum paralleling the phenotypic plasticity of vascular mural cells. The hypothesis that a subgroup of PWTs could arise from a pluripotent mesenchymal perivascular wall cell was also considered and may explain the diverse differentiation of canine PWTs.

The photoreceptive cells of the pineal gland in adult zebrafish (Danio rerio).

PubMed

Laurà, Rosaria; Magnoli, Domenico; Zichichi, Rosalia; Guerrera, Maria Cristina; De Carlos, Felix; Suárez, Alberto Álvarez; Abbate, Francesco; Ciriaco, Emilia; Vega, Jose Antonio; Germanà, Antonino

2012-03-01

The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions. Copyright © 2011 Wiley Periodicals, Inc.

Critical Structure for Telescopic Movement of Honey bee (Insecta: Apidae) Abdomen: Folded Intersegmental Membrane.

PubMed

Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

2016-01-01

The folded intersegmental membrane is a structure that interconnects two adjacent abdominal segments; this structure is distributed in the segments of the honey bee abdomen. The morphology of the folded intersegmental membrane has already been documented. However, the ultrastructure of the intersegmental membrane and its assistive role in the telescopic movements of the honey bee abdomen are poorly understood. To explore the morphology and ultrastructure of the folded intersegmental membrane in the honey bee abdomen, frozen sections were analyzed under a scanning electron microscope. The intersegmental membrane between two adjacent terga has a Z-S configuration that greatly influences the daily physical activities of the honey bee abdomen. The dorsal intersegmental membrane is 2 times thicker than the ventral one, leading to asymmetric abdominal motion. Honey bee abdominal movements were recorded using a high-speed camera and through phase-contrast computed tomography. These movements conformed to the structural features of the folded intersegmental membrane. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

[Trichomycosis (trichobacteriosis) capitis in an infant: Microbiological, dermoscopic and ultrastructural features].

PubMed

Bonifaz, Alexandro; Ramírez-Ricarte, Ixchel; Rodríguez-Leviz, Alejandra; Hernández, Marco A; Mena, Carlos; Valencia, Adriana

2017-04-01

Trichomycosis is a superficial infection caused by Corynebacterium flavescens, which regularly affects axillary, and to a a lesser extent, pubic, scrotal and intergluteal, and exceptionally, head hairs or trichomycosis capitis (TC). This condition is characterised by the formation of bacterial nodules. Clinically, it can be confused with white piedra or pediculosis. The diagnosis is made by microscopic and dermoscopic observation and confirmed by culture. To present a case of TC in an infant and illustrate the microscopic, dermoscopic, and ultrastructural characteristics. A 6 month-old boy, otherwise healthy, with multiple yellowish concretions on the hairs of the head. TC was confirmed by yellow fluorescence with Wood’s light; white-yellowish beads, like “rosaries of crystalline stones’’ were observed on dermoscopy, direct examination showed bacterial masses, and Corynebacterium flavescens was identified by culture. A superficial infection, without perforation of the hairs, was confirmed by electron microscopy. Treatment with fusidic acid for 3 weeks achieved a clinical and microbiological cure. TC is a rare condition that affects children, and tends to be mistaken for other diseases of the hair, such as pediculosis and mycotic infections.

Scanning electron microscopic study of a Ciloxan bottle blocked by ciprofloxacin crystals.

PubMed

John, T

2001-12-01

To report blockage of a commercially available ciprofloxacin bottle by white crystalline deposits. This study evaluated the ultrastructural features of the ciprofloxacin crystals. A patient underwent intensive topical treatment of an infectious corneal ulcer with commercially available ciprofloxacin 0.3% ophthalmic solution. During treatment, the patient was unable to obtain medication from the ciprofloxacin bottle and required a new prescription. Examination of the bottle revealed that about 50% of the medication remained, but compression of the bottle with any amount of force failed to deliver any medication. On closer examination, a white material partially filled the nozzle track of the bottle and was on the outer bottle near the nozzle and the inner surface of the bottle cap. These white crystalline deposits were evaluated by scanning electron microscopy. Plate-like, needle, cable and spaghetti-like crystals were found. The needle crystals formed multiple petaloid patterns. This is the first report of blockage of a commercially available ciprofloxacin 0.3% bottle by ciprofloxacin crystals and the inability to deliver medication from the bottle. Ultrastructural study of the white crystalline deposits revealed four types of ciprofloxacin crystals.

On-line transmission electron microscopic image analysis of chromatin texture for differentiation of thyroid gland tumors.

PubMed

Kriete, A; Schäffer, R; Harms, H; Aus, H M

1987-06-01

Nuclei of the cells from the thyroid gland were analyzed in a transmission electron microscope by direct TV scanning and on-line image processing. The method uses the advantages of a visual-perception model to detect structures in noisy and low-contrast images. The features analyzed include area, a form factor and texture parameters from the second derivative stage. Three tumor-free thyroid tissues, three follicular adenomas, three follicular carcinomas and three papillary carcinomas were studied. The computer-aided cytophotometric method showed that the most significant differences were the statistics of the chromatin texture features of homogeneity and regularity. These findings document the possibility of an automated differentiation of tumors at the ultrastructural level.

Ultrastructural researches on rabbit myxomatosis. Lymphnodal lesions.

PubMed

Marcato, P S; Simoni, P

1977-07-01

Ultrastructural examination of head and neck lymph nodes in rabbits with spontaneous subacute myxomatosis showed fusion of immature reticuloendothelial cells which lead to the formation of polykarocytes. There was no ultrastructural evidence of viral infection of these polykaryocytes. Histiosyncytial lymphadenitis can be considered a specific lesion of myxomatosis.

Histopathology, Immunohistochemistry, and Electron Microscopic features of a Dacryocystorhinostomy Ostium Cicatrix.

PubMed

Ali, Mohammad Javed; Mishra, Dilip Kumar; Baig, Farhana; Naik, Milind N

2016-01-01

The aim of this study is to report the histopathological, Immunohistochemical, and ultrastructural features of a dacryocystorhinostomy ostium cicatrix. A prospective histopathological study was performed in a tertiary eye care setting. Scarred nasal mucosal tissues obtained during endoscopic revisions of 10 previously failed dacryocystorhinostomies secondary to complete cicatricial closure of the ostia were studied. The tissue specimens were analyzed using hematoxylin and eosin, periodic acid-Schiff staining. Special stains used include Masson's trichrome and Alizarin red. Immunohistochemistry was performed using vimentin, smooth muscle actin, CD3, CD5, and CD20. Specimens were processed for ultrastructural analysis as per standard protocols for transmission electron microscopy. The respiratory epithelial regeneration was noted to be complete. Irregular laying of deeply eosinophilic and hyalinized collagen with intervening fibroblasts was noted. Focal areas of new bone formation were seen within the cicatricial tissue with osteocytes and ongoing osteoblastic rimming. The infiltrates were mixture of both T and B lymphocytes and were positive for CD3, CD5, and CD20 immunostaining. Electron microscopy showed disorganized collagen fibrils with numerous fibroblasts and mononuclear inflammatory infiltrate. Amorphous bony osteoid within a fibrillar background with metabolically active osteoblasts showed a vesicular cytoplasm, hyperplastic proliferating mitochondria, large Golgi apparatus, and dense endoplasmic reticulum. There is new bone formation within the dense connective tissues of a dacryocystorhinostomy cicatrix. This study may provide useful inputs for further basic science studies aimed at better understanding of wound healing in failed dacryocystorhinostomy.

The intriguing nature of dorsal root ganglion neurons: linking structure with polarity and function.

PubMed

Nascimento, Ana Isabel; Mar, Fernando Milhazes; Sousa, Mónica Mendes

2018-05-02

Dorsal root ganglion (DRG) neurons are the first neurons of the sensory pathway. They are activated by a variety of sensory stimuli that are then transmitted to the central nervous system. An important feature of DRG neurons is their unique morphology where a single process -the stem axon- bifurcates into a peripheral and a central axonal branch, with different functions and cellular properties. Distinctive structural aspects of the two DRG neuron branches may have important implications for their function in health and disease. However, the link between DRG axonal branch structure, polarity and function has been largely neglected in the field, and relevant information is rather scattered across the literature. In particular, ultrastructural differences between the two axonal branches are likely to account for the higher transport and regenerative ability of the peripheral DRG neuron axon when compared to the central one. Nevertheless, the cell intrinsic factors contributing to this central-peripheral asymmetry are still unknown. Here we critically review the factors that may underlie the functional asymmetry between the peripheral and central DRG axonal branches. Also, we discuss the hypothesis that DRG neurons may assemble a structure resembling the axon initial segment that may be responsible, at least in part, for their polarity and electrophysiological features. Ultimately, we suggest that the clarification of the axonal ultrastructure of DRG neurons using state-of-the-art techniques will be crucial to understand the physiology of this peculiar cell type. Copyright © 2018. Published by Elsevier Ltd.

Atomic force microscopic imaging of Acanthamoeba castellanii and Balamuthia mandrillaris trophozoites and cysts.

PubMed

Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Ateeq, Muhammad; Raza Shah, Muhammad; Kulsoom, Huma; Khan, Naveed Ahmed

2015-01-01

Light microscopy and electron microscopy have been successfully used in the study of microbes, as well as free-living protists. Unlike light microscopy, which enables us to observe living organisms or the electron microscope which provides a two-dimensional image, atomic force microscopy provides a three-dimensional surface profile. Here, we observed two free-living amoebae, Acanthamoeba castellanii and Balamuthia mandrillaris under the phase contrast inverted microscope, transmission electron microscope and atomic force microscope. Although light microscopy was of lower magnification, it revealed functional biology of live amoebae such as motility and osmoregulation using contractile vacuoles of the trophozoite stage, but it is of limited value in defining the cyst stage. In contrast, transmission electron microscopy showed significantly greater magnification and resolution to reveal the ultra-structural features of trophozoites and cysts including intracellular organelles and cyst wall characteristics but it only produced a snapshot in time of a dead amoeba cell. Atomic force microscopy produced three-dimensional images providing detailed topographic description of shape and surface, phase imaging measuring boundary stiffness, and amplitude measurements including width, height and length of A. castellanii and B. mandrillaris trophozoites and cysts. These results demonstrate the importance of the application of various microscopic methods in the biological and structural characterization of the whole cell, ultra-structural features, as well as surface components and cytoskeleton of protist pathogens. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

Modifications in plasma membrane lipid composition and morphological features of AH-130 hepatoma cells by polyenylphosphatidylcholine in vivo treatment.

PubMed

Cinosi, Vincenzo; Antonini, Roberto; Crateri, Pasqualina; Arancia, Giuseppe

2011-07-01

The plasma membrane lipid composition in AH-130 hepatoma cells was found to change remarkably after polyenylphosphatidylcholine (PPC) treatment. Plasma membranes from cells grown in rats treated for 7 days i.v. with 20 mg/kg/day PPC, when compared to those of control cells, did not show significantly different amounts of cholesterol or phospholipids relative to protein content, but, surprisingly, the individual phospholipid distribution inside the two membrane leaflets changed dramatically. Phosphatidylcholine (PC), the major phospholipid in the external membrane leaflet, increased ~47% (p<0.001). By contrast, phosphatidylethanolamine (PE), the most important component of the inner leaflet, decreased nearly 37% (p<0.001), while sphingomyelin (SM) also decreased ~17%, (p=0.1). Tumor cells collected from control rats at the same time interval and observed by scanning electron microscopy, exhibited a spherical shape with numerous and randomly distributed long microvilli, the same morphological and ultrastructural features displayed by the implanted cells. Conversely, tumor cells from PPC-treated rats no longer showed the roundish cell profile, and microvilli appeared shortened and enlarged, with the formation of surface blebs. Transmission electron microscopy observations confirmed the morphological and ultrastructural cell changes, mainly seen as loss of microvilli and intense cytoplasmic vacuolization. Taken together, these results indicate that the new phospholipid class distribution in the plasma membrane leaflets, modifying tumor cell viable structures, produced heavy cell damage and in many cases brought about complete cellular disintegration.

Visualization of HIV T Cell Virological Synapses and Virus-Containing Compartments by Three-Dimensional Correlative Light and Electron Microscopy

PubMed Central

Wang, Lili; Eng, Edward T.; Law, Kenneth; Gordon, Ronald E.; Rice, William J.

2016-01-01

ABSTRACT Virological synapses (VS) are adhesive structures that form between infected and uninfected cells to enhance the spread of HIV-1. During T cell VS formation, viral proteins are actively recruited to the site of cell-cell contact where the viral material is efficiently translocated to target cells into heterogeneous, protease-resistant, antibody-inaccessible compartments. Using correlative light and electron microscopy (CLEM), we define the membrane topography of the virus-containing compartments (VCC) where HIV is found following VS-mediated transfer. Focused ion beam scanning electron microscopy (FIB-SEM) and serial sectioning transmission electron microscopy (SS-TEM) were used to better resolve the fluorescent Gag-containing structures within the VCC. We found that small punctate fluorescent signals correlated with single viral particles in enclosed vesicular compartments or surface-localized virus particles and that large fluorescent signals correlated with membranous Gag-containing structures with unknown pathological function. CLEM imaging revealed distinct pools of newly deposited viral proteins within endocytic and nonendocytic compartments in VS target T cells. IMPORTANCE This study directly correlates individual virus-associated objects observed in light microscopy with ultrastructural features seen by electron microscopy in the HIV-1 virological synapse. This approach elucidates which infection-associated ultrastructural features represent bona fide HIV protein complexes. We define the morphology of some HIV cell-to-cell transfer intermediates as true endocytic compartments and resolve unique synapse-associated viral structures created by transfer across virological synapses. PMID:27847357

Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

NASA Technical Reports Server (NTRS)

Cook, Martha E.; Croxdale, Judith G.; Tibbitts, T. W. (Principal Investigator)

2003-01-01

Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

Novel features of Brassica napus embryogenic microspores revealed by high pressure freezing and freeze substitution: evidence for massive autophagy and excretion-based cytoplasmic cleaning.

PubMed

Corral-Martínez, Patricia; Parra-Vega, Verónica; Seguí-Simarro, Jose M

2013-07-01

Induction of embryogenesis from isolated microspore cultures is a complex experimental system where microspores undergo dramatic changes in developmental fate. After ~40 years of application of electron microscopy to the study of the ultrastructural changes undergone by the induced microspore, there is still room for new discoveries. In this work, high pressure freezing and freeze substitution (HPF/FS), the best procedures known to date for ultrastructural preservation, were used to process Brassica napus microspore cultures covering all the stages of microspore embryogenesis. Analysis of these cultures by electron microscopy revealed massive processes of autophagy exclusively in embryogenic microspores, but not in other microspore-derived structures also present in cultures. However, a significant part of the autophagosomal cargo was not recycled. Instead, it was transported out of the cell, producing numerous deposits of extracytoplasmic fibrillar and membranous material. It was shown that commitment of microspores to embryogenesis is associated with both massive autophagy and excretion of the removed material. It is hypothesized that autophagy would be related to the need for a profound cytoplasmic cleaning, and excretion would be a mechanism to avoid excessive growth of the vacuolar system. Together, the results also demonstrate that the application of HPF/FS to the study of the androgenic switch is the best option currently available to identify the complex and dramatic ultrastructural changes undergone by the induced microspore. In addition, they provide significant insights to understand the cellular basis of induction of microspore embryogenesis, and open a new door for the investigation of this intriguing developmental pathway.

Characterization of amyloid in equine recurrent uveitis as AA amyloid.

PubMed

Ostevik, L; de Souza, G A; Wien, T N; Gunnes, G; Sørby, R

2014-01-01

Two horses with chronic uveitis and histological lesions consistent with equine recurrent uveitis (ERU) were examined. Microscopical findings in the ciliary body included deposits of amyloid lining the non-pigmented epithelium, intracytoplasmic, rod-shaped, eosinophilic inclusions and intraepithelial infiltration of T lymphocytes. Ultrastructural examination of the ciliary body of one horse confirmed the presence of abundant extracellular deposits of non-branching fibrils (9-11 nm in diameter) consistent with amyloid. Immunohistochemistry revealed strong positive labelling for AA amyloid and mass spectrometry showed the amyloid to consist primarily of serum amyloid A1 in both cases. The findings suggest that localized, intraocular AA amyloidosis may occur in horses with ERU. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evolutionary diversification of secondary mechanoreceptor cells in tunicata.

PubMed

Rigon, Francesca; Stach, Thomas; Caicci, Federico; Gasparini, Fabio; Burighel, Paolo; Manni, Lucia

2013-06-04

Hair cells are vertebrate secondary sensory cells located in the ear and in the lateral line organ. Until recently, these cells were considered to be mechanoreceptors exclusively found in vertebrates that evolved within this group. Evidence of secondary mechanoreceptors in some tunicates, the proposed sister group of vertebrates, has recently led to the hypothesis that vertebrate and tunicate secondary sensory cells share a common origin. Secondary sensory cells were described in detail in two tunicate groups, ascidians and thaliaceans, in which they constitute an oral sensory structure called the coronal organ. Among thaliaceans, the organ is absent in salps and it has been hypothesised that this condition is due to a different feeding system adopted by this group of animals. No information is available as to whether a comparable structure exists in the third group of tunicates, the appendicularians, although different sensory structures are known to be present in these animals. We studied the detailed morphology of appendicularian oral mechanoreceptors. Using light and electron microscopy we could demonstrate that the mechanosensory organ called the circumoral ring is composed of secondary sensory cells. We described the ultrastructure of the circumoral organ in two appendicularian species, Oikopleura dioica and Oikopleura albicans, and thus taxonomically completed the data collection of tunicate secondary sensory cells. To understand the evolution of secondary sensory cells in tunicates, we performed a cladistic analysis using morphological data. We constructed a matrix consisting of 19 characters derived from detailed ultrastructural studies in 16 tunicate species and used a cephalochordate and three vertebrate species as outgroups. Our study clearly shows that the circumoral ring is the appendicularian homologue of the coronal organ of other tunicate taxa. The cladistic analysis enabled us to reconstruct the features of the putative ancestral hair cell in tunicates, represented by a simple monociliated cell. This cell successively differentiated into the current variety of oral mechanoreceptors in the various tunicate lineages. Finally, we demonstrated that the inferred evolutionary changes coincide with major transitions in the feeding strategies in each respective lineage.

Ultrastructural and geochemical characterization of Archean-Paleoproterozoic graphite particles: implications for recognizing traces of life in highly metamorphosed rocks.

PubMed

Schiffbauer, James D; Yin, Leiming; Bodnar, Robert J; Kaufman, Alan J; Meng, Fanwei; Hu, Jie; Shen, Bing; Yuan, Xunlai; Bao, Huiming; Xiao, Shuhai

2007-08-01

Abundant graphite particles occur in amphibolite-grade quartzite of the Archean-Paleoproterozoic Wutai Metamorphic Complex in the Wutaishan area of North China. Petrographic thin section observations suggest that the graphite particles occur within and between quartzite clasts and are heterogeneous in origin. Using HF maceration techniques, the Wutai graphite particles were extracted for further investigation. Laser Raman spectroscopic analysis of a population of extracted graphite discs indicated that they experienced a maximum metamorphic temperature of 513 +/- 50 degrees C, which is consistent with the metamorphic grade of the host rock and supports their indigenicity. Scanning and transmission electron microscopy revealed that the particles bear morphological features (such as hexagonal sheets of graphite crystals) related to metamorphism and crystal growth, but a small fraction of them (graphite discs) are characterized by a circular morphology, distinct marginal concentric folds, surficial wrinkles, and complex nanostructures. Ion microprobe analysis of individual graphite discs showed that their carbon isotope compositions range from -7.4 per thousand to -35.9 per thousand V-PDB (Vienna Pee Dee Belemnite), with an average of -20.3 per thousand, which is comparable to bulk analysis of extracted carbonaceous material. The range of their size, ultrastructures, and isotopic signatures suggests that the morphology and geochemistry of the Wutai graphite discs were overprinted by metamorphism and their ultimate carbon source probably had diverse origins that included abiotic processes. We considered both biotic and abiotic origins of the carbon source and graphite disc morphologies and cannot falsify the possibility that some circular graphite discs characterized by marginal folds and surficial wrinkles represent deflated, compressed, and subsequently graphitized organic-walled vesicles. Together with reports by other authors of acanthomorphic acritarchs from greenschist-amphibolite-grade metamorphic rocks, this study suggests that it is worthwhile to examine carbonaceous materials preserved in highly metamorphosed rocks for possible evidence of ancient life.

Ultrastructure of the external gill epithelium of the axolotl, Ambystoma mexicanum with reference to ionic transport.

PubMed

Jarial, M S; Wilkins, J H

2003-10-01

The ultrastructure of the external gill epithelium of the axolotl, Ambystoma mexicanum, has been examined using conventional transmission electron microscopy to elucidate its role in ionic transport. Four cell types are identified in the gill filament and primary gill bar epithelium. These are granular, ciliated, Leydig and basal cells. A fifth cell type, the flat mitochondria-rich cell is only found in the gill bar epithelium. The predominant granular cells display microvilli at their surface and their cytoplasm contains abundant mitochondria, rough endoplasmic reticulum, Golgi complexes, vesicles and PAS+ secretory granules that are extruded at the surface, which along with secretions from the Leydig cells form a mucous coat. The granular cells are joined apically by junctional complexes consisting of zonulae occludens, zonulae adherens and desmosomes. The lateral membranes of granular cells enclose large intercellular spaces that are closed at the apical ends but remain open at the basal ends adjoining capillaries. In AgNO3-treated axolotl, the gills become darkly stained, the silver grains penetrate apical membranes and appear in the cytoplasm, accumulating near the lateral membranes and also enter the intercellular spaces. These findings are consistent with the dual role of the gill epithelium in mucus production and active ionic transport.

Ecologically Driven Ultrastructural and Hydrodynamic Designs in Stomatopod Cuticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grunenfelder, Lessa Kay; Milliron, Garrett; Herrera, Steven

Ecological pressures and varied feeding behaviors in a multitude of organ-isms have necessitated the drive for adaptation. One such change is seen in the feeding appendages of stomatopods, a group of highly predatory marine crustaceans. Stomatopods include “spearers,” who ambush and snare soft bodied prey, and “smashers,” who bludgeon hard-shelled prey with a heavily mineralized club. The regional substructural complexity of the stomatopod dactyl club from the smashing predator Odontodactylus scyllarus represents a model system in the study of impact tolerant biominerals. The club consists of a highly mineralized impact region, a characteristic Bouligand architec-ture (common to arthropods), and amore » unique section of the club, the striated region, composed of highly aligned sheets of mineralized fibers. Detailed ultrastructural investigations of the striated region within O. scyllarus and a related species of spearing stomatopod, Lysiosquillina maculate show consistent organization of mineral and organic, but distinct differences in macro-scale architecture. Evidence is provided for the function and substructural exaptation of the striated region, which facilitated redeployment of a rapto-rial feeding appendage as a biological hammer. Furthermore, given the need to accelerate underwater and “grab” or “smash” their prey, the spearer and smasher appendages are specifically designed with a significantly reduced drag force.« less

Ecologically Driven Ultrastructural and Hydrodynamic Designs in Stomatopod Cuticles

DOE PAGES

Grunenfelder, Lessa Kay; Milliron, Garrett; Herrera, Steven; ...

2018-01-16

Ecological pressures and varied feeding behaviors in a multitude of organ-isms have necessitated the drive for adaptation. One such change is seen in the feeding appendages of stomatopods, a group of highly predatory marine crustaceans. Stomatopods include “spearers,” who ambush and snare soft bodied prey, and “smashers,” who bludgeon hard-shelled prey with a heavily mineralized club. The regional substructural complexity of the stomatopod dactyl club from the smashing predator Odontodactylus scyllarus represents a model system in the study of impact tolerant biominerals. The club consists of a highly mineralized impact region, a characteristic Bouligand architec-ture (common to arthropods), and amore » unique section of the club, the striated region, composed of highly aligned sheets of mineralized fibers. Detailed ultrastructural investigations of the striated region within O. scyllarus and a related species of spearing stomatopod, Lysiosquillina maculate show consistent organization of mineral and organic, but distinct differences in macro-scale architecture. Evidence is provided for the function and substructural exaptation of the striated region, which facilitated redeployment of a rapto-rial feeding appendage as a biological hammer. Furthermore, given the need to accelerate underwater and “grab” or “smash” their prey, the spearer and smasher appendages are specifically designed with a significantly reduced drag force.« less

Ultrastructural and Molecular Characterisation of an Heterosporis-Like Microsporidian in Australian Sea Snakes (Hydrophiinae)

PubMed Central

Gillett, Amber K.; Ploeg, Richard; O’Donoghue, Peter J.; Chapman, Phoebe A.; Webb, Richard I.; Flint, Mark; Mills, Paul C.

2016-01-01

Four sea snakes (two Hydrophis major, one Hydrophis platurus, one Hydrophis elegans) were found washed ashore on different beaches in the Sunshine Coast region and Fraser Island in Queensland, Australia between 2007–2013. Each snake had multiple granulomas and locally extensive regions of pallor evident in the hypaxial and intercostal musculature along the body. Lesions in two individuals were also associated with vertebral and rib fractures. Histological examination revealed granulomas scattered throughout skeletal muscle, subcutaneous adipose tissue and fractured bone. These were composed of dense aggregates of microsporidian spores surrounded by a mantle of macrophages. Sequences (ssrRNA) were obtained from lesions in three sea snakes and all revealed 99% similarity with Heterosporis anguillarum from the Japanese eel (Anguillarum japonica). However, ultrastructural characteristics of the organism were not consistent with those of previous descriptions. Electron microscopic examination of skeletal muscle revealed large cysts (not xenomas) bound by walls of fibrillar material (Heterosporis-like sporophorocyst walls were not detected). The cysts contained numerous mature microsporidian spores arranged in small clusters, sometimes apparently within sporophorous vesicles. The microspores were monomorphic, oval and measured 2.5–3.0 μm by 1.6–1.8 μm. They contained isofilar polar filaments with 11 (infrequently 9–12) coils arranged in two ranks. This is the first published report of a microsporidian infection in hydrophiid sea snakes. This discovery shows microsporidia with molecular affinities to Heterosporis anguillarum but ultrastructural characters most consistent with the genus Pleistophora (but no hitherto described species). Further studies are required to determine whether the microsporidian presented here belongs to the genus Heterosporis, or to a polymorphic species group as suggested by the recognition of a robust Pleistophora/Heterosporis clade by molecular studies. The gross and histological pathology associated with these infections are described. PMID:27007116

Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

PubMed

House, Alisoun; Balkwill, Kevin

2016-03-01

External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance.

Ultrastructural instability of paired helical filaments from corticobasal degeneration as examined by scanning transmission electron microscopy.

PubMed Central

Ksiezak-Reding, H.; Tracz, E.; Yang, L. S.; Dickson, D. W.; Simon, M.; Wall, J. S.

1996-01-01

Paired helical filaments (PHFs) accumulate in the brains of subjects affected with Alzheimer's disease (AD) and certain other neurodegenerative disorders, including corticobasal degeneration (CBD). Electron microscope studies have shown that PHFs from CBD differ from those of AD by being wider and having a longer periodicity of the helical twist. Moreover, PHFs from CBD have been shown to be primarily composed of two rather than three highly phosphorylated polypeptides of tau (PHF-tau), with these polypeptides expressing no exons 3 and 10. To further explore the relationship between the heterogeneity of PHF-tau and the appearance of abnormal filaments, the ultrastructure and physical parameters such as mass per unit length and dimensions were compared in filaments from CBD and AD using high resolution scanning transmission electron microscopy (STEM). Filament-enriched fractions were isolated as Sarcosyl-insoluble pellets and for STEM studies, samples were freeze-dried without prior fixation or staining. Ultrastructurally, PHFs from CBD were shown to be a heterogeneous population as double- and single-stranded filaments could be identified based on their width and physical mass per unit length expressed in kilodaltons (kd) per nanometer (nm). Less abundant, double-stranded filaments had a maximal width of 29 nm and a mass per unit length of 133 kd/nm, whereas three times more abundant single-stranded filaments were 15 nm wide and bad a mass per unit length of 62 kd/nm. Double-stranded filaments also displayed a distinct axial region of less dense mass, which appeared to divide the PHFs into two protofilament-like strands. Furthermore, these filaments were frequently observed to physically separate along the long axis into two single strands or to break longitudinally. In contrast, PHFs from AD were ultrastructurally stable and uniform both in their width (22 nm) and physical mass per unit length (104 kd/nm). The ultrastructural features indicate that filaments of CBD and AD differ both in stability and packing of tau and that CBD filaments, composed of two distinct protofilaments, are more labile under STEM conditions. As fixed and stained filaments from CBD have been shown to be stable and uniform in size by conventional transmission electron microscopy, STEM studies may be particularly suitable for detecting instability of unstained and unfixed filaments. The results also suggest that molecular heterogeneity and/or post-translational modifications of tau may strongly influence the morphology and stability of abnormal filaments. Images Figure 1 Figure 2 Figure 3 PMID:8702002

SOME ULTRASTRUCTURAL EFFECTS OF INSULIN, HYDROCORTISONE, AND PROLACTIN ON MAMMARY GLAND EXPLANTS

PubMed Central

Mills, Elinor S.; Topper, Yale J.

1970-01-01

The effects of insulin, hydrocortisone, and prolactin on the morphology of explants from midpregnant mouse mammary glands were studied. Insulin promotes the formation of daughter cells within the alveolar epithelium which are ultrastructurally indistinguishable from the parent cells. The addition of hydrocortisone to the medium containing insulin brings the daughter cells to a new, intermediate level of ultrastructural development by effecting an extensive increase of the rough endoplasmic reticulum (RER) throughout the cytoplasm and an increase in the lateral paranuclear Golgi apparatus. When prolactin is added to the insulin-hydrocortisone medium, the daughter cells complete their ultrastructural differentiation. There is a translocation of the RER, Golgi apparatus, and nucleus and the appearance of secretory protein granules within the cytoplasm. There is excellent correlation between the ultrastructural appearance of the alveoli and their capacity to synthesize casein. PMID:5460752

Natural history of experimental intestinal atresia: morphologic and ultrastructural study.

PubMed

Baglaj, S M; Czernik, J; Kuryszko, J; Kuropka, P

2001-09-01

The aim of this study was to evaluate a natural history of congenital intestinal atresia (IA) in the chick embryo and to assess the type and nature of changes in the intestine at various developmental stages. Chick embryos underwent operative induction of IA on the 12th day of incubation. The procedure consisted of electrocoagulation of the mesenteric vessels supplying a 7- to 8-mm intestinal segment. The embryos were subjected to macroscopic examination, histologic and ultrastructural studies of the preatretic and postatretic bowel using the light microscope, scanning, and transmission electron microscopes. All investigations were performed in an experimental group (operated embryos), in a control group, and in a sham-operated group on the 15th, 17th, 19th, and 21st day of incubation. The original technique of an iatrogenic "vascular event" proved to be effective because IA developed in 96% of embryos surviving the procedure. The affected portion of the bowel underwent progressive necrosis, and signs of bowel obstruction could be observed 48 hours after operation. Cord atresia (type II) developed in 81% of embryos. Histologic investigations showed progressive thinning of mucosa, flattening of mucosal folds, and epithelial detachment within the intestine proximal to atresia. There was only mild hypertrophy of the muscular layers. All these pathomorphologic changes were of rapidly progressive nature until the 17th day of incubation. Later, the rate of distension of preatretic bowel and histologic changes were less. Ultrastructural investigation of the proximal bowel showed progressive flattening of the enterocytes associated with their apical bulging, widening of the intercellular spaces, and microvilli atrophy. Surprisingly, at days 19 and 21 of incubation, signs of induction of adaptive mechanisms with partial restoration of near-normal microvilli pattern were observed. Study of natural history of experimental IA indicates that histologic and ultrastructural lesions of the bowel are of dynamic nature and are not only the effect of pathologic intraluminal pressure. Copyright 2001 by W.B. Saunders Company.

Ultrastructure of spermatozoa of Onthophagus taurus (Coleoptera, Scarabaeidae) exhibits heritable variation

NASA Astrophysics Data System (ADS)

Werner, Michael; Simmons, Leigh W.

2011-03-01

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.

Observations on the anterior testicular ducts in snakes with emphasis on sea snakes and ultrastructure in the yellow-bellied sea snake, Pelamis platurus.

PubMed

Sever, David M; Freeborn, Layla R

2012-03-01

The anterior testicular ducts of squamates transport sperm from the seminiferous tubules to the ductus deferens. These ducts consist of the rete testis, ductuli efferentes, and ductus epididymis. Many histological and a few ultrastructural studies of the squamate reproductive tract exist, but none concern the Hydrophiidae, the sea snakes and sea kraits. In this study, we describe the anterior testicular ducts of six species of hydrophiid snakes as well as representatives from the Elapidae, Homolapsidae, Leptotyphlopidae, and Uropeltidae. In addition, we examine the ultrastructure of these ducts in the yellow-bellied Sea Snake, Pelamis platurus, only the third such study on snakes. The anterior testicular ducts are similar in histology in all species examined. The rete testis is simple squamous or cuboidal epithelium and transports sperm from the seminiferous tubules to the ductuli efferentes in the extratesticular epididymal sheath. The ductuli efferentes are branched, convoluted tubules composed of simple cuboidal, ciliated epithelium, and many species possess periodic acid-Schiff+ granules in the cytoplasm. The ductus epididymis at the light microscopy level appears composed of pseudostratified columnar epithelium. At the ultrastructural level, the rete testis and ductuli efferentes of P. platurus possess numerous small coated vesicles and lack secretory vacuoles. Apocrine blebs in the ductuli efferentes, however, indicate secretory activity, possibly by a constitutive pathway. Ultrastructure reveals three types of cells in the ductus epididymis of P. platurus: columnar principal cells, squamous basal cells, and mitochondria-rich apical cells. This is the first report of apical cells in a snake. In addition, occasional principal cells possess a single cilium, which has not been reported in reptiles previously but is known in some birds. Finally, the ductus epididymis of P. platurus differs from other snakes that have been studied in possession of apical, biphasic secretory vacuoles. All of the proximal ducts are characterized by widening of adjacent plasma membranes into wide intercellular spaces, especially between the principal cells of the ductus epididymis. Our results contribute to a larger, collaborative study of the evolution of the squamate reproductive tract and to the potential for utilizing cellular characters in future phylogenetic inferences. Copyright © 2011 Wiley Periodicals, Inc.

Cutaneous Malignant Melanoma With Rhabdoid Morphology and Smooth Muscle Differentiation: A Challenging Histopathologic Diagnosis.

PubMed

Prieto-Torres, Lucía; Alegría-Landa, Victoria; Llanos, Concepción; Córdoba, Alicia; Kutzner, Heinz; Requena, Luis

2017-05-01

Divergent differentiation or metaplastic change is a rare feature exhibited occasionally in malignant melanoma (MM), which is characterized by the development of morphologically, immunochemically, and/or ultrastructurally nonmelanocytic cells within the tumor. Smooth muscle differentiation in MM is an exceedingly rare phenomenon reported only in a few cases in the literature. We report the case of a 69-year-old woman who presented with a pure dermal amelanotic MM with smooth muscle cell differentiation and an area of rhabdoid morphology, which made the accurate histopathologic diagnostic of MM challenging.

Attenuation of endocrine-exocrine pancreatic communication in type 2 diabetes: pancreatic extracellular matrix ultrastructural abnormalities.

PubMed

Hayden, Melvin R; Patel, Kamlesh; Habibi, Javad; Gupta, Deepa; Tekwani, Seema S; Whaley-Connell, Adam; Sowers, James R

2008-01-01

Ultrastructural observations reveal a continuous interstitial matrix connection between the endocrine and exocrine pancreas, which is lost due to fibrosis in rodent models and humans with type 2 diabetes mellitus (T2DM). Widening of the islet-exocrine interface appears to result in loss of desmosomes and adherens junctions between islet and acinar cells and is associated with hypercellularity consisting of pericytes and inflammatory cells in T2DM pancreatic tissue. Organized fibrillar collagen was closely associated with pericytes, which are known to differentiate into myofibroblasts-pancreatic stellate cells. Of importance, some pericyte cellular processes traverse both the connecting islet-exocrine interface and the endoacinar interstitium of the exocrine pancreas. Loss of cellular paracrine communication and extracellular matrix remodeling fibrosis in young animal models and humans may result in a dysfunctional insulino-acinar-ductal-incretin gut hormone axis, resulting in pancreatic insufficiency and glucagon-like peptide deficiency, which are known to exist in prediabetes and overt T2DM in humans.

Attenuation of Endocrine-Exocrine Pancreatic Communication in Type 2 Diabetes: Pancreatic Extracellular Matrix Ultrastructural Abnormalities

PubMed Central

Hayden, Melvin R; Patel, Kamlesh; Habibi, Javad; Gupta, Deepa; Tekwani, Seema S.; Whaley-Connell, Adam; Sowers, James R.

