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1

Transgenic rats carrying the mouse renin gene—Morphological characterization of a low-renin hypertension model  

Microsoft Academic Search

Transgenic rats carrying the mouse renin gene—Morphological characterization of a low-renin hypertension model. Transgenic rats [TGR; strain name TGR(mRen2)27] harboring the mouse Ren-2 renin gene have been recently generated as a model for the study of primary hypertension that offers the advantage of a clearly-defined genetic alteration. Expression of the mouse Ren-2 gene causes severe hypertension (200 to 260 mm

Sebastian Bachmann; Jörg Peters; Eberhard Engler; Detlev Ganten; John Mullins

1992-01-01

2

Morphological characterization of rat entorhinal neurons in vivo: soma-dendritic structure and axonal domains  

Microsoft Academic Search

We used in vivo intracellular labeling with horseradish peroxidase in order to study the somadendritic morphology and axonal projections of rat entorhinal neurons. The cells responded to hippocampal stimulation with inhibitory postsynaptic potentials, and thus likely received direct or indirect hippocampal input. All cells (n = 24) showed extensive dendritic domains that extended in some cases for more than 1

K. Lingenhöhl; D. M. Finch

1991-01-01

3

Morphological and functional characterization of a rat vaginal smooth muscle sphincter.  

PubMed

The aim of the present study was to gain information about adrenergic-, cholinergic- and non-adrenergic, non-cholinergic (NANC)- transmitter systems/mediators in the rat vagina, and to characterize its smooth muscles functionally. Tissue sections from vagina of Sprague Dawley rats were immunolabelled with antibodies against protein gene product 9.5 (PGP), synaptophysin (Syn), tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP). Circularly cut vaginal smooth muscle preparations from the distal vagina were studied in organ baths. In the paravaginal tissue, a large number of PGP-, NOS-, TH-, VIP-immunoreactive (IR) and few CGRP-IR nerve trunks were observed, giving off branches to the smooth muscle wall. The smooth muscle wall was supplied by a large number of PGP-, Syn-, VAChT-, NPY-, NOS- and TH- IR nerve terminals, whilst only a moderate to few numbers of CGRP-, VIP- and PACAP-IR terminals were identified. Especially the distal part of the vaginal wall, where the circularly running smooth muscle was thickened into a distinct sphincter structure, was very richly innervated, predominantly by PGP- and NOS-IR terminals. Below and within the basal parts of the epithelium in the distal half of the vagina, a large number of PGP- and few NOS- and PACAP-IR varicose terminals were observed. The vaginal arteries were encircled by plexuses of nerve terminals. A large number of these were PGP-, Syn-, VAChT-, NOS-, TH-, NPY- and VIP-IR, and few were CGRP- and PACAP-IR. In isolated preparations of the distal vagina, electrical field stimulation (EFS) caused frequency-dependent contractions, which were reduced by sildenafil, tetrodotoxin (TTX) and phentolamine. In preparations contracted by norepinephrine (NA), EFS produced frequency-dependent relaxations. Pretreatment with the NOS-inhibitor N(G)-nitro-L-arginine, TTX, or the inhibitor of soluble guanylate cyclase, ODQ, abolished the EFS relaxations. In NE precontracted preparations, cumulative addition of sildenafil caused concentration-dependent relaxation. Carbachol contracted the strips concentration-dependently from baseline. It can be concluded that the distal part of the rat vagina forms a distinct smooth muscle sphincter, which is richly innervated by adrenergic, cholinergic and NANC nerves. The present studies suggest that in the rat the L-arginine/NO-system not only plays an important role in the regulation of vaginal smooth muscle tone, but also affects blood flow, and may have sensory functions. PMID:12152117

Giraldi, A; Alm, P; Werkström, V; Myllymäki, L; Wagner, G; Andersson, K E

2002-08-01

4

Biochemical and morphological characterization of carbon tetrachloride-induced lung fibrosis in rats  

Microsoft Academic Search

The short-term and long-term lung CCl4 injuries in rats were studied by i.p. CCl4 for 2 or 5 weeks, respectively, and the lung injury in the third progression group receiving i.p. CCl4 for 2 weeks followed by 3 weeks without. Acute haemorrhagic interstitial pneumonia resulted from short-term injury; chronic\\u000a interstitial pneumonia from long term injury, and residua of injury or

Paavo Pääkkö; Sisko Anttila; Raija Sormunen; Leena Ala-Kokko; Raija Peura; Victor J. Ferrans; Lasse Ryhänen

1996-01-01

5

Transcellular transport of polymeric IgA in the rat hepatocyte: biochemical and morphological characterization of the transport pathway  

Microsoft Academic Search

Polymeric IgA (plgA) is transported by liver parenchymal cells (hepatocytes) from blood to bile via a receptor-mediated process. We have studied the intracellular pathway taken by a TEPC15 mouse myeioma plgA. When from 1 pg to 1 mg 12Sl-plgA was injected into the saphenous vein of a rat, 36% was transported as intact protein into the bile over a 3-h

CRAIG A. HOPPE; TIMOTHY P. CONNOLLY; ANN L. HUBBARD

1985-01-01

6

Isolation and characterization of epithelial and myogenic cells by "fishing" for the morphologically distinct cell types in rat primary periodontal ligament cultures.  

PubMed

The periodontal ligament (PDL) contains various cell populations and plays a central role in the maintenance, repair, and regeneration of the periodontium, i.e., tooth-supporting structures. Because primary cells isolated from PDL tissue are heterogeneous, the establishment of an effective isolation method for cells of interest is desired. In the present study, two morphologically distinct cell types were identified in confluent primary cultures derived from rat PDL. To isolate these cell populations, a small piece of filter paper soaked with trypsin-EDTA was placed directly onto the target cell population, enabling the cells to detach from the culture dish. The filter papers were then transferred into fresh culture dishes to establish outgrowth cultures; these two steps constitute the "cell fishing" method. The "fished" cell types were propagated and subcultured for further analyses. In morphological evaluation, immunocytochemical analyses, and reverse transcription-polymerase chain reaction, the isolated cells exhibited a polygonal appearance or a mono- or multinucleated appearance, with a high cytoplasm-to-nucleus ratio, leading to their being characterized as epithelial or myogenic cell populations, respectively. Surprisingly, a notable proportion of the multinuclear cells in the primary and subsequent isolated cultures demonstrated dramatic, spontaneous contractions, a feature typical of skeletal muscle cells. Finally, the isolated cell populations maintained a normal karyotype with a diploid chromosomal number. These results demonstrated that physiological epithelial and skeletal muscle cells can be obtained from primary PDL cultures without artificial induction using growth factors or chemicals, and can be propagated as individual lineage-committed cell populations; the populations consisted of differentiated and progenitor cells that maintained chromosomal stability. This simple, classical culture procedure provides new insights into the biological properties of PDL cells, which are potentially important for the differentiation of tissue or somatic stem cells and for the development of future cell-based therapies for dental and muscular diseases. PMID:23649106

Tominaga, Noriko; Nakahara, Taka; Nasu, Masanori; Satoh, Tazuko

2013-05-04

7

Transcellular transport of polymeric IgA in the rat hepatocyte: biochemical and morphological characterization of the transport pathway  

PubMed Central

Polymeric IgA (pIgA) is transported by liver parenchymal cells (hepatocytes) from blood to bile via a receptor-mediated process. We have studied the intracellular pathway taken by a TEPC15 mouse myeloma pIgA. When from 1 microgram to 1 mg 125I-pIgA was injected into the saphenous vein of a rat, 36% was transported as intact protein into the bile over a 3-h period. The concentration of transported 125I-pIgA was maximal in bile 30-60 min after injection, and approximately 80% of the total 125I-pIgA ultimately transported had been secreted into bile by 90 min. A horseradish peroxidase-pIgA conjugate (125I-pIgA-HRP) was transported to a similar extent and with kinetics similar to that of unconjugated 125I-pIgA and was therefore used to visualize the transport pathway. Peroxidase cytochemistry of livers fixed in situ 2.5 to 10 min after 125I-pIgA-HRP injection demonstrated a progressive redistribution of labeled structures from the sinusoidal area to intermediate and bile canalicular regions of the hepatocyte cytoplasm. Although conjugate-containing structures began accumulating in the bile canalicular region at these early times, no conjugate was present in bile until 20 min. From 7.5 to 45 min after injection approximately 30% of the labeled structures were in regions that contained Golgi complexes and lysosomes; however, we found no evidence that either organelle contained 125I-pIgA-HRP. At least 85% of all positive structures in the hepatocyte were vesicles of 110-160-nm median diameters, with the remaining structures accounted for by tubules and multivesicular bodies. Vesicles in the bile canalicular region tended to be larger than those in the sinusoidal region. Serial sectioning showed that the 125I-pIgA-HRP-containing structures were relatively simple (predominantly vesicular) and that extensive interconnections did not exist between structures in the sinusoidal and bile canalicular regions.