2009-01-01

Ultrastructural observations reveal a continuous interstitial matrix connection between the endocrine and exocrine pancreas, which is lost due to fibrosis in rodent models and humans with type 2 diabetes mellitus (T2DM). Widening of the islet exocrine interface (IEI) appears to result in loss of desmosomes and adherens junctions between islet and acinar cells and is associated with hypercellularity consisting of pericytes and inflammatory cells in T2DM pancreatic tissue. Organized fibrillar collagen was closely associated with pericytes, which are known to differentiate into myofibroblasts – pancreatic stellate cells. Importantly, some pericyte cellular processes traverse both the connecting IEI and the endoacinar interstitium of the exocrine pancreas. Loss of cellular paracrine communication and extracellular matrix remodeling fibrosis in young animal models and humans may result in a dysfunctional insulino-acinar-ductal – incretin gut hormone axis resulting in pancreatic insufficiency and glucagon like peptide deficiency known to exist in prediabetes and overt T2DM in humans. PMID:19040593

Microanatomy and ultrastructure of the excretory system of two pelagic opisthobranch species (Gastropoda: Gymnosomata and Thecosomata).

PubMed

Fahrner, A; Haszprunar, G

2000-04-01

The microanatomy and ultrastructure of the excretory system of Pneumoderma sp. (Gymnosomata) and Creseis virgula Rang, 1828 (Thecosomata) have been investigated by means of semithin serial sections, reconstructions and transmission electron microscopy. The studies revealed a functional metanephridial system consisting of a heart with a single ventricle and auricle in a pericardial cavity and a single kidney in both species. Podocytes in the atrial wall of the pericardial epithelium are the site of ultrafiltration, whereas the flat epithelium of the kidney with numerous basal infoldings and a dense microvillous border on the luminal surface suggests modification of the ultrafiltrate. In Pneumoderma sp., additional loci of ultrafiltration with identical fine structure (meandering slits with diaphragms covered by extracellular matrix) occur in the solitary rhogocytes (pore cells). The presence of podocytes situated on the atrial wall in representatives of two higher opisthobranch taxa contradicts former ideas on the loss of the primary site of ultrafiltration in the ancestors of the Opisthobranchia.

Clathrin-independent carriers form a high capacity endocytic sorting system at the leading edge of migrating cells

PubMed Central

Howes, Mark T.; Kirkham, Matthew; Riches, James; Cortese, Katia; Walser, Piers J.; Simpson, Fiona; Hill, Michelle M.; Jones, Alun; Lundmark, Richard; Lindsay, Margaret R.; Hernandez-Deviez, Delia J.; Hadzic, Gordana; McCluskey, Adam; Bashir, Rumasia; Liu, Libin; Pilch, Paul; McMahon, Harvey; Robinson, Phillip J.; Hancock, John F.; Mayor, Satyajit

2010-01-01

Although the importance of clathrin- and caveolin-independent endocytic pathways has recently emerged, key aspects of these routes remain unknown. Using quantitative ultrastructural approaches, we show that clathrin-independent carriers (CLICs) account for approximately three times the volume internalized by the clathrin-mediated endocytic pathway, forming the major pathway involved in uptake of fluid and bulk membrane in fibroblasts. Electron tomographic analysis of the 3D morphology of the earliest carriers shows that they are multidomain organelles that form a complex sorting station as they mature. Proteomic analysis provides direct links between CLICs, cellular adhesion turnover, and migration. Consistent with this, CLIC-mediated endocytosis of key cargo proteins, CD44 and Thy-1, is polarized at the leading edge of migrating fibroblasts, while transient ablation of CLICs impairs their ability to migrate. These studies provide the first quantitative ultrastructural analysis and molecular characterization of the major endocytic pathway in fibroblasts, a pathway that provides rapid membrane turnover at the leading edge of migrating cells. PMID:20713605

[Ultrastructural observation of tendonization of artificial tendon 109HH in rabbit].

PubMed

Liu, L; Cao, Q; Xiao, H

1995-09-01

Ten New Zealand rabbits were divided into 5 groups at random. Calcaneal tendons were cut bilaterally, then atificial tendon 109HH was used to connect the two ends of the cut tendon. Ultrastructural changes of control group and experimental groups at 2, 6, 12, 28 weeks after section were observed. The results showed that fibroblast proliferated and a lot of ribosome and RER appeared in plasm during 2 approximately 6 weeks, indicating artificial tendon caused fibroblast proliferation. During this period, fibroblast over synthesized collagenous protein and the synthesis of collagenous fibers peaked. During 12-28 weeks, the number of fibroblasts and the synthesis of collagenous protein decreased. Finally, fibroblasts became inactive tendon cells. With the formation of new tendons, the artificial tendens were degradated and absorbed, and disappeared after 12 weeks. The new tendon fibers became thicker and had the correct direction through reconstruction. The structure and function of new tendons could be restored to be consistent with normal values.

Cilia-like structures anchor the amphioxus notochord to its sheath.

PubMed

Bočina, Ivana; Ljubešić, Nikola; Saraga-Babić, Mirna

2011-01-01

Body stiffness is important during undulatory locomotion in fish. In amphioxus, the myosepta play an important role in transmission of muscular forces to the notochord. In order to define the specific supporting role of the notochord in amphioxus during locomotion, the ultrastructure of 10 adult amphioxus specimens was analyzed using transmission electron microscopy. Numerous cilia-like structures were found on the surface of each notochordal cell at the sites of their attachment to the notochordal sheath. Ultrastructurally, these structures consisted of the characteristic arrangement of peripheral and central microtubular doublets and were anchored to the inner layer of the notochordal sheath. Immunohistochemically, a positive reaction to applied dynein and β-tubulin antibodies characterized the area of the cilia-like structures. We propose that reduced back-and-forth movements of the cilia-like structures might contribute to the flow of the fluid content inside the notochord, thus modulating the stiffness of the amphioxus body during its undulatory locomotion. Copyright © 2009 Elsevier GmbH. All rights reserved.

Image analysis of pubic bone for age estimation in a computed tomography sample.

PubMed

López-Alcaraz, Manuel; González, Pedro Manuel Garamendi; Aguilera, Inmaculada Alemán; López, Miguel Botella

2015-03-01

Radiology has demonstrated great utility for age estimation, but most of the studies are based on metrical and morphological methods in order to perform an identification profile. A simple image analysis-based method is presented, aimed to correlate the bony tissue ultrastructure with several variables obtained from the grey-level histogram (GLH) of computed tomography (CT) sagittal sections of the pubic symphysis surface and the pubic body, and relating them with age. The CT sample consisted of 169 hospital Digital Imaging and Communications in Medicine (DICOM) archives of known sex and age. The calculated multiple regression models showed a maximum R (2) of 0.533 for females and 0.726 for males, with a high intra- and inter-observer agreement. The method suggested is considered not only useful for performing an identification profile during virtopsy, but also for application in further studies in order to attach a quantitative correlation for tissue ultrastructure characteristics, without complex and expensive methods beyond image analysis.

Ultrastructural characterization of primary cilia in pathologically characterized human glioblastoma multiforme (GBM) tumors.

PubMed

Moser, Joanna J; Fritzler, Marvin J; Rattner, Jerome B

2014-01-01

Primary cilia are non-motile sensory cytoplasmic organelles that are involved in cell cycle progression. Ultrastructurally, the primary cilium region is complex, with normal ciliogenesis progressing through five distinct morphological stages in human astrocytes. Defects in early stages of ciliogenesis are key features of astrocytoma/glioblastoma cell lines and provided the impetus for the current study which describes the morphology of primary cilia in molecularly characterized human glioblastoma multiforme (GBM) tumors. Seven surgically resected human GBM tissue samples were molecularly characterized according to IDH1/2 mutation status, EGFR amplification status and MGMT promoter methylation status and were examined for primary cilia expression and structure using indirect immunofluorescence and electron microscopy. We report for the first time that primary cilia are disrupted in the early stages of ciliogenesis in human GBM tumors. We confirm that immature primary cilia and basal bodies/centrioles have aberrant ciliogenesis characteristics including absent paired vesicles, misshaped/swollen vesicular hats, abnormal configuration of distal appendages, and discontinuity of centriole microtubular blades. Additionally, the transition zone plate is able to form in the absence of paired vesicles on the distal end of the basal body and when a cilium progresses beyond the early stages of ciliogenesis, it has electron dense material clumped along the transition zone and a darkening of the microtubules at the proximal end of the cilium. Primary cilia play a role in a variety of human cancers. Previously primary cilia structure was perturbed in cultured cell lines derived from astrocytomas/glioblastomas; however there was always some question as to whether these findings were a cell culture phenomena. In this study we confirm that disruptions in ciliogenesis at early stages do occur in GBM tumors and that these ultrastructural findings bear resemblance to those previously observed in cell cultures. This is the first study to demonstrate that defects in cilia expression and function are a true hallmark of GBM tumors and correlate with their unrestrained growth. A review of the current ultrastructural profiles in the literature provides suggestions as to the best possible candidate protein that underlies defects in the early stages of ciliogenesis within GBM tumors.

Ependymal cells variations in the central canal of the rat spinal cord filum terminale: an ultrastructural investigation.

PubMed

Mitro, A; Gallatz, K; Palkovits, M; Kiss, A

2013-04-01

The ependymal cells, considered today as an active participant in neuroendocrine functions, were investigated by electron microscopy in the central canal of the lowest spinal cord, the filum terminale (FT), in adult rats. In this area of the spinal cord, the central canal is covered by a heterogeneous population of ependymal cells. The aim of the present work was to compare the regional features of the ependymal cells in two different parts of the FT with a special regard to their ultrastructure. Two parts of the FT were selected for the ultrastructural observations: the rostral (rFT) and the caudal (cFT) ones. The rTF was removed at the level of the immediate continuation of the conus medullaris, while the cFT 30 mm further caudally. After formaldehyde fixation, the spinal cord was removed and cut into small blocks for electron microscopic processing. The material was embedded into durcupan, contrasted with uranyl acetate, lead citrate as well as osmium tetroxide, and investigated under JEOL 1200 EX electron microscope. In the rFT, the ependymal lining is pseudostratified and one-layered in the cFT, whereas the shape of the ependymal cells may vary from cuboidal to flatten in the rostro-caudal direction. The basal membrane of many ependymal cells possesses deep invaginations, so called "filum terminale labyrinths". Many neuronal processes occur in the pericanalicular neuropil. In contrast to the rFT, the cFT is less rich in the neuropil particles. Some of the ependymal cells concurrently reach both the intracanalicular and extracanalicular cerebrospinal fluid (CSF), thus they may represent a new variant of the ependymal cells designated as "bridge cells of the FT". The present data indicate that the FT ependymal cells exhibit clear differences in anatomy as well as ultrastructure that may reflect their distinct functional activity. Therefore, observations presented here may serve for the better understanding of the physiological role of the individual ependymal areas in this special portion of the rat spinal cord.

[Cellphone electromagnetic radiation damages the testicular ultrastructure of male rats].

PubMed

Gao, Xiao-Hui; Hu, Hui-Rong; Ma, Xue-Lian; Chen, Jie; Zhang, Guo-Hong

2016-06-01

To investigate the influence of cellphone electromagnetic radiation (CER) on the testicular ultrastructure and the apoptosis of spermatogenic cells in male rats.atability, feasibility, applicability, and controllability in the construction of experimental animal models, we compared the major anatomic features of the penis of 20 adult beagle dogs with those of 10 adult men. Using microsurgical techniques, we performed cross-transplantation of the penis in the 20 (10 pairs) beagle dogs and observed the survival rate of the transplanted penises by FK506+MMF+MP immune induction. We compared the relevant indexes with those of the 10 cases of microsurgical replantation of the amputated penis. Thirty adult male SD rats were equally randomized into a 2 h CER, a 4 h CER, and a normal control group, the former two groups exposed to 30 days of 900 MHz CER for 2 and 4 hours a day, respectively, while the latter left untreated. Then the changes in the ultrastructure of the testis tissue were observed under the transmission electron microscope and the apoptosis of the spermatogenic cells was determined by TUNEL. Compared with the normal controls, the rats of the 2 h CER group showed swollen basement membrane of seminiferous tubules, separated tight junction of Sertoli cells, increased cell intervals, apparent vacuoles and medullization in some mitochondria, and increased apoptosis of spermatogenic cells, mainly the apoptosis of primary spermatocytes (P<0.05 ). In comparison with the 2 h CER group, the animals of the 4 h CER group exhibited swollen basement membrane of seminiferous tubules, more separated tight junction of Sertoli cells, wider cell intervals, incomplete membrane of spermatogonial cells, fragments of cytoplasm, nuclear pyknosis and notch, slight dilation of perinuclear space, abnormalities of intracellular mitochondria with vacuoles, fuzzy structure, and fusion or disappearance of some cristae, and increased damage of mitochondria and apoptosis of spermatogenic cells, including the apoptosis of spermatogonial cells, primary spermatocytes, and secondary spermatocytes (P<0.05 ). CER can damage the testicular ultrastructure and increase the apoptosis of spermatogenic cells of the male rat in a time-dependent manner, and the apoptosis of spermatogenic cells may be associated with the damage to mitochondria.

Ultrastructure and morphogenesis of the wing scales in Heliconius erato phyllis (Lepidoptera: Nymphalidae): what silvery/brownish surfaces can tell us about the development of color patterning?

PubMed

Aymone, A C B; Valente, V L S; de Araújo, A M

2013-09-01

Usually the literature on Heliconius show three types of scales, classified based on the correlation between color and ultrastructure: type I - white and yellow, type II - black, and type III - orange and red. The ultrastructure of the scales located at the silvery/brownish surfaces of males/females is for the first time described in this paper. Besides, we describe the ontogeny of pigmentation, the scale morphogenesis and the maturation timing of scales fated to different colors in Heliconius erato phyllis. The silvery/brownish surfaces showed ultrastructurally similar scales to the type I, II and III. The ontogeny of pigmentation follows the sequence red, black, silvery/brownish and yellow. The maturation of yellow-fated scales, however, occurred simultaneously with the red-fated scales, before the pigmentation becomes visible. In spite of the scales at the silvery/brownish surfaces being ultrastructurally similar to the yellow, red and black scales, they mature after them; this suggests that the maturation timing does not show a relationship with the scale ultrastructure, with the deposition timing of the yellow pigment. The analysis of H. erato phyllis scale morphogenesis, as well as the scales ultrastructure and maturation timing, provided new findings into the developmental architecture of color pattern in Heliconius. Copyright © 2013 Elsevier Ltd. All rights reserved.

Value of transmission electron microscopy for primary ciliary dyskinesia diagnosis in the era of molecular medicine: Genetic defects with normal and non-diagnostic ciliary ultrastructure.

PubMed

Shapiro, Adam J; Leigh, Margaret W

2017-01-01

Primary ciliary dyskinesia (PCD) is a genetic disorder causing chronic oto-sino-pulmonary disease. No single diagnostic test will detect all PCD cases. Transmission electron microscopy (TEM) of respiratory cilia was previously considered the gold standard diagnostic test for PCD, but 30% of all PCD cases have either normal ciliary ultrastructure or subtle changes which are non-diagnostic. These cases are identified through alternate diagnostic tests, including nasal nitric oxide measurement, high-speed videomicroscopy analysis, immunofluorescent staining of axonemal proteins, and/or mutation analysis of various PCD causing genes. Autosomal recessive mutations in DNAH11 and HYDIN produce normal TEM ciliary ultrastructure, while mutations in genes encoding for radial spoke head proteins result in some cross-sections with non-diagnostic alterations in the central apparatus interspersed with normal ciliary cross-sections. Mutations in nexin link and dynein regulatory complex genes lead to a collection of different ciliary ultrastructures; mutations in CCDC65, CCDC164, and GAS8 produce normal ciliary ultrastructure, while mutations in CCDC39 and CCDC40 cause absent inner dynein arms and microtubule disorganization in some ciliary cross-sections. Mutations in CCNO and MCIDAS cause near complete absence of respiratory cilia due to defects in generation of multiple cellular basal bodies; however, the scant cilia generated may have normal ultrastructure. Lastly, a syndromic form of PCD with retinal degeneration results in normal ciliary ultrastructure through mutations in the RPGR gene. Clinicians must be aware of these genetic causes of PCD resulting in non-diagnostic TEM ciliary ultrastructure and refrain from using TEM of respiratory cilia as a test to rule out PCD.

Observations on the sexual segment of the kidney of snakes with emphasis on ultrastructure in the yellow-bellied sea snake, Pelamis platurus.

PubMed

Sever, David M; Rheubert, Justin L; Gautreaux, Jillian; Hill, Toren G; Freeborn, Layla R

2012-05-01

The sexual segment of the kidney (SSK) is an accessory sex structure in male lizards and snakes (Squamata). We describe histology of the SSK in 12 species of snakes, including one from the basal Scolecophidia, Leptotyphlops dulcis, and from the more advanced Alethinophidia, species from the Acrochordidae (Acrochordus granulatus), Homalopsidae (Cerberus rynchops), Uropeltidae (Teretrurus sanguineus), and eight species from the Elapidae, including six species of sea snakes. We also describe the ultrastructure of the SSK of the sea snake, Pelamis platurus. The SSK of L. dulcis does not include the ureter but does include distal convoluted tubules (DCTs) and collecting ducts. In all other snakes examined, the SSK is limited to the DCTs and does not differ in histology by any consistent character. We found apparently mature individuals of several species with inactive SSKs. Hypertrophied SSKs give positive reactions for protein secretions but variable reactions for carbohydrates. Ultrastructure of the SSK of P. platurus reveals nuclei situated medially in the epithelium and mature electron dense secretory vacuoles in other areas of the cytoplasm. Product release is apocrine. Junctional complexes only occur at the luminal border, and intercellular canaliculi become widened and are open basally. No cytologically unique characters occur in the SSK of P. platurus. The ancestral condition of the SSK in squamates is the presence of simple columnar epithelium specialized for secretion of a protein + carbohydrate product that matures and is released seasonally. Copyright © 2012 Wiley Periodicals, Inc.

Effects of mild ozonisation on gene expression and nuclear domains organization in vitro.

PubMed

Scassellati, C; Costanzo, M; Cisterna, B; Nodari, A; Galiè, M; Cattaneo, A; Covi, V; Tabaracci, G; Bonvicini, C; Malatesta, M

2017-10-01

In the last two decades, the use of ozone (O 3 ) as a complementary medical approach has progressively been increasing; however, its application is still limited due to the numerous doubts about its possible toxicity, despite the low concentrations used in therapy. For an appropriate and safe clinical application of a potentially toxic agent such as O 3 , it is crucial to elucidate the cellular response to its administration. Molecular analyses and transmission electron microscopy were here combined to investigate in vitro the effects of O 3 administration on transcriptional activity and nuclear domains organization of cultured SH-SY5Y neuronal cells; low O 3 concentrations were used as those currently administered in clinical practice. Mild ozonisation did not affect cell proliferation or death, while molecular analyses showed an O 3 -induced modulation of some genes involved in the cell response to stress (HMOX1, ERCC4, CDKN1A) and in the transcription machinery (CTDSP1). Ultrastructural cytochemistry after experiments of bromouridine incorporation consistently demonstrated an increased transcriptional rate at both the nucleoplasmic (mRNA) and the nucleolar (rRNA) level. No ultrastructural alteration of nuclear domains was observed. Our molecular, ultrastructural and cytochemical data demonstrate that a mild toxic stimulus such as mild ozonisation stimulate cell protective pathways and nuclear transcription, without altering cell viability. This could possibly account for the positive effects observed in ozone-treated patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

A proteomic and ultrastructural characterization of Aspergillus fumigatus' conidia adaptation at different culture ages.

PubMed

Anjo, Sandra I; Figueiredo, Francisco; Fernandes, Rui; Manadas, Bruno; Oliveira, Manuela

2017-05-24

The airborne fungus Aspergillus fumigatus is one of the most common agents of human fungal infections with a remarkable impact on public health. However, A. fumigatus conidia atmospheric resistance and longevity mechanisms are still unknown. Therefore, in this work, the processes underlying conidial adaptation were studied by a time course evaluation of the proteomics and ultrastructural changes of A. fumigatus' conidia at three time-points selected according to relevant changes previously established in conidial survival rates. The proteomics characterization revealed that conidia change from a highly active metabolic to a dormant state, culminating in cell autolysis as revealed by the increased levels of hydrolytic enzymes. Structural characterization corroborates the proteomics data, with noticeable changes observed in mitochondria, nucleus and plasma membrane ultrastructure, accompanied by the formation of autophagic vacuoles. These changes are consistent with both apoptotic and autophagic processes, and indicate that the changes in protein levels may anticipate those in cell morphology. The findings presented in this work not only clarify the processes underlying conidial adaptation to nutrient limiting conditions but can also be exploited for improving infection control strategies and in the development of new therapeutical drugs. Additionally, the present study was deposited in a public database and thus, it may also be a valuable dataset to be used by the scientific community as a tool to understand and identified other potential targets associated with conidia resistance. Copyright © 2017. Published by Elsevier B.V.

Ultrastructure of the mycangium of the southern pine beetle, Dendroctonus frontalis (Coleoptera: Curculionidae, Scolytinae): complex morphology for complex interactions

Treesearch

Cetin Yuceer; Chuan-Yu Hsu; Nadir Erbilgin; Kier D. Klepzig

2011-01-01

The southern pine beetle (SPB) (Dendroctonus frontalis Zimmermann) is the most economically important pest of southern pine forests. Beetles carry fungal cells within specialised cuticular structures, called mycangia. Little is known about the mycangia ultrastructure or function. We used cryo-fracturing and scanning electron microscopy to examine the ultrastructural...

Protothecal granulomatous meningoencephalitis in a dog.

PubMed

Salvadori, C; Gandini, G; Ballarini, A; Cantile, C

2008-10-01

A case of central nervous system protothecosis in a dog is reported. A three-year-old male Maremma sheepdog was referred with a two month history of diarrhoea associated with progressive tetraparesis, depression and right circling. Stupor, severe proprioceptive deficits, bilateral decreased thoracic limb flexor reflexes and bilateral deficit of the menace reaction were detected on neurological examination and a multi-focal neurological localisation was suspected. Histopathological evaluation revealed multi-focal granulomatous foci in the thalamus, hippocampus and caudal brainstem containing numerous oval-rounded organisms with a thick, periodic acid-Schiff-positive and Gomori's methenamine silver-positive cell wall, a basophilic cytoplasm and one nucleus. Scattered sporangia containing two to four endospores were also observed. Morphological features were consistent with Prototheca species. Ultrastructurally, numerous degenerated algae were present within macrophages mainly lacking nuclei and cytoplasmic organelles. Generally, protothecosis in dogs is characterised by systemic signs because of a multi-organ involvement, and haemorrhagic colitis or ophthalmologic signs are the most frequent presenting signs. However, protothecosis should be added, also in Europe, to the list of the differential diagnoses in adult dogs with a multi-focal neurological localisation even in absence of other clinical signs.

Imidazole-containing phthalazine derivatives inhibit Fe-SOD performance in Leishmania species and are active in vitro against visceral and mucosal leishmaniasis.

PubMed

Sánchez-Moreno, M; Gómez-Contreras, F; Navarro, P; Marín, C; Ramírez-Macías, I; Rosales, M J; Campayo, L; Cano, C; Sanz, A M; Yunta, M J R

2015-07-01

The in vitro leishmanicidal activity of a series of imidazole-containing phthalazine derivatives 1-4 was tested on Leishmania infantum, Leishmania braziliensis and Leishmania donovani parasites, and their cytotoxicity on J774·2 macrophage cells was also measured. All compounds tested showed selectivity indexes higher than that of the reference drug glucantime for the three Leishmania species, and the less bulky monoalkylamino substituted derivatives 2 and 4 were clearly more effective than their bisalkylamino substituted counterparts 1 and 3. Both infection rate measures and ultrastructural alterations studies confirmed that 2 and 4 were highly leishmanicidal and induced extensive parasite cell damage. Modifications to the excretion products of parasites treated with 2 and 4 were also consistent with substantial cytoplasmic alterations. On the other hand, the most active compounds 2 and 4 were potent inhibitors of iron superoxide dismutase enzyme (Fe-SOD) in the three species considered, whereas their impact on human CuZn-SOD was low. Molecular modelling suggests that 2 and 4 could deactivate Fe-SOD due to a sterically favoured enhanced ability to interact with the H-bonding net that supports the antioxidant features of the enzyme.

Association of eosinophilic myositis with an unusual species of Sarcocystis in a beef cow.

PubMed Central

Gajadhar, A A; Yates, W D; Allen, J R

1987-01-01

The carcass of a mature cow had numerous, disseminated lesions typical of eosinophilic myositis. To elucidate the nature and possible cause of the lesions, histological sections were examined by light microscopy and selected areas were removed and processed for electron microscopy. The lesions were granulomatous in nature. Each granuloma contained at its centre an intact or ruptured sarcocyst associated with degenerate muscle fibers. Surrounding this was a layer of epithelioid cells and an intense accumulation of inflammatory cells, most of which were eosinophils. The primary cyst wall of the sarcocysts in these granulomas consisted of hair-like protrusions that featured many unusual electron-dense bodies. Sarcocysts with ultrastructures characteristic of Sarcocystis cruzi and Sarcocystis hirsuta were also present in muscle from the same animal, but these sarcocysts lacked any associated cellular responses. The eosinophilic myositis in this case appeared to be associated with sarcocystosis of an unknown species. Possibly, the inflammatory reaction was due to the host-parasite interaction in an unusual host. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:3115553

Spindle cell oncocytomas and granular cell tumors of the pituitary are variants of pituicytoma.

PubMed

Mete, Ozgur; Lopes, Maria Beatriz; Asa, Sylvia L

2013-11-01

Pituicytomas are neoplasms that arise from pituicytes, which are specialized glia of the posterior pituitary. Pituicytes have 5 ultrastructural variants: light, dark, granular, ependymal, and oncocytic. Granular cell tumors of the pituitary gland are thought to arise from granular pituicytes. Spindle cell oncocytomas are considered to arise from folliculostellate cells, which are sustentacular cells of the adenohypophysis. Recent data suggest that, whereas pituicytes and all 3 tumor types are positive for TTF-1, folliculostellate cells are negative for TTF-1. We investigated 7 spindle cell oncocytomas, 4 pituicytomas, and 3 granular cell tumors for their genetic (BRAF(V600E) mutation and BRAF-KIAA fusion), immunohistochemical (GFAP, vimentin, S100 protein, olig2, IDH1-R132H, NF, galectin-3, chromogranin-A, CD56, EMA, CAM5.2, CD68, TTF-1, and bcl-2), and ultrastructural features to refine their classification. All tumors had nuclear positivity for TTF-1 and were negative for CAM5.2, chromogranin-A, and NF. GFAP, vimentin, S100, galectin-3, EMA, and CD68 were variably positive in the majority of the 3 tumor groups. Olig2 was only positive in 1 pituicytoma. Whereas granular cell tumors were negative for bcl-2 and CD56, pituicytomas and spindle cell oncocytomas showed variable positivity. All tumors were negative with the IDH1-R132H mutation-specific antibody, and none had evidence of BRAF alterations (BRAF(V600E) mutation and BRAF-KIAA fusion). Diffuse TTF-1 expression in nontumorous pituicytes, pituicytomas, spindle cell oncocytomas, and granular cell tumors indicates a common pituicyte lineage. The ultrastructural variants of pituicytes are reflected in these 3 morphologic variants of tumors arising from these cells. We propose the terminology "oncocytic pituicytomas" and "granular cell pituicytomas" to refine the classification of these lesions.

Intermediate filament proteins and actin isoforms as markers for soft-tissue tumor differentiation and origin. III. Hemangiopericytomas and glomus tumors.

PubMed Central

Schürch, W.; Skalli, O.; Lagacé, R.; Seemayer, T. A.; Gabbiani, G.

1990-01-01

Intermediate filament proteins and actin isoforms of a series of 12 malignant hemangiopericytomas and five glomus tumors were examined by light microscopy, transmission electron microscopy, two-dimensional gel electrophoresis (2D-GE), and by immunohistochemistry, the latter using monoclonal or affinity-purified polyclonal antibodies to desmin, vimentin, cytokeratins, alpha-smooth muscle, and alpha-sarcomeric actins. By light microscopy, all hemangiopericytomas disclosed a predominant vascular pattern with scant storiform, myxoid and spindle cell areas, and with variable degrees of perivascular fibrosis. By ultrastructure, smooth muscle differentiation was observed in each hemangiopericytoma. Immunohistochemically, neoplastic cells of hemangiopericytomas expressed vimentin as the sole intermediate filament protein and lacked alpha-smooth muscle or alpha-sarcomeric actins. 2D-GE revealed only beta and gamma actins, in proportions typical for fibroblastic tissues. Glomus tumors revealed vimentin and alpha-smooth muscle actin within glomus cells by immunohistochemical techniques and disclosed ultrastructurally distinct smooth muscle differentiation. Therefore hemangiopericytomas represent a distinct soft-tissue neoplasm with uniform morphologic, immunohistochemical, and biochemical features most likely related to glomus tumors, the former representing an aggressive and potentially malignant neoplasm of vascular smooth muscle cells and the latter a well-differentiated neoplasm of vascular smooth muscle cells. Because malignant hemangiopericytomas disclose smooth muscle differentiation by ultrastructure, but do not express alpha-smooth muscle actin, as normal pericytes and glomus cells, it is suggested that these neoplasms represent highly vascularized smooth muscle neoplasms, ie, poorly differentiated leiomyosarcomas derived from vascular smooth muscle cells or their equivalent, the pericytes, which have lost alpha-smooth muscle actin as a differentiation marker that is similar to many conventional poorly differentiated leiomyosarcomas. Images Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2158236

Tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages

PubMed Central

Woo, Ho-Choon; Hong, Sung-Jong

2002-01-01

The present study was performed to observe tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages. Worms (1, 3, 5 and 15-day old) were recovered from chicks experimentally infected with metacercariae from Radix auricularia coreana. One-day old worms were elongated and ventrally concave, and covered with peg-like tegumental spines except the adjacent areas of the head crown and excretory pore. Type I sensory papillae were distributed on the lip of the oral sucker, and grouped ciliated papillae were around the oral sucker. Peg-like tegumental spines were densely distributed on the anterior surface of the ventral sucker level. The ventral sucker had an aspinous tegument and no sensory papillae. Tegumental spines on the posterior surface of the ventral sucker level were sparsely distributed and disappeared posteriorly. In 3 and 5-day old worms, the tegument around the oral sucker was aspinose and wrinkled concentrically. The ventral sucker had a wrinkled tegument and many bulbous papillae. Type I sensory papillae were distributed between the bulbous papillae. Tegumental spines were spade-shaped with a terminal tip. A total of 45 collar spines including 4 end group ones on both ventral corners was alternately arranged in 2 rows. The 15-day old worms were very stout and their tegumental spines were tongue-shaped without a terminal tip. From the above results, it is confirmed that the surface ultrastructure of E. recurvatum was generally similar to that of other echinostomatid flukes. However, some features, i.e., morphological change of tegumental spines and appearence of sensory papillae on the ventral sucker according to development, and number, shape and arrangement of collar spines, were characteristic, which may be of taxonomic and bioecological significance. PMID:12073731

Ultrastructure of hybrid chitosan-glycerol phosphate blood clots by environmental scanning electron microscopy.

PubMed

Iliescu, M; Hoemann, C D; Shive, M S; Chenite, A; Buschmann, M D

2008-03-01

Chitosan-based polymers have been extensively studied for biomedical applications. Recently, liquid solutions of chitosan in a glycerol phosphate buffer (chitosan-GP) with physiological pH and osmolality were mixed with autologous blood to form hybrid chitosan-GP/blood implants that improved the repair of articular cartilage lesions in a large animal model. The mixture of chitosan-GP and blood forms a viscous liquid, which solidifies in minutes via normal blood coagulation as well as chitosan-mediated mechanisms. Here we have examined the ultrastructure of these chitosan-GP/blood clots as well as regular blood clots and chitosan-GP gels, the latter produced by heating. Both unfixed and fixed samples of chitosan-GP/blood clots, regular blood clots, and chitosan-GP gels were investigated by environmental scanning electron microscopy (ESEM) in conjunction with energy dispersive X-ray spectrometry (EDS), the former permitting direct observation of the ultrastructure in hydrated conditions simulating the natural state. By examination of unfixed specimens using ESEM we found that chitosan formed a network structure in both chitosan-GP gels and chitosan-GP/blood clots; however this structure was altered by aldehyde fixation to produce artifactual aggregates of chitosan microparticles. We were also able to identify chitosan in chitosan-GP/blood clots by washing samples in low concentration NaCl solutions followed by local EDS analyses to identify excess chloride versus sodium, and thus presence of cationic chitosan in analyzed features. Additional results indicated that the majority of glycerol phosphate diffuses freely from chitosan-GP gels (by EDS of phosphorus) and that hyperosmotic paraformaldehyde-based fixatives (i.e. 4% w/v) significantly disturb erythrocyte morphology in fixed whole blood clots. (c) 2007 Wiley-Liss, Inc.

Ultrastructure of spermatozoa of spider crabs, family Mithracidae (Crustacea, Decapoda, Brachyura): Integrative analyses based on morphological and molecular data.

PubMed

Assugeni, Camila de O; Magalhães, Tatiana; Bolaños, Juan A; Tudge, Christopher C; Mantelatto, Fernando L; Zara, Fernando J

2017-12-01

Recent studies based on morphological and molecular data provide a new perspective concerning taxonomic aspects of the brachyuran family Mithracidae. These studies proposed a series of nominal changes and indicated that the family is actually represented by a different number and representatives of genera than previously thought. Here, we provide a comparative description of the ultrastructure of spermatozoa and spermatophores of some species of Mithracidae in a phylogenetic context. The ultrastructure of the spermatozoa and spermatophore was observed by scanning and transmission electron microscopy. The most informative morphological characters analysed were thickness of the operculum, shape of the perforatorial chamber and shape and thickness of the inner acrosomal zone. As a framework, we used a topology based on a phylogenetic analysis using mitochondrial data obtained here and from previous studies. Our results indicate that closely related species share a series of morphological characteristics of the spermatozoa. A thick operculum, for example, is a feature observed in species of the genera Amphithrax, Teleophrys, and Omalacantha in contrast to the slender operculum observed in Mithraculus and Mithrax. Amphithrax and Teleophrys have a rhomboid perforatorial chamber, while Mithraculus, Mithrax, and Omalacantha show a wider, deltoid morphology. Furthermore, our results are in agreement with recently proposed taxonomic changes including the separation of the genera Mithrax (previously Damithrax), Amphithrax (previously Mithrax) and Mithraculus, and the synonymy of Mithrax caribbaeus with Mithrax hispidus. Overall, the spermiotaxonomy of these species of Mithracidae represent a novel set of data that corroborates the most recent taxonomic revision of the family and can be used in future taxonomic and phylogenetic studies within this family. © 2017 Wiley Periodicals, Inc.

Ultrastructural evidence of a vesicle-mediated mode of cell degranulation in chicken chromaffin cells during the late phase of embryonic development

PubMed Central

Crivellato, Enrico; Nico, Beatrice; Travan, Luciana; Isola, Miriam; Ribatti, Domenico

2009-01-01

In the present investigation, we attempted to determine whether ultrastructural features indicative of a vesicle-mediated mode of cell secretion were detectable in chick chromaffin cells during embryo development. The adrenal anlagen of domestic fowls were examined at embryonic days (E) 12, 15, 19 and 21 by electron microscopy quantitative analysis. Morphometric evaluation revealed a series of granule and cytoplasmic changes highly specific for piecemeal degranulation (PMD), a secretory process based on vesicular transport of cargoes from within granules for extracellular release. At E19 and E21 we found a significant peak in the percentage of granules exhibiting changes indicative of progressive release of secretory materials, i.e. granules with lucent areas in their cores, reduced electron density, disassembled matrices, residual cores and membrane empty containers. A dramatic raise in the density of 30–80-nm-diameter, membrane-bound, electron-dense and electron-lucent vesicles – which were located either next to granules or close to the plasma membrane – was recognizable at E19, that is, during the prehatching phase. The cytoplasmic burst of dense and clear vesicles was paralleled by the appearance of chromaffin granules showing outpouches or protrusions of their profiles (‘budding features’). These ultrastructural data are indicative of an augmented vesicle-mediated transport of chromaffin granule products for extracellular release in chick embryo chromaffin cells during the prehatching stage. In conclusion, this study provides new data on the fine structure of chromaffin cell organelles during organ development and suggests that PMD may be part of an adrenomedullary secretory response that occurs towards the end of chicken embryogenesis. From an evolutionary point of view, this study lends support to the concept that PMD is a secretory mechanism highly conserved throughout vertebrate classes. PMID:19245498

Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development.

PubMed

Schaeffer, Scott M; Christian, Ryan; Castro-Velasquez, Nohely; Hyden, Brennan; Lynch-Holm, Valerie; Dhingra, Amit

2017-10-01

Comparative ultrastructural developmental time-course analysis has identified discrete stages at which the fruit plastids undergo structural and consequently functional transitions to facilitate subsequent development-guided understanding of the complex plastid biology. Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids-chromoplasts-are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant 'Granny Smith', carotenoid-predominant 'Golden Delicious', and anthocyanin-predominant 'Top Red Delicious'. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex biochemistry of plastids in perennial non-model systems.

Ultrastructural features of vagina at different phases of the oestrous cycle in the female African giant rat (Cricetomys gambianus Waterhouse).

PubMed

Akinloye, Adebayo K; Oke, Bankole O

2014-06-01

The ultrastructures of the vagina at various stages of the oestrous cycle in female African giant rats (Cricetomys gambianus Waterhouse) were described in the present study. At mid-proestrus, late proestrus (LP)/early estrus (EE) and mid-estrus (ME) as well as late metestrus (LM)/early diestrus (ED) and mid-diestrus (MD), complex interface of epithelium and lamina propria were observed. Cells of the stratum basale formed finger-like extensions into the underlying lamina propria and tips of the extensions displayed hemidesmosome while basal lamina followed the contour of the extensions. At mid-metestrus (MM) and late diestrus/early proestrus, well developed, relatively straight basal lamina interfaced between the stratum basale and the lamina propria without finger-like projections. Polygonal cells with indented nuclei and, cytoplasm containing ribosomes, polysomes, intermediate filaments, and mitochondria were observed in stratum spinosum at all the phases of the oestrus cycle. At MM, LM/ED, and MD, the stratum spinosum had numerous desmosomes with tonofilaments, large microvilli that intermingled at the intercellular spaces and evidence of trapped/migrating neutrophils and lymphocytes. The superficial layer displayed short microvilli at mid-proestrus, cornification at LP/EE and desquamation at ME while it showed condensation of intermediate filaments; projections of large microvilli into the luminal surface at MM, and embeddement of neutrophils at LM/ED as well as MD. This study looked into the reproductive biology of female African giant rats to produce baseline information on its reproductive organs and represented the first comprehensive description of the vagina at the ultrastructural level during oestrous cycle. © 2014 Wiley Periodicals, Inc.

Immunochemical, ultrastructural and electrophysiological investigations of bone-derived stem cells in the course of neuronal differentiation.

PubMed

Wenisch, Sabine; Trinkaus, Katja; Hild, Anne; Hose, Dirk; Heiss, Christian; Alt, Volker; Klisch, Christopher; Meissl, Hilmar; Schnettler, Reinhard

2006-06-01

Numerous reports have highlighted the use of mesenchymal stem cells (MSC) for tissue engineering because of the capacity of the cells to differentiate along the osteogenic, chondrogenic or adipogenic pathway. As MSC also display neuronal morphologies under appropriate culture conditions, the differentiation capacity of stem cells seems to be more complex than initially thought, but it requires careful characterization of the cells. This is especially the case because recently it has been suggested that neuronal differentiation of stem cells is only an artifact. Here, we investigate the sequence of ultrastructural changes of bone-derived stem cells during neuronal induction and compare these data with immunocytochemical and electrophysiological properties of the cells. For further comparative analyses, stem cells were incubated with non-neurologically inducing stressors. The stem cells were harvested from human osseous debris and were characterized morphologically, immunocytochemically and by using FACS. After 6 h of neuronal induction, the cells had assumed neuronal morphologies and expressed neuron-specific enolase, beta-III-tubulin, neurofilament-H and HNK-1, while only a subpopulation expressed CD15 and synaptophysin. However, electrical signaling could not be detected, neither spontaneously nor after electrical stimulation. Nevertheless, transmission electron microscopy revealed cellular features of neuritogenesis and synaptogenesis in the course of neuronal induction and suggested that the cells have features similar to those observed in immature neurons. Based upon the results, it can be concluded that neuronal induction had initiated the early steps of neuronal differentiation, while exposure of the cells to non-neurological stressors had caused necrotic alterations.

Degeneration and regeneration of neuromuscular junction architecture in rat skeletal muscle fibers damaged by bupivacaine hydrochloride.

PubMed

Nishizawa, Tomie; Tamaki, Hiroyuki; Kasuga, Norikatsu; Takekura, Hiroaki

2003-01-01

We evaluated the degeneration and regeneration of neuromuscular junctions (NMJs) on the extensor digitorum longus muscle of Fischer 344 rats between 4 h and 3 weeks after bupivacaine hydrochloride (BPVC) injection, which induces muscle fiber necrosis, using histochemical staining by acetylcholine esterase (AchE)-silver and electron microscopy. Degeneration of muscle fibers and NMJs was observed 4 h after BPVC injection. One week after BPVC injection, some terminal axons were almost completely retracted, and the level of basal lamina-associated AchE in some NMJ regions had gradually disappeared. At that time, the depression contained a few, mostly pit-like or elongated oval invaginations: the incipient junctional folds and some NMJs did not have any secondary junctional fold. By 2 weeks after the BPVC injection, secondary junctional folds began to develop: however, the number of secondary junctional folds was clearly less than that in normal NMJs. At 3 weeks when regeneration of muscle fibers was well advanced, the staining for AchE at the end-plates became stronger and better-defined. The volume density of mitochondria in the terminal area of the terminal significantly decreased upon BPVC-induced destruction of the NMJ, and the density reached the lowest value 24 h after BPVC injection. Significant changes in the ultrastructural features of the architecture of NMJs occurred in skeletal muscle fibers damaged by BPVC during both the degeneration and regeneration processes. The changes in the ultrastructural and morphological features of the NMJ architecture during the regeneration of degenerated muscle fibers resembled those that occur during the differentiation of normal muscle fibers.

Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions.

PubMed

Piccinato, Carla A; Montrezor, Luis H; Collares, Cristhianna A V; Vireque, Alessandra A; Rosa e Silva, Alzira A M

2012-11-22

Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE) in the steroid hormone profile of a serum-free granulosa cell (GC) culture system in the context of follicular development and dominance. Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose-response study. The highest tested concentration of NE (10 (-7) M) resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone production was further investigated by incubating GCs with propranolol (10 (-8) M), a non-selective beta-adrenergic antagonist. The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

Pathogenesis of Acute and Delayed Corneal Lesions After Ocular Exposure to Sulfur Mustard Vapor

DTIC Science & Technology

2012-03-01

using a vapor cup delivery system. The transition from acute to delayed injury was characterized by clinical, histological, and ultrastructural metrics...These data demonstrate a system-based approach combining ultrastructural analysis , histochemistry, and molecular evaluation that links architectural...predictive of the 11% of corneas that underwent asymptomatic recovery. Ultrastructural comparison of asymptomatic and MGK corneas at 8 weeks indicates that MGK

Mitochondrial Dysfunction and Oxidative Stress Promote Apoptotic Cell Death in the Striatum via Cytochrome c/Caspase-3 Signaling Cascade Following Chronic Rotenone Intoxication in Rats

PubMed Central

Lin, Tsu-Kung; Cheng, Ching-Hsiao; Chen, Shang-Der; Liou, Chia-Wei; Huang, Chi-Ren; Chuang, Yao-Chung

2012-01-01

Parkinson’s disease (PD) is a progressive neurological disorder marked by nigrostriatal dopaminergic degeneration. Evidence suggests that mitochondrial dysfunction may be linked to PD through a variety of different pathways, including free-radical generation and dysfunction of the mitochondrial Complex I activity. In Lewis rats, chronic systemic administration of a specific mitochondrial Complex I inhibitor, rotenone (3 mg/kg/day) produced parkinsonism-like symptoms. Increased oxidized proteins and peroxynitrite, and mitochondrial or cytosol translocation of Bim, Bax or cytochrome c in the striatum was observed after 2–4 weeks of rotenone infusion. After 28 days of systemic rotenone exposure, imunohistochemical staining for tyrosine hydroxylase indicated nigrostriatal dopaminergic neuronal cell degeneration. Characteristic histochemical (TUNEL or activated caspase-3 staining) or ultrastructural (electron microscopy) features of apoptotic cell death were present in the striatal neuronal cell after chronic rotenone intoxication. We conclude that chronic rotenone intoxication may enhance oxidative and nitrosative stress that induces mitochondrial dysfunction and ultrastructural damage, resulting in translocation of Bim and Bax from cytosol to mitochondria that contributes to apoptotic cell death in the striatum via cytochrome c/caspase-3 signaling cascade. PMID:22942730

Kindler syndrome: a new mutation and new diagnostic possibilities.

PubMed

Burch, Joanna M; Fassihi, Hiva; Jones, Catherine A; Mengshol, Sarah C; Fitzpatrick, James E; McGrath, John A

2006-05-01

Kindler syndrome (KS) is a rare genetic disorder that is characterized by blistering in infancy, followed by the onset of poikiloderma and photosensitivity in childhood. The recently elucidated molecular pathogenesis involves mutations in KIND1, a gene encoding the protein kindlin-1, which is involved in the attachment of the actin cytoskeleton to the extracellular matrix in basal keratinocytes. We describe a child with the neonatal diagnosis of epidermolysis bullosa simplex who developed poikiloderma and skin fragility at 6 years of age. His skin showed diminished staining with anti-kindlin-1 antibody, and genetic analysis revealed that he was a compound heterozygote with a previously unreported mutation in KIND1. Ultrastructural clues to the diagnosis of KS were present in a biopsy specimen that was obtained when the patient was 10 months old, before he developed poikiloderma and photosensitivity. In this case, a combination of a known mutation (R271X) and a newly described mutation (1755delT) in the KIND1 gene produced loss of function in kindlin-1, leading to the clinical features of KS. Ultrastructural findings characteristic of KS were evident years before the onset of poikiloderma and sun sensitivity. In infancy, electron microscopy can enable early, accurate diagnosis of KS.

Ultrastructure of inclusion bodies in annulus cells in the degenerating human intervertebral disc.

PubMed

Gruber, H E; Hanley, E N

2009-06-01

The rough endoplasmic reticulum (rER) of the cell has an architectural editing function that checks whether protein structure and three-dimensional assembly have occurred properly prior to export of newly synthesized material out of the cell. If these have been faulty, the material is retained within the rER as an inclusion body. Inclusion bodies have been identified previously in chondrocytes and osteoblasts in chondrodysplasias and osteogenesis imperfecta. Inclusion bodies in intervertebral disc cells, however, have only recently been recognized. Our objectives were to use transmission electron microscopy to analyze more fully inclusion bodies in the annulus pulposus and to study the extracellular matrix (ECM) surrounding cells containing inclusion bodies. ECM frequently encapsulated cells with inclusion bodies, and commonly contained prominent banded aggregates of Type VI collagen. Inclusion body material had several morphologies, including relatively smooth, homogeneous material, or a rougher, less homogeneous feature. Such findings expand our knowledge of the fine structure of the human disc cell and ECM during disc degeneration, and indicate the potential utility of ultrastructural identification of discs with intracellular inclusion bodies as a screening method for molecular studies directed toward identification of defective gene products in degenerating discs.

[Ultrastructural characteristics of the vitellaria, uterus and vagina of Amphilina foliacea Rudolphi, 1819 (Cestoda: Amphilinidea)].

PubMed

Poddubnaia, L G

2013-01-01

The ultrastructural features of the vitelline follicles, uterus and vagina of the amphilinid cestode Amphilina foliacea from the body cavity of Acipenser ruthenus of the Volga basin are described. Some new distinguishing characters are revealed, including the presence of a single type of the cellular component in the vitelline follicles with sarcoplasmic processes filling the space around and within vitellocytes. The,uterus of this species is recognized by the presence of the syncytial epithelial lining with underlying secretory perikaria and different kinds of luminal projections. The most distal part of the uterus, situated closely to the uterine pore, is characterized by nuclei occupying the syncytial uterine epithelium. Slightly further proximally, they are located basally and then transformed into sunken perikaria. The vaginal epithelium is characterized by the syncytial structure with underlying epithelial perikaria in its distal region, with intraepithelial location of the nuclei slightly further proximally and the absence of the nuclei in its proximal region (the seminal receptacle). The syncytial cytoplasm of the vagina contains numerous vesicles and possesses microvilli-like surface structures. The morphological aspects of the female reproductive system of A. foliacea are compared with those of other Cestoda and Neodermata.

LMX1B Mutations Cause Hereditary FSGS without Extrarenal Involvement

PubMed Central

Boyer, Olivia; Woerner, Stéphanie; Yang, Fan; Oakeley, Edward J.; Linghu, Bolan; Gribouval, Olivier; Tête, Marie-Josèphe; Duca, José S.; Klickstein, Lloyd; Damask, Amy J.; Szustakowski, Joseph D.; Heibel, Françoise; Matignon, Marie; Baudouin, Véronique; Chantrel, François; Champigneulle, Jacqueline; Martin, Laurent; Nitschké, Patrick; Gubler, Marie-Claire; Johnson, Keith J.; Chibout, Salah-Dine

2013-01-01

LMX1B encodes a homeodomain-containing transcription factor that is essential during development. Mutations in LMX1B cause nail-patella syndrome, characterized by dysplasia of the patellae, nails, and elbows and FSGS with specific ultrastructural lesions of the glomerular basement membrane (GBM). By linkage analysis and exome sequencing, we unexpectedly identified an LMX1B mutation segregating with disease in a pedigree of five patients with autosomal dominant FSGS but without either extrarenal features or ultrastructural abnormalities of the GBM suggestive of nail-patella–like renal disease. Subsequently, we screened 73 additional unrelated families with FSGS and found mutations involving the same amino acid (R246) in 2 families. An LMX1B in silico homology model suggested that the mutated residue plays an important role in strengthening the interaction between the LMX1B homeodomain and DNA; both identified mutations would be expected to diminish such interactions. In summary, these results suggest that isolated FSGS could result from mutations in genes that are also involved in syndromic forms of FSGS. This highlights the need to include these genes in all diagnostic approaches to FSGS that involve next-generation sequencing. PMID:23687361

Ultrastructural characterization of melanosomes of the human pathogenic fungus Fonsecaea pedrosoi.

PubMed

Franzen, Anderson J; Cunha, Marcel M L; Miranda, Kildare; Hentschel, Joachim; Plattner, Helmut; da Silva, Moises B; Salgado, Claudio G; de Souza, Wanderley; Rozental, Sonia

2008-04-01

Melanin is a complex polymer widely distributed in nature and has been described as an important virulence factor in pathogenic fungi. In the majority of fungi, the mechanism of melanin formation remains unclear. In Fonsecaea pedrosoi, the major etiologic agent of chromoblastomycosis, melanin is stored in intracellular vesicles, named melanosomes. This paper details the ultrastructural aspects of melanin formation, its storage and transportation to the cell wall in the human pathogenic fungus F. pedrosoi. In this fungus, melanin synthesis within melanosomes also begins with a fibrillar matrix formation, displaying morphological and structural features similar to melanosomes from amphibian and mammalian cells. Silver precipitation based on Fontana-Masson technique for melanin detection and immunocytochemistry showed that melanosome fuses with fungal cell membrane where the melanin is released and reaches the cell wall. Melanin deposition in the fungal cell wall occurs in concentric layers. Antibodies raised against F. pedrosoi melanin revealed the sites of melanin production and storage in the melanosomes. In addition, a preliminary description of the elemental composition of this organelle by X-ray microanalysis and elemental mapping revealed the presence of calcium, phosphorus and iron concentrated in its matrix, suggesting a new functional role for these organelles as iron storage compartments.

How effectively does a clinostat mimic the ultrastructural effects of microgravity on plant cells?

NASA Technical Reports Server (NTRS)

Moore, R.

1990-01-01

Columella cells of seedlings of Zea mays L. cv. Bear Hybrid grown in the microgravity of orbital flight allocate significantly larger relative-volumes to hyaloplasm and lipid bodies, and significantly smaller relative-volumes to dictyosomes, plastids, and starch than do columella cells of seedlings grown at 1 g. The ultrastructure of columella cells of seedlings grown at 1 g and on a rotating clinostat is not significantly different. However, the ultrastructure of cells exposed to these treatments differs significantly from that of seedlings grown in microgravity. These results indicate that the actions of a rotating clinostat do not mimic the ultrastructural effects of microgravity in columella cells of Z. mays.

From Voxels to Knowledge: A Practical Guide to the Segmentation of Complex Electron Microscopy 3D-Data

PubMed Central

Tsai, Wen-Ting; Hassan, Ahmed; Sarkar, Purbasha; Correa, Joaquin; Metlagel, Zoltan; Jorgens, Danielle M.; Auer, Manfred

2014-01-01

Modern 3D electron microscopy approaches have recently allowed unprecedented insight into the 3D ultrastructural organization of cells and tissues, enabling the visualization of large macromolecular machines, such as adhesion complexes, as well as higher-order structures, such as the cytoskeleton and cellular organelles in their respective cell and tissue context. Given the inherent complexity of cellular volumes, it is essential to first extract the features of interest in order to allow visualization, quantification, and therefore comprehension of their 3D organization. Each data set is defined by distinct characteristics, e.g., signal-to-noise ratio, crispness (sharpness) of the data, heterogeneity of its features, crowdedness of features, presence or absence of characteristic shapes that allow for easy identification, and the percentage of the entire volume that a specific region of interest occupies. All these characteristics need to be considered when deciding on which approach to take for segmentation. The six different 3D ultrastructural data sets presented were obtained by three different imaging approaches: resin embedded stained electron tomography, focused ion beam- and serial block face- scanning electron microscopy (FIB-SEM, SBF-SEM) of mildly stained and heavily stained samples, respectively. For these data sets, four different segmentation approaches have been applied: (1) fully manual model building followed solely by visualization of the model, (2) manual tracing segmentation of the data followed by surface rendering, (3) semi-automated approaches followed by surface rendering, or (4) automated custom-designed segmentation algorithms followed by surface rendering and quantitative analysis. Depending on the combination of data set characteristics, it was found that typically one of these four categorical approaches outperforms the others, but depending on the exact sequence of criteria, more than one approach may be successful. Based on these data, we propose a triage scheme that categorizes both objective data set characteristics and subjective personal criteria for the analysis of the different data sets. PMID:25145678

[Clinicopathologic study of sinonasal inflammatory myofibroblastic tumor].

PubMed

He, Chun-yan; Jin, Yu-lan; Yang, Dong-mei; Liu, Hong-gang

2010-03-01

To study the clinicopathologic features, immunophenotype and ultrastructural features of sinonasal inflammatory myofibroblastic tumors (IMT). The clinical and histologic features of 5 cases of sinonasal IMT were reviewed. Immunohistochemical study for vimentin, MSA, SMA, calponin, h-caldesmon, desmin, ALK, fibronectin, CK, S-100 and Ki-67 was carried out. Ultrastructural examination was also performed in two of the cases. The patients age ranged from 28 to 62 years (mean = 43 years). The male-to-female ratio was 2:3. The clinical presentation included nasal obstruction, nasal discharge, nasal bleeding, facial pain, facial swelling, toothache and tear overflow. All of the 5 patients suffered from disease relapses; and 4 of them had recurrences for more than 5 times. One patient had lymph node metastasis and 3 patients died of the disease. Histologically, the tumor cells were arranged in interlacing fascicles and sometimes haphazard in fashion. They were spindly in shape, cytoplasm eosinophilic with mild nuclear atypia and a low mitotic activity. The intervening stroma was myxoid in appearance accompanied by lymphocyte and plasma cell infiltration, abundant blood vessels and focal collagenized areas. In 3 of the recurrent cases, the tumor cells displayed increased nuclear atypia and mitotic activity (average about 5 to 6 per 10 high-power fields), accompanied by patchy necrosis, less inflammatory cell infiltration and focal sarcomatous changes. Immunohistochemical study showed that the tumor cells were diffusely positive for vimentin. SMA, MSA, calponin and fibronectin were variably expressed. Desmin was weakly positive in 1 case. The staining for h-caldesmon, ALK, S-100 and CK was negative. The Ki-67 proliferation index increased with tumor recurrences. Electron microscopy revealed abundant rough endoplasmic reticulum and dense body formation in the cytoplasm. There were an increased amount of collagen fibers in the stroma. IMT rarely occurs in nasal cavity and paranasal sinuses. The tumor is prone to local invasion and recurrences, with subsequent progression to frank malignancy and distant metastasis, resulting in high mortality and poor prognosis. Complete surgical resection remains the main modality of treatment.

Heterogeneity of the calcium-induced permeability transition in isolated non-synaptic brain mitochondria.

PubMed

Kristián, Tibor; Weatherby, Tina M; Bates, Timothy E; Fiskum, Gary

2002-12-01

Calcium overload of neural cell mitochondria plays a key role in excitotoxic and ischemic brain injury. This study tested the hypothesis that brain mitochondria consist of subpopulations with differential sensitivity to calcium-induced inner membrane permeability transition, and that this sensitivity is greatly reduced by physiological levels of adenine nucleotides. Isolated non-synaptosomal rat brain mitochondria were incubated in a potassium-based medium in the absence or presence of ATP or ADP. Measurements were made of medium and intramitochondrial free calcium, light scattering, mitochondrial ultrastructure, and the elemental composition of electron-opaque deposits within mitochondria treated with calcium. In the absence of adenine nucleotides, calcium induced a partial decrease in light scattering, accompanied by three distinct ultrastructural morphologies, including large-amplitude swelling, matrix vacuolization and a normal appearance. In the presence of ATP or ADP the mitochondrial calcium uptake capacity was greatly enhanced and calcium induced an increase rather than a decrease in mitochondrial light scattering. Approximately 10% of the mitochondria appeared damaged and the rest contained electron-dense precipitates that contained calcium, as determined by electron-energy loss spectroscopy. These results indicate that brain mitochondria are heterogeneous in their response to calcium. In the absence of adenine nucleotides, approximately 20% of the mitochondrial population exhibit morphological alterations consistent with activation of the permeability transition, but less than 10% exhibit evidence of osmotic swelling and membrane disruption in the presence of ATP or ADP.

[The ultrastructure and activities of free radical scavenger in discolored gingiva adjacent to porcelain fused to metal crowns].

PubMed

Zhang, Zhong-ti; Yan, Lu; Zhong, Ming; Yang, Xiao-dong; Ai, Hong-jun

2007-04-01

This study was designed to study the discolored gingiva adjacent to porcelain fused to metal (PFM) crowns in terms of ultrastructure , SOD and GSH activities in 40 cases. The discolored gingival ultrastructures were observed and metal X-ray energy level was analyzed;The activities of SOD and GSH were measured and compared with normal control by student's t test and one-way ANOVA with SPSS10.0 software package. The discolored gingival ultrastructure had changes compared with the normal gingiva. Nickel and chromium were not found in the particles through X-ray energy machine within the discolored gingiva adjacent to PFM crown. The activities of SOD and GSH in discolored gingiva were significantly different from control(P<0.05) and the values at 6 to 18 months were significantly different from those at other times. The ultrastructure underwent changes in discolored gingiva after PFM restoration; the activity of SOD and GSH in discolored gingiva changed to result in apoptosis, and discoloration.

Flight duration and flight muscle ultrastructure of unfed hawk moths.

PubMed

Wone, Bernard W M; Pathak, Jaika; Davidowitz, Goggy

2018-06-13

Flight muscle breakdown has been reported for many orders of insects, but the basis of this breakdown in insects with lifelong dependence on flight is less clear. Lepidopterans show such muscle changes across their lifespans, yet how this change affects the ability of these insects to complete their life cycles is not well documented. We investigated the changes in muscle function and ultrastructure of unfed aging adult hawk moths (Manduca sexta). Flight duration was examined in young, middle-aged, and advanced-aged unfed moths. After measurement of flight duration, the main flight muscle (dorsolongitudinal muscle) was collected and histologically prepared for transmission electron microscopy to compare several measurements of muscle ultrastructure among moths of different ages. Muscle function assays revealed significant positive correlations between muscle ultrastructure and flight distance that were greatest in middle-aged moths and least in young moths. In addition, changes in flight muscle ultrastructure were detected across treatment groups. The number of mitochondria in muscle cells peaked in middle-aged moths. Many wild M. sexta do not feed as adults; thus, understanding the changes in flight capacity and muscle ultrastructure in unfed moths provides a more complete understanding of the ecophysiology and resource allocation strategies of this species. Copyright © 2018 Elsevier Ltd. All rights reserved.

Floral features of two species of Bulbophyllum section Lepidorhiza Schltr.: B. levanae Ames and B. nymphopolitanum Kraenzl. (Bulbophyllinae Schltr., Orchidaceae).

PubMed

Wiśniewska, Natalia; Kowalkowska, Agnieszka K; Kozieradzka-Kiszkurno, Małgorzata; Krawczyńska, Agnieszka T; Bohdanowicz, Jerzy

2018-03-01

Two representatives of section Lepidorhiza, previously sometimes considered conspecific, Bulbophyllum levanae and Bulbophyllum nymphopolitanum, demonstrated both similarities and differences in floral features. There were significant differences in the length of sepals and micromorphological features of the labellum. In both species, osmophores are located on the extended apices of sepals and possibly on petals. An abundance of proteins in tepals is probably associated with the unpleasant scent of the flowers, whereas the thin wax layers on the epidermis are probably involved in the maintenance of the brilliance of floral tepals, which strongly attracts flies. In all tepals of both species, we noted the presence of dihydroxyphenolic globules in the cytoplasm after staining with FeCl 3 . Comparison with ultrastructure results revealed that they were associated with plastids containing plastoglobuli. The most remarkable feature was the presence of a prominent periplasmic space in the epidermal cells of both investigated species. Furthermore, in the labellum of B. levanae, the cuticle contained microchannels. The combination of periplasmic space and microchannels has not previously been recorded.

Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells

PubMed Central

2013-01-01

Objective The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level. Methods The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy. Results IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs. Conclusions Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells. PMID:23421382

Pituitary carcinoma diagnosed on fine needle aspiration: Report of a case and review of pathogenesis

PubMed Central

Yakoushina, Tatiana V.; Lavi, Ehud; Hoda, R. S.

2010-01-01

Pituitary carcinoma (PC) is a very rare entity (0.2% of all pituitary tumors), with only about 140 cases reported in English literature. There are no reliable histological, immunohistochemical or ultrastructural features distinguishing pituitary adenoma (PA) from PC. By definition, a diagnosis of PC is made after a patient with PA develops non-contiguous central nervous system (CNS) or systemic metastases. To date, only three cases of PC have been reportedly diagnosed on fine needle aspiration (FNA). Two of the reported cases were diagnosed on FNA of the cervical lymph nodes and one on FNA of the vertebral bone lesion. Herein, we present a case of PC, diagnosed on FNA of the liver lesion. In this case, we describe cytologic features of PC and compare them to histologic features of the tumor in the pituitary. Clinical behavior of tumor, pathogenesis of metastasis and immunochemical and prognostic markers will also be described. PMID:20806088

A Fine-Scale Functional Logic to Convergence from Retina to Thalamus.

PubMed

Liang, Liang; Fratzl, Alex; Goldey, Glenn; Ramesh, Rohan N; Sugden, Arthur U; Morgan, Josh L; Chen, Chinfei; Andermann, Mark L

2018-05-31

Numerous well-defined classes of retinal ganglion cells innervate the thalamus to guide image-forming vision, yet the rules governing their convergence and divergence remain unknown. Using two-photon calcium imaging in awake mouse thalamus, we observed a functional arrangement of retinal ganglion cell axonal boutons in which coarse-scale retinotopic ordering gives way to fine-scale organization based on shared preferences for other visual features. Specifically, at the ∼6 μm scale, clusters of boutons from different axons often showed similar preferences for either one or multiple features, including axis and direction of motion, spatial frequency, and changes in luminance. Conversely, individual axons could "de-multiplex" information channels by participating in multiple, functionally distinct bouton clusters. Finally, ultrastructural analyses demonstrated that retinal axonal boutons in a local cluster often target the same dendritic domain. These data suggest that functionally specific convergence and divergence of retinal axons may impart diverse, robust, and often novel feature selectivity to visual thalamus. Copyright © 2018 Elsevier Inc. All rights reserved.

Cell biology of prokaryotic organelles.

PubMed

Murat, Dorothee; Byrne, Meghan; Komeili, Arash

2010-10-01

Mounting evidence in recent years has challenged the dogma that prokaryotes are simple and undefined cells devoid of an organized subcellular architecture. In fact, proteins once thought to be the purely eukaryotic inventions, including relatives of actin and tubulin control prokaryotic cell shape, DNA segregation, and cytokinesis. Similarly, compartmentalization, commonly noted as a distinguishing feature of eukaryotic cells, is also prevalent in the prokaryotic world in the form of protein-bounded and lipid-bounded organelles. In this article we highlight some of these prokaryotic organelles and discuss the current knowledge on their ultrastructure and the molecular mechanisms of their biogenesis and maintenance.

Ultra structural changes occurring in duct ectasia and periductal mastitis and their significance in etiopathogenesis.

PubMed

Ramalingam, Kirithiga; Vuthaluru, Seenu; Srivastava, Anurag; Dinda, Amit Kumar; Dhar, Anita

2017-01-01

Duct ectasia (DE) and periductal mastitis (PDM) are the most common benign breast conditions seen in women. The etiopathogenesis of these entities is still not clear and most of the theories regarding the causation are based on the histological features as seen on light microscopy. The ultramicroscopic features associated with these conditions that may give more insight to the etiopathogenesis are unknown. To study the ultrastructural changes occurring in mammary duct cones in patients with DE and PDM using Transmission Electron Microscopic (TEM). Major ducts removed by radical duct excision from 21 patients with final histopathological diagnosis of DE and PDM were subjected to TEM study with 2 normal duct samples as controls. The TEM features of DE were denudation of the epithelial cells with focal loss of microvilli, widening of the inter-epithelial junctions with focal disruption of the T bars, periductal collagenisation without inflammation, and features suggestive of Epithelial Mesenchymal Transition (EMT). PDM features are intact epithelial lining with proliferative epithelium and periductal collagenisation with inflammation. Based on the TEM findings, we suggest that DE and PDM are two different entities. EMT a novel finding observed in DE in this study.

Ultra structural changes occurring in duct ectasia and periductal mastitis and their significance in etiopathogenesis

PubMed Central

Ramalingam, Kirithiga; Vuthaluru, Seenu; Srivastava, Anurag; Dinda, Amit Kumar; Dhar, Anita

2017-01-01

Introduction Duct ectasia (DE) and periductal mastitis (PDM) are the most common benign breast conditions seen in women. The etiopathogenesis of these entities is still not clear and most of the theories regarding the causation are based on the histological features as seen on light microscopy. The ultramicroscopic features associated with these conditions that may give more insight to the etiopathogenesis are unknown. Aim To study the ultrastructural changes occurring in mammary duct cones in patients with DE and PDM using Transmission Electron Microscopic (TEM). Method Major ducts removed by radical duct excision from 21 patients with final histopathological diagnosis of DE and PDM were subjected to TEM study with 2 normal duct samples as controls. Results The TEM features of DE were denudation of the epithelial cells with focal loss of microvilli, widening of the inter-epithelial junctions with focal disruption of the T bars, periductal collagenisation without inflammation, and features suggestive of Epithelial Mesenchymal Transition (EMT). PDM features are intact epithelial lining with proliferative epithelium and periductal collagenisation with inflammation. Conclusions Based on the TEM findings, we suggest that DE and PDM are two different entities. EMT a novel finding observed in DE in this study. PMID:28273122

[A rare tumor of the parapharyngeal space: myxoid chondrosarcoma].

PubMed

Bahri, I; Boudawara, T; Sellami, A; Khabir, A; Ghorgel, M; Drira, M; Daoud, J; Jlidi, R

2002-01-01

Extrasqueletal myxoid chondrosarcoma (EMC) is an uncommon soft tissue malignant tumor, locally aggressive with a high incidence of distant metastasis. It has distinctive clinical, immunophenotypic, cytogenetic and ultrastructural features. Most EMC are associated with the translocation t(9;22) (q22;q12). Their occurrence in the parapharyngeal space is extremely rare. Our objective is to discuss the difficulties of the histological diagnosis of EMC and to describe its immunophenotypic, cytogenetic features and clinical behavior. We report a case of a 67 years old woman who presented with a five months history of dysphagia. The oral examination found a mass displacing the posterior and left walls of the pharynx. Surgical resection of the tumor was undertaken. The pathologic examination concluded to the diagnosis of an EMC of the left parapharygeal space. Now, the patient is receiving an adjuvant radiotherapy.

Pelizaeus-Merzbacher disease. The Löwenberg-Hill type.

PubMed

Bruyn, G W; Weenink, H R; Bots, G T; Teepen, J L; van Wolferen, W J

1985-01-01

The clinical and neuropathological findings are reported of two sibs with adult type PMD. Clinical features deviating from the usual pattern included: no psychosis, no measurable dementia, no dwarfism, no microcephaly, no (marked) involuntary movements, but conspicuous generalised muscle atrophy and denervation, impairment of vital and gnostic sensation, thoracolumbar vertebral anomalies, and aplasia of os coccygis. Neuropathological findings were as usual, with additional unusual features: pinhead-size areas of acute myelin-abbau products, involvement of grey in addition to white matter, and upon ultrastructure, the new finding of intra-oligodendroglial fingerprint bodies, both in neuronal satellite and in white matter oligoglia, but not in astrocytes, ganglion cells, or pericytes. This excludes the origin of the stored material in the lysosomes as to derive exclusively from demyelination and would possibly imply PMD to be an oligodendroglial lysosomal storage disease.

[Clinical aspects, imaging and neuropathology of Kii ALS/PDC].

PubMed

Kokubo, Yasumasa

2007-11-01

During 1996 and 2006, we examined clinically 37 patients and neuropathologically 13 autopsy cases with amyotrophic lateral sclerosis/parkinsonism-dementia complex of the Kii peninsula (Kii ALS/PDC). The ages of onset were between 52 years and 74 years (mean age: 65.3 years). The male to female ratio was 1:1.85. The ratio of positive family history where ALS or PDC occurred within the fourth degree of the relatives was 78.4% in the patients with Kii ALS/PDC. The average duration of the illness was 6.47 years. Kii ALS/PDC was divided into five clinical subtypes, pure ALS form, ALS with dementia form, PDC with parkinsonism predominant form, PDC with dementia predominant form (that is called late-life dementia in Guam) and PDC with ALS features form. Unique pigmentary retinopathy was found in 33.3% of the patients with Kii ALS/PDC. CT/MRI images showed atrophy of the frontal and temporal lobes and SPECT images showed a decrease in the blood flow of the frontal and temporal lobes. The cardiac 123I-MIBG uptake was decreased in 4 out of 8 patients with ALS/PDC and the decrease in uptake correlated with the modified Hoehn-Yahr staging. The cardinal neuropathological features of Kii ALS/PDC were abundant neurofibrillary tangles (NFTs) associated with loss of nerve cells in the cerebral cortex and the brain stem, and findings of ALS neuropathology. Ultrastructurally, NFTs consisted of paired helical filaments. Tau protein, a main component of NFTs, was consisted of 3R and 4R tau isoforms, and phosphoryrated at 18 sites of tau phosphoryrated sites. The neurons of dentate gyrus of hippocampus and anterior horn cells were stained with anti-TDP-43 antibody. The clinical and neuropathological aspects of Kii ALS/PDC are regarded as being identical with those of Guam ALS/PDC.

An immunohistochemical and ultrastructural study of the pericellular matrix of uneroded hypertrophic chondrocytes in the mandibular condyle of aged c-src-deficient mice.

PubMed

Shibata, Shunichi; Baba, Otto; Oda, Tsuyoshi; Yokohama-Tamaki, Tamaki; Qin, Chunlin; Butler, William T; Sakakura, Yasunori; Takano, Yoshiro

2008-03-01

Previous studies indicate that hypertrophic chondrocytes can transdifferentiate or dedifferentiate and redifferentiate into bone cells during the endochondral bone formation. Mandibular condyle in aged c-src-deficient mice has incremental line-like striations consisting of cartilaginous and non-cartilaginous layers, and the former contains intact hypertrophic chondrocytes in uneroded lacunae. The purpose of this study is to determine the phenotype changes of uneroded hypertrophic chondrocytes. Immunohistochemical and ultrastructural examinations of the pericellular matrix of hypertrophic chondrocytes in the upper, middle, and lower regions of the mandibular condyle were conducted in aged c-src-deficient mice, using several antibodies of cartilage/bone marker proteins. Co-localisation of aggrecan, type I collagen, and dentin matrix protein-1 (DMP-1) or matrix extracellular phosphoprotein (MEPE) was detected in the pericellular matrix of the middle region. Ultrastructurally, granular substances in the pericellular matrix of the middle region were the remains of upper region chondrocytes, which were mixed with thick collagen fibrils. In the lower region, the width of the pericellular matrix and the amount of collagen fibrils were increased. Versican, type I collagen, DMP-1, and MEPE were detected in the osteocyte lacunae. Additionally, DMP-1 and MEPE were detected in the pericellular matrix of uneroded hypertrophic chondrocytes located in the lower, peripheral region of the mandibular condyle in younger c-src-deficient mice, but not in the aged wild-type mice. These results indicate that long-term survived, uneroded hypertrophic chondrocytes, at least in a part, acquire osteocytic characteristics.