1985-01-01

8

Morphological modifications in clitoris and vagina in spontaneously hypertensive rats  

Microsoft Academic Search

We evaluated possible morphological alteration in clitoris and vagina from spontaneous hypertensive rats (SHR) and normotensive WKY rats. Clitoris and vagina were processed by Masson's trichrome, anti-?-smooth-muscle actin, anticollagen type I (COL I) and type III (COL III), and anti-TGF?1. SHR presented higher amount of clitoral cavernous smooth muscle (CSM), vascular smooth muscle; TGF?1 in clitoral vessel wall; higher wall\\/lumen

A J Bechara; G Cao; A R Casabé; S V Romano; J E Toblli

2003-01-01

9

Social Structure Predicts Genital Morphology in African Mole-Rats  

Microsoft Academic Search

BackgroundAfrican mole-rats (Bathyergidae, Rodentia) exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals

Marianne L. Seney; Diane A. Kelly; Bruce D. Goldman; Radim Sumbera; Nancy G. Forger; Anna Dornhaus

2009-01-01

10

Comparative morphology and tumourigenicity of human hepatocellular carcinoma cell lines in athymic rats and mice  

Microsoft Academic Search

Four human hepatoma cell lines PLC\\/PRF\\/5, Hep G2, Sk-Hep 1 and Mahlavu were inoculated subcutaneously into athymic Balb\\/c nude mice and N\\/NIH outbred nude rats, producing well encapsulated tumours. The 4 hepatoma tumour types in the athymic rodents differ morphologically. PLC\\/PRF\\/5 and Hep G2 cells are well differentiated polygonal cells which resemble normal hepatocytes. Tumour arrangement is characterized by solid

Daniel Shouval; Lucia Schuger; Itzhak S. Levij; Lola M. Reid; Zvi Neeman; David A. Shafritz

1988-01-01

11

Proliferative and morphologic changes in rat colon following bypass surgery.  

PubMed Central

In this study the proliferative and morphologic changes that occur in the colon of normal and dimethylhydrazine-treated rats following surgical bypass of the middle third of the colon are reported. Proliferative changes were measured by estimating accumulated mitotic indexes following vinblastine treatment and morphologic changes were observed with the use of light microscopy and scanning electron microscopy. Data were collected on Days 0, 7, 14, 30, and 72 after surgery. The results show that surgical bypass produces contrasting effects in the segments proximal to and distal to the suture line. In the proximal segment there was morphologic evidence of hyperplasia, although proliferative activity was unchanged except for an increase at 7 days in normal rats. In the distal segment there was a long-lived increase in the mitotic index, although morphologic changes were not seen. The results for DMH-treated rats were similar to those in normal rats. Groups of isolated dysplastic epithelial cells were often seen in the submucosa adjacent to sutures up to 72 days after surgery. Increased lymphoid infiltration was seen in segments proximal to but not distal to the suture line. It is hypothesized that the different responses of the proximal and distal segments may be related to the different embryologic origins of those segments. It is also hypothesized that the seeding of the submucosa with epithelial cells during suturing may be a factor in tumor recurrence. Images Figure 19 Figure 20 Figure 21 Figure 22 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18

Barkla, D. H.; Tutton, P. J.

1985-01-01

12

Comparative morphology of interstitial cells of Cajal: ultrastructural characterization.  

PubMed

The shape, distribution, and ultrastructural features of interstitial cells of Cajal (ICC) of different tissue layers and organs of the rat and guinea-pig digestive tract were described and compared with the corresponding cells in other species including mice, dogs, and humans, as reported in the literature. By light microscopy, the best marker for ICC appeared to be immunoreactivity for c-Kit. Ultrastructurally, ICC were characterized by the presence of many mitochondria, bundles of intermediate filaments, and gap junctions, which linked ICC with each other. However, ICC were morphologically heterogeneous and had particular features, depending on their tissue and organ location and species. ICC in the deep muscular plexus of the small intestine and in the submuscular plexus of the colon were the most like smooth muscle cells, and had a distinct basal lamina and numerous caveolae. In contrast, ICC of Auerbach's plexus at all levels of the gastrointestinal tract were the least like smooth muscle cells. They most closely resembled unremarkable fibroblasts. ICC within the circular muscle layer were intermediate in form. In addition to the tissue specificity, some organ and species specificity could be distinguished. The structural differences between ICC may be determined by their microenvironment, including the effects of mechanical force, type of nerve supply, and spacial relationship with smooth muscle cells. PMID:10602287

Komuro, T

1999-11-15

13

Morphological characterization of Korean and Turkish watermelon germplasm1  

Microsoft Academic Search

A total of 67 watermelon accessions of Korean (37 accessions) and Turkish (27 accessions) germplasm and 3 accessions of other species were characterized for morphological characteristics. The accessions were characterized according to UPOV descriptor list for 56 characters (6 seedling, 4 plant, 11 leaf, 5 flower, 23 fruit and 7 seed). Eight quantitative characters (hypocotyl length, cotyledon width, cotyledon length,

Y. C. Huh; I. Solmaz; N. Sari

14

Gastrointestinal morphological alterations in obese rats kept under hypercaloric diets.  

PubMed

Hypercaloric diets have been successfully used as experimental models of obesity. This work compared morphological characteristics of inferior gastrointestinal organs. The experiment lasted 10 weeks, during which the rats' food consumption, body weight, distance between the mouth and neck, distance between mouth and neck, distance between neck and tail, and abdominal circumference were evaluated weekly. After the sacrifice of the rats, 20 variables referring to inferior gastrointestinal morphology were assessed. The results comprised descriptive statistics of the data, analysis of main components, linear correlation, and t-tests. Significant differences were found between the two groups for the variables of abdominal circumference, retroperitoneal fat, ratio between retroperitoneal fat/animal weight, stomach weight, ratio between animal weight/intestine weight and mesentery/animal weight, length of small intestine, length of large intestine, and lateral line of the cecum. The data allow us to state that a hypercaloric diet can be responsible an increase in fat in the abdominal cavity as well as gastrointestinal morphological alterations, principally in stomach development. PMID:23807857

Nascimento, Raphael Castiglioni; Mabel, Haryanne; Queiroz, Bruna Nunes; Paresque, Roberta

2013-06-14

15

Gastrointestinal morphological alterations in obese rats kept under hypercaloric diets  

PubMed Central

Hypercaloric diets have been successfully used as experimental models of obesity. This work compared morphological characteristics of inferior gastrointestinal organs. The experiment lasted 10 weeks, during which the rats’ food consumption, body weight, distance between the mouth and neck, distance between mouth and neck, distance between neck and tail, and abdominal circumference were evaluated weekly. After the sacrifice of the rats, 20 variables referring to inferior gastrointestinal morphology were assessed. The results comprised descriptive statistics of the data, analysis of main components, linear correlation, and t-tests. Significant differences were found between the two groups for the variables of abdominal circumference, retroperitoneal fat, ratio between retroperitoneal fat/animal weight, stomach weight, ratio between animal weight/intestine weight and mesentery/animal weight, length of small intestine, length of large intestine, and lateral line of the cecum. The data allow us to state that a hypercaloric diet can be responsible an increase in fat in the abdominal cavity as well as gastrointestinal morphological alterations, principally in stomach development.

Nascimento, Raphael Castiglioni; Mabel, Haryanne; Queiroz, Bruna Nunes; Paresque, Roberta

2013-01-01

16

Isolation and characterization of rat alveolar bone cells.  

PubMed

Samples of rat alveolar bone were first treated by collagenase digestion and then used as explants for cell culture. The cells obtained were subcultured and characterized by morphological and functional criteria. Their alkaline phosphatase activity was increased after incubation in 1,25-(OH)2 vitD3 10(-8) M whereas with gingival cells it did not change. The bone derived-cells organized nodular structures, synthesized type I collagen, Gla-protein, few type III collagen, and fibronectin. In the defined culture conditions no mineralization was observed. However, the method used allows to obtain cells from rat alveolar bone displaying some features of the osteoblastic phenotype. PMID:1657392

Bouvier, M; Couble, M L; Hartmann, D J; Magloire, H

1991-01-01

17

Morphological Characterization of High Performance Polymer Fibers Via SAXS Technique  

Microsoft Academic Search

Two-dimensional small-angle X-ray scattering (SAXS) method is frequently used to characterize the morphology of high performance semicrystalline polymer fibers such as polyaramids and polyimides. These systems usually exhibit only an elongated diffuse scattering profile along the equator. We have evaluated several two-dimensional analysis techniques to extract morphological variables (sizes of the anisotropic domain and misorientation) from the 2-D SAXS data.

Benjamin Hsiao; Amit Biswas; Malcolm Capel; Stephen Cheng

1996-01-01

18

Characterizing titanium powder: morphology, flow and segregation  

NASA Astrophysics Data System (ADS)

Powder metallurgy manufacturing with titanium could achieve near-net shape for parts with high strength-to-weight ratio. However, pure titanium (Ti) powders have large aspect ratios that prevent smooth flow. Features of Ti powder were examined experimentally to understand its limited flowability. The surface morphology was measured using a SEM for both raw powder as well as those made ``uniform'' via milling. The poly-disperse mixture had particle sizes between 45--700 ?m, of which a significant concentration were <45?m, which results in a very steep and unsteady angle of repose when the powder was placed in a rotating tumbler. The flat surface and steady flow typical of macroscopic particles is not present, but instead has slumping motion as material piles up and collapses intermittently. Spectral analysis indicates that increasing Froude number causes the slumping behavior to move to higher frequencies, but spread over a larger range. Size segregation causes porous streaks to form at the periphery of the tumbler where the angular separation of the streaks decreases with increasing Froude number. The overall conclusion is that more narrow ranges of particle size are necessary to yield usable titanium in powder metallurgy manufacturing.