Remodeling of the rat distal colon in diabetes: function and ultrastructure.

PubMed

Siegman, Marion J; Eto, Masumi; Butler, Thomas M

2016-01-15

This study seeks to define and explain remodeling of the distal colon in the streptozotocin (STZ)-treated rat model of diabetes through analysis of resting and active length dependence of force production, chemical composition, and ultrastructure. Compared with untreated controls, the passive stiffness on extension of the diabetic muscle is high, and active force produced at short muscle lengths is amplified but is limited by an internal resistance to shortening. The latter are accounted for by a significant increase in collagen type 1, with no changes in types 3 and 4. In the diabetic colon, ultrastructural studies show unique, conspicuous pockets of collagen among muscle cells, in addition to a thickened basement membrane and an extracellular space filled with collagen fibers and various fibrils. Measurements of DNA and total protein content revealed that the diabetic colon underwent hypertrophy, along with a proportional increase in actin and myosin contents, with no change in the actin-to-myosin ratio. Active force production per cross-sectional area was not different in the diabetic and normal muscles, consistent with the proportionality of changes in contractile proteins. The stiffness and the limit to shortening of the diabetic colon were significantly reduced by treatment with the glycation breaker alagebrium chloride (ALT-711), with no change in collagen contents. Functionally, this study shows that, in diabetes, the production of collagen type 1 and glycation increase stiffness, which limits distensibility on filling and limits shortening and expulsion of contents, both of which can be alleviated by treatment with ALT-711. Copyright © 2016 the American Physiological Society.

[Ultrastructure and Raman Spectral Characteristics of Two Kinds of Acute Myeloid Leukemia Cells].

PubMed

Liang, Hao-Yue; Cheng, Xue-Lian; Dong, Shu-Xu; Zhao, Shi-Xuan; Wang, Ying; Ru, Yong-Xin

2018-02-01

To investigate the Raman spectral characteristics of leukemia cells from 4 patients with acute promyelocytic leukemia (M 3 ) and 3 patients with acute monoblastic leukemia (M 5 ), establish a novel Raman label-free method to distinguish 2 kinds of acute myeloid leukemia cells so as to provide basis for clinical research. Leukemia cells were collected from bone marrow of above-mentioned patients. Raman spectra were acquired by Horiba Xplora Raman spectrometer and Raman spectra of 30-50 cells from each patient were recorded. The diagnostic model was established according to principle component analysis (PCA), discriminant function analysis (DFA) and cluster analysis, and the spectra of leukemia cells from 7 patients were analyzed and classified. Characteristics of Raman spectra were analyzed combining with ultrastructure of leukemia cells. There were significant differences between Raman spectra of 2 kinds of leukemia cells. Compared with acute monoblastic leukemia cells, the spectra of acute promyelocytic leukemia cells showed stronger peaks in 622, 643, 757, 852, 1003, 1033, 1117, 1157, 1173, 1208, 1340, 1551, 1581 cm -1 . The diagnostic models established by PCA-DFA and cluster analysis could successfully classify these Raman spectra of different samples with a high accuracy of 100% (233/233). The model was evaluated by "Leave-one-out" cross-validation and reached a high accuracy of 97% (226/233). The level of macromolecules of M 3 cells is higher than that of M 5 . The diagnostic models established by PCA-DFA can classify these Raman spectra of different cells with a high accuracy. Raman spectra shows consistent result with ultrastructure by TEM.

Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever.

PubMed

Rikihisa, Y; Perry, B D; Cordes, D O

1985-09-01

Potomac horse fever is characterized by fever, anorexia, leukopenia, profuse watery diarrhea, dehydration, and high mortality. An ultrastructural investigation was made to search for any unusual microorganisms in the digestive system, lymphatic organs, and blood cells of ponies that had developed clinical signs after transfusion with whole blood from horses naturally infected with Potomac horse fever. A consistent finding was the presence of rickettsial organisms in the wall of the intestinal tract of these ponies. The organisms were found mostly in the wall of the large colon, but fewer organisms were found in the small colon, jejunum, and cecum. The organisms were also detected in cultured blood monocytes. In the intestinal wall, many microorganisms were intracytoplasmic in deep glandular epithelial cells and mast cells. Microorganisms were also found in macrophages migrating between glandular epithelial cells in the lamina propria and submucosa. The microorganisms were round, very pleomorphic, and surrounded by a host membrane. They contained fine strands of DNA and ribosomes and were surrounded by double bileaflet membranes. Their ultrastructure was very similar to that of the genus Ehrlichia, a member of the family Rickettsiaceae. The high frequency of detection of the organism in the wall of the intestinal tract, especially in the large colon, indicates the presence of organotrophism in this organism. Infected blood monocytes may be the vehicle for transmission between organs and between animals. The characteristic severe diarrhea may be induced by the organism directly by impairing epithelial cell functions or indirectly by perturbing infected macrophages and mast cells in the intestinal wall or by both.

Alternate Modes of Photosynthate Transport in the Alternating Generations of Physcomitrella patens

PubMed Central

Regmi, Kamesh C.; Li, Lin; Gaxiola, Roberto A.

2017-01-01

Physcomitrella patens has emerged as a model moss system to investigate the evolution of various plant characters in early land plant lineages. Yet, there is merely a disparate body of ultrastructural and physiological evidence from other mosses to draw inferences about the modes of photosynthate transport in the alternating generations of Physcomitrella. We performed a series of ultrastructural, fluorescent tracing, physiological, and immunohistochemical experiments to elucidate a coherent model of photosynthate transport in this moss. Our ultrastructural observations revealed that Physcomitrella is an endohydric moss with water-conducting and putative food-conducting cells in the gametophytic stem and leaves. Movement of fluorescent tracer 5(6)-carboxyfluorescein diacetate revealed that the mode of transport in the gametophytic generation is symplasmic and is mediated by plasmodesmata, while there is a diffusion barrier composed of transfer cells that separates the photoautotrophic gametophyte from the nutritionally dependent heterotrophic sporophyte. We posited that, analogous to what is found in apoplasmically phloem loading higher plants, the primary photosynthate sucrose, is actively imported into the transfer cells by sucrose/H+ symporters (SUTs) that are, in turn, powered by P-type ATPases, and that the transfer cells harbor an ATP-conserving Sucrose Synthase (SUS) pathway. Supporting our hypothesis was the finding that a protonophore (2,4-dinitrophenol) and a SUT-specific inhibitor (diethyl pyrocarbonate) reduced the uptake of radiolabeled sucrose into the sporangia. In situ immunolocalization of P-type ATPase, Sucrose Synthase, and Proton Pyrophosphatase – all key components of the SUS pathway – showed that these proteins were prominently localized in the transfer cells, providing further evidence consistent with our argument. PMID:29181017

Trematode reproduction in the molluscan host: an ultrastructural study of the germinal mass in the rediae of Himasthla elongata (Mehlis, 1831) (Digenea: Echinostomatidae).

PubMed

Podvyaznaya, Irina M; Galaktionov, Kirill V

2014-03-01

The germinal mass in Himasthla elongata rediae was studied in detail using transmission electron microscopy. It was shown to be a specialized reproductive organ consisting of germinal cells at various maturation stages, supporting cells and stem cells. The germinal mass also contains early cercarial embryos emerging as a result of cleavage division of mature germinal cells. The stem cells that give rise to germinal cells have heterochromatin-rich nuclei with distinct nucleoli and scarce cytoplasm containing mainly free ribosomes and few mitochondria. The differentiating germinal cells undergo a growth, which is accompanied by an emergence of annulate lamellae and the nuage in their cytoplasm, a noticeable development of RER and Golgi apparatus and an increase in the number of mitochondria. The mitochondria form a large group at one of the cell poles. During differentiation, the nucleus and nucleolus of the germinal cell enlarge while the chromatin becomes gradually less condensed. The supporting tissue of the germinal mass is made up of cells connected by septate junctions. These supporting cells are distinctly different in cellular shape and nuclear ultrastructure. Their outgrowths form a tight meshwork housing stem cells, germinal cells and early cercarial embryos. The cytoplasm of the supporting cells in the mesh area is separated into fine parallel layers by labyrinthine narrow cavities communicating with the intercellular space. The supporting tissue contains differentiating and degenerating cells which indicates its renewal. The results of this ultrastructural study lend support to the hypothesis that the germinal cells of digeneans are germ line cells.

A new technique for the rapid screening and selection of large pieces of tissue for ultrastructural evaluation.

PubMed

Dalley, B K; Seliger, W G

1980-05-01

A simple and rapid technique is described for the screening of Epon embedded organ slices for the location, isolation, and removal of small specific sites for ultrastructural study with the transmission electron microscope. This procedure consists of perfusion fixation followed by making 1 to 21/2 mm thick slices of relatively large pieces of the organs, control of the degree and evenness of the osmium staining by addition of 3% sodium iodate, and infiltration with a fluorescent dye prior to embedment in Epon. Tissue slices are embedded in wafer-shaped blocks, generally with several slices in one "wafer", and are examined in a controlled manner using a rapid form of serial surface polishing. Each level of the polished wafer is examined using an epi-illuminated fluorescence microscope, and selected sites are chosen at each level for ultrastructural study. Methods are also described for marking each selected site using a conventional slide marker, and for the removal of the selected site in the form of a small disc of Epon, after which the Epon wafer can be further serially polished and the examination continued. Areas to be thin-sectioned are removed using a core drill mounted on a model-maker's drill press. The technique is simple, does not require the destruction of remaining tissues to evaluate more critically a single small site, allows for the easy maintenance of tissue orientation, and the most time-consuming portions of the technique can be quickly taught to a person with no previous histological training.

Spontaneous rat nephroblastoma: ultrastructure of a transplant line.

PubMed

Hard, G C; Noble, R L

1982-08-01

Tumor tissue derived from a nephroblastoma arising spontaneously in an Nb hooded rat and carried for 56 generations as a subcutaneous syngeneic transplant was examined by electron microscopy. Histologically, the transplant showed the typical pattern of dense clusters or sheets of basophilic epithelioid cells set within ramifying tracts of fibrous mesenchyme. At the ultrastructural level, the tumor cells within dense clusters were arranged in anastomotic cords that circumscribed clear intervening spaces. The tumor cells were a monomorphic population possessing the morphologic characteristics of blast cells, including polyribosomes as the predominant cytoplasmic organelle. Furthermore, the close contiguity of cells within the cords, their polyhedral form, and their connection by intercellular junctions established the tumor cell type as epithelial. Consistent with benign stroma, mesenchymal tracts contained highly differentiated, mature fibroblasts, collagen, phagocytes, cells of the lymphoid series, and normal blood vessels. No transitional forms between epithelium and mesenchyme suggestive of bipotential differentiation were seen. Although the data represent only a single transplantation line, the observations support the contention (based on light microscopic appraisal of a number of primary tumors) that nephroblastoma in te rat can be a purely epithelial neoplasm.

Cadmium induced changes in Solidago chilensis Meyen (Asteraceae) grown on organically fertilized soil with reference to mycorrhizae, metabolism, anatomy and ultrastructure.

PubMed

Pereira, Lidiane Silva; de Araújo, Romária Pereira; de Oliveira, Priscila Souza; da Silva, Leandro Dias; Alves, Patricia Alves Casaes; Fernandes, Valéria Ferreira; Gross, Eduardo

2018-04-15

Solidago chilensis Meyen (Asteraceae) is a medicinal important plant with few studies on nutrition and metabolism and none information on cadmium phytotoxicity. The objective of this study was to investigate Cd induced responses on the growth and metabolism in S. chilensis and on arbuscular mycorrhiza (AM). The experiment was carried out in a greenhouse, consisting of a 5 × 4 factorial with five doses of manure (0, 3.5, 7, 14 and 21gdm -3 ) and four doses of cadmium (0, 25, 50 and 75mgdm -3 ) applied to a Dystrophic Ultisol. After 250 days of plant cultivation, biomass, nutrient content, photosynthetic rate, guaiacol peroxidase activity, mycorrhizal colonization, glomalin content, anatomical and ultrastucture were evaluated. Plants were significantly affected by interaction of manure and Cd doses with anatomical, ultrastructural, physiological and nutritional modifications. Manure applied into Cd contaminated soil significantly improved mycorrhizal colonization and glomalin production. The highest organic manure dose (21gdm -3 ) alleviated toxicity symptoms of Cd on S. chilensis. Copyright © 2017 Elsevier Inc. All rights reserved.

Complexity, adaptations and variations in the secondary insemination system of female Dermanyssina mites (Acari: Anactinothrichida: Gamasida): the case of Afrocypholaelaps africana.

PubMed

Di Palma, A; Seeman, O D; Alberti, G

2017-07-01

Gamasine mites, mainly of the taxon Dermanyssina, possess a secondarily evolved insemination system (sperm access system), of which there are two, generally recognized, structurally different types, the laelapid- and the phytoseiid-type. The ultrastructure of the female sperm access system in Afrocypholaelaps africana is described. It consists of paired insemination pores, opening between the bases of legs three and four, and paired cuticle-lined tubules that converge into a large, sack-like spermatheca, remarkably cuticle-lined as well. The entire spermatheca and part of the tubules are embedded in a peculiar syncytial tissue where numerous sperm cells are present. The general organization of this insemination system is of the laelapid-type. However, it presents striking structural differences, compared with the systems described in Varroa destructor and Hattena cometis, the other gamasine mites having a laelapid-type system studied ultrastructurally until now. The functional morphology, complexity and variations of the sperm access system in Dermanyssina are discussed and correlated with the evolutionary biology of the group.

Glomerular Lesions in Proteinuric Miniature Schnauzer Dogs.

PubMed

Furrow, E; Lees, G E; Brown, C A; Cianciolo, R E

2017-05-01

Miniature Schnauzer dogs are predisposed to idiopathic hypertriglyerceridemia, which increases risk for diseases such as pancreatitis and gallbladder mucocele. Recently, elevated triglyceride concentrations have been associated with proteinuria in this breed, although it is difficult to determine which abnormality is primary. Retrospective review of renal tissue from 27 proteinuric Miniature Schnauzers revealed that 20 dogs had ultrastructural evidence of osmophilic globules consistent with lipid in glomerular tufts. Seven of these dogs had lipid thromboemboli in glomerular capillary loops that distorted their shape and compressed circulating erythrocytes. Triglyceride concentrations were reported in 6 of these 7 dogs, and all were hypertriglyceridemic. In addition, glomerular lipidosis (defined as accumulation of foam cells within peripheral capillary loops) was identified in a single dog. The remaining 12 dogs had smaller amounts of lipid that could only be identified ultrastructurally. Neither signalment data nor clinicopathologic parameters (serum albumin, serum creatinine, urine protein-to-creatinine ratio, and blood pressure) differed among the various types of lipid lesions. During the time course of this study, all dogs diagnosed with glomerular lipid thromboemboli were Miniature Schnauzers, underscoring the importance of recognizing these clear spaces within capillary loops as lipid.

Ultrastructure of the platypus and echidna mandibular glands.

PubMed

Krause, W J

2011-10-01

The secretory units of the platypus and echidna mandibular glands consist of a single serous cell type. Secretory granules within the cells of the platypus mandibular gland stained intensely with the periodic acid-Schiff staining procedure but failed to stain with Alcian Blue, suggesting the granules contained neutral glycoproteins. Secretory granules within the mandibular glands of the echidna failed to stain with the methods used indicating little if any glycoprotein was associated with the secretory granules. Ultrastructurally, secretory granules of the platypus mandibular gland were electron dense with a central core of less electron-dense material and were membrane bound. In contrast, those of the echidna presented a lamellated appearance and also were limited by a membrane. These secretory granules appeared to form as a result of concentric layering of lamellae within cisternae of the Golgi membranes. The intralobular ductal system of the platypus was more extensively developed than that of the echidna. The striated ducts of both species were characterized by elaborate infoldings of the basolateral plasmalemma and an abundance of associated mitochondria. © 2011 Blackwell Verlag GmbH.

Cytological stress and element uptake in moss and lichen exposed in bags in urban area.

PubMed

Spagnuolo, V; Zampella, M; Giordano, S; Adamo, P

2011-07-01

In this study cytological ultrastructure, total content of C, N and S, and cellular location of major and trace elements (K, Ca, Mg, Cu, Pb and Zn) were investigated in the moss Hypnum cupressiforme and in the lichen Pseudevernia furfuracea exposed in bags for a spring-summer 12-weeks period in the urban area of Naples city. In the moss, severe ultrastructural damages, such as membrane interruptions and dehydration, developed after exposure supporting the occurrence of a dead biomonitor. In the lichen, the post-exposure stress marks, such as the development of lysosome-like vesicles and concentric bodies, or the production of melanin, were overall compatible with life. With exposure, N, S, major and trace element contents all increased in both biomonitors, while C remained substantially unchanged. Copper and Pb were mainly retained in extracellular and particulate forms. Intracellular concentration of Zn consistently increased in both biomonitors, irrespective of their vitality. In transplants, cellular location of elements can better reflect the form in which they occur in the environment. Copyright © 2011 Elsevier Inc. All rights reserved.

3-D Ultrastructure of O. tauri: Electron Cryotomography of an Entire Eukaryotic Cell

PubMed Central

Henderson, Gregory P.; Gan, Lu; Jensen, Grant J.

2007-01-01

The hallmark of eukaryotic cells is their segregation of key biological functions into discrete, membrane-bound organelles. Creating accurate models of their ultrastructural complexity has been difficult in part because of the limited resolution of light microscopy and the artifact-prone nature of conventional electron microscopy. Here we explored the potential of the emerging technology electron cryotomography to produce three-dimensional images of an entire eukaryotic cell in a near-native state. Ostreococcus tauri was chosen as the specimen because as a unicellular picoplankton with just one copy of each organelle, it is the smallest known eukaryote and was therefore likely to yield the highest resolution images. Whole cells were imaged at various stages of the cell cycle, yielding 3-D reconstructions of complete chloroplasts, mitochondria, endoplasmic reticula, Golgi bodies, peroxisomes, microtubules, and putative ribosome distributions in-situ. Surprisingly, the nucleus was seen to open long before mitosis, and while one microtubule (or two in some predivisional cells) was consistently present, no mitotic spindle was ever observed, prompting speculation that a single microtubule might be sufficient to segregate multiple chromosomes. PMID:17710148

Evolution of Cellular Inclusions in Bietti's Crystalline Dystrophy.

PubMed

Furusato, Emiko; Cameron, J Douglas; Chan, Chi-Chao

2010-03-09

Bietti's crystalline dystrophy (BCD) consists of small, yellow-white, glistening intraretinal crystals in the posterior pole, tapetoretinal degeneration with atrophy of the retinal pigment epithelium (RPE) and "sclerosis" of the choroid; in addition, sparking yellow crystals in the superficial marginal cornea are also found in many patients. BCD is inherited as an autosomal-recessive trait (4q35-tel) and usually has its onset in the third decade of life. This review focuses on the ultrastructure of cellular crystals and lipid inclusions of BCD.

Ultrastructural Correlates of the Protection Afforded by Niacinamide against Sulfur Mustard-Induced Cytotoxicity of Human Lymphocytes in Vitro

DTIC Science & Technology

1988-12-01

Page No. 1. Light Microscopy of Human Skin Grafted onto Congenitally Athymic Nude Mice .................. 4 2. Ultrastructural Changes Produced by HD...laboratory published a report on the ultrastructure of the pathogenesis of blister formation following exposure to sulfur mustard of human- skin grafted to...candidate prophylactic compounds such as niacirnamide. By way of review, hD-induced pathology of human skin grafted onto congenitally athymic nude mice was

Microstructure and Ultrastructure Alterations in the Pallium of Immature Mice Exposed to Cadmium.

PubMed

Yang, X F; Han, Q G; Liu, D Y; Zhang, H T; Fan, G Y; Ma, J Y; Wang, Z L

2016-11-01

The aim of this study was to investigate microstructure and ultrastructure alterations in the pallium of immature mice exposed to cadmium. Forty immature mice were randomly divided into control, 1/100 LD 50 (1.87 mg/kg, low), 1/50 LD 50 (3.74 mg/kg, medium), and 1/25 LD 50 (7.48 mg/kg, high) dose groups. After oral cadmium exposure for 40 days, the pallium of mice was obtained for microstructure and ultrastructure studies. The results showed that both microstructure and ultrastructure alterations of the pallium were observed in all treated mice and the most obvious alterations were in the high dose group. Microstructural analysis showed seriously congested capillary in the pia mater of the pallium in the high cadmium group. Meanwhile, vacuolar degenerate or karyopyknosis presented in some neurocytes, capillary quantity, and the number of apoptotic cells increased, some neurocytes became hypertrophy, the pia mater separated from the cortex, and local hemorrhage and accompanied inflammatory cell infiltration were also observed. Ultrastructural analysis showed that rough endoplasmic reticulum was expanded, heterochromatin marginalized, perinuclear space distinctly broadened, swelling and vacuolization mitochondria appeared, synapse was swelling, presynaptic and postsynaptic membranes presented fusion, and most of mitochondrial cristae were ambiguous. The results indicated that cadmium exposure for 40 days induced dose-dependent microstructure and ultrastructure alterations in pallium of immature mice.

Reptilian spermatogenesis

PubMed Central

2011-01-01

Until recently, the histology and ultrastructural events of spermatogenesis in reptiles were relatively unknown. Most of the available morphological information focuses on specific stages of spermatogenesis, spermiogenesis, and/or of the mature spermatozoa. No study to date has provided complete ultrastructural information on the early events of spermatogenesis, proliferation and meiosis in class Reptilia. Furthermore, no comprehensive data set exists that describes the ultrastructure of the entire ontogenic progression of germ cells through the phases of reptilian spermatogenesis (mitosis, meiosis and spermiogenesis). The purpose of this review is to provide an ultrastructural and histological atlas of spermatogenesis in reptiles. The morphological details provided here are the first of their kind and can hopefully provide histological information on spermatogenesis that can be compared to that already known for anamniotes (fish and amphibians), birds and mammals. The data supplied in this review will provide a basic model that can be utilized for the study of sperm development in other reptiles. The use of such an atlas will hopefully stimulate more interest in collecting histological and ultrastructural data sets on spermatogenesis that may play important roles in future nontraditional phylogenetic analyses and histopathological studies in reptiles. PMID:22319673

Microwave Processing for Sample Preparation to Evaluate Mitochondrial Ultrastructural Damage in Hemorrhagic Shock

NASA Astrophysics Data System (ADS)

Josephsen, Gary D.; Josephsen, Kelly A.; Beilman, Greg J.; Taylor, Jodie H.; Muiler, Kristine E.

2005-12-01

This is a report of the adaptation of microwave processing in the preparation of liver biopsies for transmission electron microscopy (TEM) to examine ultrastructural damage of mitochondria in the setting of metabolic stress. Hemorrhagic shock was induced in pigs via 35% total blood volume bleed and a 90-min period of shock followed by resuscitation. Hepatic biopsies were collected before shock and after resuscitation. Following collection, biopsies were processed for TEM by a rapid method involving microwave irradiation (Giberson, 2001). Samples pre- and postshock of each of two animals were viewed and scored using the mitochondrial ultrastructure scoring system (Crouser et al., 2002), a system used to quantify the severity of ultrastructural damage during shock. Results showed evidence of increased ultrastructural damage in the postshock samples, which scored 4.00 and 3.42, versus their preshock controls, which scored 1.18 and 1.27. The results of this analysis were similar to those obtained in another model of shock (Crouser et al., 2002). However, the amount of time used to process the samples was significantly shortened with methods involving microwave irradiation.

Dermal Ultrastructure in Low Beighton Score Members of 17 Families with Hypermobile-Type Ehlers-Danlos Syndrome

PubMed Central

Hermanns-Lê, Trinh; Reginster, Marie-Annick; Piérard-Franchimont, Claudine; Delvenne, Philippe; Piérard, Gérald E.; Manicourt, Daniel

2012-01-01

The distinction between the Ehlers-Danlos syndrome hypermobile type (EDSH) and the benign joint hypermobility syndrome (BJHS) is unclear. The aim of the present study was to compare skin ultrastructural abnormalities of EDSH and BJHS among different families. Skin of 23 EDSH, 27 BJHS, and 41 asymptomatic subjects from 17 families was examined using transmission electron microscopy. Similar ultrastructural abnormalities were found irrespective of the Beighton score. Flower-like collagen fibrils represented the key change and elastic fibers were altered as well. Beighton score is a clinical parameter rating joint mobility that appeared unrelated to quantitative and qualitative collagen ultrastructural alterations in the skin. Some EDSH family members fit with BJHS diagnosis. BJHS possibly represents a mild variant of EDSH. PMID:23091361

Both necrosis and apoptosis contribute to HIV-1-induced killing of CD4 cells

NASA Technical Reports Server (NTRS)

Plymale, D. R.; Tang, D. S.; Comardelle, A. M.; Fermin, C. D.; Lewis, D. E.; Garry, R. F.

1999-01-01

BACKGROUND: Data currently available on HIV-1-induced cytopathology is unclear regarding the mechanism of cell killing. OBJECTIVE: To clarify the extent to which apoptosis or necrosis is involved in HIV-1-induced cell death in view of conflicting existing data. METHODS: T lymphoblastoid cells or peripheral blood mononuclear cells were infected by various strains of HIV-1 and the numbers of apoptotic or necrotic cells were quantified at various times after infection using video-image analysis techniques; the results were compared with the amount of fragmented DNA using a quantitative method. Measurement of mitochondrial transmembrane potential (deltapsi(m)) and intracellular calcium concentrations [Ca2+]i was performed with fluorescent probes and fluorescence concentration analysis (FCA). RESULTS: Although lymphoblastoid and monocytoid cells acutely infected by HIV-1 had increased levels of fragmented DNA, a marker of apoptotic cell death, few (<12%) had condensed chromatin and fragmented nuclei, the morphological features of apoptosis. The predominant alterations in acutely infected cells were distended endoplasmic reticulum and abnormal mitochondria; these ultrastructural changes are consistent with necrosis, although some infected cells simultaneously displayed features of both necrosis and apoptosis. Viability of cells persistently infected by HIV-1 was only minimally reduced from that of uninfected cells. This reduction was accounted for by an increased propensity of the persistently infected cells to die by apoptosis. Alterations in [Ca2+]i and deltapsi(m) occurred in both acutely and persistently infected cells. CONCLUSION: Both necrosis and apoptosis contribute to HIV-1-induced killing of CD4 cells.

Papillary tumor of the pineal region: two case studies and a review of the literature.

PubMed

Rickard, Kyle A; Parker, John R; Vitaz, Todd W; Plaga, Alexis R; Wagner, Stephanie; Parker, Joseph C

2011-01-01

Papillary tumor of the pineal region (PTPR) is a newly recognized distinct entity in the 2007 World Health Organization nomenclature. This tumor is characterized by epithelial-appearing areas with papillary features and more densely cellular areas that often display ependymal-like differentiation. Ultrastructurally, this rare neuroepithelial tumor possesses neuroendocrine, secretory, and ependymal organelles that likely originate from the subcommissural organ (SCO) near the aqueduct of Sylvius. To date, approximately fifty-seven described cases worldwide have been recognized, with ages ranging from 5 years to 66 years (mean age=32 years). Clinical presentation most often includes headache and obstructive hydrocephalus. The tumor, which is well circumscribed, may be cystic and radiographically is often considered to be consistent with the findings of a pineocytoma. Microscopic evaluation often demonstrates a lesion with papillary areas lined by epithelioid tumor cells with eosinophilic cytoplasm and more cellular areas with cells exhibiting clear or vacuolated cytoplasm. Perivascular and true rosettes may be identified. Distinctive immunohistochemical features including reactivity for keratins (AE1/AE3, CAM 5.2, CK18) and only focal GFAP staining help distinguish this neoplasm from an ependymoma. The relative paucity of data compiled for this tumor makes giving an accurate diagnosis and prognosis a daunting task. We discuss two additional cases of PTPR that presented to us within a three-month span in order to more fully elucidate the possible presentations of this rare entity. Furthermore, we examine now 59 reported cases of PTPR in order to review the current diagnostic and treatment modalities in addition to exploring emerging research encompassing this unusual neoplasm.

Type 1 diabetes mellitus effects on dental enamel formation revealed by microscopy and microanalysis.

PubMed

Silva, Bruna Larissa Lago; Medeiros, Danila Lima; Soares, Ana Prates; Line, Sérgio Roberto Peres; Pinto, Maria das Graças Farias; Soares, Telma de Jesus; do Espírito Santo, Alexandre Ribeiro

2018-03-01

Type 1 diabetes mellitus (T1DM) largely affects children, occurring therefore at the same period of deciduous and permanent teeth development. The aim of this work was to investigate birefringence and morphology of the secretory stage enamel organic extracellular matrix (EOECM), and structural and mechanical features of mature enamel from T1DM rats. Adult Wistar rats were maintained alive for a period of 56 days after the induction of experimental T1DM with a single dose of streptozotocin (60 mg/kg). After proper euthanasia of the animals, fixed upper incisors were accurately processed, and secretory stage EOECM and mature enamel were analyzed by transmitted polarizing and bright field light microscopies (TPLM and BFLM), energy-dispersive x-ray (EDX) analysis, scanning electron microscopy (SEM), and microhardness testing. Bright field light microscopies and transmitted polarizing light microscopies showed slight morphological changes in the secretory stage EOECM from diabetic rats, which also did not exhibit statistically significant alterations in birefringence brightness when compared to control animals (P > .05). EDX analysis showed that T1DM induced statistically significant little increases in the amount of calcium and phosphorus in outer mature enamel (P < .01) with preservation of calcium/phosphorus ratio in that structure (P > .05). T1DM also caused important ultrastructural alterations in mature enamel as revealed by SEM and induced a statistically significant reduction of about 13.67% in its microhardness at 80 μm from dentin-enamel junction (P < .01). This study shows that T1DM may disturb enamel development, leading to alterations in mature enamel ultrastructure and in its mechanical features. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sensitivity of Aspergillus nidulans to the Cellulose Synthase Inhibitor Dichlobenil: Insights from Wall-Related Genes’ Expression and Ultrastructural Hyphal Morphologies

PubMed Central

Obersriebnig, Michael; Salerno, Marco; Pum, Dietmar; Strauss, Joseph

2013-01-01

The fungal cell wall constitutes an important target for the development of antifungal drugs, because of its central role in morphogenesis, development and determination of fungal-specific molecular features. Fungal walls are characterized by a network of interconnected glycoproteins and polysaccharides, namely α-, β-glucans and chitin. Cell walls promptly and dynamically respond to environmental stimuli by a signaling mechanism, which triggers, among other responses, modulations in wall biosynthetic genes’ expression. Despite the absence of cellulose in the wall of the model filamentous fungus Aspergillus nidulans, we found in this study that fungal growth, spore germination and morphology are affected by the addition of the cellulose synthase inhibitor dichlobenil. Expression analysis of selected genes putatively involved in cell wall biosynthesis, carried out at different time points of drug exposure (i.e. 0, 1, 3, 6 and 24 h), revealed increased expression for the putative mixed linkage β-1,3;1,4 glucan synthase celA together with the β-1,3-glucan synthase fksA and the Rho-related GTPase rhoA. We also compared these data with the response to Congo Red, a known plant/fungal drug affecting both chitin and cellulose biosynthesis. The two drugs exerted different effects at the cell wall level, as shown by gene expression analysis and the ultrastructural features observed through atomic force microscopy and scanning electron microscopy. Although the concentration of dichlobenil required to affect growth of A. nidulans is approximately 10-fold higher than that required to inhibit plant cellulose biosynthesis, our work for the first time demonstrates that a cellulose biosynthesis inhibitor affects fungal growth, changes fungal morphology and expression of genes connected to fungal cell wall biosynthesis. PMID:24312197

Cytokines profile and peripheral blood mononuclear cells morphology in Rett and autistic patients.

PubMed

Pecorelli, Alessandra; Cervellati, Franco; Belmonte, Giuseppe; Montagner, Giulia; Waldon, PhiAnh; Hayek, Joussef; Gambari, Roberto; Valacchi, Giuseppe

2016-01-01

A potential role for immune dysfunction in autism spectrum disorders (ASD) has been well established. However, immunological features of Rett syndrome (RTT), a genetic neurodevelopmental disorder closely related to autism, have not been well addressed yet. By using multiplex Luminex technology, a panel of 27 cytokines and chemokines was evaluated in serum from 10 RTT patients with confirmed diagnosis of MECP2 mutation (typical RTT), 12 children affected by classic autistic disorder and 8 control subjects. The cytokine/chemokine gene expression was assessed by real time PCR on mRNA of isolated peripheral blood mononuclear cells (PBMCs). Moreover, ultrastructural analysis of PBMCs was performed using transmission electron microscopy (TEM). Significantly higher serum levels of interleukin-8 (IL-8), IL-9, IL-13 were detected in RTT compared to control subjects, and IL-15 shows a trend toward the upregulation in RTT. In addition, IL-1β and VEGF were the only down-regulated cytokines in autistic patients with respect to RTT. No difference in cytokine/chemokine profile between autistic and control groups was detected. These data were also confirmed by ELISA real time PCR. At the ultrastructural level, the most severe morphological abnormalities were observed in mitochondria of both RTT and autistic PBMCs. In conclusion, our study shows a deregulated cytokine/chemokine profile together with morphologically altered immune cells in RTT. Such abnormalities were not quite as evident in autistic subjects. These findings indicate a possible role of immune dysfunction in RTT making the clinical features of this pathology related also to the immunology aspects, suggesting, therefore, novel possible therapeutic interventions for this disorder. Copyright © 2015 Elsevier Ltd. All rights reserved.

The mandibular ridge oral mucosa model of stromal influences on the endothelial tip cells: an immunohistochemical and TEM study.

PubMed

Rusu, Mugurel Constantin; Didilescu, Andreea Cristiana; Stănescu, Ruxandra; Pop, Florinel; Mănoiu, Valentina Mariana; Jianu, Adelina Maria; Vâlcu, Marek

2013-02-01

This study aimed to evaluate by immunohistochemistry and transmission electron microscopy (TEM) the morphological features of the oral mucosa endothelial tip cells (ETCs) and to determine the immune and ultrastructural patterns of the stromal nonimmune cells which could influence healing processes. Immune labeling was performed on bioptic samples obtained from six edentulous patients undergoing surgery for dental implants placement; three normal samples were collected from patients prior to the extraction of the third mandibular molar. The antibodies were tested for CD34, CD117(c-kit), platelet derived growth factor receptor-alpha (PDGFR-α), Mast Cell Tryptase, CD44, vimentin, CD45, CD105, alpha-smooth muscle actin, FGF2, Ki67. In light microscopy, while stromal cells (StrCs) of the reparatory and normal oral mucosa, with a fibroblastic appearance, were found positive for a CD34/CD44/CD45/CD105/PDGFR-α/vimentin immune phenotype, the CD117/c-kit labeling led to a positive stromal reaction only in the reparatory mucosa. In TEM, non-immune StrCs presenting particular ultrastructural features were identified as circulating fibrocytes (CFCs). Within the lamina propria CFCs were in close contact with ETCs. Long processes of the ETCs were moniliform, and hook-like collaterals were arising from the dilated segments, suggestive for a different stage migration. Maintenance and healing of oral mucosa are so supported by extensive processes of angiogenesis, guided by ETCs that, in turn, are influenced by the CFCs that populate the stromal compartment both in normal and reparatory states. Therefore, CFCs could be targeted by specific therapies, with pro- or anti-angiogenic purposes. Copyright © 2012 Wiley Periodicals, Inc.

Membrane properties and cell ultrastructure of taste receptor cells in Necturus lingual slices.

PubMed

Bigiani, A; Kim, D J; Roper, S D

1996-05-01

1. Whole cell patch-clamp recordings and electron micrographs were obtained from cells in Necturus taste buds in lingual slices to study their membrane properties and to correlate these properties with cell ultrastructure. 2. Two different populations of taste receptor cells could be identified: one type possessed voltage-gated Na+ and K+ (noninactivating) currents (group 1 cells); the other type possessed only K+ (inactivating) currents (group 2 cells). 3. The zero-current ("resting") potential (Vo) and whole cell resistance (Ro) of these two types of taste cells differed significantly. For group 1 cells, on average, Vo = -75 mV and Ro = 24.6 G omega, and for group 2 cells, Vo = -49 mV and Ro = 48.9 G omega. The difference in Ro was not explained completely by differences in cell sizes, suggesting that intrinsic membrane properties differed between the populations. 4. Cells injected with biocytin were the electron microscope after tissues were reacted with majority (14 of 16) of cells with voltage-gated Na+ and K+ currents (group 1 cells) were characterized by abundant rough endoplasmic reticulum and dense granular packets in the apical process. These are features of dark cells. All the cells that only possessed K+ currents (group 2 cells) were characterize by well-developed smooth endoplasmic reticulum and an absence granular packets. These features characterize light cells. 5. These findings indicate that there is a good, although not exact, correlation between electrophysiological properties and cell morphotype in Necturus taste bud cells. All dark cells possessed Na+ and K+ currents and thus would be expected to be capable of generating action potentials. Most light cells only possessed outward K+ currents and thus would be incapable of generating action potentials.