Pohlman, Nicholas A.; Roberts, John A.; Gonser, Matthew

2011-11-01

19

Morphologic effects of cysteamine on the rat adenohypophysis  

SciTech Connect

In pituitary lactotrophs of female Sprague-Dawley rats given cysteamine (300 mg/kg, per os/day) for 7 days, forming granules were increased in number and contained many separate electron-dense structures suggesting crinophagy. Compared to control values, cysteamine treatment caused no change in blood prolactin (PRL) levels, measured by radioimmunoassay (RIA). 17 beta-Estradiol (50 micrograms, sc/day) for 7 days, induced lactotroph hyperplasia and increased blood PRL levels which were unaffected by simultaneous cysteamine administration. The ultrastructural changes did not reflect those due to bromocriptine suppression of secretory activity, and supported the concept that cysteamine altered lactotroph morphology by an unknown mechanism. In pituitary gonadotrophs following cysteamine treatment, increased electron lucency of luminal contents of dilated rough endoplasmic reticulum was noted; however, blood luteinizing hormone (LH) levels did not differ from those of control values. In ovariectomized rats, cysteamine suppressed castration cell formation and reduced blood LH levels, suggesting an interference with the cell's ability to respond to GnRH stimulation. The morphologic effects of cysteamine appeared to be selective to lactotrophs and gonadotrophs, and were not secondary to vascular impairment, as capillary endothelial cells were undamaged.

Cairns, P.D.; McComb, D.J.; Horvath, E.; Kovacs, K.; Milligan, J.V.; Szabo, S.

1984-12-01

20

Polarized light scattering technique for morphological characterization of waterborne pathogens  

Microsoft Academic Search

We have recently developed an elliptically polarized light scattering (EPLS) technique to characterize the morphology of fine particles suspended in an optically non-absorbing medium such as water. This technique provides the size distribution, shape and agglomeration characteristics of suspended particles. This technique can be used to detect various types of biological pathogens such as bacteria, protozoa and viruses in potable

Venkat V. Devarakonda; Sivakumar Manickavasagam

2009-01-01

21

Lamellar diblock copolymer grain boundary morphology. 1. Twist boundary characterization  

Microsoft Academic Search

Grain boundary morphologies in poly(styrene-b-butadiene) lamellar diblock copolymers were characterized using transmission electron microscopy (TEM). Two types of twist grain boundaries were observed in which microphase separation of the two blocks was maintained in the grain boundary region by intermaterial dividing surfaces that approximate classically known minimal surfaces. The geometry of these interfaces was demonstrated by comparing experimental TEM images

Samuel P. Gido; Janelle Gunther; Edwin L. Thomas; David Hoffman

1993-01-01

22

Characterization of the Han:SPRD rat model for hereditary polycystic kidney disease  

Microsoft Academic Search

Characterization of the Han:SPRD rat model for hereditary polycystic kidney disease. The Han:SPRD rat model for inherited polycystic kidney disease (PKD) was characterized (clinical parameters, morphology, immunohistochemistry and in situ hybridization). Homozygous animals died of uremia after three to four weeks with severe cystic transformation of virtually all nephrons and collecting ducts (serum urea: 616 ± 195 mg\\/d1; kidney-to-body weight

Katrin Schäfer; Norbert Gretz; Michael Bader; Ilse Oberbäumer; Kai-Uwe Eckardt; Wilhelm Kriz; Sebastian Bachmann

1994-01-01

23

Morphological, Host Range, and Genetic Characterization of Two Coliphages  

Microsoft Academic Search

Two coliphages, AR1 and LG1, were characterized based on their morphological, host range, and genetic properties. Transmission electron microscopy showed that both phages belonged to the Myoviridae; phage particles of LG1 were smaller than those of AR1 and had an isometric head 68 nm in diameter and a complex contractile tail 111 nm in length. Transmission electron micrographs of AR1

Lawrence Goodridge; Alicia Gallaccio; Mansel W. Griffiths

2003-01-01

24

Differential morphological effects in rat corpora lutea among ethylene glycol monomethyl ether, atrazine, and bromocriptine.  

PubMed

Ethylene glycol monomethyl ether (EGME) or atrazine induces luteal cell hypertrophy in rats. Our previous study suggested that EGME stimulates both new and old corpora lutea (CL), while atrazine stimulates new CL. Bromocriptine (BRC) is known to suppress the luteolysis in rats. This study investigated the light- and electron-microscopic luteal changes induced by EGME, atrazine, or BRC. Female rats were treated with EGME (300 mg/kg/day), BRC (2 mg/kg/day), EGME and BRC (EGME + BRC), or atrazine (300 mg/kg/day) for 7 days. Luteal cell hypertrophy induced by EGME, EGME + BRC, and atrazine was subclassified into the following two types: CL hypertrophy, vacuolated type (CL-V) characterized by intracytoplasmic fine vacuoles, and CL hypertrophy, eosinophilic type (CL-E) characterized by eosinophilic and abundant cytoplasm. The proportions of CL-V and CL-E were different among the treatments. BRC-treated old CL showed lower proportion of endothelial cells and fibroblasts than normal old CL. Ultrastructural observation revealed that the luteal cells of CL-V contained abundant lipid droplets, whereas those of CL-E in EGME and EGME + BRC groups showed uniformly well-developed smooth endoplasmic reticulum. No clear ultrastructural difference was observed between the control CL and atrazine-treated CL-E. These results indicate that EGME, atrazine, and BRC have differential luteal morphological effects. PMID:23076038

Taketa, Yoshikazu; Inoue, Kaoru; Takahashi, Miwa; Yamate, Jyoji; Yoshida, Midori

2012-10-17

25

Lamellar diblock copolymer grain boundary morphology. 1. Twist boundary characterization  

SciTech Connect

Grain boundary morphologies in poly(styrene-b-butadiene) lamellar diblock copolymers were characterized using transmission electron microscopy (TEM). Two types of twist grain boundaries were observed in which microphase separation of the two blocks was maintained in the grain boundary region by intermaterial dividing surfaces that approximate classically known minimal surfaces. The geometry of these interfaces was demonstrated by comparing experimental TEM images with ray tracing computer simulations of the model surfaces as the projection direction was systematically varied in both the experimental and simulated images. The two morphologies observed were found to have intermaterial dividing surfaces that approximate either Scherk's first (doubly periodic) surface or a section of the right helicoid. The helicoid section boundary was observed at low twist angles, less than or equal to about 15. The Scherk surface family of boundary morphologies, which consists of a doubly periodic array of saddle surfaces, was found over the entire twist range from 0 to 90[degree]. As the twist angle approaches 0[degree] the Scherk surface grain boundary morphology is transformed into a single screw dislocation that has an intermaterial dividing surface with the geometry of a single helicoid. Direct TEM imaging of the detailed core structure of this screw dislocation is presented. These images demonstrate that in the lamellar diblock copolymer the screw dislocation core is nonsingular. This nonsingular core structure represents a radical departure from the singular core structures observed in classical studies of dislocations in atomic crystals.

Gido, S.P.; Gunther, J.; Thomas, E.L. (Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Materials Science and Engineering); Hoffman, D. (Univ. of Massachusetts, Amherst, MA (United States). Dept. of Mathematics and Statistics)

1993-08-16

26

Genomic Characterization of Human and Rat Prolactinomas  

PubMed Central

Although prolactinomas can be effectively treated with dopamine agonists, about 20% of patients develop dopamine resistance or tumor recurrence after surgery, indicating a need for better understanding of underlying disease mechanisms. Although estrogen-induced rat prolactinomas have been widely used to investigate the development of this tumor, the extent that the model recapitulates features of human prolactinomas is unclear. To prioritize candidate genes and gene sets regulating human and rat prolactinomas, microarray results derived from human prolactinomas and pituitaries of estrogen-treated ACI rats were integrated and analyzed. A total of 4545 differentially expressed pituitary genes were identified in estrogen-treated ACI rats [false discovery rate (FDR) < 0.01]. By comparing pituitary microarray results derived from estrogen-treated Brown Norway rats (a strain not sensitive to estrogen), 4073 genes were shown specific to estrogen-treated ACI rats. Human prolactinomas exhibited 1177 differentially expressed genes (FDR < 0.05). Combining microarray data derived from human prolactinoma and pituitaries of estrogen-treated ACI rat, 145 concordantly expressed genes, including E2F1, Myc, Igf1, and CEBPD, were identified. Gene set enrichment analysis revealed that 278 curated pathways and 59 gene sets of transcription factors were enriched (FDR < 25%) in estrogen-treated ACI rats, suggesting a critical role for Myc, E2F1, CEBPD, and Sp1 in this rat prolactinoma. Similarly increased Myc, E2F1, and Sp1 expression was validated using real-time PCR and Western blot in estrogen-treated Fischer rat pituitary glands. In summary, characterization of individual genes and gene sets in human and in estrogen-induced rat prolactinomas validates the model and provides insights into genomic changes associated with this commonly encountered pituitary tumor.

Tong, Yunguang; Zheng, Yun; Zhou, Jin; Oyesiku, Nelson M.; Koeffler, H. Phillip

2012-01-01

27

Morphological and molecular characterization of adult midgut compartmentalization in Drosophila.  