A cytochemical and radioautographic study of the ultrastructural organization of puff-like fibrillar structures in plant interphase nuclei (Allium porrum).

PubMed

Lafontaine, J G; Luck, B T; Dontigny, D

1979-10-01

Loose, fibrillar, spherical structures have been observed during recent years in interphase nuclei of both animal and plant cells. These nuclear formations have been referred to as karyosomes, fibrillar bodies, micropuffs and centromeres. In order to gain further information on the nature of these structures, a cytochemical and radioautographic investigation was undertaken using plant meristematic cells (Allium porrum). For that purpose roots were fixed with either formaldehyde or glutaraldehyde in order to carry out cytochemical tests for DNA, RNA and proteins. Certain of the preparations were also first digested with DNase, RNase or proteinase K and then stained according to different procedures. Other specimens were labelled with thymidine for high-resolution radioautographic observations. Staining with diaminobenzidine (DAB) revealed that these nuclear puff-like formations consisted partly of a loose fibrillar meshwork containing nucleic acids. Part of this fine fibrillar reticulum persisted whether the preparations were digested with DNase or RNase before staining with DAB, thus indicating that these nuclear structures contained both DNA and RNA. The fact that these formations incorporate thymidine furnished additional support for the view that they correspond to specific chromosome segments. Staining with ethanolic phosphotungstic acid or digestion of specimens with proteinase K showed that these loose fibrillar structures also consisted of proteins. Judging from their ultrastructure, their association with the chromatin reticulum as well as from their cytochemical characteristics, these nuclear formations most likely correspond to centromeres. In view of the presence of DNA within these structures, it is possible to distinguish them from other equally spherical nuclear formations, observed in certain plant species, that have generally been referred to as karyosomes or micronucleoli and that appear to consist of ribonucleoproteins.

Ultrastructural identification of peripheral myelin proteins by a pre-embedding immunogold labeling method.

PubMed

Canron, Marie-Hélène; Bouillot, Sandrine; Favereaux, Alexandre; Petry, Klaus G; Vital, Anne

2003-03-01

Ultrastructural immunolabeling of peripheral nervous system components is an important tool to study the relation between structure and function. Owing to the scarcity of certain antigens and the dense structure of the peripheral nerve, a pre-embedding technique is likely appropriate. After several investigations on procedures for pre-embedding immunolabeling, we propose a method that offers a good compromise between detection of antigenic sites and preservation of morphology at the ultrastructural level, and that is easy to use and suitable for investigations on peripheral nerve biopsies from humans. Pre-fixation by immersion in paraformaldehyde/glutaraldehyde is necessary to stabilize the ultrastructure. Then, ultrasmall gold particles with silver enhancement are advised. Antibodies against myelin protein zero and myelin basic protein were chosen for demonstration. The same technique was applied to localize a 35 kDa myelin protein.

Relationship between histopathological changes in post partum renal biopsies and renal function tests of African women with early onset pre-eclampsia.

PubMed

Khedun, S M; Naicker, T; Moodley, J

2000-05-01

To improve the diagnostic accuracy of concurrent renal disease in hypertension of pregnancy, biopsy evaluation is essential. In addition, establishing underlying renal disease is important for prognosis on future pregnancies. We therefore designed a study to determine the diagnostic yield of postpartum renal biopsy and the nature and frequency of complications associated with this procedure. Also, to determine relationships, if any, between renal function tests and ultrastructural and histopathological findings. Fifty renal biopsies were performed in the immediate postpartum period in black African women with early onset pre-eclampsia. Each biopsy specimen was placed in a separate container and coded so that sampling was unknown to the electron microscopist. Each biopsy specimen was divided into three parts, and processed and stained for light, fluorescent and transmission electron microscopy using conventional techniques. Renal tissue biopsies were adequate for diagnostic purposes in all cases. There were no complications in any of the 50 patients studied. Ultrastructural examination confirmed the light microscopy findings. In addition the ultrastructural findings showed intramembranous deposits, foot process fusion and mesangial deposits. In 16 patients with normal renal function tests; the biopsies evaluation from these patients showed ultrastructural changes. In the remaining 34 patients with abnormal renal function tests of varying severity; biopsy evaluation from these patients showed both ultrastructural and histopathological changes. Renal biopsy procedure is safe, and ultrastructural and histological findings obtained from postpartum renal biopsies are more informative than the routine renal function tests.

Spermiogenesis and Taxonomical Values of Sperm Ultrastructures in Male Crassostrea ariakensis (Fujita & Wakiya, 1929) (Pteroirmorphia: Ostreidae) in the Estuary of the Seomjin River, Korea

PubMed Central

Son, Pal Won; Chung, Jae Seung; Kim, Jin Hee; Kim, Sung Han; Chung, Ee-Yung

2014-01-01

Characteristics of the developmental stages of spermatids during spermiogenesis and phylogenetic classicfication of the species using sperm ultrastructures in male Crassostrea ariakensis were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of Ostreidae. Ultrastructures of mature sperms are composed of broad, modified cap-shaped acrosomal vesicle and an axial rod in subacrosomal materials on an oval nucleus, four spherical mitochondria in the sperm midpiece, and satellite fibres which appear near the distal centriole. The axoneme of the sperm tail shows a 9+2 structure. Accordingly, the ultrastructural characteristics of mature sperm of C. ariakensis resemble to those of other investigated ostreids in Ostreidae in the subclass Pteriomorphia. In this study, particularly, two transverse bands (stripes) appear at the anterior region of the acrosomal vesicle of this species, unlike two or three transverse bands (stripes) in C. gigas. It is assumed that differences in this acrosomal substructure are associated with the inability of fertilization between the genus Crassostrea and other genus species in Ostreidae. Therefore, we can use sperm ultrastructures and morphologies in the resolution of taxonomic relationships within the Ostreidae in the subclass Pteriomorphia. These spermatozoa, which contain several ultrastructures such as acrosomal vesicle, an axial rod in the sperm head part and four mitochondria and satellite fibres in the sperm midpiece, belong to the family Ostreidae in the subclass Pteriomorphia. PMID:25949188

The effect of starvation and re-feeding on mitochondrial potential in the midgut of Neocaridina davidi (Crustacea, Malacostraca)

PubMed Central

Włodarczyk, Agnieszka; Sonakowska, Lidia; Kamińska, Karolina; Marchewka, Angelika; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena

2017-01-01

The midgut in the freshwater shrimp Neocaridina davidi (previously named N. heteropoda) (Crustacea, Malacostraca) is composed of a tube-shaped intestine and a large hepatopancreas that is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous papers, while here we focused on the ultrastructural changes that occurred in the midgut epithelial cells (D-cells in the intestine, B- and F- cells in the hepatopancreas) after long-term starvation and re-feeding. We used transmission electron microscopy, light and confocal microscopes and flow cytometry to describe all of the changes that occurred due to the stressor with special emphasis on mitochondrial alterations. A quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is a relationship between starvation, re-feeding and the inactivation/activation of mitochondria. The results of our studies showed that in the freshwater shrimp N. davidi that were analyzed, long-term starvation activates the degeneration of epithelial cells at the ultrastructural level and causes an increase of cells with depolarized (non-active) mitochondria. The process of re-feeding leads to the gradual regeneration of the cytoplasm of the midgut epithelial cells; however, these changes were observed at the ultrastructural level. Additionally, re-feeding causes the regeneration of mitochondrial ultrastructure. Therefore, we can state that the increase in the number of cells with polarized mitochondria occurs slowly and does not depend on ultrastructural alterations. PMID:28282457

The effect of starvation and re-feeding on mitochondrial potential in the midgut of Neocaridina davidi (Crustacea, Malacostraca).

PubMed

Włodarczyk, Agnieszka; Sonakowska, Lidia; Kamińska, Karolina; Marchewka, Angelika; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena

2017-01-01

The midgut in the freshwater shrimp Neocaridina davidi (previously named N. heteropoda) (Crustacea, Malacostraca) is composed of a tube-shaped intestine and a large hepatopancreas that is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous papers, while here we focused on the ultrastructural changes that occurred in the midgut epithelial cells (D-cells in the intestine, B- and F- cells in the hepatopancreas) after long-term starvation and re-feeding. We used transmission electron microscopy, light and confocal microscopes and flow cytometry to describe all of the changes that occurred due to the stressor with special emphasis on mitochondrial alterations. A quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is a relationship between starvation, re-feeding and the inactivation/activation of mitochondria. The results of our studies showed that in the freshwater shrimp N. davidi that were analyzed, long-term starvation activates the degeneration of epithelial cells at the ultrastructural level and causes an increase of cells with depolarized (non-active) mitochondria. The process of re-feeding leads to the gradual regeneration of the cytoplasm of the midgut epithelial cells; however, these changes were observed at the ultrastructural level. Additionally, re-feeding causes the regeneration of mitochondrial ultrastructure. Therefore, we can state that the increase in the number of cells with polarized mitochondria occurs slowly and does not depend on ultrastructural alterations.

Balantioides coli: morphological and ultrastructural characteristics of pig and non-human primate isolates.

PubMed

Barbosa, Alynne da Silva; Barbosa, Helene Santos; Souza, Sandra Maria de Oliveira; Dib, Laís Verdan; Uchôa, Claudia Maria Antunes; Bastos, Otilio Machado Pereira; Amendoeira, Maria Regina Reis

2018-06-26

Balantioides coli is a ciliated protozoon that inhabits the intestine of pigs, non-human primates and humans. Light microscopy studies have described over 50 species of the genus Balantioides but their validity is in doubt. Due to the limited information about this genus, this study is aimed to identify morphological characteristics of Balantioides coli isolated using fluorescence microscopy and both scanning (SEM) and transmission electron microscopy (TEM). Trophozoites isolated from the feces of pig and macaque were washed and subjected to centrifugation. These cells were fixed with paraformaldehyde for immunofluorescence. Other aliquots of these trophozoites were fixed with glutaraldehyde, post fixed with osmium tetroxide and processed for SEM and TEM. Immunofluorescence studies revealed microtubules with a longitudinal distribution to the main axis of the parasite and in the constitution of cilia. SEM demonstrated a high concentration of cilia covering the oral apparatus and a poor presence of such structures in cytopyge. TEM revealed in the plasma membrane, several associated structures were observed to delineate the cellular cortex and mucocysts. The cytoskeleton of the oral region was observed in detail and had an organization pattern consisting of microtubules, which formed files and nematodesmal networks. Organelles such as hydrogenosomes like and peroxisomes were observed close to the cortex. Macronuclei were observed, but structures that were consistent with micronuclei were not identified. Ultrastructural morphological analysis of isolates confirms its similarity to Balantioides coli. In this study were identified structures that had not yet been described, such as hydrogenosomes like and cytoskeletal structures.

Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer's disease.

PubMed

Sharoar, M G; Shi, Q; Ge, Y; He, W; Hu, X; Perry, G; Zhu, X; Yan, R

2016-09-01

Pathological features in Alzheimer's brains include mitochondrial dysfunction and dystrophic neurites (DNs) in areas surrounding amyloid plaques. Using a mouse model that overexpresses reticulon 3 (RTN3) and spontaneously develops age-dependent hippocampal DNs, here we report that DNs contain both RTN3 and REEPs, topologically similar proteins that can shape tubular endoplasmic reticulum (ER). Importantly, ultrastructural examinations of such DNs revealed gradual accumulation of tubular ER in axonal termini, and such abnormal tubular ER inclusion is found in areas surrounding amyloid plaques in biopsy samples from Alzheimer's disease (AD) brains. Functionally, abnormally clustered tubular ER induces enhanced mitochondrial fission in the early stages of DN formation and eventual mitochondrial degeneration at later stages. Furthermore, such DNs are abrogated when RTN3 is ablated in aging and AD mouse models. Hence, abnormally clustered tubular ER can be pathogenic in brain regions: disrupting mitochondrial integrity, inducing DNs formation and impairing cognitive function in AD and aging brains.

The ameliorative effect of thymol against hydrocortisone-induced hepatic oxidative stress injury in adult male rats.

PubMed

Aboelwafa, Hanaa R; Yousef, Hany N

2015-08-01

The aim of the present study was to investigate whether hydrocortisone induces oxidative stress in hepatocytes and to evaluate the possible ameliorative effect of thymol against such hepatic injury. Twenty-four adult male rats were divided into control, thymol, hydrocortisone, and hydrocortisone+thymol groups. The 4 groups were treated daily for 15 days. Hydrocortisone significantly induced oxidative stress in the liver tissues, marked by increased serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total oxidative capacity (TOC), and tumor necrosis factor-alpha (TNF-α) accompanied by marked decline of serum levels of total protein, albumin, and total antioxidant capacity (TAC). Also, marked elevation in the levels of the thiobarbituric acid reactive substances (TBARS) and TNF-α, beside significant decrease in the level of glutathione (GSH) in hepatic tissues were recorded. These biochemical alterations were accompanied by histopathological changes marked by destruction of the normal hepatic architecture, in addition to ultrastructural alterations represented by degenerative features covering almost all the cytoplasmic organelles of the hepatocytes. Supplementation of hydrocortisone-treated rats with thymol reversed most of the biochemical, histological, and ultrastructural alterations. The results of our study confirm that thymol has strong ameliorative effect against hydrocortisone-induced oxidative stress injury in hepatic tissues.

Ultrastructure of the spermatozoa of Corystes cassivelaunus (Corystidae), Platepistoma nanum (Cancridae) and Cancer pagurus (Cancridae) supports recognition of the Corystoidea (Crustacea, Brachyura, Heterotremata)

NASA Astrophysics Data System (ADS)

Jamieson, B. G. M.; Guinot, D.; Tudge, C. C.; Richer de Forges, B.

1997-03-01

A combination of characters, not individually unique, possessed by the corystid, Corystes cassivelaunus, and the two cancrids, Platepistoma nanum and Cancer pagurus, defines a corystoid-type of spermatozoon: the basally bulbous, anteriorly narrowing perforatorium, the extent of this almost to the plasma membrane through a widely perforate operculum, and the simple inner acrosome zone, lacking an acrosome ray zone. The sperm of the two cancrids are closely similar, that of the corystid differing, for instance, in the less pointed, and less tapered, form of the perforatorium. This relative uniformity of spermatozoal ultrastructure in the cancrid+corystid assemblage so far investigated supports inclusion of the two families in the superfamily Corystoidea by Guinot (1978). The combination of perforation of the operculum and absence of an acrosome ray zone (at least in a clearly recognizable form) are features of the Potamidae which possibly indicate that the latter family, modified for a freshwater existence, is related to the cancrid+corystid assemblage. Some elongation of the centrioles, apparent at least in Corystes, may be a further link with potamids in which they are greatly elongated. The coenospermial spermatophores of cancridoids are a notable difference from the cleistospermia of potamids; but the latter is probably an apomorphic modification for fertilization biology.

Trachyrhizium urniformis n. g., n. sp., a Novel Marine Filose Thecate Amoeba Related to a Cercozoan Environmental Clade (Novel Clade 4).

PubMed

Shiratori, Takashi; Ishida, Ken-Ichiro

2016-11-01

A novel cercozoan filose thecate amoeba, Trachyrhizium urniformis n. g., n. sp., was isolated from a marine sediment sample collected at Agenashiku Island, Okinawa, Japan. We performed light and electron microscopic observations, and a molecular phylogenetic analysis using the small subunit ribosomal RNA gene of the isolate. Cells of T. urniformis are spherical in shape and are covered by a thin theca possessing a wide rounded aperture. Branching and occasionally anastomosing filopodia with small granules emerge from the aperture. The granules are transported in the filopodia bidirectionally. Transmission electron microscopy showed that cells of T. urniformis possess nucleus with permanently condensed chromatin, Golgi apparatuses, microbodies, mitochondria with tubular cristae, and extrusomes. Several morphological and ultrastructural features of T. urniformis (the presence of thecae and nucleus with permanently condensed chromatin) show similarities with those of Thecofilosea. In a phylogenetic analysis, T. urniformis included in Thecofilosea with weak statistical supports and formed a clade with two sequences that constitutes a cercozoan environmental clade, novel clade 4. On the basis of morphological and ultrastructural information and the results of the phylogenetic analysis, we propose T. urniformis as a new member of class Thecofilosea. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Morphology and ultrastructure of the esophagus during the ontogeny of the spider crab Maja brachydactyla (Decapoda, Brachyura, Majidae).

PubMed

Castejón, Diego; Rotllant, Guiomar; Ribes, Enric; Durfort, Mercè; Guerao, Guillermo

2018-06-01

The esophagus of the eucrustaceans is known as a short tube that connects the mouth with the stomach but has generally received little attention by the carcinologists, especially during the larval stages. By this reason, the present study is focused on the morphology and ultrastructure of the esophagus in the brachyuran Maja brachydactyla during the larval development and adult stage. The esophagus shows internally four longitudinal folds. The simple columnar epithelium is covered by a thick cuticle. The epithelial cells of the adults are intensively interdigitated and show abundant apical mitochondria and bundles of filamentous structures. The cuticle surface has microspines and mutually exclusive pores. Three muscle layers surrounded by the connective tissue are reported: circular muscles forming a broad continuous band, longitudinal muscle bundles adjacent to the circular muscles, and dilator muscles crossing the connective tissue vertically toward the epithelium. The connective tissue has rosette glands. The esophagus of the larvae have epithelial cells with big vesicles but poorly developed interdigitations and filamentous structures, the cuticle is formed by a procuticle without differentiated exocuticle and endocuticle, the connective layer is thin and the rosette glands are absent. The observed features can be explained by his role in the swallowing of the food. © 2018 Wiley Periodicals, Inc.

An ultrastructural study of Paraphysoderma sedebokerense (Blastocladiomycota), an epibiotic parasite of microalgae.

PubMed

Letcher, Peter M; Lee, Philip A; Lopez, Salvador; Burnett, Micheal; McBride, Robert C; Powell, Martha J

2016-03-01

Successful algal cultivation for biofuel production is one path in the transition to a renewable energy economy. The green alga Scenedesmus dimorphus is a candidate for biofuel production, but is subject to parasitism and subsequent population crash when cultivated in open ponds. From an open pond cultivating S. dimorphus for biofuel production in New Mexico, USA, an amoeboid parasite was isolated, designated as isolate FD61, and its rDNA operon sequenced. A BLAST search for nuc 18S rDNA (18S) sequence similarity identified the parasite as Paraphysoderma sedebokerense (Blastocladiomycota). Here, we examine the ultrastructure of P. sedebokerense and compare it with that of a sister taxon, Physoderma maydis. The parasite has thin-walled vegetative sporangia and thick-walled resting sporangia. Our observations indicate that amoeboid swarmers are produced in the vegetative phase, while either amoeboid swarmers or zoospores are the product of meiosis in resting sporangia. Meiosis is confirmed by the presence of synaptonemal complexes in resting sporangia nuclei. Notably, P. sedebokerense has a Golgi apparatus with stacked cisternae, a feature reported for P. maydis, but which is absent in all other examined taxa in Blastocladiomycota. This report furthers our knowledge of the life cycle of P. sedebokerense. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Organization of testicular interstitial tissue of an Australian rodent, the spinifex hopping mouse, Notomys alexis.

PubMed

Peirce, E J; Breed, W G

1990-05-01

The organization of testicular interstitial tissue of the spinifex hopping mouse, Notomys alexis differs from that of other rodents. It comprises between 10.3% and 17.3% (average 15.0%) of the total testicular volume, and is variable in its organization both at different locations within the testis of the one animal and among different individuals. Abundant, closely packed Leydig cells are usually present; however, in some regions large, thick-walled blood vessels and extensive peritubular lymphatic spaces, often lacking an endothelium adjacent to the Leydig cells, are also prominent. The Leydig cells in contact with the large blood vessels and lymphatics, unlike those in regions where lymph is sparse, are not densely packed and sometimes contain numerous lipid droplets. Ultrastructure of Leydig cells is typical of steroid-producing cells; however, mitochondria are often extremely large, unusual in shape or bizarrely arranged in relation to one another. Also electron-dense bodies displaying a paracrystalline-like internal structure of parallel, electron-dense filaments arranged in a lattice pattern occur in the cytoplasm of many cells. The significance of these unusual ultrastructural features and the organization of the interstitial tissue remain to be determined conclusively, but may relate to steroid synthesis, secretion and uptake.

Differential diagnosis between mesothelioma and adenocarcinoma: a multimodal approach based on ultrastructure and immunocytochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bedrossian, C.W.; Bonsib, S.; Moran, C.

1992-05-01

Most compensations for asbestos-related deaths secondary to cancer center around mesothelioma and bronchogenic carcinoma. The differential diagnosis between mesothelioma and adenocarcinoma is a common and troublesome one, necessitating the correlation between clinical history, radiographic findings, and pathologic examination of tissues and cells. We describe a multimodal approach based on the use of routine and special stains, immunocytochemistry, and electron microscopy for distinguishing between mesothelioma and adenocarcinoma. Once a malignant diagnosis is arrived at by careful pathological examination, the tumor is classified as mesothelioma if mesothelial cells are identified as the constituent cells of the neoplasm. Mesothelial cells are recognized bymore » (1) their main ultrastructural features: slender and elongated microvilli, abundant intermediate filaments, and lacking secretory granules; and (2) their characteristic immunocytochemical reactivity: positivity for cytokeratin, EMA, and vimentin, and negativity for carcinoembryonic antigen (CEA), B72-3, Leu-M1, and other gland-cell markers. A variety of methods have been attempted in an effort to distinguish between reactive and malignant mesothelial cells. In practice, however, such distinction depends more on experience and expertise than in any fool-proof ancillary tests. A number of these tests are discussed along with the illustration of classical and unusual examples of mesothelioma and other pleural tumors.« less

Sebaceous Gland, Hair Shaft, and Epidermal Barrier Abnormalities in Keratosis Pilaris with and without Filaggrin Deficiency

PubMed Central

Gruber, Robert; Sugarman, Jeffrey L.; Crumrine, Debra; Hupe, Melanie; Mauro, Theodora M.; Mauldin, Elizabeth A.; Thyssen, Jacob P.; Brandner, Johanna M.; Hennies, Hans-Christian; Schmuth, Matthias; Elias, Peter M.

2016-01-01

Although keratosis pilaris (KP) is common, its etiopathogenesis remains unknown. KP is associated clinically with ichthyosis vulgaris and atopic dermatitis and molecular genetically with filaggrin-null mutations. In 20 KP patients and 20 matched controls, we assessed the filaggrin and claudin 1 genotypes, the phenotypes by dermatoscopy, and the morphology by light and transmission electron microscopy. Thirty-five percent of KP patients displayed filaggrin mutations, demonstrating that filaggrin mutations only partially account for the KP phenotype. Major histologic and dermatoscopic findings of KP were hyperkeratosis, hypergranulosis, mild T helper cell type 1-dominant lymphocytic inflammation, plugging of follicular orifices, striking absence of sebaceous glands, and hair shaft abnormalities in KP lesions but not in unaffected skin sites. Changes in barrier function and abnormal paracellular permeability were found in both interfollicular and follicular stratum corneum of lesional KP, which correlated ultrastructurally with impaired extracellular lamellar bilayer maturation and organization. All these features were independent of filaggrin genotype. Moreover, ultrastructure of corneodesmosomes and tight junctions appeared normal, immunohistochemistry for claudin 1 showed no reduction in protein amounts, and molecular analysis of claudin 1 was unremarkable. Our findings suggest that absence of sebaceous glands is an early step in KP pathogenesis, resulting in downstream hair shaft and epithelial barrier abnormalities. PMID:25660180

Three-dimensional analysis of synapses in the transentorhinal cortex of Alzheimer's disease patients.

PubMed

Domínguez-Álvaro, M; Montero-Crespo, M; Blazquez-Llorca, L; Insausti, R; DeFelipe, J; Alonso-Nanclares, L

2018-03-02

Synaptic dysfunction or loss in early stages of Alzheimer's disease (AD) is thought to be a major structural correlate of cognitive dysfunction. Early loss of episodic memory, which occurs at the early stage of AD, is closely associated with the progressive degeneration of medial temporal lobe (MTL) structures of which the transentorhinal cortex (TEC) is the first affected area. However, no ultrastructural studies have been performed in this region in human brain samples from AD patients. In the present study, we have performed a detailed three-dimensional (3D) ultrastructural analysis using focused ion beam/scanning electron microscopy (FIB/SEM) to investigate possible synaptic alterations in the TEC of patients with AD. Surprisingly, the analysis of the density, morphological features and spatial distribution of synapses in the neuropil showed no significant differences between AD and control samples. However, light microscopy studies showed that cortical thickness of the TEC was severely reduced in AD samples, but there were no changes in the volume occupied by neuronal and glial cell bodies, blood vessels, and neuropil. Thus, the present results indicate that there is a dramatic loss of absolute number of synapses, while the morphology of synaptic junctions and synaptic spatial distribution are maintained. How these changes affect cognitive impairment in AD remains to be elucidated.

Isolation, Chemical Composition, and Ultrastructural Features of the Cell Membrane of the Mycoplasma-Like Organism Spiroplasma citri

PubMed Central

Razin, Shmuel; Hasin, Miriam; Ne'eman, Zvi; Rottem, Shlomo

1973-01-01

Thin sections of Spiroplasma citri, a mycoplasma-like organism isolated from citrus infected with “Stubborn” disease, showed the organisms to be limited by a single trilaminar plasma membrane. An additional outer layer could, however, be frequently seen in freeze-etched preparations of unwashed cells. The organisms were found to be extremely sensitive to lysis by osmotic shock. The cell membrane of S. citri isolated in this way resembled that of mycoplasmas in ultrastructure and gross chemical composition. The isolated membranes showed the characteristic trilaminar shape in section and the typical particle-studded fracture faces in freeze-etched preparations. Protein and lipid formed over 80% of the total dry weight of the membrane, which had a density of ~1.180 g/cm3. Cholesterol constituted over 20% of the total membrane lipid. Phosphatidyl-glycerol, synthesized by the organisms, was the major phospholipid. Significant amounts of hexosamine (15 to 35 μg/mg of membrane protein) could be found in the membrane preparations. Our results support the thesis that S. citri does not possess a cell wall, either of the gram-positive or the gram-negative type, though it may be coated by some other type of an envelope or by a slime layer, at least temporarily. Images PMID:4127633

Direct electric current modifies important cellular aspects and ultrastructure features of Candida albicans yeasts: Influence of doses and polarities.

PubMed

Barbosa, Gleyce Moreno; Dos Santos, Eldio Gonçalves; Capella, Francielle Neves Carvalho; Homsani, Fortune; de Pointis Marçal, Carina; Dos Santos Valle, Roberta; de Araújo Abi-Chacra, Érika; Braga-Silva, Lys Adriana; de Oliveira Sales, Marcelo Henrique; da Silva Neto, Inácio Domingos; da Veiga, Venicio Feo; Dos Santos, André Luis Souza; Holandino, Carla

2017-02-01

Available treatments against human fungal pathogens present high levels of resistance, motivating the development of new antifungal therapies. In this context, the present work aimed to analyze direct electric current (DC) antifungal action, using an in vitro apparatus equipped with platinum electrodes. Candida albicans yeast cells were submitted to three distinct conditions of DC treatment (anodic flow-AF; electroionic flow-EIF; and cathodic flow-CF), as well as different charges, ranging from 0.03 to 2.40 C. Our results indicated C. albicans presented distinct sensibility depending on the DC intensity and polarity applied. Both the colony-forming unit assay and the cytometry flow with propidium iodide indicated a drastic reduction on cellular viability after AF treatment with 0.15 C, while CF- and EIF-treated cells stayed alive when DC doses were increased up to 2.40 C. Additionally, transmission electron microscopy revealed important ultrastructural alterations in AF-treated yeasts, including cell structure disorganization, ruptures in plasmatic membrane, and cytoplasmic rarefaction. This work emphasizes the importance of physical parameters (polarity and doses) in cellular damage, and brings new evidence for using electrotherapy to treat C. albicans pathology process. Bioelectromagnetics. 38:95-108, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Marine bivalve shell geochemistry and ultrastructure from modern low pH environments: environmental effect versus experimental bias

NASA Astrophysics Data System (ADS)

Hahn, S.; Rodolfo-Metalpa, R.; Griesshaber, E.; Schmahl, W. W.; Buhl, D.; Hall-Spencer, J. M.; Baggini, C.; Fehr, K. T.; Immenhauser, A.

2012-05-01

Bivalve shells can provide excellent archives of past environmental change but have not been used to interpret ocean acidification events. We investigated carbon, oxygen and trace element records from different shell layers in the mussels Mytilus galloprovincialis combined with detailed investigations of the shell ultrastructure. Mussels from the harbour of Ischia (Mediterranean, Italy) were transplanted and grown in water with mean pHT 7.3 and mean pHT 8.1 near CO2 vents on the east coast of the island. Most prominently, the shells recorded the shock of transplantation, both in their shell ultrastructure, textural and geochemical record. Shell calcite, precipitated subsequently under acidified seawater responded to the pH gradient by an in part disturbed ultrastructure. Geochemical data from all test sites show a strong metabolic effect that exceeds the influence of the low-pH environment. These field experiments showed that care is needed when interpreting potential ocean acidification signals because various parameters affect shell chemistry and ultrastructure. Besides metabolic processes, seawater pH, factors such as salinity, water temperature, food availability and population density all affect the biogenic carbonate shell archive.

Ultrastructural and cytochemical evidence for single impulse initiation zones in vestibular macular nerve fibers of rat

NASA Technical Reports Server (NTRS)

Ross, Muriel D.; Chee, Oliver; Black, Samuel; Cutler, Lynn

1991-01-01

Cupric ion-ferricyanide labeling methods and related ferrocyanide-stained tissues were used to locate the characterize, at the ultrastructural level, presumptive impulse initiation zones in the three types of vestibular macular nerve fibers. Large-diameter, M-type vestibular nerve fibers terminate in a calyx at the heminode, and labeling is coextensive with the base of the calyx. Intermediate, M/U-type nerve fibers have short, unmyelinated preterminal segments that sometimes bifurcate intamacularly, and small-diameter, U-type nerve fibers have long, unmyelinated preterminal axons and up to three branches. Preterminals of these nerve fibers display ultrastructural heterogeneity that is correlated with labeling patterns for sodium channels and/or associated polyanionic sites. They have a nodelike ultrastructure and label heavily from near the heminode to the base of the macula. Their intramacular branches, less organized ultrastructurally, label only slightly. Results indicate that vestibular nerve fibers have one impulse initiation zone, located near the heminode, that varies in length according to nerve fiber type. Structural heterogeneity may favor impulse conduction in the central direction, and length of the impulse initiation zone could influence nerve discharge patterns.

Changes in ultrastructure and histochemistry of two red macroalgae strains of Kappaphycus alvarezii (Rhodophyta, Gigartinales), as a consequence of ultraviolet B radiation exposure.

PubMed

Schmidt, Eder Carlos; Scariot, Lidiane Angela; Rover, Ticiane; Bouzon, Zenilda Laurita

2009-12-01

Ultraviolet radiation (UVR) affects macroalgae in many important ways, including reduced growth rate, reduction of primary productivity and changes in cell biology and ultrastructure. Among red macroalgae, Kappaphycus alvarezii is of economic interest by its production of kappa carrageenan. Only a few reports have examined the changes in macroalgae ultrastructure and cell biology resulting from UVB radiation exposure. Therefore, we examined two strains of K. alvarezii (green and red) exposed to UVB for 3 h per day during 28 days and then processed them for histochemical and electron microscopy analysis. Reaction with Toluidine Blue showed an increase in the thickness of the cell wall and Periodic Acid-Schiff stain showed a decrease in the number of starch grains. UVBR also caused changes in the ultrastructure of cortical and subcortical cells, which included increased thickness of the cell wall and number of free ribosomes and plastoglobuli, reduced intracellular spaces, changes in the cell contour, and destruction of chloroplast internal organization. Based on these lines of evidence, it was evident by the ultrastructural changes observed that UVBR negatively affects intertidal macroalgae and, by extension, their economic viability.

Techniques to assess bone ultrastructure organization: orientation and arrangement of mineralized collagen fibrils

PubMed Central

Georgiadis, Marios; Müller, Ralph; Schneider, Philipp

2016-01-01

Bone's remarkable mechanical properties are a result of its hierarchical structure. The mineralized collagen fibrils, made up of collagen fibrils and crystal platelets, are bone's building blocks at an ultrastructural level. The organization of bone's ultrastructure with respect to the orientation and arrangement of mineralized collagen fibrils has been the matter of numerous studies based on a variety of imaging techniques in the past decades. These techniques either exploit physical principles, such as polarization, diffraction or scattering to examine bone ultrastructure orientation and arrangement, or directly image the fibrils at the sub-micrometre scale. They make use of diverse probes such as visible light, X-rays and electrons at different scales, from centimetres down to nanometres. They allow imaging of bone sections or surfaces in two dimensions or investigating bone tissue truly in three dimensions, in vivo or ex vivo, and sometimes in combination with in situ mechanical experiments. The purpose of this review is to summarize and discuss this broad range of imaging techniques and the different modalities of their use, in order to discuss their advantages and limitations for the assessment of bone ultrastructure organization with respect to the orientation and arrangement of mineralized collagen fibrils. PMID:27335222

Testicular immunohistochemical and Ultrastructural changes associated with chronic cholestasis in rats: Effect of ursodeoxycholic acid.

PubMed

Mahmoud, Yomna I

2015-09-01

Testicular atrophy has been commonly reported in patients with chronic liver diseases. Ursodeoxycholic acid is the most widely used drug for the treatment of many liver diseases. However, its effect on testicular ultrastructure associated with chronic cholestasis has never been studied. Thus, this study aimed to assess how chronic obstructive jaundice affects the testicular ultrastructure and whether it affects the androgen receptor or the proliferating cell nuclear antigen. The role of ursodeoxycholic acid was also investigated. Cholestasis was induced by bile duct ligation. Samples were collected 4weeks postoperative. Testicular changes were assessed using immunohistochemistry and transmission electron microscopy. Chronic cholestasis resulted in testicular atrophy evidenced by shrinkage and deformation of seminiferous tubules, thickening of peritubular boundaries, vacuolation, disorganization of germ cells, and maturation arrest. This was accompanied by decreased immunoreactivity of androgen receptors and proliferating cell nuclear antigen. Administration of ursodeoxycholic acid improved the testicular morphology and reversed cholestasis-induced immunohistochemical and ultrastructural changes. Ursodeoxycholic acid can improve the testicular ultrastructure and restore the spermatogenic process in rats with chronic cholestasis. These findings support the clinical application of ursodeoxycholic acid in cholestatic patients especially those with hypogonadism. Copyright © 2015. Published by Elsevier Inc.

Antigenic specificity and morphologic characteristics of Chlamydia trachomatis, strain SFPD, isolated from hamsters with proliferative ileitis.

PubMed

Fox, J G; Stills, H F; Paster, B J; Dewhirst, F E; Yan, L; Palley, L; Prostak, K

1993-10-01

Profound diarrhea associated with proliferating intestinal cells containing intraepithelial campylobacter-like organisms (ICLO) occurs in a variety of mammalian hosts, particularly swine and hamsters. Recently, intracellular bacteria were isolated from proliferative intestinal tissue of hamsters and propagated in intestine cell line 407. Oral inoculation of hamsters with cell culture lysates containing these organisms reproduced the disease in susceptible hamsters. In the present study, an intracellular bacterium from the INT 407 cell line was shown by a variety of techniques to be a member of the genus Chlamydia and has been designated Chlamydia sp. strain SFPD. McCoy cells infected with Chlamydia sp. strain SFPD demonstrated bright fluorescent-stained intracytoplasmic inclusions when examined with fluorescein-labeled species-specific C. trachomatis monoclonal antibodies. The organism also reacted to fluorescein-labeled polyclonal but not monoclonal ICLO "omega" antisera. Ultrastructural examination of the Chlamydia sp. strain SFPD from McCoy cells revealed electrondense elementary bodies and a less electron-dense reticulate-like body that was circular; both features are consistent in morphology to developmental forms of Chlamydia and do not conform to ICLO morphology. Molecular studies, 16S ribosomal sequence analysis, and sequencing of the outer membrane protein confirmed that the isolate is a C. trachomatis closely related to the mouse pneumonitis strain of C. trachomatis.

The candidate sour taste receptor, PKD2L1, is expressed by type III taste cells in the mouse.

PubMed

Kataoka, Shinji; Yang, Ruibiao; Ishimaru, Yoshiro; Matsunami, Hiroaki; Sévigny, Jean; Kinnamon, John C; Finger, Thomas E

2008-03-01

The transient receptor potential channel, PKD2L1, is reported to be a candidate receptor for sour taste based on molecular biological and functional studies. Here, we investigated the expression pattern of PKD2L1-immunoreactivity (IR) in taste buds of the mouse. PKD2L1-IR is present in a few elongate cells in each taste bud as reported previously. The PKD2L1-expressing cells are different from those expressing PLCbeta2, a marker of Type II cells. Likewise PKD2L1-immunoreactive taste cells do not express ecto-ATPase which marks Type I cells. The PKD2L1-positive cells are immunoreactive for neural cell adhesion molecule, serotonin, PGP-9.5 (ubiquitin carboxy-terminal transferase), and chromogranin A, all of which are present in Type III taste cells. At the ultrastructural level, PKD2L1-immunoreactive cells form synapses onto afferent nerve fibers, another feature of Type III taste cells. These results are consistent with the idea that different taste cells in each taste bud perform distinct functions. We suggest that Type III cells are necessary for transduction and/or transmission of information about "sour", but have little or no role in transmission of taste information of other taste qualities.

The candidate sour taste receptor, PKD2L1, is expressed by type III taste cells in the mouse

PubMed Central

Kataoka, Shinji; Yang, Ruibiao; Ishimaru, Yoshiro; Matsunami, Hiroaki; Kinnamon, John C.; Finger, Thomas E.

2008-01-01

The transient receptor potential (TRP) channel, PKD2L1, is reported to be a candidate receptor for sour taste based on molecular biological and functional studies. Here, we investigated the expression pattern of PKD2L1-immunoreactivity (IR) in taste buds of the mouse. PKD2L1-IR is present in a few elongate cells in each taste bud as reported previously. The PKD2L1-expressing cells are different from those expressing PLCβ2, a marker of Type II cells. Likewise PKD2L1-immunoreactive taste cells do not express ecto-ATPase which marks Type I cells. The PKD2L1 positive cells are immunoreactive for NCAM, serotonin, PGP-9.5 (ubiquitin carboxy terminal transferase) and chromogranin A, all of which are present in Type III taste cells. At the ultrastructural level, PKD2L1-immunoreactive cells form synapses onto afferent nerve fibers, another feature of Type III taste cells. These results are consistent with the idea that different taste cells in each taste bud perform distinct functions. We suggest that Type III cells are necessary for transduction and/or transmission of information about “sour”, but have little or no role in transmission of taste information of other taste qualities. PMID:18156604

Effects of simulated acid rain on pollen physiology and ultrastructure in the apple.

PubMed

Bellani, L M; Rinallo, C; Muccifora, S; Gori, P

1997-01-01

Viability, germination and tube length were investigated in pollen grains of field-grown 'Summerred' apple trees (Malus domestica Borkh) exposed to deionized water, rainfall or simulated acid rain at pH 5.6, 4.0 and 3.0. Pollen viability and germination significantly decreased with lower values of pH and with increasing number of treatments. The effects of pH 5.6 and natural rainfall were not significant. Electron microscope investigation of vegetative pollen cells of plants exposed to acid rain at pH 4.0 and 3.0 showed modified features in mitochondria, plastids and endoplasmic reticulum.

"Cercariform" cells: a clue to the cytodiagnosis of transitional cell origin of metastatic neoplasms?

PubMed

Powers, C N; Elbadawi, A

1995-07-01

The "cercariform" cell is described as a distinct cytomorphologic clue that may be helpful in the diagnosis of metastatic transitional cell neoplasms, particularly low grade. This cell has a nucleated globular body and a cytoplasmic process with a nontapering, flattened, bulbous or fishtail-like end. The cercariform cell corresponds to intermediate cells in histologic and ultrastructural preparations of normal urothelium. The cercariform appearance is the result of pseudostratification of both normal and low-grade neoplastic urothelium. The unique features of cercariform cells make them readily distinguishable from neoplastic squamous cells as well as spindle cells of mesenchymal origin.

Feline vaccine-associated fibrosarcoma: an ultrastructural study of 20 tumors (1996-1999).

PubMed

Madewell, B R; Griffey, S M; McEntee, M C; Leppert, V J; Munn, R J

2001-03-01

Twenty feline vaccine-associated sarcomas were examined by transmission electron microscopy. Tumors contained pleomorphic spindle cells, histiocytoid cells, and giant cells. Most tumors contained myofibroblasts, which had morphologic features similar to those of fibroblasts. These cells were further distinguished by subplasmalemmal dense plaques and thin cytoplasmic actin myofilaments organized as elongated bundles concentrated at irregular intervals forming characteristic dense bodies. Intracellular crystalline particulate material was found in 5 of the 20 tumors. Energy dispersive X-ray spectroscopy was used to identify the crystalline material within one tumor as aluminum-based. One tumor from a feline leukemia virus-infected cat contained budding and immature retroviral particles.

[The microcirculatory bed of the human epididymis].

PubMed

Aleksieiev, O M

1998-08-01

Based on the material of 24 human epididymides at ages 18 to 54, hemomicrocirculatory bed was studied of epididymis in man with the aid of a complex of morphologic techniques (injection of 20% Chinese ink-gelatine suspension, injection of a weak solution of caustic silver, transmission electron microscopy). It has been ascertained that architectonics and ultrastructural features of various links of the hemomicrocirculatory bed have signs of regional specificity for the subcapsular vascular network, small seminal ducts of caput epididymidis, ductus epididymidis of the head, body and tail of the organ. Reasons are discussed why specific hemomicrocirculatory bed should be caused to develop in different parts of the organ.

Lymphatic endothelial cell line (CH3) from a recurrent retroperitoneal lymphangioma.

PubMed

Way, D; Hendrix, M; Witte, M; Witte, C; Nagle, R; Davis, J

1987-09-01

An endothelial cell line derived from a massive recurrent chyle-containing retroperitoneal lymphangioma was isolated in monolayer culture. Scanning and transmission electron microscopy and immunohistochemistry confirmed a close resemblance to blood vascular endothelium with typical cobblestone morphology, positive immunofluorescence staining for endothelial marker Factor VIII-associated antigen and fibronectin, and prominent Weibel-Palade bodies. The endothelial cells also exhibited other ultrastructural features characteristic of lymphatic endothelium, including sparse microvillous surface projections, overlapping intercellular junctions, and abundant intermediate filaments. This endothelial cell line represents a new source of proliferating lymphatic endothelium for future study, including structural and functional comparison to blood vascular endothelium.

The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers1[OPEN

PubMed Central

Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K.; Dyer, John M.; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Jenks, Matthew A.

2017-01-01

We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4’s principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation’s effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. PMID:28069670

Ultrastructural organisation of HCV from the bloodstream of infected patients revealed by electron microscopy after specific immunocapture.

PubMed

Piver, Eric; Boyer, Audrey; Gaillard, Julien; Bull, Anne; Beaumont, Elodie; Roingeard, Philippe; Meunier, Jean-Christophe

2017-08-01

HCV particles are associated with very low-density lipoprotein components in chronically infected patients. These hybrid particles, or 'lipo-viro particles' (LVPs), are rich in triglycerides, and contain the viral RNA, the capsid protein, E1E2 envelope glycoproteins and apolipoproteins B and E. However, their specific ultrastructural organisation has yet to be determined. We developed a strategy for the preparation of any viral sample that preserves the native structure of the LVPs, facilitating their precise morphological characterisation. Using a strategy based on the direct specific immunocapture of particles on transmission electron microscopy (TEM) grids, we characterised the precise morphology of the viral particle by TEM. The LVP consists of a broad nucleocapsid surrounding an electron-dense centre, presumably containing the HCV genome. The nucleocapsid is surrounded by an irregular, detergent-sensitive crescent probably composed of lipids. Lipid content may determine particle size. These particles carry HCV E1E2, ApoB and ApoE, as shown in our immuno-EM analysis. Our results also suggest that these putative LVPs circulate in the serum of patients as part of a mixed population, including lipoprotein-like particles and complete viral particles. Twenty-five years after the discovery of HCV, this study finally provides information about the precise morphological organisation of viral particles. It is truly remarkable that our TEM images fully confirm the ultrastructure of LVPs predicted by several authors, almost exclusively from the results of molecular biology studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Charting the Isophasic Endophyte of Dwarf Mistletoe Arceuthobium douglasii (Viscaceae) in Host Apical Buds

PubMed Central

LYE, DAVID

2006-01-01

• Background and Aims Dwarf mistletoes (Arceuthobium; Viscaceae) are highly specialized dioecious angiosperms parasitic on many gymnosperm hosts in the northern hemisphere. Several dwarf mistletoe species are capable of inducing an unusual form of isophasic infection in which the internal (endophytic) system proliferates even into the apical buds of its hosts. Studies of the internal endophytic system have, for the most part, focused on the parasite within secondary host tissues. The present anatomical and ultrastructural study characterizes the growth pattern of the isophasic endophytic system of Arceuthobium douglasii within the dormant apical buds of Pseudotsuga menziesii. • Methods Semi-thin serial sections from dwarf mistletoe-infected host apical buds were mounted, stained and micrographed. Graphic files were created from the serial micrographs and these files were stacked. These stacked files were utilized to describe the pattern of growth of the endophyte within the host tissue. The interface between cells of the mistletoe and host was also examined at the ultrastructural level by transmission electron microscopy. • Key Results By utilizing a novel technique of superimposed graphics, the current study reveals an organized pattern of mistletoe distribution that penetrates further into host tissues than previously known. A consistent pattern of growth occurring even into the preformed leaves of the host is documented. • Conclusions The apparently non-intrusive growth of the parasite appears to be developmentally synchronized with that of the host. No symplastic connections were observed in the ultrastructural examination of the parasite/host interface within the apical buds of Pseudotsuga menziesii parasitized by A. douglasii or of Pinus contorta parasitized by A. americanum. PMID:16613903

The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers.

PubMed

Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou

2017-02-01

We report n-6 monounsaturated primary alcohols (C 26:1 , C 28:1 , and C 30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. © 2017 American Society of Plant Biologists. All Rights Reserved.

Ultrastructural properties of laser-irradiated and heat-treated dentin.

PubMed

Rohanizadeh, R; LeGeros, R Z; Fan, D; Jean, A; Daculsi, G

1999-12-01

Previous studies using scanning electron microscopy and infrared absorption spectroscopy reported that laser irradiation causes compositional changes in enamel. The purpose of this study was to evaluate the ultrastructural and compositional changes in dentin caused by irradiation with a short-pulse laser (Q-switched Nd:YAG). The irradiated and non-irradiated areas of the lased dentin samples were investigated by scanning (SEM) and transmission electron microscopy (TEM), micro-micro electron diffraction, and electron microprobe analysis of dispersive energy (EDX). Heat-treated dentin was similarly investigated. This study demonstrated that laser irradiation resulted in the recrystallization of dentin apatite and in the formation of additional calcium phosphate phases consisting of magnesium-substituted beta-tricalcium phosphate, beta-TCMP, beta-(Ca,Mg)3(PO4)2, and tetracalcium phosphate, TetCP, Ca4(PO4)O. TEM analyses of the modified and unmodified zones of the irradiated areas showed two types of crystal populations: much larger crystals from the modified zone and crystals with size and morphology similar to those of dentin apatite in the unmodified zone. The morphology of crystals in the modified zones in the irradiated dentin resembled those of dentin sintered at 800 or 950 degrees C. In the irradiated areas (modified and unmodified zones), the Ca/P ratio was lower compared with that in the non-irradiated dentin. The Mg/Ca ratio in the modified zones was higher than that in the unmodified zones and in the non-irradiated dentin. In sintered dentin, the Mg/Ca ratio increased as a function of sintering temperature. The ultrastructural and compositional changes observed in laser-irradiated dentin may be attributed to high temperature and high pressure induced by microplasma during laser irradiation. These changes may alter the solubility of the irradiated dentin, making it less susceptible to acid dissolution or to the caries process.

A morphometric analysis of cellular differentiation in caps of primary and lateral roots of Helianthus annuus

NASA Technical Reports Server (NTRS)

Moore, R.

1985-01-01

In order to determine if patterns of cell differentiation are similar in primary and lateral roots, I performed a morphometric analysis of the ultrastructure of calyptrogen, columella, and peripheral cells in primary and lateral roots of Helianthus annuus. Each cell type is characterized by a unique ultrastructure, and the ultrastructural changes characteristic of cellular differentiation in root caps are organelle specific. No major structural differences exist in the structures of the composite cell types, or in patterns of cell differentiation in caps of primary vs. lateral roots.

Cell Wall Ultrastructure of Stem Wood, Roots, and Needles of a Conifer Varies in Response to Moisture Availability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pattathil, Sivakumar; Ingwers, Miles W.; Victoriano, Olivia L.

The composition, integrity, and architecture of the macromolecular matrix of cell walls, collectively referred to as cell wall ultrastructure, exhibits variation across species and organs and among cell types within organs. Indirect approaches have suggested that modifications to cell wall ultrastructure occur in response to abiotic stress; however, modifications have not been directly observed. Glycome profiling was used to study cell wall ultrastructure by examining variation in composition and extractability of non-cellulosic glycans in cell walls of stem wood, roots, and needles of loblolly pine saplings exposed to high and low soil moisture. Soil moisture influenced physiological processes and themore » overall composition and extractability of cell wall components differed as a function of soil moisture treatments. The strongest response of cell wall ultrastructure to soil moisture was increased extractability of pectic backbone epitopes in the low soil moisture treatment. The higher abundance of these pectic backbone epitopes in the oxalate extract indicate that the loosening of cell wall pectic components could be associated with the release of pectic signals as a stress response. The increased extractability of pectic backbone epitopes in response to low soil moisture availability was more pronounced in stem wood than in roots or needles. Additional responses to low soil moisture availability were observed in lignin associated carbohydrates released in chlorite extracts of stem wood, including an increased abundance of pectic arabinogalactan epitopes. Overall, these results indicate that cell walls of loblolly pine organs undergo changes in their ultrastructural composition and extractability as a response to soil moisture availability and that cell walls of the stem wood are more responsive to low soil moisture availability compared to cell walls of roots and needles. In conclusion, to our knowledge, this is the first direct evidence, delineated by glycomic analyses, that abiotic stress affects cell wall ultrastructure. This study is also unique in that glycome profiling of pine needles has never before been reported.« less

Cell Wall Ultrastructure of Stem Wood, Roots, and Needles of a Conifer Varies in Response to Moisture Availability.

PubMed

Pattathil, Sivakumar; Ingwers, Miles W; Victoriano, Olivia L; Kandemkavil, Sindhu; McGuire, Mary Anne; Teskey, Robert O; Aubrey, Doug P

2016-01-01

The composition, integrity, and architecture of the macromolecular matrix of cell walls, collectively referred to as cell wall ultrastructure, exhibits variation across species and organs and among cell types within organs. Indirect approaches have suggested that modifications to cell wall ultrastructure occur in response to abiotic stress; however, modifications have not been directly observed. Glycome profiling was used to study cell wall ultrastructure by examining variation in composition and extractability of non-cellulosic glycans in cell walls of stem wood, roots, and needles of loblolly pine saplings exposed to high and low soil moisture. Soil moisture influenced physiological processes and the overall composition and extractability of cell wall components differed as a function of soil moisture treatments. The strongest response of cell wall ultrastructure to soil moisture was increased extractability of pectic backbone epitopes in the low soil moisture treatment. The higher abundance of these pectic backbone epitopes in the oxalate extract indicate that the loosening of cell wall pectic components could be associated with the release of pectic signals as a stress response. The increased extractability of pectic backbone epitopes in response to low soil moisture availability was more pronounced in stem wood than in roots or needles. Additional responses to low soil moisture availability were observed in lignin-associated carbohydrates released in chlorite extracts of stem wood, including an increased abundance of pectic arabinogalactan epitopes. Overall, these results indicate that cell walls of loblolly pine organs undergo changes in their ultrastructural composition and extractability as a response to soil moisture availability and that cell walls of the stem wood are more responsive to low soil moisture availability compared to cell walls of roots and needles. To our knowledge, this is the first direct evidence, delineated by glycomic analyses, that abiotic stress affects cell wall ultrastructure. This study is also unique in that glycome profiling of pine needles has never before been reported.

Cell Wall Ultrastructure of Stem Wood, Roots, and Needles of a Conifer Varies in Response to Moisture Availability

DOE PAGES

Pattathil, Sivakumar; Ingwers, Miles W.; Victoriano, Olivia L.; ...

2016-06-24

The composition, integrity, and architecture of the macromolecular matrix of cell walls, collectively referred to as cell wall ultrastructure, exhibits variation across species and organs and among cell types within organs. Indirect approaches have suggested that modifications to cell wall ultrastructure occur in response to abiotic stress; however, modifications have not been directly observed. Glycome profiling was used to study cell wall ultrastructure by examining variation in composition and extractability of non-cellulosic glycans in cell walls of stem wood, roots, and needles of loblolly pine saplings exposed to high and low soil moisture. Soil moisture influenced physiological processes and themore » overall composition and extractability of cell wall components differed as a function of soil moisture treatments. The strongest response of cell wall ultrastructure to soil moisture was increased extractability of pectic backbone epitopes in the low soil moisture treatment. The higher abundance of these pectic backbone epitopes in the oxalate extract indicate that the loosening of cell wall pectic components could be associated with the release of pectic signals as a stress response. The increased extractability of pectic backbone epitopes in response to low soil moisture availability was more pronounced in stem wood than in roots or needles. Additional responses to low soil moisture availability were observed in lignin associated carbohydrates released in chlorite extracts of stem wood, including an increased abundance of pectic arabinogalactan epitopes. Overall, these results indicate that cell walls of loblolly pine organs undergo changes in their ultrastructural composition and extractability as a response to soil moisture availability and that cell walls of the stem wood are more responsive to low soil moisture availability compared to cell walls of roots and needles. In conclusion, to our knowledge, this is the first direct evidence, delineated by glycomic analyses, that abiotic stress affects cell wall ultrastructure. This study is also unique in that glycome profiling of pine needles has never before been reported.« less

The chorion ultrastructure of ova of Lophius spp.

PubMed

Colmenero, A I; Tuset, V M; Fortuño, J-M; Sánchez, P

2015-06-01

The chorion surface ultrastructure of unfertilized eggs of black anglerfish Lophius budegassa and white anglerfish Lophius piscatorius was examined by scanning electron microscopy. Species-specific differences were observed. © 2015 The Fisheries Society of the British Isles.

Pulmonary Veno-Occlusive Disease: A Newly Recognized Cause of Severe Pulmonary Hypertension in Dogs.

PubMed

Williams, K; Andrie, K; Cartoceti, A; French, S; Goldsmith, D; Jennings, S; Priestnall, S L; Wilson, D; Jutkowitz, A

2016-07-01

Pulmonary hypertension is a well-known though poorly characterized disease in veterinary medicine. In humans, pulmonary veno-occlusive disease (PVOD) is a rare cause of severe pulmonary hypertension with a mean survival time of 2 years without lung transplantation. Eleven adult dogs (5 males, 6 females; median age 10.5 years, representing various breeds) were examined following the development of severe respiratory signs. Lungs of affected animals were evaluated morphologically and with immunohistochemistry for alpha smooth muscle actin, desmin, CD31, CD3, CD20, and CD204. All dogs had pulmonary lesions consistent with PVOD, consisting of occlusive remodeling of small- to medium-sized pulmonary veins, foci of pulmonary capillary hemangiomatosis (PCH), and accumulation of hemosiderophages; 6 of 11 dogs had substantial pulmonary arterial medial and intimal thickening. Ultrastructural examination and immunohistochemistry showed that smooth muscle cells contributed to the venous occlusion. Increased expression of CD31 was evident in regions of PCH indicating increased numbers of endothelial cells in these foci. Spindle cells strongly expressing alpha smooth muscle actin and desmin co-localized with foci of PCH; similar cells were present but less intensely labeled elsewhere in non-PCH alveoli. B cells and macrophages, detected by immunohistochemistry, were not co-localized with the venous lesions of canine PVOD; small numbers of CD3-positive T cells were occasionally in and around the wall of remodeled veins. These findings indicate a condition in dogs with clinically severe respiratory disease and pathologic features resembling human PVOD, including foci of pulmonary venous remodeling and PCH. © The Author(s) 2016.

Histology and ultrastructure of the coenenchyme of the octocoral Swiftia exserta, a model organism for innate immunity/graft rejection.

PubMed

Menzel, L P; Tondo, C; Stein, B; Bigger, C H

2015-04-01

The octocoral Swiftia exserta has been utilized extensively in our laboratory to study innate immune reactions in Cnidaria such as wound healing, auto- and allo-graft reactions, and for some classical "foreign body" phagocytosis experiments. All of these reactions occur in the coenenchyme of the animal, the colonial tissue surrounding the axial skeleton in which the polyps are embedded, and do not rely on nematocysts or directly involve the polyps. In order to better understand some of the cellular reactions occurring in the coenenchyme, the present study employed several cytochemical methods (periodic acid-Schiff reaction, Mallory's aniline blue collagen stain, and Gomori's trichrome stain) and correlated the observed structures with electron microscopy (both scanning and transmission). Eight types of cells were apparent in the coenenchyme of S. exserta, exclusive of gastrodermal tissue: (i) epithelial ectoderm cells, (ii) oblong granular cells, (iii) granular amoebocytes, (iv) morula-like cells, (v) mesogleal cells, (vi) sclerocytes, (vii) axial epithelial cells, and (viii) cnidocytes with mostly atrichous isorhiza nematocysts. Several novel organizational features are now apparent from transmission electron micrographs: the ectoderm consists of a single layer of flat epithelial cells, the cell types of the mesoglea extend from beneath the thin ectoderm throughout the mesogleal cell cords, the organization of the solenia gastroderm consists of a single layer of cells, and two nematocyst types have been found. A new interpretation of the cellular architecture of S. exserta, and more broadly, octocoral biology is now possible. Copyright © 2014 Elsevier GmbH. All rights reserved.

Histology and ultrastructure of the coenenchyme of the octocoral Swiftia exserta, a model organism for innate immunity/graft rejection

PubMed Central

Menzel, L.P.; Tondo, C.; Stein, B.; Bigger, C.H.

2015-01-01

The octocoral Swiftia exserta has been utilized extensively in our laboratory to study innate immune reactions in Cnidaria such as wound healing, auto- and allo-graft reactions, and for some classical “foreign body” phagocytosis experiments. All of these reactions occur in the coenenchyme of the animal, the colonial tissue surrounding the axial skeleton in which the polyps are embedded, and do not rely on nematocysts or directly involve the polyps. In order to better understand some of the cellular reactions occurring in the coenenchyme, the present study employed several cytochemical methods (periodic acid–Schiff reaction, Mallory’s aniline blue collagen stain, and Gomori’s trichrome stain) and correlated the observed structures with electron microscopy (both scanning and transmission). Eight types of cells were apparent in the coenenchyme of S. exserta, exclusive of gastrodermal tissue: (i) epithelial ectoderm cells, (ii) oblong granular cells, (iii) granular amoebocytes, (iv) morula-like cells, (v) mesogleal cells, (vi) sclerocytes, (vii) axial epithelial cells, and (viii) cnidocytes with mostly atrichous isorhiza nematocysts. Several novel organizational features are now apparent from transmission electron micrographs: the ectoderm consists of a single layer of flat epithelial cells, the cell types of the mesoglea extend from beneath the thin ectoderm throughout the mesogleal cell cords, the organization of the solenia gastroderm consists of a single layer of cells, and two nematocyst types have been found. A new interpretation of the cellular architecture of S. exserta, and more broadly, octocoral biology is now possible. PMID:25596959

Efficacy of a New Ocular Surface Modulator in Restoring Epithelial Changes in an In Vitro Model of Dry Eye Syndrome.

PubMed

Barabino, Stefano; De Servi, Barbara; Aragona, Salvatore; Manenti, Demetrio; Meloni, Marisa

2017-03-01

So far tear substitutes have demonstrated a limited role in restoring ocular surface damage in dry eye syndrome (DES). The aim of this study was to assess the efficacy of a new ocular surface modulator in an in vitro model of human corneal epithelium (HCE) damaged by severe osmotic stress mirroring the features of dry eye conditions. A reconstructed HCE model challenged by the introduction of sorbitol in the culture medium for 16 h was used to induce an inflammatory pathway and to impair the tight junctions integrity determining a severe modification of the superficial layer ultrastructure. At the end of the overnight stress period in the treated HCE series, 30 μl of the ocular surface modulator (T-LysYal, Sildeha, Switzerland) and of hyaluronic acid (HA) in the control HCE series were applied for 24 h. The following parameters were quantified: scanning electron microscopy (SEM), trans-epithelial electrical resistance (TEER), immunofluorescence analysis of integrin β1 (ITG-β1), mRNA expression of Cyclin D-1 (CCND1), and ITG-β1. In the positive control after the osmotic stress the HCE surface damage was visible at the ultrastructural level with loss of cell-cell interconnections, intercellular matrix destruction, and TEER reduction. After 24 h of treatment with T-LysYal, HCE showed a significant improvement of the ultrastructural morphological organization and increased expression of ITG-β1 at the tissue level when compared to positive and control series. A significant increase of mRNA expression for ITG-β1 and CCND1 was shown in the HA-treated cells compared to T-LysYal. TEER measurement showed a significant reduction in all groups after 16 h without modifications after the treatment period. This study has shown the possibility of a new class of agents denominated ocular surface modulators to restore corneal cells damaged by dry eye conditions. Further in vivo studies are certainly necessary to confirm these results.

The Challenges of Diagnosing Primary Ciliary Dyskinesia

PubMed Central

O'Callaghan, Christopher; Knowles, Michael R.

2011-01-01

Primary ciliary dyskinesia (PCD) is a rare genetic disorder of ciliary structure and function. The diagnosis can be challenging, particularly when using nongenetic assays. The “gold standard” diagnostic test is ultrastructural analysis of respiratory cilia obtained by nasal scrape or brush biopsy. A few specialized centers use high-speed videomicroscopy to examine ciliary beat. Certain beat patterns correlate with ultrastructural defects, and, in some cases, subtle alterations in beat pattern can be seen when ultrastructure is normal. Recent studies have shown that nasal nitric oxide (NO) is very low in patients with PCD compared with healthy control subjects; therefore, this assay may be a useful screening or adjunctive test for PCD. Because acute respiratory illnesses may yield alterations in ciliary ultrastructure, ciliary beat, and nasal NO values, these tests should be performed during a stable baseline period. Identification of an array of PCD genes has provided the opportunity for making a definitive genetic diagnosis for PCD in some cases. All of these approaches have a role in diagnosing PCD. For example, PCD has been confirmed by identifying disease-causing mutations in a heavy dynein chain gene in individuals with normal ciliary ultrastructure but subtle defects in ciliary beat and low nasal NO. Priorities to improve nongenetic diagnostic capability include standardization of nasal NO as a screening test and the development of specialized centers using uniform approaches for the analysis of ciliary ultrastructure and ciliary beat pattern. Another chapter in this issue (see Zariwala and colleagues, pp. 430) addresses the progress toward improved capabilities for definitive genetic testing PMID:21926395

Linearized texture of three-dimensional extracellular matrix is mandatory for bladder cancer cell invasion.

PubMed

Alfano, Massimo; Nebuloni, Manuela; Allevi, Raffaele; Zerbi, Pietro; Longhi, Erika; Lucianò, Roberta; Locatelli, Irene; Pecoraro, Angela; Indrieri, Marco; Speziali, Chantal; Doglioni, Claudio; Milani, Paolo; Montorsi, Francesco; Salonia, Andrea

2016-10-25

In the fields of biomaterials and tissue engineering simulating the native microenvironment is of utmost importance. As a major component of the microenvironment, the extracellular matrix (ECM) contributes to tissue homeostasis, whereas modifications of native features are associated with pathological conditions. Furthermore, three-dimensional (3D) geometry is an important feature of synthetic scaffolds favoring cell stemness, maintenance and differentiation. We analyzed the 3D structure, geometrical measurements and anisotropy of the ECM isolated from (i) human bladder mucosa (basal lamina and lamina propria) and muscularis propria; and, (ii) bladder carcinoma (BC). Next, binding and invasion of bladder metastatic cell line was observed on synthetic scaffold recapitulating anisotropy of tumoral ECM, but not on scaffold with disorganized texture typical of non-neoplastic lamina propria. This study provided information regarding the ultrastructure and geometry of healthy human bladder and BC ECMs. Likewise, using synthetic scaffolds we identified linearization of the texture as a mandatory feature for BC cell invasion. Integrating microstructure and geometry with biochemical and mechanical factors could support the development of an innovative synthetic bladder substitute or a tumoral scaffold predictive of chemotherapy outcomes.

A comparison of Giardia microti and Spironucleus muris cysts in the vole: an immunocytochemical, light, and electron microscopic study.

PubMed

Januschka, M M; Erlandsen, S L; Bemrick, W J; Schupp, D G; Feely, D E

1988-06-01

We have shown that cysts of the genus Spironucleus share many common morphological features with Giardia cysts including: 2-4 nuclei, flagellar axonemes, a distinct cyst wall, and they even display the same immunostaining as Giardia cysts when labeled with antibodies specific for Giardia cyst wall. A direct comparison of Spironucleus muris and Giardia microti cysts have revealed that cysts of S. muris are significantly smaller than cysts of G. miroti. At the ultrastructural level, the cyst walls are similar in fibrillar appearance, but the width of the S. muris cyst wall is significantly less than that of G. microti. The cysts of S. muris also differ from G. microti in that they contain a striated rootlet fiber, flagellar sheath, and numerous glycogen rosettes. Characteristic features of Giardia include the adhesive disc and median body. Although the cysts of Spironucleus and Giardia are similar in appearance, these unique morphological features can be used to distinguish between the 2 protozoa and should be employed in the detection of Giardia cysts in water samples.

Skin tightening technologies.

PubMed

Greene, Ryan M; Green, Jeremy B

2014-02-01

Radiofrequency (RF) and intense focused ultrasound (IFUS) are increasingly used to address skin laxity of the face and neck. Both nonablative RF and ultrasound create a heat-induced tissue response that leads to collagen remodeling and other ultrastructural changes. Although these treatments are not meant to replace surgical procedures, patient satisfaction in the majority of studies has been consistently high. This article discusses the various RF and IFUS technologies currently in use and reviews pertinent clinical studies evaluating their efficacy and safety. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Ultrastructural Changes in Human Striated Muscle Using Three Methods of Training

ERIC Educational Resources Information Center

Penman, Kenneth A.

1969-01-01

There have been many attempts to describe what happens when a muscle gets stronger. However, little has been done to examine possible structural changes at the ultrastructural level when a muscle becomes stronger or hypertrophied. (CK)

Effects of management in gestational diabetes mellitus with normal prepregnancy body mass index on pregnancy outcomes and placental ultrastructures: a prospective cohort study.

PubMed

Han, Yun; Zheng, Yan-Li; Wu, Ai-Min; Liu, Hong-Bin; Su, Jian-Bin; Lu, Xiao-Yan; Han, Yu-Wen; Ji, Jin-Long; Ji, Ju-Hua; Shi, Yue

2016-12-01

A great quantity of gestational diabetes mellitus with normal prepregnancy body mass index have emerged with the new criteria of gestational diabetes mellitus in China based on the International Diabetes in Pregnancy Consensus group criteria, and understanding placental changes and how they affect outcomes are necessary in order to develop effective management approach. The aim of this study was to prospectively explore the effect of active management starting from the late second trimester in gestational diabetes mellitus women with normal prepregnancy body mass index on pregnancy outcomes and placental ultrastructures, and to provide scientific evidences for optimizing the management of gestational diabetes mellitus in China. Gestational diabetes mellitus women with normal prepregnancy body mass index in the same period of this prospective cohort study were divided into intervention group (n = 51) and control group (n = 55). The intervention group was managed rigorously, while the control group received conventional prenatal cares. The glucose profile, gestational weight gain and pregnancy outcomes were followed up and placental ultrastructures were observed and recorded by transmission electron microscopy. The blood glucose level and gestational weight gain in intervention group were significantly better controlled than those in control group (P < 0.01). The incidences of fetal distress, cesarean section and large for gestational age were significantly lower in intervention group than in control group (P < 0.05). There was a significant reduction in the incidence of abnormal placental ultrastructure in the intervention group (P < 0.01). After adjustment for confounding factors, the undesirable glycemic control and conventional management were related to abnormal placental ultrastructure (P < 0.05). Meanwhile, the undesirable glycemic control, abnormal placental ultrastructure and conventional management made sense in the incidence of fetal distress (P < 0.05), and the target glycemic control, recommend weight gain and active management were associated with reductions in the prevalence of cesarean delivery and large for gestational age (P < 0.05). The active management of gestational diabetes mellitus women with normal prepregnancy body mass index can improve pregnancy outcomes and placental ultrastructures, and the abnormal placental ultrastructure might be closely associated with the undesirable glycemic control and adverse pregnancy outcomes.

Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

PubMed

Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

1992-10-01

The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tendons, while in the optic nerve sheath the fibrils appear smaller and uniform, similar to those commonly observed in reticular tissues, vessel walls and skin. Freeze-fracture also reveals these fibrils to have different subfibrillar architectures, straight or helical, which correspond to 2 distinct forms of collagen fibril previously described (Raspanti et al. 1989). The other extracellular matrix components also vary with the particular collagen fibril structure. Despite their common embryological derivation, the dura mater, optic nerve sheath and sclera exhibit diversification of their extracellular matrix consistent with the mechanical loads to which these tissues are subjected. Our observations indicate that the outermost sheath of the optic nerve resembles the epineurium of peripheral nerves rather than the dura to which it is commonly likened.

Glomerular Lesions in Proteinuric Miniature Schnauzer Dogs

PubMed Central

Furrow, E.; Lees, G. E.; Brown, C. A.; Cianciolo, R. E.

2017-01-01

Miniature Schnauzer dogs are predisposed to idiopathic hypertriglyerceridemia, which increases risk for diseases such as pancreatitis and gallbladder mucocele. Recently, elevated triglyceride concentrations have been associated with proteinuria in this breed, although it is difficult to determine which abnormality is primary. Retrospective review of renal tissue from 27 proteinuric Miniature Schnauzers revealed that 20 dogs had ultrastructural evidence of osmophilic globules consistent with lipid in glomerular tufts. Seven of these dogs had lipid thromboemboli in glomerular capillary loops that distorted their shape and compressed circulating erythrocytes. Triglyceride concentrations were reported in 6 of these 7 dogs, and all were hypertriglyceridemic. In addition, glomerular lipidosis (defined as accumulation of foam cells within peripheral capillary loops) was identified in a single dog. The remaining 12 dogs had smaller amounts of lipid that could only be identified ultrastructurally. Neither signalment data nor clinicopathologic parameters (serum albumin, serum creatinine, urine protein-to-creatinine ratio, and blood pressure) differed among the various types of lipid lesions. During the time course of this study, all dogs diagnosed with glomerular lipid thromboemboli were Miniature Schnauzers, underscoring the importance of recognizing these clear spaces within capillary loops as lipid. PMID:28005494

The myocardial microangiopathy in human and experimental diabetes mellitus. (A microscopic, ultrastructural, morphometric and computer-assisted symbolic-logic analysis).

PubMed

Taşcă, C; Stefăneanu, L; Vasilescu, C

1986-01-01

The following microscopical aspects were found in the small intramural arteries in the myocardium of 30 diabetic patients: endothelial proliferations with focal protuberances leading to partial narrowing of the lumen, increased thickness of the arterial wall due to fibrosis and accumulations of neutral mucopolysaccharides: alteration of elastic fibres. Morphometrically, the arterial wall thickness and the arterial diameter were increased whereas the arterial density decreased in the diabetic heart. In 25 rats with streptozotocin-induced diabetes the small intramyocardial arteries were investigated at 11 to 40 weeks of diabetic state. Using morphometrical analysis a constant increase of arterial wall thickness paralleling the diabetes duration was found. Microscopically, the lesions consist in endothelial proliferation with bridging across the vascular lumen and slight perivascular and diffuse fibrosis. Ultrastructurally, the capillary basal lamina was thickened in the diabetic myocardium. In order to investigate the morphometrical data we used symbolic-logic as a decision method, by applying an original computer program based on the Quine-McCluskey algorithm. All our results together with the final symbolic-logic expression suggest that damage of the small intramyocardial arteries plays an important role in the pathogenesis of diabetic cardiomyopathy.

Implications of obesity for tendon structure, ultrastructure and biochemistry: a study on Zucker rats.

PubMed

Biancalana, Adriano; Velloso, Lício Augusto; Taboga, Sebastião Roberto; Gomes, Laurecir

2012-02-01

The extracellular matrix consists of collagen, proteoglycans and non-collagen proteins. The incidence of obesity and associated diseases is currently increasing in developed countries. Obesity is considered to be a disease of modern times, and genes predisposing to the disease have been identified in humans and animals. The objective of the present study was to compare the morphological and biochemical aspects of the deep digital flexor tendon of lean (Fa/Fa or Fa/fa) and genetically obese (fa/fa) Zucker rats. Ultrastructural analysis showed the presence of lipid droplets in both groups, whereas disorganized collagen fibril bundles were observed in obese animals. Lean animals presented a larger amount of non-collagen proteins and glycosaminoglycans than obese rats. We propose that the overweight and lesser physical activity in obese animals may have provoked the alterations in the composition and organization of extracellular matrix components but a genetic mechanism cannot be excluded. These alterations might be related to organizational and structural modifications in the collagen bundles that influence the mechanical properties of tendons and the progression to a pathological state. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ultrastructural cytochemical prospective study of adult acute lymphoblastic leukemia: detection of peroxidase activity in patients failing to respond to treatment.