PubMed

Although the gut is a central organ of Eumetazoans and is essential for organismal health, our understanding of its morphological and molecular determinants remains rudimentary. Here, we provide a comprehensive atlas of Drosophila adult midgut. Specifically, we uncover a fine-grained regional organization consisting of 14 subregions with distinct morphological, histological, and genetic properties. We also show that Drosophila intestinal regionalization is defined after adult emergence, remains stable throughout life, and reestablishes following acute tissue damage. Additionally, we show that this midgut compartmentalization is achieved through the interplay between pan-midgut and regionalized transcription factors, in concert with spatial activities of morphogens. Interestingly, disruption of the midgut compartmentalization leads to a loss of intestinal homeostasis characterized by an increase in stem cell proliferation and aberrant immune responses. Our integrative analysis of Drosophila midgut compartmentalization provides insights into the conserved mechanisms underlying intestinal regionalization in metazoans. PMID:23643535

Buchon, Nicolas; Osman, Dani; David, Fabrice P A; Fang, Hsiao Yu; Boquete, Jean-Philippe; Deplancke, Bart; Lemaitre, Bruno

2013-05-02

28

The Morphology of the Rat Vibrissal Array: A Model for Quantifying Spatiotemporal Patterns of Whisker-Object Contact  

PubMed Central

In all sensory modalities, the data acquired by the nervous system is shaped by the biomechanics, material properties, and the morphology of the peripheral sensory organs. The rat vibrissal (whisker) system is one of the premier models in neuroscience to study the relationship between physical embodiment of the sensor array and the neural circuits underlying perception. To date, however, the three-dimensional morphology of the vibrissal array has not been characterized. Quantifying array morphology is important because it directly constrains the mechanosensory inputs that will be generated during behavior. These inputs in turn shape all subsequent neural processing in the vibrissal-trigeminal system, from the trigeminal ganglion to primary somatosensory (“barrel”) cortex. Here we develop a set of equations for the morphology of the vibrissal array that accurately describes the location of every point on every whisker to within ±5% of the whisker length. Given only a whisker's identity (row and column location within the array), the equations establish the whisker's two-dimensional (2D) shape as well as three-dimensional (3D) position and orientation. The equations were developed via parameterization of 2D and 3D scans of six rat vibrissal arrays, and the parameters were specifically chosen to be consistent with those commonly measured in behavioral studies. The final morphological model was used to simulate the contact patterns that would be generated as a rat uses its whiskers to tactually explore objects with varying curvatures. The simulations demonstrate that altering the morphology of the array changes the relationship between the sensory signals acquired and the curvature of the object. The morphology of the vibrissal array thus directly constrains the nature of the neural computations that can be associated with extraction of a particular object feature. These results illustrate the key role that the physical embodiment of the sensor array plays in the sensing process.

Gopal, Venkatesh; Solomon, Joseph H.; Hartmann, Mitra J. Z.

2011-01-01

29

Synthesis and morphology characterization of polydimethylsiloxane-containing block copolymers  

NASA Astrophysics Data System (ADS)

The thin film morphology characteristics of polydimethylsiloxane-containing block copolymers have been investigated. For this investigation, a commercially available hydroxyl terminated PDMS was purchased from Gelest and attached to a carboxylic acid functional reversible addition-fragmentation chain transfer (RAFT) agent by Steglich esterification. This produced macro-RAFT agents to which styrene monomer was polymerized. By using this approach the generation of low polydispersity polystyrene-block-polydimethylsiloxane (PS-block-PDMS) copolymers of various molecular weights spanning a wide volume fraction range in which the PDMS block remained the same in each polymerization. Synthesized block copolymers were characterized by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. Bulk and thin film characterization of PS-block-PDMS copolymers was done by small-angle x-ray scattering (SAXS), transmission electron microscopy (TEM), contact angle measurements, scanning force microscopy (SFM), and grazing incidence small-angle X-ray scattering (GISAXS). The following observations have been made. For PS-rich PS-block -PDMS copolymer thin films the low surface tension of PDMS caused it to migrate to the film surface regardless of solvent choice. The surface morphology was found to depend strongly on the solubility parameter of the solvent and exhibited SFM images consistent with parallel cylinder, perforated lamellar, and lamellar surface layers with increasing solvent solubility parameter. This behavior was due to the selective swelling of the individual blocks under slightly selective, good solvent conditions. A custom solvent annealing apparatus provided similar results in which order-order transitions in the thin films were observed with increasing solvent solubility parameter. Additionally improvements in the long-range order were observed after 1 h of solvent annealing. PS-rich PS-block-PDMS copolymer thin films also displayed PDMS rich surfaces after casting. Etching of this wetting layer by exposure to ultraviolet/ozone (UVO) cleaner allowed characterization of the interior film morphology. GISAXS was also able to characterize domain orientation in the as-cast and selectively etched thin films. PDMS cylinder orientation in PS-block-PDMS copolymer was found to be dependent on solvent choice and polymer molecular weight. The likely mechanism for perpendicularly oriented PDMS cylinders in selective solvents was an order-order transition to spheres where cylinders would nucleate at the air/film surface and template a perpendicularly oriented morphology during evaporation induced ordering. Perpendicularly oriented PDMS cylinders were observed in the lower molecular weight PS-rich PS- block-PDMS thin film samples indicating a preferential molecular weight range for the formation of perpendicular domains. Solvent annealing in PS selective chlorobenzene improved the long range order, but was not a strong driving force in altering domain orientation.

Wadley, Maurice

30

Divergent projections of physiologically characterized rat ventral cochlear nucleus neurons as shown by intra-axonal injection of horseradish peroxidase  

Microsoft Academic Search

An attempt was made to correlate electrophysiological and morphological characteristics of rat ventral cochlear nucleus neurons. Their axonal course and their soma morphology were investigated using the intra-axonal horseradish peroxidase method. Prior to labeling, neurons were characterized by recording their response patterns to acoustic stimulation with pure tones. Three types of cells were found: Category I (37 neurons) exhibited “primarylike”

E. Friauf; J. Ostwald

1988-01-01

31

Characterizing a rat Brca2 knockout model  

Microsoft Academic Search

Evidence exists that BRCA2 carriers may have an elevated risk of breast, ovarian, colon, prostate, and pancreatic cancer. In general, carriers are defined as individuals with protein truncating mutations within the BRCA2 gene. Many Brca2 knockout lines have been produced and characterized in the mouse. We previously produced a rat Brca2 knockout strain in which there is a nonsense mutation

M S Cotroneo; J D Haag; Y Zan; C C Lopez; P Thuwajit; G V Petukhova; R D Camerini-Otero; A Gendron-Fitzpatrick; A E Griep; C J Murphy; R R Dubielzig; M N Gould

2007-01-01

32

Structural characterization of semicrystalline polymer morphologies by imaging-SANS  

NASA Astrophysics Data System (ADS)

Control and optimization of polymer properties require the global knowledge of the constitutive microstructures of polymer morphologies in various conditions. The microstructural features can be typically explored over a wide length scale by combining pinhole-, focusing- and ultra-small-angle neutron scattering (SANS) techniques. Though it proved to be a successful approach, this involves major efforts related to the use of various scattering instruments and large amount of samples and the need to ensure the same crystallization kinetics for the samples investigated at various facilities, in different sample cell geometries and at different time intervals. With the installation and commissioning of the MgF2 neutron lenses at the KWS-2 SANS diffractometer installed at the Heinz Maier-Leibnitz neutron source (FRMII reactor) in Garching, a wide Q-range, between 10-4Å-1 and 0.5Å-1, can be covered at a single instrument. This enables investigation of polymer microstructures over a length scale from lnm up to 1?m, while the overall polymer morphology can be further examined up to 100?m by optical microscopy (including crossed polarizers). The study of different semi-crystalline polypropylene-based polymers in solution is discussed and the new imaging-SANS approach allowing for an unambiguous and complete structural characterization of polymer morphologies is presented.

Radulescu, A.; Fetters, L. J.; Richter, D.

2012-02-01

33

First morphological characterization of 'Candidatus Mycoplasma turicensis' using electron microscopy  

PubMed Central

At least three haemotropic mycoplasmas have been recognized in cats: Mycoplasma haemofelis (Mhf), ‘Candidatus Mycoplasma haemominutum’ (CMhm) and ‘Candidatus M. turicensis’ (CMt). The latter was originally identified in a Swiss pet cat with haemolytic anaemia and shown to be prevalent in domestic cats and wild felids worldwide using molecular methods. So far, there has been no confirmatory morphological evidence of the existence of CMt presumably due to low blood loads during infection while CMhm has only been characterized by light microscopy with discrepant results. This study aimed to provide for the first time electron microscopic characteristics of CMt and CMhm and to compare them to Mhf. Blood samples from cats experimentally infected with CMt, CMhm and Mhf were used to determine copy numbers in blood by real-time PCR and for transmission and scanning electron microscopy. High resolution scanning electron microscopy revealed CMt and CMhm to be discoid-shaped organisms of 0.3 ?m in diameter attached to red blood cells (RBCs). In transmission electron microscopy of CMt, an oval organism of about 0.25 ?m with several intracellular electron dense structures was identified close to the surface of a RBC. CMhm and CMt exhibited similar morphology to Mhf but had a smaller diameter. This is the first study to provide morphological evidence of CMt thereby confirming its status as a distinct haemoplasma species, and to present electron microscopic features of CMhm.