PubMed

Reiffers, J; Darmendrail, V; Larrue, J; Villenave, I; Bernard, P; Boisseau, M; Broustet, A

1981-08-15

Ultrastructural cytochemical studies revealed peroxidase activity in five of 25 adult patients with apparent null lymphoblastic leukemia (ALL) in whom the peroxidase reaction studied with light microscopy was negative. None of these 5 patients responded to a chemotherapy regimen used for adult ALL. The importance of ultrastructural cytochemistry which allows the recognition of myeloblastic differentiation in undifferentiated blast cells is also demonstrated. The correct classification of such cases may be important for prognosis because they appear to be resistant to the chemotherapy used in treating ALL.

[Silymarin in pregnancy and during hormonal contraceptive treatment. Blood chemistry and ultrastructural findings in the experimental model].

PubMed

Martines, G; Piva, M; Copponi, V; Cagnetta, G

1979-01-01

Further systematic study of the relation between drugs and the ultrastructure of the liver is reported with regard to the experimental administration of silimarin to pregnant women and others on the pill. Marked signs of ultrastructural alteration of the REL and biliary cell pole were noted, matched, by evidence of throbophilia and changes in protein activity and lipid synthesis, are noted in these situations, but not when suitable doses of silimarine are taken with the pill. It is suggested that silimarin may prevent and correct liver damage during pregnancy and the administration of oestroprogestins.

Marine bivalve geochemistry and shell ultrastructure from modern low pH environments

NASA Astrophysics Data System (ADS)

Hahn, S.; Rodolfo-Metalpa, R.; Griesshaber, E.; Schmahl, W. W.; Buhl, D.; Hall-Spencer, J. M.; Baggini, C.; Fehr, K. T.; Immenhauser, A.

2011-10-01

Bivalve shells can provide excellent archives of past environmental change but have not been used to interpret ocean acidification events. We investigated carbon, oxygen and trace element records from different shell layers in the mussels Mytilus galloprovincialis (from the Mediterranean) and M. edulis (from the Wadden Sea) combined with detailed investigations of the shell ultrastructure. Mussels from the harbour of Ischia (Mediterranean, Italy) were transplanted and grown in water with mean pHT 7.3 and mean pHT 8.1 near CO2 vents on the east coast of the island of Ischia. The shells of transplanted mussels were compared with M. edulis collected at pH ~8.2 from Sylt (German Wadden Sea). Most prominently, the shells recorded the shock of transplantation, both in their shell ultrastructure, textural and geochemical record. Shell calcite, precipitated subsequently under acidified seawater responded to the pH gradient by an in part disturbed ultrastructure. Geochemical data from all test sites show a strong metabolic effect that exceeds the influence of the low-pH environment. These field experiments showed that care is needed when interpreting potential ocean acidification signals because various parameters affect shell chemistry and ultrastructure. Besides metabolic processes, seawater pH, factors such as salinity, water temperature, food availability and population density all affect the biogenic carbonate shell archive.

The effects of high-power microwaves on the ultrastructure of Bacillus subtilis.

PubMed

Kim, S-Y; Jo, E-K; Kim, H-J; Bai, K; Park, J-K

2008-07-01

To investigate the microbicidal mechanisms of high-power microwave (2.0 kW) irradiation on Bacillus subtilis and to determine the effect of this procedure on the ultrastructure of the cell wall. We performed viability test, examined cells using transmission electron microscopy (TEM), and measured the release of intracellular proteins and nucleic acids. The inactivation rate of B. subtilis by 2.0-kW microwave irradiation was higher than that of a domestic microwave (0.5 kW). Few proteins were released from either microwaved or boiled cells. However, the leakage of nucleic acids from 2.0-kW-microwaved cells was significantly higher than that of 0.5-kW-microwaved or boiled cells. Therefore, we examined ultrastructural alterations of microwaved or boiled cells to analyse the pattern of release of cytoplasmic contents. Although boiled cells did not show any ultrastructural changes on TEM, 2.0-kW-microwaved cells showed disruption of the cell wall. The microbicidal mechanisms of 2.0-kW microwave irradiation include damage to the microbial cell wall, breakage of the genomic DNA, and thermal coagulation of cytoplasmic proteins. TEM images showed that the cytoplasmic protein aggregation and cell envelope damage by microwave irradiation were different from the ultrastructural changes observed after boiling.

Histochemical and ultrastructural studies on the calcareous corpuscles and eggs of Taenia taeniaeformis and Dipylidium caninum.

PubMed

Khalifa, Refaat M A; Mazen, Nawal A M; Marawan, Aziza M A; Thabit, Hasnaa T M

2011-08-01

Calcareous corpuscles were noticed by several previous workers to be present in larval and adult cestodes without knowing their function. However, nothing was mentioned in the available literature about distribution of these corpuscles and their density, structure and composition in different parts of the body of different cestodes. Hence, in the present work, a comparative study of their distribution, density, histochemical and ultrastructural characters in different parts of the body was performed in Taenia taeniaeformis and Dipylidium caninum. Due to the presence of the eggs in their gravid segments, their histochemical and ultrastructural characteristics were also studied. It was found that the size, location and density of the calcareous bodies were different in different body parts of the same and the other cestode. Histochemically, the main component of these corpuscles was calcium; while other constituents as polysaccharides, lipids, protrins and mucopolysaccharides were found in their outer rim. Ultrastructurally, they were quite similar in the two studied cestodes and different stages of their development were exhibited. Histochemically, the eggs of both cestodes were similar in their contents. However, some ultrastructural differences have been demonstrated particularly in relation to the size and shape of the rods in the embryophore and the structures in between the embryophore and onchosphere.

Ultrastructure of Plant Leaf Cuticles in relation to Sample Preparation as Observed by Transmission Electron Microscopy

PubMed Central

Guzmán, Paula; Fernández, Victoria; García, María Luisa; Fernández, Agustín; Gil, Luis

2014-01-01

The leaf cuticular ultrastructure of some plant species has been examined by transmission electron microscopy (TEM) in only few studies. Attending to the different cuticle layers and inner structure, plant cuticles have been grouped into six general morphological types. With the aim of critically examining the effect of cuticle isolation and preparation for TEM analysis on cuticular ultrastructure, adaxial leaf cuticles of blue-gum eucalypt, grey poplar, and European pear were assessed, following a membrane science approach. The embedding and staining protocols affected the ultrastructure of the cuticles analysed. The solubility parameter, surface tension, and contact angles with water of pure Spurr's and LR-White resins were within a similar range. Differences were however estimated for resin : solvent mixtures, since Spurr's resin is combined with acetone and LR-White resin is mixed with ethanol. Given the composite hydrophilic and lipophilic nature of plant cuticles, the particular TEM tissue embedding and staining procedures employed may affect sample ultrastructure and the interpretation of the results in physicochemical and biological terms. It is concluded that tissue preparation procedures may be optimised to facilitate the observation of the micro- and nanostructure of cuticular layers and components with different degrees of polarity and hydrophobicity. PMID:24895682

Effects of steroid hormones on nuclear membrane and membrane-bound heterochromatin from breast cancer cells evaluated by fractal morphometry.

PubMed

Losa, G A; Graber, R; Baumann, G; Nonnenmacher, T F

1999-10-01

To evaluate the effect of steroid hormones on the ultrastructure of nuclear heterochromatin and perinuclear membranes in human MCF-7 breast cancer cells. MCF-7 cells were cultured briefly (five minutes) in the presence of 10(-9) M estrogen 17 beta-estradiol, a stimulator of cell proliferation and/or 10(-9) M glucocorticoid dexamethasone. Changes in the morphologic complexity of nuclear membrane-bound heterochromatin (NMBHC) and nuclear membranes (ENM) were assessed by means of the fractal capacity dimension, D, a noneuclidean geometric descriptor of complex, irregular bodies. 17 beta-estradiol (10(-9) M) enhanced the ultrastructural irregularity of NMBHC, as documented by the increased value of D, whereas dexamethasone (10(-9) M) reduced it when compared to NMBHC from untreated MCF-7 control cells. In contrast, neither steroid modified ENM ultrastructure. Changes in the nuclear heterochromatin complexity induced by estrogen 17 beta-estradiol occurred concomitantly with functional changes at the cell periphery, such as activation of the phospholipase C, a cell membrane-associated enzyme involved in signal transduction. Dexamethasone reduced the ultrastructural complexity of NMBHC without affecting functional processes. Fractal morphometry proved its usefulness in quantifying early ultrastructural changes in nuclear components induced in MCF-7 cells by steroid hormones, 17 beta-estradiol and dexamethasone.

Echinococcus multilocularis Leuckart, 1863 (Taeniidae): new data on sperm ultrastructure.

PubMed

Miquel, Jordi; Świderski, Zdzisław; Azzouz-Maache, Samira; Pétavy, Anne-Françoise

2016-06-01

The present study establishes the ultrastructural organisation of the mature spermatozoon of Echinococcus multilocularis, which is essential for future research on the location of specific proteins involved in the sperm development in this species and also in Echinococcus granulosus. Thus, the ultrastructural characteristics of the sperm cell are described by means of transmission electron microscopy. The spermatozoon of E. multilocularis is a filiform cell, which is tapered at both extremities and lacks mitochondria. It exhibits all the characteristics of type VII spermatozoon of tapeworms, namely a single axoneme, crested bodies, spiralled cortical microtubules and nucleus, a periaxonemal sheath and intracytoplasmic walls. Other characteristics observed in the male gamete are the presence of a >900-nm long apical cone in its anterior extremity and only the axoneme in its posterior extremity. The ultrastructural characters of the spermatozoon of E. multilocularis are compared with those of other cestodes studied to date, with particular emphasis on representatives of the genus Taenia. The most interesting finding concerns the presence of two helical crested bodies in E. multilocularis while in the studied species of Taenia, there is only one crested body. Future ultrastructural studies of other species of the genus Echinococcus would be of particular interest in order to confirm whether or not the presence of two crested bodies is a characteristic of this genus.

[Effect of bitumen fume on neurotransmitter and ultrastructure in mice brain].

PubMed

Li, Hai-Ling; Guo, Xiang-Yun; Feng, San-Wei; Liu, Chang-Hai

2006-12-01

To observe the effects of bitumen fume on neurotransmitter and ultrastructure of mice brain and to investigate the toxicity of bitumen fume on nerve system of mice brain. The experimental mice were forced to inhale the bitumen fume at different exposure level and in different time periods. The contents of the three transmitters dopamine (DA), norepinephrine (NE), 5-hydroxytryptamine (5-HT) in mice brain were measured by the fluorescence meanwhile ultrastructure of mice brain was observed by electronic microscope. The ultrastructure of mice brain was observed under transmission electron microscopy. The contents of DA, NE and 5-HT in all groups decreased with the increasing of dose and prolonging of time (after 8 week, with the increasing of exposure lever, the content of DA, NE, 5-HT was respectively 2.194, 2.190, 2.181, 2.178 microg/g and 1.148, 1.138, 1.135 and 1.407, 1.403, 1.395 microg), but the results did not show significant differences. The structure of the mitochondria changes included the swollen mitochondria, chromatin margination, pyknosis and apoptosis in neuro cells and the processes of swollen astrocyte cells. The bitumen fume could induce changes of the ultrastructure of mice brain and affect the contents of neurotransmitter of mice brain.

Ultrastructural characteristics of some bacteria after treatment with Lubrol W.

PubMed

Cherepova, N; Spasova, D

1994-01-01

Specific ultrastructural changes occurred mainly in the cell wall and cytoplasmic membrane of Listeria monocytogenes, Salmonella typhimurium, Pseudomonas pseudomallei and Pseudomonas aeruginosa bacteria when treated with 0.5% and 1% Lubrol W1 by means of transmission and scanning electron microscopy.

Malignant lymphoma of the cervix uteri: histology and ultrastructure.

PubMed Central

Carr, I; Hill, A S; Hancock, B; Neal, F F

1976-01-01

Two cases of primary lymphoma of the cervix uteri are described. Both responded to radiotherapy; both were composed at the ultrastructural level of mature macrophages and immature, apparently neoplastic lymphoreticular cells and are classified as reticulum cell lymphoma. Images PMID:783205

Scanning electron microscopy of dentition: methodology and ultrastructural morphology of tooth wear.

PubMed

Shkurkin, G V; Almquist, A J; Pfeihofer, A A; Stoddard, E L

1975-01-01

Scanning electron micrographs were taken of sets of human molars-those of paleo-Indians used in mastication of, ostensibly, a highly abrasive diet, and those of contemporary Americans. Different ultrastructural patterns of enamel wear were observed between the groups.

Microbe-like inclusions in tree resins and implications for the fossil record of protists in amber.

PubMed

Thiel, V; Lausmaa, J; Sjövall, P; Ragazzi, E; Seyfullah, L J; Schmidt, A R

2016-07-01

During the past two decades, a plethora of fossil micro-organisms have been described from various Triassic to Miocene ambers. However, in addition to entrapped microbes, ambers commonly contain microscopic inclusions that sometimes resemble amoebae, ciliates, microfungi, and unicellular algae in size and shape, but do not provide further diagnostic features thereof. For a better assessment of the actual fossil record of unicellular eukaryotes in amber, we studied equivalent inclusions in modern resin of the Araucariaceae; this conifer family comprises important amber-producers in Earth history. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), we investigated the chemical nature of the inclusion matter and the resin matrix. Whereas the matrix, as expected, showed a more hydrocarbon/aromatic-dominated composition, the inclusions contain abundant salt ions and polar organics. However, the absence of signals characteristic for cellular biomass, namely distinctive proteinaceous amino acids and lipid moieties, indicates that the inclusions do not contain microbial cellular matter but salts and hydrophilic organic substances that probably derived from the plant itself. Rather than representing protists or their remains, these microbe-like inclusions, for which we propose the term 'pseudoinclusions', consist of compounds that are immiscible with the terpenoid resin matrix and were probably secreted in small amounts together with the actual resin by the plant tissue. Consequently, reports of protists from amber that are only based on the similarity of the overall shape and size to extant taxa, but do not provide relevant features at light-microscopical and ultrastructural level, cannot be accepted as unambiguous fossil evidence for these particular groups. © 2016 John Wiley & Sons Ltd.

Different effects of amino acid-based and glucose-based dialysate from peritoneal dialysis patients on mesothelial cell ultrastructure and function.

PubMed

Chan, Tak-Mao; Leung, Jack Kok-Hung; Sun, Yuling; Lai, Kar-Neng; Tsang, Ryan Chi-Wai; Yung, Susan

2003-06-01

Peritoneal dialysis fluid (PDF) containing amino acids has been introduced recently aiming to improve the nutritional status of PD patients. Dextrose-based PDFs have been implicated in progressive functional and structural deterioration of the peritoneal membrane. Limited data are currently available regarding the effect of amino acid-based PDF on the function and ultrastructure of human peritoneal mesothelial cells (HPMCs), which play a critical role in peritoneal membrane pathophysiology. We investigated the effects of two commercially available PDFs, which utilized dextrose (1.5% Dianeal) or amino acids (1.1% Nutrineal) as the osmotic agent, obtained from patients after a 4 h dwell, on HPMC proliferation (MTT assay and cell counting) and viability [lactate dehydrogenase (LDH)release], interleukin-6 (IL-6) secretion (commercial enzyme-linked immunosorbent assay) and ultrastructure (scanning and transmission electron microscopy). Exposure of HPMCs to 1.5% Dianeal reduced cell proliferation, total cellular protein synthesis, IL-6 secretion and cell attachment, but prolonged the cell doubling time on recovery, and increased LDH release (P<0.001, P<0.001, P<0.0001, P<0.0001, P<0.001 and P<0.001, respectively). The 1.1% Nutrineal reduced HPMC proliferation (P<0.001) and increased IL-6 secretion (P<0.0001), but did not affect cell attachment, LDH release, protein synthesis or cell doubling time. Ultrastructural studies of HPMCs exposed to Dianeal showed cell flattening, increased cell surface area, reduced microvilli, and intracellular organelles compatible with dysfunctional mitochondria. In contrast, the ultrastructural morphology of HPMCs was relatively preserved after incubation with Nutrineal. Our results showed that HPMC ultrastructure, viability and protein synthesis were better preserved with amino acid-based PDF, compared with conventional dextrose-based PDF. The significance of IL-6 induction by Nutrineal remains to be elucidated.

Combined effects of lanthanum ion and acid rain on growth, photosynthesis and chloroplast ultrastructure in soybean seedlings.

PubMed

Wen, Kejia; Liang, Chanjuan; Wang, Lihong; Hu, Gang; Zhou, Qing

2011-07-01

Rare earth elements (REEs) have been accumulated in the agricultural environment. Acid rain is a serious environmental issue. In the present work, the effects of lanthanum ion (La(3+)) and acid rain on the growth, photosynthesis and chloroplast ultrastructure in soybean seedlings were investigated using the gas exchange measurements system, chlorophyll fluorometer, transmission electron microscopy and some biochemical techniques. It was found that although the growth and photosynthesis of soybean seedlings treated with the low concentration of La(3+) was improved, the growth and photosynthesis of soybean seedlings were obviously inhibited in the combined treatment with the low concentration of La(3+) and acid rain. At the same time, the chloroplast ultrastructure in the cell of soybean seedlings was destroyed. Under the combined treatment with the high concentration of La(3+) and acid rain, the chloroplast ultrastructure in the cell of soybean seedlings was seriously destroyed, and the growth and of photosynthesis were greatly decreased compared with those of the control, the single treatment with the high concentration of La(3+) and the single treatment with acid rain, respectively. The degree of decrease and destruction on chloroplast ultrastructure depended on the increases in the concentration of La(3+) and acid rain (H(+)). In conclusion, the combined pollution of La(3+) and acid rain obviously destroyed the chloroplast ultrastructure of cell and aggravated the harmful effect of the single La(3+) and acid rain on soybean seedlings. As a new combined pollutant, the harmful effect of REEs ions and acid rain on plant should be paid attention to. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ultrastructure of pea and cress root statocytes exposed to high gradient magnetic field

NASA Astrophysics Data System (ADS)

Belyavskaya, N. A.; Chernishov, V. I.; Polishchuk, O. V.; Kondrachuk, A. V.

As it was demonstrated by Kuznetsov & Hasenstein (1996) the high gradient magnetic field (HGMF) can produce a ponderomotive force that results in displacements of amyloplasts and causes the root response similar to the graviresponse. It was suggested that the HGMF could allow to imitate the effects of gravity in microgravity and/or change them in laboratory conditions correspondingly, as well as to study statolith-related processes in graviperception. Therefore, the correlation between the direction of the ponderomotive force resulting in statolith displacements and the direction of the HGMF-induced plant curvature can be the serious argument to support this suggestion and needs the detailed ultrastructural analysis. Seeds of dicotyledon Pisum sativum L. cv. Damir-2 and monocotyledon Lepidium sativum L. cv. P896 were soaked and grown in a vertical position on moist filter paper in chambers at room temperature. Tips of primary roots of vertical control, gravistimulated and exposed to HGMF seedlings were fixed for electron microscopy using conventional techniques. At ultrastructural level, we observed no significant changes in the volume of the individual statocytes or amyloplasts, relative volumes of cellular organelles (except vacuoles), number of amyloplasts per statocyte or surface area of endoplasmic reticulum. No consistent contacts between amyloplasts and any cellular structures, including plasma membrane, were revealed at any stage of magneto- and gravistimulation. By 5 min after onset of magnetostimulation, amyloplasts were located along cell wall distant from magnets. In HGMF, the locations of amyloplasts in columella cells were similar to those in horizontally-oriented roots up to 1 h stimulation. In the latter case, there were sometimes cytoplasmic spherical bodies with a dense vesicle-rich cytoplasm in pea statocytes, which were absent in seedlings exposed to HGMF. In cress root statocytes, both gravi- and magnetostimulation were found to cause the appearance of significant amounts of electron-dense granules in the cytoplasm and the nucleus (particularly, in the nucleolus); the effect was most evident in HGMF. Testing the chemical composition of such deposits is going on. The data presented statocyte responses indicate similarity the effects of magneto- and gravistimulation at the ultrastructural level. Thus, the root curvature in HGMF is the plant response to displacement of amyloplasts by ponderomotive force, which can serve as tool for investigation of graviperception mechanism and can provide directional stimulus for plant growth in microgravity. (Financial support by STCU: NN-13R).

Ultrastructural evaluation of multiple pass low energy versus single pass high energy radio-frequency treatment.

PubMed

Kist, David; Burns, A Jay; Sanner, Roth; Counters, Jeff; Zelickson, Brian

2006-02-01

The radio-frequency (RF) device is a system capable of volumetric heating of the mid to deep dermis and selective heating of the fibrous septa strands and fascia layer. Clinically, these effects promote dermal collagen production, and tightening of these deep subcutaneous structures. A new technique of using multiple low energy passes has been described which results in lower patient discomfort and fewer side effects. This technique has also been anecdotally described as giving more reproducible and reliable clinical results of tissue tightening and contouring. This study will compare ultrastructural changes in collagen between a single pass high energy versus up to five passes of a multiple pass lower energy treatment. Three subjects were consented and treated in the preauricular region with the RF device using single or multiple passes (three or five) in the same 1.5 cm(2) treatment area with a slight delay between passes to allow tissue cooling. Biopsies from each treatment region and a control biopsy were taken immediately, 24 hours or 6 months post treatment for electron microscopic examination of the 0-1 mm and 1-2 mm levels. Sections of tissue 1 mm x 1 mm x 80 nm were examined with an RCA EMU-4 Transmission Electron Microscope. Twenty sections from 6 blocks from each 1 mm depth were examined by 2 blinded observers. The morphology and degree of collagen change in relation to area examined was compared to the control tissue, and estimated using a quantitative scale. Ultrastructural examination of tissue showed that an increased amount of collagen fibril changes with increasing passes at energies of 97 J (three passes) and 122 J (five passes), respectively. The changes seen after five multiple passes were similar to those detected after much more painful single pass high-energy treatments. This ultrastructural study shows changes in collagen fibril morphology with an increased effect demonstrated at greater depths of the skin with multiple low-fluence passes and at lesser depths with single pass higher fluence settings. Findings suggest that similar collagen fibril alteration can occur with multiple pass low-energy treatments and single pulse high-energy treatments. The lower fluence multiple pass approach is associated with less patient discomfort, less side effects, and more consistent clinical results. Copyright 2005 Wiley-Liss, Inc.

Side Effects of Neem Oil on the Midgut Endocrine Cells of the Green Lacewing Ceraeochrysa claveri (Navás) (Neuroptera: Chrysopidae).

PubMed

Scudeler, E L; Santos, D C

2014-04-01

We described the ultrastructure of Ceraeochrysa claveri (Navás) midgut endocrine cells in larva, pupa, and adult, and evaluated the side effects of ingested neem oil, a botanical insecticide obtained from the seeds of the neem tree (Azadirachta indica), on these cells. During the larval period, C. claveri were fed (ad libitum) Diatraea saccharalis (F.) eggs treated with neem oil at concentrations of 0.5%, 1%, or 2%. Transmission electron microscopy showed that two subtypes of endocrine cells, namely granular and vesicular, occurred in the midgut epithelium during the three stages of the life cycle. Both cell types did not reach the midgut lumen and were positioned basally in the epithelium. The endocrine cells did not show extensive infoldings of the basal plasma membrane, and there were numerous secretory granules in the basal region of the cytoplasm. In the granular endocrine cells, the granules were completely filled with a dense matrix. In the vesicular endocrine cells, the main secretory products consisted of haloed vesicles. Ultrastructural examination indicated that only the granular endocrine cells exhibited signs of morphologic changes of cell injury present in all life cycle stages after the larvae were chronically exposed to neem oil by ingestion. The major cellular damage consisted of dilatation and vesiculation of the rough endoplasmic reticulum and the development of smooth endoplasmic reticulum and mitochondrial swelling. Our data suggest that cytotoxic effects on midgut endocrine cells can contribute to a generalized disruption of the physiological processes in this organ due to a general alteration of endocrine function.

Histopathological and ultrastructural studies of the tapeworm Monobothrium wageneri (Caryophyllidea) in the intestinal tract of tench Tinca tinca.

PubMed

Williams, C F; Poddubnaya, L G; Scholz, T; Turnbull, J F; Ferguson, H W

2011-12-06

Monobothrium wageneri is a monozoic caryophyllidean tapeworm of tench Tinca tinca. The pathological changes caused by this parasite within the intestinal tract of wild tench are described for the first time. Parasites were found attached to the anterior third of the intestine in tight clusters comprising up to 109 tapeworms. Infection was associated with the formation of raised inflammatory swellings surrounding the parasites. This host response, combined with the deep penetration of the scolex into the gut wall, formed a very firm seat of parasite attachment. Histopathological changes were characterised by a pronounced fibrogranulomatous lesion that extended through all layers of the intestine. This was accompanied by haemorrhage, oedema, necrosis and degeneration of the muscularis. A marked eosinophilic interface layer between the scolex of the tapeworm and gut wall indicated intimate host-parasite contact. Ultrastructural examinations revealed coniform spinitriches covering the neck and lateral sides of the scolex and capilliform filitriches present on the apical end of the scolex. Numerous glandular cytons (tegumental glands) were recorded throughout the scolex tegument. Large numbers of secretory granules discharged from the glands through a network of processes onto the scolex surface were consistent with distancing the cellular responses of the host. Observations of severe inflammatory lesions, partial intestinal occlusion and the potential for intestinal perforation represent important pathological changes that are consistent with loss of normal gut function. The lesions associated with the attachment of M. wageneri are more severe than those recorded for any other tapeworm of British freshwater fish.

Ultrastructural changes in sweet orange with symptoms of huanglongbing

USDA-ARS?s Scientific Manuscript database

Citrus greening (Huanglongbing [HLB]) is one of the most destructive citrus diseases worldwide. To better understand the ultrastructural changes of sweet orange seedlings in response to infection, anatomical analyses of HLB-infected sweet orange were carried out by light and electron microscopy. A...

Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid*

PubMed Central

Kang, Guo-zhang; Wang, Zheng-xun; Xia, Kuai-fei; Sun, Gu-chou

2007-01-01

Objective: Chilling tolerance of salicylic acid (SA) in banana seedlings (Musa acuminata cv., Williams 8818) was investigated by changes in ultrastructure in this study. Methods: Light and electron microscope observation. Results: Pretreatment with 0.5 mmol/L SA under normal growth conditions (30/22 °C) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 °C could be a type of stress. During 3 d of exposure to 7 °C chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings (distilled water-pretreated). Conclusion: SA could provide some protection for cell structure of chilling-stressed banana seedling. PMID:17444604

Ultrastructural demonstration of chemical modification of melanogenesis in hairless mouse skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimura, M.; Gellin, G.A.; Hoshino, S.

1982-02-01

We investigated chemical and physical modifications of the genetically determined ultrastructure of melanosomes. The flank skin of hairless mice was treated with ultraviolet energy (UV) shorter than 320 nm or with a combination of a photosensitizer and UV (PUVA treatment). All melanosomes in the induced melanocytes and those in resident melanocytes in the ear skin showed eumelanogenesis, although the degree of melanin deposition differed considerably according to the induction process. Eumelanogenesis was most advanced in the resident melanocytes while PUVA-induced melanocytes showed more immature premelanosomes. We then topically applied 4-tertiary butyl catechol on the skin. The depigmenting agent caused anmore » appearance of pheomelanosomes. The alteration in melanogenesis was seen most distinctly in premelanosomes of the PUVA-induced cells. Altered ultrastructure was also observed in matured melanosomes; this change was most apparent in the resident melanocytes. These findings indicate that cells with eumelanogenesis may undergo pheomelanogenesis. The present study demonstrated effects of chemicals on genetically determined function of melanocytes by quantitative analysis of melanosome ultrastructure.« less

Gromochytrium mamkaevae gen. & sp. nov. and two new orders: Gromochytriales and Mesochytriales (Chytridiomycetes).

PubMed

Karpov, S A; Kobseva, A A; Mamkaeva, M A; Mamkaeva, K A; Mikhailov, K V; Mirzaeva, G S; Aleoshin, V V

2014-06-01

During the last decade several new orders were established in the class Chytridiomycetes on the basis of zoospore ultrastructure and molecular phylogeny. Here we present the ultrastructure and molecular phylogeny of strain x-51 CALU - a parasite of the alga Tribonema gayanum, originally described as Rhizophydium sp. based on light microscopy. Detailed investigation revealed that the zoospore ultrastructure of this strain has unique characters not found in any order of Chytridiomycetes: posterior ribosomal core unbounded by the endoplasmic reticulum and detached from the nucleus or microbody-lipid complex, and kinetosome composed of microtubular doublets. An isolated phylogenetic position of x-51 is further confirmed by the analysis of 18S and 28S rRNA sequences, and motivates the description of a new genus and species Gromochytrium mamkaevae. The sister position of G. mamkaevae branch relative to Mesochytrium and a cluster of environmental sequences, as well as the ultrastructural differences between Gromochytrium and Mesochytrium zoospores prompted us to establish two new orders: Gromochytriales and Mesochytriales.

Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

NASA Astrophysics Data System (ADS)

Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Carú, M.; Dalcero, A.; Rosa, C. A. R.

2011-05-01

The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

Electron microscopy for ultrastructural analysis and protein localization in Saccharomyces cerevisiae

PubMed Central

Frankl, Andri; Mari, Muriel; Reggiori, Fulvio

2015-01-01

The yeast Saccharomyces cerevisiae is a key model system for studying of a multitude of cellular processes because of its amenability to genetics, molecular biology and biochemical procedures. Ultrastructural examinations of this organism, though, are traditionally difficult because of the presence of a thick cell wall and the high density of cytoplasmic proteins. A series of recent methodological and technical developments, however, has revived interest in morphological analyses of yeast (e.g. 123). Here we present a review of established and new methods, from sample preparation to imaging, for the ultrastructural analysis of S. cerevisiae. We include information for the use of different fixation methods, embedding procedures, approaches for contrast enhancement, and sample visualization techniques, with references to successful examples. The goal of this review is to guide researchers that want to investigate a particular process at the ultrastructural level in yeast by aiding in the selection of the most appropriate approach to visualize a specific structure or subcellular compartment. PMID:28357267

A comparative ultrastructural study of spermatozoa of the teiid lizards Cnemidophorus gularis gularis, Cnemidophorus ocellifer, and Kentropyx altamazonica (Reptilia, Squamata, Teiidae).

PubMed

Teixeira, R D; Scheltinga, D M; Trauth, S E; Colli, G R; Báo, S N

2002-06-01

The ultrastructure of the spermatozoa of Cnemidophorus gularis gularis, Cnemidophorus ocellifer, and Kentropyx altamazonica is described for the first time. Mature spermatozoa of Cnemidophorus spp. and K. altamazonica differ in the occurrence of a perforatorial base plate, the enlargement of axonemal fibers 3 and 8, and shape of mitochondria. The comparisons of the ultrastructure sperm of Cnemidophorus spp. and K. altamazonica with Ameiva ameiva [J. Morphol. (2002) in press] suggest that Ameiva and Cnemidophorus are more similar to each other than either is to Kentropyx. Statistical analyses reveal that sperm of all three species studied are significantly different in the following dimensions: head, acrosome, distal centriole length, and nuclear shoulders width. There was no variable statistically different between the Cnemidophorus spp. only. The length of the tail, midpiece, entire sperm, and nuclear rostrum are significantly different between K. altamazonica and Cnemidophorus spp. Our results indicate that sperm ultrastructure presents intra and intergeneric variability.

Physiological, cellular and molecular aspects of the desiccation tolerance in Anadenanthera colubrina seeds during germination.

PubMed

Castro, L E; Guimarães, C C; Faria, J M R

2017-11-01

During germination, orthodox seeds become gradually intolerant to desiccation, and for this reason, they are a good model for recalcitrance studies. In the present work, physiological, biochemical, and ultrastructural aspects of the desiccation tolerance were characterized during the germination process of Anadenanthera colubrina seeds. The seeds were imbibed during zero (control), 2, 8, 12 (no germinated seeds), and 18 hours (germinated seeds with 1 mm protruded radicle); then they were dried for 72 hours, rehydrated and evaluated for survivorship. Along the imbibition, cytometric and ultrastructural analysis were performed, besides the extraction of the heat-stable proteins. Posteriorly to imbibition and drying, the evaluation of ultrastructural damages was performed. Desiccation tolerance was fully lost after root protrusion. There was no increase in 4C DNA content after the loss of desiccation tolerance. Ultrastructural characteristics of cells from 1mm roots resembled those found in the recalcitrant seeds, in both hydrated and dehydrated states. The loss of desiccation tolerance coincided with the reduction of heat-stable proteins.

Ultrastructural and elemental analysis of sialoliths and their comparison with nephroliths.

PubMed

Rakesh, Nagaraju; Bhoomareddy Kantharaj, Yashoda Devi; Agarwal, Manjushree; Agarwal, Kunal

2014-02-01

Sialoliths are common in the submandibular gland and its duct system, although their exact cause of formation is still a matter of debate. The aims of this study were to: (a) analyze sialoliths ultrastructurally, and to determine the role of foreign bodies or organic materials in the formation of sialolith nuclei; and (b) compare nephroliths with sialoliths ultrastructurally. Three sialoliths and two nephroliths were analyzed ultrastructurally by a scanning electron microscope and X-ray diffractometer. The main structures of the sialoliths were found to be hydroxyapatite crystals. No organic cores were observed in the central parts of the sialoliths. In nephroliths, calcium oxalate, calcium phosphate, and struvite crystals were found. The energy-dispersive X-ray microanalysis found that sialoliths and nephroliths were predominantly composed of elements comprising calcium, phosphorous, magnesium, sodium, chloride, silicon, iron, and potassium. Sialoliths in the submandibular salivary glands might form secondary to sialadenitis, but not via a luminal organic nidus. © 2014 Wiley Publishing Asia Pty Ltd.

[Comparative ultrastructural study of parotid gland, lacrimal gland and pituitary gland between miniature pig and mouse].

PubMed

Yan, Xing; Hai, Bo; Sun, Yi-lin; Zhang, Chun-mei; Wang, Song-ling

2009-02-01

To study the ultrastructure of parotid glands, lacrimal glands and pituitary glands between miniature pig and mouse. Five adult miniature pigs and 5 mice were studied. Ultrastructure of their parotid glands, lacrimal glands, and pituitary glands was observed. The secretary granules in acinar cell of miniature pig parotid glands showed higher density and more aequalis than those of mice. The cell apparatus in acinar cell of mouse parotid glands were more plentiful than those of miniature pigs. The secretary granules on blood vessel wall were richer in parotid gland of miniature pigs compared with mouse parotid gland. Lacrimal gland had the similar ultrastructure to parotid gland in these two animals. Many blood vessel antrum were found in pituitary glands of these two animals. Compared with mouse parotid glands, there are more secretary granules in acinar cells and vascular endothelial cells in miniature pig parotid glands, which might enter blood stream and have function of endocrine secretion.

Ultrastructure of sea urchin calcified tissues after high-pressure freezing and freeze substitution.

PubMed

Ameye, L; Hermann, R; Dubois, P

2000-08-01

The improvements brought by high-pressure freezing/freeze substitution fixation methods to the ultrastructural preservation of echinoderm mineralized tissues are investigated in developing pedicellariae and teeth of the echinoid Paracentrotus lividus. Three freeze substitution (FS) protocols were tested: one in the presence of osmium tetroxide, one in the presence of uranyl acetate, and the last in the presence of gallic acid. FS in the presence of osmium tetroxide significantly improved cell ultrastructure preservation and should especially be used for ultrastructural studies involving vesicles and the Golgi apparatus. With all protocols, multivesicular bodies, suggested to contain Ca(2+), were evident for the first time in skeleton-forming cells. FS in the presence of gallic acid allowed us to confirm the structured and insoluble character of a part of the organic matrix of mineralization in the calcification sites of the tooth, an observation which modifies the current understanding of biomineralization control in echinoderms. Copyright 2000 Academic Press.