Willi, Barbara; Museux, Kristina; Novacco, Marilisa; Schraner, Elisabeth M.; Wild, Peter; Groebel, Katrin; Ziegler, Urs; Wolf-Jackel, Godelind A.; Kessler, Yvonne; Geret, Catrina; Tasker, Severine; Lutz, Hans; Hofmann-Lehmann, Regina

2011-01-01

34

Morphological and cytohistochemical evaluation of renal effects of cadmium-doped silica nanoparticles given intratracheally to rat  

NASA Astrophysics Data System (ADS)

Renal morphological parameters were determined in rats intratracheally instilled with model cadmium-containing silica nanoparticles (Cd-SiNPs, 1mg/rat), also exploring whether their potential modifications would be associated with toxicogenomic changes. Cd-SiNP effects, evaluated 7 and 30 days post-exposure, were assessed by (i) histopathology (Haematoxylin/Eosin Staining), (ii) characterization of apoptotic features by TUNEL staining. Data were compared with those obtained by CdCl2 (400?g/rat), SiNPs (600?g/rat), 0.1 ml saline. Area-specific cell apoptosis was observed in all treatment groups: cortex and inner medulla were the most affected regions. Apoptotic changes were apparent at 7 days post-exposure in both areas, and were still observable in inner medulla 30 days after treatment. Increase in apoptotic frequency was more pronounced in Cd-SiNP-treated animals compared to either CdCl2 or SiNPs. Histological findings showed comparable alterations in the renal glomerular (cortex) architecture occurring in all treatment groups at both time-points considered. The glomeruli appeared often collapsed, showing condensed, packed mesangial and endothelial cells. Oedematous haemorrhagic glomeruli were also observed in Cd-SiNPs-treated animals. Bare SiNPs caused morphological and apoptotic changes without modifying the renal gene expression profile. These findings support the concept that multiple assays and an integrated testing strategy should be recommended to characterize toxicological responses to nanoparticles in mammalian systems.

Coccini, T.; Roda, E.; Barni, S.; Manzo, L.

2013-04-01

35

Morphological comparisons between outer and inner ramifying alpha cells of the albino rat retina  

Microsoft Academic Search

The somato-dendritic morphologies of large ganglion cells were studied by intracellular injections of Lucifer yellow in perfusedin vitro preparations of the albino rat retina. The ganglion cells were prelabeled with retrogradely transported granular blue or labeled with acridine orange dropped into the perfusate ofin vitro preparations. After the dye injection, somato-dendritic morphologies were successfully studied for 210 cells, the majority

M. Tauchi; K. Morigiwa; Y. Fukuda

1992-01-01

36

Morphological, Host Range, and Genetic Characterization of Two Coliphages  

PubMed Central

Two coliphages, AR1 and LG1, were characterized based on their morphological, host range, and genetic properties. Transmission electron microscopy showed that both phages belonged to the Myoviridae; phage particles of LG1 were smaller than those of AR1 and had an isometric head 68 nm in diameter and a complex contractile tail 111 nm in length. Transmission electron micrographs of AR1 showed phage particles consisting of an elongated isometric head of 103 by 74 nm and a complex contractile tail 116 nm in length. Both phages were extensively tested on many strains of Escherichia coli and other enterobacteria. The results showed that both phages could infect many serotypes of E. coli. Among the enterobacteria, Proteus mirabilis, Shigella dysenteriae, and two Salmonella strains were lysed by the phages. The genetic material of AR1 and LG1 was characterized. Phage LG1 had a genome size of 49.5 kb compared to 150 kb for AR1. Restriction endonuclease analysis showed that several restriction enzymes could degrade DNA from both phages. The morphological, genome size, and restriction endonuclease similarities between AR1 and phage T4 were striking. Southern hybridizations showed that AR1 and T4 are genetically related. The wide host ranges of phages AR1 and LG1 suggest that they may be useful as biocontrol, therapeutic, or diagnostic agents to control and detect the prevalence of E. coli in animals and food.

Goodridge, Lawrence; Gallaccio, Alicia; Griffiths, Mansel W.

2003-01-01

37

Morphological Characterization of the Polyflux 210H Hemodialysis Filter Pores  

PubMed Central

Background. Morphological characterization of hemodialysis membranes is necessary to improve pore design. Aim. To delineate membrane pore structure of a high flux filter, Polyflux 210H. Methods. We used a Joel JSM-6010LV scanning electron microscope (SEM) and a SU6600 Hitachi field emission scanning electron microscope (FESEM) to characterize the pore and fiber morphology. The maximal diameters of selected uremic toxins were calculated using the macromolecular modeling Crystallographic Object-Oriented Toolkit (COOT) software. Results. The mean pore densities on the outermost and innermost surfaces of the membrane were 36.81% and 5.45%, respectively. The membrane exhibited a tortuous structure with poor connection between the inner and outer pores. The aperture's width in the inner surface ranged between 34 and 45?nm, which is 8.76–11.60 times larger than the estimated maximum diameter of ?2-microglobulin (3.88?nm). Conclusion. The results suggest that the diameter size of inner pore apertures is not a limiting factor to middle molecules clearance, the extremely diminished density is. Increasing inner pore density and improving channel structure are strategies to improve clearance of middle molecules.

Hedayat, A.; Szpunar, J.; Kumar, N. A. P. Kiran; Peace, R.; Elmoselhi, H.; Shoker, A.

2012-01-01

38

The effects of creatine long-term supplementation on muscle morphology and swimming performance in rats  

Microsoft Academic Search

Creatine (Cr) has been shown to increase the total muscle mass. The purpose of this study was to investigate the effect of Cr supplementation on muscle morphology and swimming performance, using an animal model. Each rat was subjected to exercise 15-minute period daily for the 12 weeks. The rats were randomly divided into four groups: no Cr supplementation (CON), no

Ahmet Yildiz; Ercan Ozdemir; Sefa Gulturk; Sena Erdal

2009-01-01

39

Restoration of mechanical strength and morphological features of the periodontal ligament following orthodontic retention in the rat mandibular first molar  

Microsoft Academic Search

SUMMARY Biomechanical properties and morphological features of the periodontal ligament (PDL) in the rat mandibular molars were examined during orthodontic retention. Seventy-three male rats of the Wistar strain, 8 weeks of age, were used for biomechanical analysis and six rats for morphological analysis. An elastic band was inserted between the mandibular first and second molars for 4 days; after removal

Tadayoshi Fukui; Akira Yamane; Koichiro Komatsu; Mototsugu Chiba

40

Endotoxin alters biochemical and morphological responses to pneumonectomy in adult rats.  

PubMed

Adult rats treated with endotoxin, like untreated neonatal rats, are resistant to O2 toxicity and manifest very similar lung biochemical responses. We hypothesized that endotoxin might also alter the adult pneumonectomy response to resemble the accelerated response of younger animals. Adult and 19-day rats underwent pneumonectomy, followed in 24 h by endotoxin or saline injection. Pneumonectomized rats, shams, and controls were killed 72 h after surgery for lung biochemistry and morphometry. Compared with adult saline-pneumonectomized rats, adult endotoxin-pneumonectomized rats, adult endotoxin-pneumonectomized rats demonstrated a significantly greater growth response and a lung biochemical response pattern (increased RNA, markedly increased RNA/DNA) similar to 19-day rats. Morphologically, endotoxin-pneumonectomized rats showed a different pattern of lung regrowth (significantly larger air spaces). Saline pressure-volume curves were not different between the two groups. We conclude that endotoxin administration to pneumonectomized adult rats resulted in accelerated lung regrowth, a lung biochemical response pattern similar to 19-day rats, but a paradoxical morphological pattern resembling more closely that of the adult than the neonatal animal. PMID:2409822

Sosenko, I R; Frank, L

1985-07-01

41

Physiological, Morphological and Neurochemical Characterization of Neurons Modulated by Movement  

PubMed Central

The role of individual neurons and their function in neuronal circuits is fundamental to understanding the neuronal mechanisms of sensory and motor functions. Most investigations of sensorimotor mechanisms rely on either examination of neurons while an animal is static1,2 or record extracellular neuronal activity during a movement.3,4 While these studies have provided the fundamental background for sensorimotor function, they either do not evaluate functional information which occurs during a movement or are limited in their ability to fully characterize the anatomy, physiology and neurochemical phenotype of the neuron. A technique is shown here which allows extensive characterization of individual neurons during an in vivo movement. This technique can be used not only to study primary afferent neurons but also to characterize motoneurons and sensorimotor interneurons. Initially the response of a single neuron is recorded using electrophysiological methods during various movements of the mandible followed by determination of the receptive field for the neuron. A neuronal tracer is then intracellularly injected into the neuron and the brain is processed so that the neuron can be visualized with light, electron or confocal microscopy (Fig. 1). The detailed morphology of the characterized neuron is then reconstructed so that neuronal morphology can be correlated with the physiological response of the neuron (Figs. 2,3). In this communication important key details and tips for successful implementation of this technique are provided. Valuable additional information can be determined for the neuron under study by combining this method with other techniques. Retrograde neuronal labeling can be used to determine neurons with which the labeled neuron synapses; thus allowing detailed determination of neuronal circuitry. Immunocytochemistry can be combined with this method to examine neurotransmitters within the labeled neuron and to determine the chemical phenotypes of neurons with which the labeled neuron synapses. The labeled neuron can also be processed for electron microscopy to determine the ultrastructural features and microcircuitry of the labeled neuron. Overall this technique is a powerful method to thoroughly characterize neurons during in vivo movement thus allowing substantial insight into the role of the neuron in sensorimotor function.