Ultra-Structure database design methodology for managing systems biology data and analyses

PubMed Central

Maier, Christopher W; Long, Jeffrey G; Hemminger, Bradley M; Giddings, Morgan C

2009-01-01

Background Modern, high-throughput biological experiments generate copious, heterogeneous, interconnected data sets. Research is dynamic, with frequently changing protocols, techniques, instruments, and file formats. Because of these factors, systems designed to manage and integrate modern biological data sets often end up as large, unwieldy databases that become difficult to maintain or evolve. The novel rule-based approach of the Ultra-Structure design methodology presents a potential solution to this problem. By representing both data and processes as formal rules within a database, an Ultra-Structure system constitutes a flexible framework that enables users to explicitly store domain knowledge in both a machine- and human-readable form. End users themselves can change the system's capabilities without programmer intervention, simply by altering database contents; no computer code or schemas need be modified. This provides flexibility in adapting to change, and allows integration of disparate, heterogenous data sets within a small core set of database tables, facilitating joint analysis and visualization without becoming unwieldy. Here, we examine the application of Ultra-Structure to our ongoing research program for the integration of large proteomic and genomic data sets (proteogenomic mapping). Results We transitioned our proteogenomic mapping information system from a traditional entity-relationship design to one based on Ultra-Structure. Our system integrates tandem mass spectrum data, genomic annotation sets, and spectrum/peptide mappings, all within a small, general framework implemented within a standard relational database system. General software procedures driven by user-modifiable rules can perform tasks such as logical deduction and location-based computations. The system is not tied specifically to proteogenomic research, but is rather designed to accommodate virtually any kind of biological research. Conclusion We find Ultra-Structure offers substantial benefits for biological information systems, the largest being the integration of diverse information sources into a common framework. This facilitates systems biology research by integrating data from disparate high-throughput techniques. It also enables us to readily incorporate new data types, sources, and domain knowledge with no change to the database structure or associated computer code. Ultra-Structure may be a significant step towards solving the hard problem of data management and integration in the systems biology era. PMID:19691849

Community Composition and Ultrastructure of a Nitrate-Dependent Anaerobic Methane-Oxidizing Enrichment Culture.

PubMed

Gambelli, Lavinia; Guerrero-Cruz, Simon; Mesman, Rob J; Cremers, Geert; Jetten, Mike S M; Op den Camp, Huub J M; Kartal, Boran; Lueke, Claudia; van Niftrik, Laura

2018-02-01

Methane is a very potent greenhouse gas and can be oxidized aerobically or anaerobically through microbe-mediated processes, thus decreasing methane emissions in the atmosphere. Using a complementary array of methods, including phylogenetic analysis, physiological experiments, and light and electron microscopy techniques (including electron tomography), we investigated the community composition and ultrastructure of a continuous bioreactor enrichment culture, in which anaerobic oxidation of methane (AOM) was coupled to nitrate reduction. A membrane bioreactor was seeded with AOM biomass and continuously fed with excess methane. After 150 days, the bioreactor reached a daily consumption of 10 mmol nitrate · liter -1 · day -1 The biomass consisted of aggregates that were dominated by nitrate-dependent anaerobic methane-oxidizing " Candidatus Methanoperedens"-like archaea (40%) and nitrite-dependent anaerobic methane-oxidizing " Candidatus Methylomirabilis"-like bacteria (50%). The " Ca Methanoperedens" spp. were identified by fluorescence in situ hybridization and immunogold localization of the methyl-coenzyme M reductase (Mcr) enzyme, which was located in the cytoplasm. The " Ca Methanoperedens" sp. aggregates consisted of slightly irregular coccoid cells (∼1.5-μm diameter) which produced extruding tubular structures and putative cell-to-cell contacts among each other. " Ca Methylomirabilis" sp. bacteria exhibited the polygonal cell shape typical of this genus. In AOM archaea and bacteria, cytochrome c proteins were localized in the cytoplasm and periplasm, respectively, by cytochrome staining. Our results indicate that AOM bacteria and archaea might work closely together in the process of anaerobic methane oxidation, as the bacteria depend on the archaea for nitrite. Future studies will be aimed at elucidating the function of the cell-to-cell interactions in nitrate-dependent AOM. IMPORTANCE Microorganisms performing nitrate- and nitrite-dependent anaerobic methane oxidation are important in both natural and man-made ecosystems, such as wastewater treatment plants. In both systems, complex microbial interactions take place that are largely unknown. Revealing these microbial interactions would enable us to understand how the oxidation of the important greenhouse gas methane occurs in nature and pave the way for the application of these microbes in wastewater treatment plants. Here, we elucidated the microbial composition, ultrastructure, and physiology of a nitrate-dependent AOM community of archaea and bacteria and describe the cell plan of " Ca Methanoperedens"-like methanotrophic archaea. Copyright © 2018 American Society for Microbiology.

Electron microscopy of two viruses of deadly nightshade (Atropa belladonna L.).

PubMed

Fránová, J

2000-02-01

Deadly nightshade plants showing severe necrotic lesions on leaves were observed in southern Bohemia. In negatively stained preparations of spontaneously infected deadly nightshade, artificially inoculated host plants and purified preparations two types of virus particles, isometric ones of about 26 nm in diameter and flexuous ones with length of 765 nm were seen by electron microscopy. The virus with isometric particles was identified as belladonna mottle virus (BMV), indistinguishable serologically from the Hungarian isolate of this virus. Identification of the virus with flexuous particles is discussed. Observations of the ultrastructure revealed the presence of filamentous virus particle aggregates and chloroplasts with peripheral vesicles bounded by double membranes, a feature typical for tymoviruses.

Brain metastasis of crystal-deficient, CD68-positive alveolar soft part sarcoma: ultrastructural features and differential diagnosis

PubMed Central

Cykowski, Matthew D.; Hicks, John; Sandberg, David I.; Olar, Adriana; Bridge, Julia A.; Greipp, Patricia T.; Navarro, Patricia; Kolodziej, Steven; Bhattacharjee, Meenakshi B.

2014-01-01

We report a case of alveolar soft part sarcoma (ASPS) presenting as an isolated frontal lobe metastasis. The tumor demonstrated little or no immunoreactivity for a broad panel of antibodies yet strong, diffuse immunoreactivity with CD68. On electron microscopy, characteristic rectangular to rhomboid crystalline inclusions were not present. Electron-dense granules resembling peroxisomes were present, sometimes in association with elongated granular structures having a periodic, lattice-like arrangement. Metastatic ASPS was confirmed by demonstration of an ASPSCR1-TFE3 fusion and imaging studies that excluded metastatic Xp11.2 translocation renal cell carcinoma. The primary site was subsequently identified in the lower extremity. PMID:25268941

Identification of Prevotella in pedal osteomyelitis of a diabetic patient.

PubMed

Dominiak, Barbara J; Oxberry, William; Chen, Patrick C

2003-01-01

Osteomyelitis in a diabetic patient with a nonhealing foot ulcer, multiple medical conditions, and recurrent hospitalization for antibiotic therapy was found to be associated with gram-negative bacteria Prevotella melanginoganica and Prevotella melaninoganica hemagglutinating variant. Those organisms were identified due to the morphologically distinct features in electron microscopy and sequencing of the genes after Polymerase chain reaction amplification from the pathological material. The bacteria invaded the bone and resided in osteocyte, osteoblast, and endothelial cells. The bacteria are usually associated with periodontal plaques, causing inflammation and destruction of gingival tissue and resorption of the alveolar bone. This is the first ultrastructural and molecular study of a diabetic bone lesion with anaerobic bacterial infection.

Further description of Cruzia tentaculata (Rudolphi, 1819) Travassos, 1917 (Nematoda: Cruzidae) by light and scanning electron microscopy.

PubMed

Adnet, F A O; Anjos, D H S; Menezes-Oliveira, A; Lanfredi, R M

2009-04-01

Species of Cruzia are parasites of the large intestine of marsupials, reptiles, amphibians, and mammalians. Cruzia tentaculata specimens were collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Colombia (new geographical record) and from Brazil and analyzed by light and scanning electron microscopy. The morphology of males and females by light microscopy corroborated most of the previous description and the ultrastructure by scanning electron microscopy evidence: the topography of the cuticle, deirids, amphids, phasmids in both sexes, a pair of papillae near the vulva opening, and the number and location of male caudal papillae, adding new features for species identification only observed by this technique.

Ultrastructure of the root cap of Arabidopsis Thaliana L. Heynh under spaceflight conditions

NASA Technical Reports Server (NTRS)

1983-01-01

Peculiarities of the ultrastructural organization of Arabidopsis root cap cells grown from the stage of two cotyledonous leaves in the Svetoblok-1 apparatus aboard the Salyut 6 research orbital station and in the laboratory are assessed. It is established that under conditions of real space flight vacuolization of the root cap cells increses considerably compared to the control variant. Changes in the topography and ulstrastructure of amyloplasts as well as lysis of cell walls are observed in the material under study. An assumption is advanced on analogous cell responses observed at the ultrastructural level to weightlessness and clinostatic conditions.

Electron microscopic examination of the myelinated axons of corpus callosum in perfused young and old rats.

PubMed

Sargon, Mustafa F; Denk, C Cem; Celik, H Hamdi; Surucu, H Selcuk; Aldur, M Mustafa

2007-07-01

In this study, the myelinated axons of parts of the corpus callosums of young and old rats were examined under the electron microscope and a grading system was performed for quantitating the ultrastructural pathological changes of these axons. Except the old splenium group, the only ultrastructural pathological change, observed in the myelinated axons was the separation in myelin configuration. In addition to this finding, in the old splenium group, in some of the myelinated axons, an interruption was observed in the myelin configuration. Additionally, these ultrastructural pathological findings were present in the larger sized myelinated axons of the corpus callosum.

Evaluation of ultrastructural hepatic response to environmental toxicants in wild cotton rats (Sigmodon hispidus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elangbam, C.S.; Qualls, C.W.; Confer, A.W.

1991-08-01

Hepatic lobules are composed of hepatocytes organized in three microcirculatory zones (periportal, midzonal, and centrilobular). The hepatocytes in each of these zones contain enzymes which are involved in various biochemical reactions. The predominant location of the mixed-function oxidation system in the liver lobule is the centrilobular zone. Ultrastructural changes in the hepatocytes not only correlate with biochemical events of detoxification but also with toxic effects of a parent compound or its metabolites. The objectives of this study was to characterize the ultrastructural alterations in the liver of wild cotton rats (Sigmodon hispidus) following exposure to polychlorinated biphenyls (PCB) contaminated habitat.

Keratoconus corneal architecture after riboflavin/ultraviolet A cross-linking: Ultrastructural studies

PubMed Central

Almubrad, Turki; Paladini, Iacopo; Mencucci, Rita

2013-01-01

Purpose Study to investigate the effects of collagen cross-linking on the ultrastructural organization of the corneal stroma in the human keratoconus cornea (KC). Methods Three normal, three keratoconus (KC1, KC2, KC3), and three cross-linked keratoconus (CXL1, CXL2, CXL3) corneas were analyzed. The KC corneas were treated with a riboflavin-ultraviolet A (UVA) treatment (CXL) method described by Wollensak et al. Penetrating keratoplasty (PKP) was performed 6 months after treatment. All samples were processed for electron microscopy. Results The riboflavin-UVA-treated CXL corneal stroma showed interlacing lamellae in the anterior stroma followed by well-organized parallel running lamellae. The lamellae contained uniformly distributed collagen fibrils (CFs) decorated with normal proteoglycans (PGs). The CF diameter and interfibrillar spacing in the CXL cornea were significantly increased compared to those in the KC cornea. The PG area in the CXL corneas were significantly smaller than the PGs in the KC cornea. The epithelium and Bowman’s layer were also normal. On rare occasions, a thick basement membrane and collagenous pannus were also observed. Conclusions Corneal cross-linking leads to modifications of the cornea stroma. The KC corneal structure showed a modification in the CF diameter, interfibrillar spacing, and PG area. This resulted in a more uniform distribution of collagen fibrils, a key feature for corneal transparency. PMID:23878503

Low grade malignant peripheral nerve sheath tumour: varied cytological and histological patterns

PubMed Central

Yamaguchi, U; Hasegawa, T; Hirose, T; Chuman, H; Kawai, A; Ito, Y; Beppu, Y

2003-01-01

Background: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. Aims: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. Methods: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. Results: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. Conclusions: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST. PMID:14600126

Differential enrichment of TTF-I and Tip5 in the T-like promoter structures of the rDNA contribute to the epigenetic response of Cyprinus carpio during environmental adaptation.

PubMed

Nardocci, Gino; Simonet, Nicolas G; Navarro, Cristina; Längst, Gernot; Alvarez, Marco

2016-08-01

To ensure homeostasis, ectothermic organisms adapt to environmental variations through molecular mechanisms. We previously reported that during the seasonal acclimatization of the common carp Cyprinus carpio, molecular and cellular functions are reprogrammed, resulting in distinctive traits. Importantly, the carp undergoes a drastic rearrangement of nucleolar components during adaptation. This ultrastructural feature reflects a fine modulation of rRNA gene transcription. Specifically, we identified the involvement of the transcription termination factor I (TTF-I) and Tip-5 (member of nucleolar remodeling complex, NoRC) in the control of rRNA transcription. Our results suggest that differential Tip5 enrichment is essential for silencing carp ribosomal genes and that the T0 element is key for regulating the ribosomal gene during the acclimatization process. Interestingly, the expression and content of Tip5 were significantly higher in winter than in summer. Since carp ribosomal gene expression is lower in the winter than in summer, and considering that expression concomitantly occurs with nucleolar ultrastructural changes of the acclimatization process, these results indicate that Tip5 importantly contributes to silencing the ribosomal genes. In conclusion, the current study provides novel evidence on the contributions of TTF-I and NoRC in the environmental reprogramming of ribosomal genes during the seasonal adaptation process in carp.

Malignant melanoma with a rhabdoid phenotype: histologic, immunohistochemical, and ultrastructural study of a case and review of the literature.

PubMed

Abbott, Jared J; Amirkhan, Robin H; Hoang, Mai P

2004-06-01

Malignant melanoma is known to display tremendous histologic diversity. One rare variant is the rhabdoid phenotype, so called because of the appearance of cells resembling rhabdomyoblasts seen in malignant rhabdoid tumors of the kidney. We present the histologic, immunohistochemical, and ultrastructural features of a malignant melanoma composed entirely of rhabdoid cells. A 62-year-old man presented with a 6.5-cm lung mass. Although presumed to be a metastatic lesion, extensive workup failed to reveal a primary tumor site. Histologic sections showed a mass composed entirely of polygonal neoplastic cells with prominent nucleoli and large hyaline cytoplasmic inclusions. The tumor cells were strongly immunoreactive with S100 protein, vimentin, and CD56, and were focally reactive with Mart-1. Tumor cells were negative for Melan-A, tyrosinase, HMB-45, AE1/AE3, cytokeratin (CK) 7, CK8/ 18, CK20, CK903, CAM 5.2, epithelial membrane antigen, smooth muscle actin, desmin, leukocyte common antigen, Bcl-2, CD3, CD20, CD30, CD138, kappa and lambda light chains, CD68, CD34, factor VIII, synaptophysin, and glial fibrillary acidic protein. Electron microscopy showed cytoplasmic whorls of intermediate filaments containing entrapped rough endoplasmic reticulum, mitochondria, and lipid. Recognition of this rare variant of malignant melanoma is important in the evaluation of tumors with rhabdoid morphology.

Comparative ultrastructure of vallate, foliate and fungiform taste buds of golden Syrian hamster.

PubMed

Miller, R L; Chaudhry, A P

1976-01-01

A fine-structure study of the hamster fungiform, foliate and vallate taste buds was undertaken for comparative purposes. All three taste bud types shared in common composition of the dark cells, light cells, basal cells, nerve fibers and nerve endings and undifferentiated peripheral cells, but morphological difference existed among them. The foliate and vallate taste buds were quite similar in their ultrastructural morphology. Their dark cells displayed long apical necks, long apical microvilli, apical osmiophilic secretory granules and an abundant rough endoplasmic reticulum. The dark cells of the fungiform taste buds, however, showed no neck formation and lacked apical osmiophilic granules. They had short apical microvilli and relatively scant rough endoplasmic reticulum. There was no difference in the fine structure features of the light cells, basal cells and neural elements of different types of taste buds. Both light and dark cells were much more readily distinguishable in foliate and vallate buds than in fungiform buds at both light-and electron-microscopic levels. Foliate and vallate buds demonstrated homogeneous dense substance within the taste pores while fungiform pores were frequently empty. It is speculated that the differences in taste bud morphology may be due to their different lingual locations and/or may be a reflection of the differences in the inductive influences from different nerves. Furthermore, structural differences may be responsible for varying thresholds to different taste modalities.

Chromaffin granules in the rat adrenal medulla release their secretory content in a particulate fashion.

PubMed

Crivellato, Enrico; Belloni, Anna; Nico, Beatrice; Nussdorfer, Gastone G; Ribatti, Domenico

2004-03-01

Exocytosis is considered the main route of granule discharge in chromaffin cells. We recently provided ultrastructural evidence suggesting that piecemeal degranulation (PMD) occurs in mouse adrenal chromaffin cells. In the present study, we processed rat adrenal glands for transmission electron microscopy (TEM), and examined chromaffin cells for changes characteristic of PMD. Both adrenaline (A)- and noradrenaline (NA)-storing cells express ultrastructural features suggestive of a slow and particulate mode of granule discharge. In adrenaline-containing cells, some granules present enlarged dimensions accompanied by eroded or dissolved matrices. Likewise, a number of granules in NA-releasing cells show content reduction with variably expanded granule chambers. Dilated, empty granule containers are recognizable in the cytoplasm of both cell types. Characteristically, altered granules and empty containers are seen intermingled with normal, resting granules. In addition, chromaffin granules often show irregular profiles, with budding or tail-like projections of their limiting membranes. Thirty 150-nm-diameter membrane-bound vesicles with a moderately electron-dense or -lucent internal structure are observable in the cytoplasm of both cell types. These vesicles are seen among the granules and some of them are fused with the perigranule membranes in the process of attachment to or budding from the granules. These data add further support to the concept that PMD may be an alternative secretory pathway in adrenal chromaffin cells. Copyright 2004 Wiley-Liss, Inc.

Expression of the inclusion body myopathy 3 mutation in Drosophila depresses myosin function and stability and recapitulates muscle inclusions and weakness.

PubMed

Wang, Yang; Melkani, Girish C; Suggs, Jennifer A; Melkani, Anju; Kronert, William A; Cammarato, Anthony; Bernstein, Sanford I

2012-06-01

Hereditary myosin myopathies are characterized by variable clinical features. Inclusion body myopathy 3 (IBM-3) is an autosomal dominant disease associated with a missense mutation (E706K) in the myosin heavy chain IIa gene. Adult patients experience progressive muscle weakness. Biopsies reveal dystrophic changes, rimmed vacuoles with cytoplasmic inclusions, and focal disorganization of myofilaments. We constructed a transgene encoding E706K myosin and expressed it in Drosophila (E701K) indirect flight and jump muscles to establish a novel homozygous organism with homogeneous populations of fast IBM-3 myosin and muscle fibers. Flight and jump abilities were severely reduced in homozygotes. ATPase and actin sliding velocity of the mutant myosin were depressed >80% compared with wild-type myosin. Light scattering experiments and electron microscopy revealed that mutant myosin heads bear a dramatic propensity to collapse and aggregate. Thus E706K (E701K) myosin appears far more labile than wild-type myosin. Furthermore, mutant fly fibers exhibit ultrastructural hallmarks seen in patients, including cytoplasmic inclusions containing aberrant proteinaceous structures and disorganized muscle filaments. Our Drosophila model reveals the unambiguous consequences of the IBM-3 lesion on fast muscle myosin and fibers. The abnormalities observed in myosin function and muscle ultrastructure likely contribute to muscle weakness observed in our flies and patients.

Pathological studies on chlamydiosis in parakeets (Psittacula krameri manillensis).

PubMed

Suwa, T; Touchi, A; Hirai, K; Itakura, C

1990-04-01

Histological, immunohistochemical and ultrastructural findings are described in 20 parakeets (Psittacula krameri ntanillensis) affected with chlamydiosis. The main histological lesions consisted of focal necrosis in the liver and adrenal gland, lymphocytic depletion with fibrin exudation in the splenic sinuses and follicles and fibrinopurulent airsacculitis. In these lesions basophilic chlamydial inclusion bodies were found. Macrophages and plasma cells increased mainly in the liver and spleen. Immunohistochemically. more chlamydial inclusion bodies were observed in cells of various organs and tissues including epithelial cells, capillary endothelium and proliferated macrophages. With an electron microscope, the chlamydial inclusion bodies were shown to consist of chlamydial organisms in developmental stages. Concurrent lesions of pulmonary herpesvirus infection appeared frequently in the present cases and seemed to have a close relationship with the chlamydiosis onset.

Histologic and ultrastructural evaluation of fresh and frozen-thawed human ovarian xenografts in nude mice.

PubMed

Nisolle, M; Casanas-Roux, F; Qu, J; Motta, P; Donnez, J

2000-07-01

To compare histologic and ultrastructural characteristics of fresh and frozen-thawed human ovarian cortical tissue grafted into nude mice. Experimental prospective study. An academic research environment. Ovarian biopsy specimens were obtained from 13 women undergoing laparoscopy for tubal ligation or infertility. Forty nude mice. A minilaparotomy was performed to place fresh and frozen-thawed ovarian grafts subcutaneously (sc) or intraperitoneally (ip). Removal of the ovarian grafts was performed at 24 days. [1] the follicular population, [2] fibrosis, [3] vascularization of the grafted tissue, and [4] ultrastructural evaluation. A greater fibrosis relative surface area was noted in frozen-thawed transplanted tissue than in fresh transplants. Regardless of this fibrosis, a similar follicular density was observed in fresh and frozen-thawed ovarian tissue 24 days after transplantation. Active angiogenesis was proved by both immunohistochemical study of the vascular endothelial growth factor and morphometric study of the vascular network. Normal ultrastructural characteristics were noted in frozen-thawed ovarian biopsies. Angiogenesis allows implantation of the graft even if it has been cryopreserved and thawed similarly to implantation of fresh tissue. The greater fibrosis observed in grafts after cryopreservation and implantation does not seem to affect the primordial and primary ovocyte population and their ultrastructural characteristics, but further studies must be conducted to prove that after cryopreservation and transplantation, ovocytes may achieve full maturation and fertilization.

Ultrastructural Effects of Bacillus thuringiensis var. san diego on Midgut Cells of the Cottonwood Leaf Beetle1

Treesearch

Leah S. Bauer; Stuart H. Pankratz

1992-01-01

Sequential observations of the ultrastructural effects of Bacillus thuringiensis var. san diego were made on midgut epithelial cells of the cottonwood leaf beetle, Chrysomela scripta F. Larvae imbibed a droplet of B. thuringiensis var. san diego containing endotoxin and live...

HEPATOBLASTOMAS IN THE MUMMICHOG, FUNDULUS HETEROCLITUS (L.), FROM A CREOSOTE-CONTAMINATED ENVIRONMENT: A HISTOLOGIC, ULTRASTRUCTURAL AND IMMUNOHISTOCHEMICAL STUDY

EPA Science Inventory

A detailed histologic and ultrastructural description of two cases of hepatoblastoma, a primitive liver cell neoplasm, is provided from mummichog, Fundulus heteroclitus(L.), inhabiting a creosote-contaminated site in the Elizabeth River, Virginia, USA. Both neoplasms were multifo...

Ultrastructure of myocardial widened Z bands and endocardial cells in two teleostean species.

PubMed

Leknes, I L

1981-01-01

Widened myocardial Z bands and endocardial cells are described in two teleostean species Cichlasoma meeki and Corydoras aeneus. Widened Z bands containing mainly amorphous and electron-dense material were seen in a number of myocardial cells. Further, similar material may occur in large amounts beneath the sarcolemma and at intercellular junctions. Occasionally, we observed continuity between the latter material and that in expanded Z bands. In C. meeki the ventricular endocardial layer consists of two structurally different cell types, whereas in C. aeneus only one cell type was seen. The functional aspects of widened Z bands are discussed.

Rumen Bacterial Degradation of Forage Cell Walls Investigated by Electron Microscopy

PubMed Central

Akin, Danny E.; Amos, Henry E.

1975-01-01

The association of rumen bacteria with specific leaf tissues of the forage grass Kentucky-31 tall fescue (Festuca arundinacea Schreb.) during in vitro degradation was investigated by transmission and scanning electron microscopy. Examination of degraded leaf cross-sections revealed differential rates of tissue degradation in that the cell walls of the mesophyll and pholem were degraded prior to those of the outer bundle sheath and epidermis. Rumen bacteria appeared to degrade the mesophyll, in some cases, and phloem without prior attachment to the plant cell walls. The degradation of bundle sheath and epidermal cell walls appeared to be preceded by attachment of bacteria to the plant cell wall. Ultrastructural features apparently involved in the adhesion of large cocci to plant cells were observed by transmission and scanning electron microscopy. The physical association between plant and rumen bacterial cells during degradation apparently varies with tissue types. Bacterial attachment, by extracellular features in some microorganisms, is required prior to degradation of the more resistant tissues. Images PMID:16350017

Connexin36 vs. connexin32, "miniature" neuronal gap junctions, and limited electrotonic coupling in rodent suprachiasmatic nucleus.

PubMed

Rash, J E; Olson, C O; Pouliot, W A; Davidson, K G V; Yasumura, T; Furman, C S; Royer, S; Kamasawa, N; Nagy, J I; Dudek, F E

2007-10-26

Suprachiasmatic nucleus (SCN) neurons generate circadian rhythms, and these neurons normally exhibit loosely-synchronized action potentials. Although electrotonic coupling has long been proposed to mediate this neuronal synchrony, ultrastructural studies have failed to detect gap junctions between SCN neurons. Nevertheless, it has been proposed that neuronal gap junctions exist in the SCN; that they consist of connexin32 or, alternatively, connexin36; and that connexin36 knockout eliminates neuronal coupling between SCN neurons and disrupts circadian rhythms. We used confocal immunofluorescence microscopy and freeze-fracture replica immunogold labeling to examine the distributions of connexin30, connexin32, connexin36, and connexin43 in rat and mouse SCN and used whole-cell recordings to re-assess electrotonic and tracer coupling. Connexin32-immunofluorescent puncta were essentially absent in SCN but connexin36 was relatively abundant. Fifteen neuronal gap junctions were identified ultrastructurally, all of which contained connexin36 but not connexin32, whereas nearby oligodendrocyte gap junctions contained connexin32. In adult SCN, one neuronal gap junction was >600 connexons, whereas 75% were smaller than 50 connexons, which may be below the limit of detectability by fluorescence microscopy and thin-section electron microscopy. Whole-cell recordings in hypothalamic slices revealed tracer coupling with neurobiotin in <5% of SCN neurons, and paired recordings (>40 pairs) did not reveal obvious electrotonic coupling or synchronized action potentials, consistent with few neurons possessing large gap junctions. However, most neurons had partial spikes or spikelets (often <1 mV), which remained after QX-314 [N-(2,6-dimethylphenylcarbamoylmethyl)triethylammonium bromide] had blocked sodium-mediated action potentials within the recorded neuron, consistent with spikelet transmission via small gap junctions. Thus, a few "miniature" gap junctions on most SCN neurons appear to mediate weak electrotonic coupling between limited numbers of neuron pairs, thus accounting for frequent detection of partial spikes and hypothetically providing the basis for "loose" electrical or metabolic synchronization of electrical activity commonly observed in SCN neuronal populations during circadian rhythms.

[Ultrastructural changes in cells of the inner enamel epithelium, stratum intermedium and reticulum stellatum in the enamel organ of the upper incisor of the Wistar rat at different phases of amelogenesis].

PubMed

Costacurta, L; de Carvalho, C A; König, B; Bilotta, J A

1976-01-01

An electronmicroscopical study of the enamel organ of the upper incisors germs of Wistar rats was performed to analyse the ultrastructural features of the cells of the inner epithelium, the intermediate layer and the stellate reticulum, during preimary, young, transitional and mineralized enamel phases of amelogenesis. So, it was observed that the mitochondria in the ameloblasts are ovoid before the beginning of the enamel matrix formation and in the primary and young enamel phases. However, in the transitional and mineralized phases, these organelles are long and tortuous and some are characterized by a compact structure. In the cells of intermediate layer and stellate reticulum, the mitochondria are ovoid until the beginning of the mineralized phase. At the ending of this phase, these organelles are very long and present irregular form; many of them show also a compact structure. The "zonula adhaerens" could be observed only in the ameloblasts of the primary and young enamel phase. The cytoplasm of ameloblasts, during primary and young enamel phases is characterized by an abundance of free ribosomes and a branular endoplasmic reticulum; but during transitional and mineralized enamel phases, the cytoplasm of these cells shows little granular endoplasmic reticulum and free ribosomes, but ehe agranular endoplasmic reticulum is present. The granular endoplasmic reticulum and free ribosomes are abundant in the cells of the intermediate layer and stellate reticulum at the ending of the young enamel phase, in the transitional enamel phase and in the beginning of the minieralized phase. During different phases of amelogenesis, in the three above referred layers of the enamel organ, were also studied the features of the Golgi apparatus the presence and topographic distribution of the pigment granules, as well as the lysosomes, desmosomes and the tonophibriles.

Telocyte dynamics in psoriasis

PubMed Central

Manole, CG; Gherghiceanu, Mihaela; Simionescu, Olga

2015-01-01

The presence of telocytes (TCs) as distinct interstitial cells was previously documented in human dermis. TCs are interstitial cells completely different than dermal fibroblasts. TCs are interconnected in normal dermis in a 3D network and may be involved in skin homeostasis, remodelling, regeneration and repair. The number, distribution and ultrastructure of TCs were recently shown to be affected in systemic scleroderma. Psoriasis is a common inflammatory skin condition (estimated to affect about 0.1–11.8% of population), a keratinization disorder on a genetic background. In psoriasis, the dermis contribution to pathogenesis is frequently eclipsed by remarkable epidermal phenomena. Because of the particular distribution of TCs around blood vessels, we have investigated TCs in the dermis of patients with psoriasis vulgaris using immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM). IHC and IF revealed that CD34/PDGFRα-positive TCs are present in human papillary dermis. More TCs were present in the dermis of uninvolved skin and treated skin than in psoriatic dermis. In uninvolved skin, TEM revealed TCs with typical ultrastructural features being involved in a 3D interstitial network in close vicinity to blood vessels in contact with immunoreactive cells in normal and treated skin. In contrast, the number of TCs was significantly decreased in psoriatic plaque. The remaining TCs demonstrated multiple degenerative features: apoptosis, membrane disintegration, cytoplasm fragmentation and nuclear extrusion. We also found changes in the phenotype of vascular smooth muscle cells in small blood vessels that lost the protective envelope formed by TCs. Therefore, impaired TCs could be a ‘missed’ trigger for the characteristic vascular pathology in psoriasis. Our data explain the mechanism of Auspitz’s sign, the most pathognomonic clinical sign of psoriasis vulgaris. This study offers new insights on the cellularity of psoriatic lesions and we suggest that TCs should be considered new cellular targets in forthcoming therapies. PMID:25991475

Involvement of autophagy and apoptosis and lipid accumulation in sclerotial morphogenesis of Morchella importuna.

PubMed

He, Peixin; Wang, Ke; Cai, Yingli; Hu, Xiaolong; Zheng, Yan; Zhang, Junjie; Liu, Wei

2018-06-01

Sclerotial formation is a key phase of the morel life cycle and lipids have been recorded as the main cytoplasmic reserves in sclerotia of Morchella fungi without any experimental verification. In this study, the ultrastructural features of the undifferentiated mycelia stage (MS) and three main sclerotial differentiation states (sclerotial initial [SI], sclerotial development [SD] and sclerotial maturation [SM]) were compared by transmission electron microscopy. The nature of the energy-rich substance in hypha and sclerotium of Morchella importuna was qualitatively investigated by confocal laser scanning microscopy and quantitatively studied by extraction of lipids. Sclerotia were observed to form from the repeated branching and enlargement of either terminal hyphae or subordinate hyphal branches, indicating a complex type of sclerotial development. Autophagy and apoptosis were involved in the sclerotial metamorphosis of the cultivated strain of M. importuna. During the SI phase, the characteristic features of autophagy (vacuolation, coalescence of small vacuoles, existence of autophagosomes and engulfment of autophagosomes by vacuoles) were observed. At the SD phase, apoptotic characteristics (condensation of the cytoplasm and nucleus, shrinkage of plasma membrane, extensive plasma membrane blebbing and existence of phagosomes) could be seen in some developing sclerotial cells. In the final stage of sclerotial morphogensis, the sclerotial cells showed a necrotic mode of cell death. In addition, confocal laser imaging studies of live cells indicated that the energy-rich substance in morel hyphae and sclerotia was lipid. The lipid content in sclerotia was significantly more than that in hyphal cells. To the best of our knowledge, this is the first detailed ultrastructural description highlighting the involvement of autophagy and apoptosis in sclerotial metamorphosis of Morchella species and lipid accumulation during morel sclerotial development was also first experimentally verified. This work will promote a better understanding of the mechanism of morel sclerotial metamorphosis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Silicon in Imperata cylindrica (L.) P. Beauv: content, distribution, and ultrastructure.

PubMed

Rufo, Lourdes; Franco, Alejandro; de la Fuente, Vicenta

2014-07-01

Silicon concentration, distribution, and ultrastructure of silicon deposits in the Poaceae Imperata cylindrica (L.) P. Beauv. have been studied. This grass, known for its medicinal uses and also for Fe hyperaccumulation and biomineralization capacities, showed a concentration of silicon of 13,705 ± 9,607 mg/kg dry weight. Silicon was found as an important constituent of cell walls of the epidermis of the whole plant. Silica deposits were found in silica bodies, endodermis, and different cells with silicon-collapsed lumen as bulliforms, cortical, and sclerenchyma cells. Transmission electron microscope observations of these deposits revealed an amorphous material of an ultrastructure similar to that previously reported in silica bodies of other Poaceae.

Leukemic blast cell colony formation in semisolid culture with erythropoietin: a case report of acute poorly differentiated erythroid leukemia.

PubMed

Tomonaga, M; Jinnai, I; Tagawa, M; Amenomori, T; Nishino, K; Yao, E; Nonaka, H; Kuriyama, K; Yoshida, Y; Matsuo, T

1987-02-01

The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

Claudins and renal salt transport.

PubMed

Muto, Shigeaki; Furuse, Mikio; Kusano, Eiji

2012-02-01

Tight junctions (TJs) are the most apical component of junctional complexes and regulate the movement of electrolytes and solutes by the paracellular pathway across epithelia. The defining ultrastructural features of TJs are strands of transmembrane protein particles that adhere to similar strands on adjacent cells. These strands are mainly composed of linearly polymerized integral membrane proteins called claudins. Claudins comprise a multigene family consisting of more than 20 members in mammals. Recent work has shown that claudins form barriers, determined by the paracellular electrical resistance and charge selectivity, and pores in the TJ strands. The paracellular pathways in renal tubular epithelia such as the proximal tubule, which reabsorbs the largest fraction of filtered NaCl and water, are important routes for the transport of electrolytes and water. Their transport characteristics vary among different nephron segments. Multiple claudins are expressed at TJs of individual nephron segments in a nephron segment-specific manner. Among them, claudin-2 is highly expressed at TJs of proximal tubules, which are leaky epithelia. Overexpression and knockdown of claudin-2 in epithelial cell lines, and knockout of the claudin-2 gene in mice, have demonstrated that claudin-2 forms high-conductance cation-selective pores in the proximal tubule. Here, we review the renal physiology of paracellular transport and the physiological roles of claudins in kidney function, especially claudin-2 and proximal tubule paracellular NaCl transport.

Retroviral envelope syncytin capture in an ancestrally diverged mammalian clade for placentation in the primitive Afrotherian tenrecs

PubMed Central

Cornelis, Guillaume; Vernochet, Cécile; Malicorne, Sébastien; Souquere, Sylvie; Tzika, Athanasia C.; Goodman, Steven M.; Catzeflis, François; Robinson, Terence J.; Milinkovitch, Michel C.; Pierron, Gérard; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

2014-01-01

Syncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Syncytins have been identified in Euarchontoglires (primates, rodents, Leporidae) and Laurasiatheria (Carnivora, ruminants) placental mammals. Here, we searched for similar genes in species that retained characteristic features of primitive mammals, namely the Malagasy and mainland African Tenrecidae. They belong to the superorder Afrotheria, an early lineage that diverged from Euarchotonglires and Laurasiatheria 100 Mya, during the Cretaceous terrestrial revolution. An in silico search for env genes with full coding capacity within a Tenrecidae genome identified several candidates, with one displaying placenta-specific expression as revealed by RT-PCR analysis of a large panel of Setifer setosus tissues. Cloning of this endogenous retroviral env gene demonstrated fusogenicity in an ex vivo cell–cell fusion assay on a panel of mammalian cells. Refined analysis of placental architecture and ultrastructure combined with in situ hybridization demonstrated specific expression of the gene in multinucleate cellular masses and layers at the materno–fetal interface, consistent with a role in syncytium formation. This gene, which we named “syncytin-Ten1,” is conserved among Tenrecidae, with evidence of purifying selection and conservation of fusogenic activity. To our knowledge, it is the first syncytin identified to date within the ancestrally diverged Afrotheria superorder. PMID:25267646