Dessem, Dean

2011-01-01

42

Spectroscopic and morphologic characterization of the dentin/adhesive interface  

NASA Astrophysics Data System (ADS)

The potential environmental risks associated with mercury release have forced many European countries to ban the use of dental amalgam. Alternative materials such as composite resins do not provide the clinical function for the length of time characteristically associated with dental amalgam. The weak link in the composite restoration is the dentin/adhesive bond. The purpose of this study was to correlate morphologic characterization of the dentin/adhesive bond with chemical analyses using micro- Fourier transform infrared and micro-Raman spectroscopy. A commercial dental adhesive was placed on dentin substrates cut from extracted, unerupted human third molars. Sections of the dentin/adhesive interface were investigated using infrared radiation produced at the Aladdin synchrotron source; visible radiation from a Kr+ laser was used for the micro-Raman spectroscopy. Sections of the dentin/adhesive interface, differentially stained to identify protein, mineral, and adhesive, were examined using light microscopy. Due to its limited spatial resolution and the unknown sample thickness the infrared results cannot be used quantitatively in determining the extent of diffusion. The results from the micro-Raman spectroscopy and light microscopy indicate exposed protein at the dentin/adhesive interface. Using a laser that reduces background fluorescence, the micro-Raman spectroscopy provides quantitative chemical and morphologic information on the dentin/adhesive interface. The staining procedure is sensitive to sites of pure protein and thus, complements the Raman results.

Lemor, R. M.; Kruger, Michael B.; Wieliczka, David M.; Swafford, Jim R.; Spencer, Paulette

1999-01-01

43

Morphological and optical characterization of polyelectrolyte multilayers incorporating nanocrystalline cellulose.  

PubMed

Aqueous layer-by-layer (LbL) processing was used to create polyelectrolyte multilayer (PEM) nanocomposites containing cellulose nanocrystals and poly(allylamine hydrochloride). Solution-dipping and spin-coating assembly methods gave smooth, stable, thin films. Morphology was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM), and film growth was characterized by X-ray photoelectron spectroscopy (XPS), ellipsometry, and optical reflectometry. Relatively few deposition cycles were needed to give full surface coverage, with film thicknesses ranging from 10 to 500 nm. Films prepared by spin-coating were substantially thicker than solution-dipped films and displayed radial orientation of the rod-shaped cellulose nanocrystals. The relationship between film color and thickness is discussed according to the principles of thin film interference and indicates that the iridescent properties of the films can be easily tailored in this system. PMID:16961313

Cranston, Emily D; Gray, Derek G

2006-09-01

44

Detailed characterization of PBX morphology for mesoscale simulations  

NASA Astrophysics Data System (ADS)

Plastic-Bonded Explosives (PBXs) are composed of energetic grains embedded in a polymeric binder. The heterogeneity at this material scale serves to localize energy during deformation, determining damage and hot spot development leading to reaction. Accurate determination of PBX morphology is needed to characterize and understand these materials, and is essential input for mesoscale simulations. X-ray microtomography was used to determine the threedimensional x-ray cross-section of a mock explosive for which all formulation details are known. Specialized image processing routines were used to identify individual features (voids, grains, binder). Mass fractions, void content, and grain size statistics were compared with the formulation. The quantity of material needed to accurately represent the mesostructure in simulations, i.e. representative volume element size, was determined, as well as grain on grain contact density, which may correlate with sensitivity. Preliminary results from computations using these mesostructures will be reported.

Bardenhagen, Scott Gary; Luo, Huiyang; Armstrong, Ronald W.; Lu, Hongbing

2012-03-01

45

Detailed Characterization of PBX Morphology for Mesoscale Simulations  

NASA Astrophysics Data System (ADS)

Plastic-Bonded Explosives (PBXs) are composed of energetic grains embedded in a polymeric binder. The heterogeneity at this material scale serves to localize energy during deformation, determining damage and hot spot development leading to reaction. Accurate determination of PBX morphology is needed to characterize and understand these materials, and is essential input for mesoscale simulations. X-ray microtomography was used to determine the three-dimensional x-ray cross-section of a mock explosive for which all formulation details are known. Specialized image processing routines were used to identify individual features (voids, grains, binder). Mass fractions, void content, and grain size statistics were compared with the formulation. The quantity of material needed to accurately represent the mesostructure in simulations, i.e. representative volume element size, was determined, as well as grain on grain contact density, which may correlate with sensitivity. Preliminary results from computations using these mesostructures will be reported.

Bardenhagen, Scott; Luo, Huiyang; Lu, Hongbing; Armstrong, Ronald

2011-06-01

46

Skin morphology and its role in thermoregulation in mole-rats, Heterocephalus glaber and Cryptomys hottentotus  

PubMed Central

The skin structure of 2 Bathyergid rodents, the naked mole-rat (Heterocephalus glaber) and the common mole-rat (Cryptomys hottentotus) is compared, to investigate whether thermoregulatory differences may be attributed to different skin features. Histological and ultrastructural studies of the dorsal skin of these closely related species show morphological and structural similarities but differences in the degree of skin folding, thickness of the integument and dermal infrastructure were evident. The skin of the common mole-rat conforms with expected morphological/histological arrangements that are commonly found in mammalian skin. Many features of the skin of the naked mole-rat, such as the lack of an insulating layer and the loosely folded morphological arrangement contribute to poikilothermic responses to changing temperatures of this mammal. Further evidence for poikilothermy in the naked mole-rat is indicated by the presence of pigment containing cells in the dermis, rather than the epidermis, as commonly occurs in homeotherms. Lack of fur is compensated by a thicker epidermal layer and a marked reduction in sweat glands. Differences in skin morphology thus contribute substantially to the different thermoregulatory abilities of the 2 Bathyergids. The skin morphology is related to the poor thermoinsulatory ability of the animals while simultaneously facilitating heat transfer from the environment to the animal by thigmothermy and/or other behavioural means.

DALY, T. JOSEPH M.; BUFFENSTEIN, ROCHELLE

1998-01-01

47

Restoration of corpus luteum angiogenesis in immature hypothyroid rdw rats after thyroxine treatment: morphologic and molecular evidence.  

PubMed

Thyroxine (T4) plus gonadotropins might stimulate ovarian follicular angiogenesis in immature infertile hypothyroid rdw rats by upregulating mRNA expression of major angiogenic factors. Development of growing corpus luteum (CL) is strongly related to angiogenesis and to morphofunctional development of microcirculation. Our aim was to investigate if T4 is involved in CL angiogenesis and in the activation of capillary cells and angiogenic factors after ovulation in a spontaneous model of hypothyroidism, the rdw rat. Rdw rats were treated with T4 plus gonadotropins (equine chorionic gonadotropin plus human chorionic gonadotropin; eCG+hCG) or gonadotropins alone in order to evaluate the effects of T4 on early luteal angiogenesis, on microvascular cells and on expression of major growth factors which are involved in the regulation of angiogenesis. Wistar-Imamichi rats treated with gonadotropins were used as controls. The ovaries were collected 4 days after hCG administration and analyzed using morphologic and molecular approaches. Thyroxine plus gonadotropins stimulated the growth of CLs and follicles as in controls, differently from rdw rats treated only with gonadotropins, in which CLs were not found and only small follicles, often atretic, could be recognized. In T4 plus gonadotropin-treated rdw rats CLs showed increased microvasculature, numerous activated capillaries characterized by sprouting and other angiogenic figures, and associated pericytes. Quantitative analysis revealed that the number of pericytes in T4 plus gonadotropin-treated rdw rats was comparable with that found in control rats and was significantly higher than that found in gonadotropin-treated rdw rats. The mRNA expression of vascular endothelial growth factor and basic fibroblast growth factor was significantly higher in control rats and in T4 plus gonadotropin-treated rdw rats than in gonadotropin-treated rdw rats. mRNA expression of tumor necrosis factor ?, transforming growth factor ?, and epidermal growth factor did not show significant changes. Our data originally demonstrated that T4 promoted the growth of an active microcirculation in developing CLs of gonadotropin-primed hypothyroid rdw rats, mainly by inducing sprouting angiogenesis, pericyte recruitment, and upregulation of mRNA expression of vascular endothelial growth factor and basic fibroblast growth factor. In conclusion, we suggest that T4 plays a key role in restoring luteal angiogenesis in ovaries of immature hypothyroid rdw rats. PMID:23122683

Macchiarelli, Guido; Palmerini, Maria Grazia; Nottola, Stefania Annarita; Cecconi, Sandra; Tanemura, Kentaro; Sato, Eimei

2012-11-02

48

Distribution and morphology of nitrergic neurons across functional domains of the rat primary somatosensory cortex  

PubMed Central

The rat primary somatosensory cortex (S1) is remarkable for its conspicuous vertical compartmentalization in barrels and septal columns, which are additionally stratified in horizontal layers. Whereas excitatory neurons from each of these compartments perform different types of processing, the role of interneurons is much less clear. Among the numerous types of GABAergic interneurons, those producing nitric oxide (NO) are especially puzzling, since this gaseous messenger can modulate neural activity, synaptic plasticity, and neurovascular coupling. We used a quantitative morphological approach to investigate whether nitrergic interneurons, which might therefore be considered both as NO volume diffusers and as elements of local circuitry, display features that could relate to barrel cortex architecture. In fixed brain sections, nitrergic interneurons can be revealed by histochemical processing for NADPH-diaphorase (NADPHd). Here, the dendritic arbors of nitrergic neurons from different compartments of area S1 were 3D reconstructed from serial 200 ?m thick sections, using 100x objective and the Neurolucida system. Standard morphological parameters were extracted for all individual arbors and compared across columns and layers. Wedge analysis was used to compute dendritic orientation indices. Supragranular (SG) layers displayed the highest density of nitrergic neurons, whereas layer IV contained nitrergic neurons with largest soma area. The highest nitrergic neuronal density was found in septa, where dendrites were previously characterized as more extense and ramified than in barrels. Dendritic arbors were not confined to the boundaries of the column nor layer of their respective soma, being mostly double-tufted and vertically oriented, except in SG layers. These data strongly suggest that nitrergic interneurons adapt their morphology to the dynamics of processing performed by cortical compartments.

Nogueira-Campos, Anaelli A.; Finamore, Deborah M.; Imbiriba, Luis A.; Houzel, Jean C.; Franca, Joao G.

2012-01-01

49

Facet Model and Mathematical Morphology for Surface Characterization  

SciTech Connect

This paper describes an algorithm for the automatic segmentation and representation of surface structures and non-uniformities in an industrial setting. The automatic image processing and analysis algorithm is developed as part of a complete on-line web characterization system of a papermaking process at the wet end. The goal is to: (1) link certain types of structures on the surface of the web to known machine parameter values, and (2) find the connection between detected structures at the beginning of the line and defects seen on the final product. Images of the pulp mixture (slurry), carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. This characterization algorithm succeeded where conventional contrast and edge detection techniques failed due to a poorly controlled environment. The images obtained have poor contrast and contain noise caused by a variety of sources. After a number of enhancement steps, conventional segmentation methods still f ailed to detect any structures and are consequently discarded. Techniques tried include the Canny edge detector, the Sobel, Roberts, and Prewitt's filters, as well as zero crossings. The facet model algorithm, is then applied to the images with various parameter settings and is found to be successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image computed. Carefully tailored morphological operators are then applied to detect and segment regions of interest. Those regions are then selected according to their size, elongation, and orientation. Their bounding rectangles are computed and represented. Also addressed in this paper are aspects of the real time implementation of this algorithm for on-line use. The algorithm is tested on over 500 images of slurry and is found to segment and characterize nonuniformities on all 500 images.

Abidi, B.R.; Goddard, J.S.; Hunt, M.A.; Sari-Sarraf, H.

1999-11-13

50

Morphological study of the mammalian stress response: characterization of changes in cytoplasmic organelles, cytoskeleton, and nucleoli, and appearance of intranuclear actin filaments in rat fibroblasts after heat-shock treatment  

Microsoft Academic Search

Using both electron microscopy and immunological methods, we have character- ized a number of changes occurring in rat fibroblasts after heat-shock treatment. Incubation of the cells for 3 h at 42°-43°C resulted in a number of changes within the cytoplasm including: a disruption and fragmentation of the Golgi complex; a modest swelling of the mitochondria and subtle alterations in the

WILLIAM I. WELCH; JOSEPH P. SUHAN

1985-01-01

51

Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats  

Microsoft Academic Search

BACKGROUND: Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats. METHODS: Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of

Kivanc Akca; Ebru Sarac; Ugur Baysal; Mete Fanuscu; Ting-Ling Chang; Murat Cehreli

2007-01-01

52

Biochemical and morphological characterization of mycobacteriophage R1.  

PubMed Central

Large-scale propagation of mycobacteriophage R1 in broth culture has allowed the isolation of quantities of virus sufficient for characterization of its nucleic acid and lipid components as well as investigation of its ultrastructural attributes. Analysis of R1 DNA indicates that it is double stranded and possesses a molecular weight of 2.5 X 10(7) and a guanine-plus-cytosine content of 65.7 +/- 0.5%. The lipid fraction of R1 accounts for 14% of the total dry weight of the virus, 20% of which was identified as free or esterified sterols. A rapid loss of viral titer occurred after seconds of exposure to organic solvents. This result suggests that the lipid fractions of R1 is essential for its infectivity. Electron microscopic investigation of solvent-extracted R1 showed extensive deterioration of its normal morphology, including nucleocapsid disintegration and base plate separation. Routine phosphotungstate preparations demonstrated a particle with an oval head and a noncontractile tail. Altering the pH of the phosphotungstate negative stain from neutrality damage the viral particles. Uranyl formate-contrasted specimens displayed an elongated hexagonal nucleocapsid with a neck region; the cross-striated tail possessed a starlike base plate. Images

Soloff, B L; Rado, T A; Henry, B E; Bates, J H

1978-01-01

53

Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe.  

PubMed

In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L(WECPN)) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe. PMID:22135145

Di, Guo-Qing; Zhou, Bing; Li, Zheng-Guang; Lin, Qi-Li

2011-12-01

54

Postnatal development of rat nucleus tractus solitarius neurons: morphological and electrophysiological evidence  

Microsoft Academic Search

Postnatal development of neurons in the caudal nucleus tractus solitarii of rats was studied using the Golgi–Cox technique and whole-cell recordings. Two cell classes were defined on the basis of somatic and dendritic morphology. Elongated neurons have two thick primary dendrites originating from the long axis of the soma. The primary dendrites, tapering distally, give rise to one to four

A. Vincent; F. Tell

1999-01-01

55

Morphological study of neurons in the nerve plexus on heart base of rats and guinea pigs  

Microsoft Academic Search

The paper describes the morphological pattern of neurons in the nerve plexus on the heart base of rats and guinea pigs. The nerve plexus, containing the investigated neurons, lies beneath the pulmonary arteries on the myocardium of the left atrium. This plexus is not covered by the epicardium. Therefore, contrary to the subepicardiac nerve plexus the investigated plexus was termed

Dainius H Pauza; Gertruda Skripkiene; Valdas Skripka; Neringa Pauziene; Rimvydas Stropus

1997-01-01

56

Effects of chlorinated paraffins on rat liver microsomal activities and morphology  

Microsoft Academic Search

Short term effects of chlorinated paraffins with different length of the carbon chain and different degree of chlorination were investigated with respect to rat liver cytochrome P-450 mediated metabolism and liver cell morphology. When paraffins were administered by i.p. injection liver weights increased inversely with the length of the carbon chain. The short carbon chain paraffins with a high degree

Odd G. Nilsen; Rune Toftgård; Hans Glaumann

1981-01-01

57

Influence of exposure regimen on nitrogen dioxide-induced morphological changes in the rat lung  

Microsoft Academic Search

Experiments were performed to study the influence of concentration, exposure pattern, and length of exposure on the degree and extent of morphological alterations in the NOâ⁻ exposed rat lung. Four weeks of continuous exposure to 20 mg NOâ\\/m³ consecutively revealed damage and loss of cilia, replacement of desquamated type I pneumocytes by type II pneumocytes resulting in a cuboidal epithelial

P. J. A. Rombout; J. A. M. A. Dormans; M. Marra; G. Vanesch

1986-01-01

58

Morphology, composition, and function of struts between cardiac myocytes of rat and hamster  

Microsoft Academic Search

The morphology, composition, and function of struts that interconnect the lateral surfaces of cardiomyocytes were examined in the hearts of rats and hamsters. Methods included brightfield and fluorescent light microscopy, secondary and backscatter scanning electron microscopy, and transmission electron microscopy in conjunction with silver stain, cationic dye, and antibody to type-I collagen. These studies reveal a twisted, beaded appearance and

Thomas F. Robinson; Stephen M. Factor; Joseph M. Capasso; Beatrice A. Wittenberg; Olga O. Blumenfeld; Sam Seifter

1987-01-01

59

Morphologic Evidence of Photoreceptor Differentiation of Pinealocytes in the Neonatal Rat.  

National Technical Information Service (NTIS)

The pineal body and the retina of the neonatal Sprague-Dawley rat were studied by light and electron microscopy, and the morphologic differentiation of the parenchymal cells of the pineal body was compared with that of the developing photoreceptor cells o...

B. L. Zimmerman M. O. M. Tso

1973-01-01

60

A morphological study of the circadian cycle of the pineal gland of the rat  

Microsoft Academic Search

To seek a morphological expression of circadian rhythm, we investigated cytologically pineal glands taken from rats every 2 to 4 h under a lighting regime of 12 h of illumination (6:00 to 18:00) and 12 h of darkness. The changes in the number of synaptic ribbons and ribbon fields was observed by electron microscopy. The number of these intracellular elements

Katsumaro Kurumado; Wataru Mori

1977-01-01

61

Correlations Between Morphology and Electrophysiology of Pyramidal Neurons in Slices of Rat Visual Cortex. II. Electrophysiology  

Microsoft Academic Search

slices of rat visual cortex were impaled with glass micro- pipettes containing horseradish peroxidase (HRP) and stud- ied using current-clamp techniques prior to pressure injec- tion of HRP into the neurons. On morphological grounds, cells stained in layer 2\\/3 were placed into a single class whereas layer 5 cells were divided into 2 classes. Cells in one of these classes

Adrian Mason; Alan Larkman

62

Morphological types of motor nerve terminals in rat hindlimb muscles, possibly innervating different muscle fiber types  

Microsoft Academic Search

With methylene blue stain, three morphological types of motor nerve terminals were distinguished in hindlimb muscles (extensor digitorum longus, semitendinosus, soleus, and tibialis anterior muscles) of rat. Type A terminals possess many long thin branches with numerous minute swellings, type C ones possess few and thick terminal branches with few large swellings, and type B ones possess intermediate characteristics. The

Ola Wserhaug; Helge Korneliussen

1974-01-01

63

[Experimental contribution on the biochemical and morphological study of lung maturation in Wistar rats].  

PubMed

This is a research on the pulmonary normal maturity of a Wistar's Rat from the biochemic and morphological point of view. To do that we have chosen 3 lots of 5 rats each. The animals were sacrificed by killing them up to 15, 18 and 21 days of pregnancy. Then we have removed the amniotic liquid of each rat to know or study the creatinin concentration and the lecithin/sphingomyelin relation or report. To every foetus that we have got from every rat we have removed or extirpated the lungs to do a study under the optic microscope by using the hematoxilin-eosin together with the Fontana-Masson techniques. PMID:654655

Saavedra, J A; Gonzalez-Espinosa, J A; Martin-Herrera, A I; Perez-Gonzalez, J; Bullon, A

1978-01-01

64

Characterization of white sapote ( Casimiroa edulis Llave & Lex.) germplasm using floral morphology, RAPD and AFLP markers  

Microsoft Academic Search

Floral morphology, random amplified polymorphic DNA (RAPD), and amplified fragment length polymorphism (AFLP) were used to characterize and verify genetic diversity within a white sapote cultivar collection and to develop molecular markers for germplasm identification. On the basis of floral morphology, the cultivars were classified into three types: type I included 23 cultivars with large ovaries and small anthers; type

Yoshimi Yonemoto; Abul Kashem Chowdhury; Hidenori Kato; Mustad Malid Macha; Hitoshi Okuda

2007-01-01

65

Vanadyl sulfate protects against streptozotocin-induced morphological and biochemical changes in rat aorta.  

PubMed

The aim of this study was to investigate the protective effects of vanadyl sulfate on aorta tissue of normal and streptozotocin (STZ)-induced diabetic rats, morphologically and biochemically. The animals were made diabetic by an intraperitoneal injection of streptozotocin (65 mg/kg) and vanadyl sulfate (100 mg/kg) that was given every day for 60 days by gavage technique to rats. Under the light and transmission electron microscopes, hypertrophy of the vessel wall, focal disruption in the elastic lamellae, an increase in thickness of total aortic wall, tunica intima, subendothelial space and adventitial layer, and a disorganization in smooth muscular cells of the tunica media were observed in diabetic animals. The aorta lipid peroxidation (LPO) levels were significantly increased and the aorta glutathione (GSH) levels were significantly reduced in STZ diabetic rats. In diabetic rats administered vanadyl sulfate for 60 days, aorta LPO levels significantly decreased and the aorta GSH level significantly increased. In conclusion, in vivo treatment with vanadyl sulfate of diabetic rats prevented the morphological and biochemical changes observed in thoracic aorta of diabetic animals. PMID:16892454

Akgün-Dar, Kadriye; Bolkent, Sehnaz; Yanardag, Refiye; Tunali, Sevim

66

Morphological Control and Characterization of Monodispersed Ceria Particles  

SciTech Connect

The morphological control of cerium oxide particles was carried out by a homogeneous precipitation followed by calcination in air at 400 deg. C. The effects of pre-aging temperature, aging time and precipitation reagents on the morphologies of final products were investigated. When urea was used as a precipitation reagent, monodispersed spherical and flake-like cerium carbonate hydroxide precursor was precipitated in the solution at 90 deg. C for 2 h after pre-aging at 25 deg. C - 50 deg. C for 24-72 h. On the other hand, monodispersed nanosize rod-like cerium hydroxide particles were obtained using triethanolamine as precipitation reagent. Ceria particles with the same morphologies and slightly smaller particle size than those of as-prepared cerium precursor could be obtained after calcination in air at 400 deg. C. Physical-chemical characteristics of the monodispersed cerium oxide particles were evaluated.

Minamidate, Y.; Yin, S.; Devaraju, M. K.; Sato, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai (Japan)

2010-11-24

67

Morphological, Pathogenic, and Molecular Characterization of Alternaria Isolates Associated with Alternaria Late Blight of Pistachio  

Microsoft Academic Search

ABSTRACT Pryor, B. M., and Michailides, T. J. 2002. Morphological, pathogenic, and molecular characterization of ,Alternaria isolates associated with Alternaria late blight of pistachio. Phytopathology 92:406-416. Alternaria isolates ,were ,obtained from ,various pistachio tissues

Barry M. Pryor; Themis J. Michailides

2002-01-01

68

Morphological characterization of leaf, flower, fruit and seed traits among Brazilian Theobroma L. species  

Microsoft Academic Search

Morphological variability of four wild species, one semi-cultivated and one cultivated species of Theobroma L., indigenous to Brazil and introduced in the Bahian cocoa-growing region, was characterized based on 35 quantitative and\\u000a 13 qualitative traits. T. cacao, which shows a great diversity of conserved germplasm and many published references for morphological characterization, besides\\u000a of being one of the most cultivated

Ronaldo Carvalho Santos; José Luiz Pires; Ronan Xavier Correa

69

The Surface Morphology Characterization of Electroless Nickel Immersion Gold Under Bump Metallurgy (UBM) Using SEM  

SciTech Connect

This paper presents the surface morphology characterization at each process step in electroless nickel immersion gold (ENIG) deposition using Scanning Electron Microscope (SEM). The characterization start at initial bond pad, followed by cleaning, activation, first zincation, zinc removal, second zincation, electroless nickel and lastly immersion gold process. The result shows that the surface morphology of initial bond pad starts to change with deposition of zinc layer and further changes with deposition of nickel and gold layer.

Arshad, M. K. Md; Isa, M. N. Md; Sohiful, Z. M. A. [School of Microelectronic, Kolej Universiti Kejuruteraan Utara Malaysia (KUKUM), Blok A, Kompleks Pusat Pengajian KUKUM, Jalan Kangar-Arau, 02600 Jejawi, Perlis (Malaysia)

2007-05-09

70

Crimp morphology in relaxed and stretched rat Achilles tendon  

PubMed Central

Fibrous extracellular matrix of tendon is considered to be an inextensible anatomical structure consisting of type I collagen fibrils arranged in parallel bundles. Under polarized light microscopy the collagen fibre bundles appear crimped with alternating dark and light transverse bands. This study describes the ultrastructure of the collagen fibrils in crimps of both relaxed and in vivo stretched rat Achilles tendon. Under polarized light microscopy crimps of relaxed Achilles tendons appear as isosceles or scalene triangles of different size. Tendon crimps observed via SEM and TEM show the single collagen fibrils that suddenly change their direction containing knots. The fibrils appear partially squeezed in the knots, bent on the same plane like bayonets, or twisted and bent. Moreover some of them lose their D-period, revealing their microfibrillar component. These particular aspects of collagen fibrils inside each tendon crimp have been termed ‘fibrillar crimps’ and may fulfil the same functional role. When tendon is physiologically stretched in vivo the tendon crimps decrease in number (46.7%) (P < 0.01) and appear more flattened with an increase in the crimp top angle (165° in stretched tendons vs. 148° in relaxed tendons, P < 0.005). Under SEM and TEM, the ‘fibrillar crimps’ are still present, never losing their structural identity in straightened collagen fibril bundles of stretched tendons even where tendon crimps are not detectable. These data suggest that the ‘fibrillar crimp’ may be the true structural component of the tendon crimp acting as a shock absorber during physiological stretching of Achilles tendon.

Franchi, Marco; Fini, Milena; Quaranta, Marilisa; De Pasquale, Viviana; Raspanti, Mario; Giavaresi, Gianluca; Ottani, Vittoria; Ruggeri, Alessandro

2007-01-01

71

Morphological Changes of Gingiva in Streptozotocin Diabetic Rats  

PubMed Central

Gingivitis and periodontitis are chronic bacterial diseases of the underlying and surrounding tooth tissues. Diabetes mellitus is responsible for tooth deprivation both by decay and periodontal disease. The streptozotocin-induced diabetes results in a diabetic status in experimental animals similar to that observed in diabetes patients. The aim of the study was to investigate the relationship between the gingival lesions and the microangiopathy changes in streptozotocin-induced diabetes mellitus. Forty male Wistar rats were divided into two groups (control and experimental). Diabetes mellitus was induced by 45?mg/kg IV streptozotocin. The histological investigation of the marginal gingival and the relevant gingival papilla showed inflammation of the lamina propria and the squamous epithelium as well as marked thickness of the arteriole in the diabetic group, but no changes were observed in the control group. The results suggested a probable application of a routine gingival histological investigation in diabetic patients in order to control the progress of disease complications. It may be concluded that histological gingival investigation can be used as a routine assay for the control of the diabetic disease and prevention of its complications.

Tesseromatis, C.; Kotsiou, A.; Parara, H.; Vairaktaris, E.; Tsamouri, M.

2009-01-01

72

Molecular and morphological characterization of Eimeria in game birds.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Coccidiosis is generally known as a disease of economic importance in chickens. However, Eimeria species also negatively impacts the game bird industry. Here we present data generated from litter samples collected from two farms experiencing coccidiosis in chukars and pheasants. From morphological...

73

Morphological and Histopathological Changes in Orofacial Structures of Experimentally Developed Acromegaly-Like Rats: An Overview  

PubMed Central

Tongue enlargement and mandibular prognathism are clinically recognized in almost all patients with acromegaly. An acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I) was used to investigate morphological and histopathological changes in orofacial structures and to clarify whether these changes were reversible. Exogenous administration of IGF-I evoked specific enlargement of the tongue with identifiable histopathological changes (increased muscle bundle width, increased space between muscle bundles, and increased epithelial thickness), elongation of the mandibular alveolar bone and ascending ramus, and lateral expansion of the mandibular dental arch. Regarding histopathological changes in the mandibular condyle, the cartilaginous layer width, bone matrix ratio, and number of osteoblasts were all significantly greater in this rat model. After normalization of the circulating IGF-I level, tongue enlargement and histopathological changes in the tongue and mandibular condyle were reversible, whereas morphological skeletal changes in the mandible remained.

Iikubo, Masahiro; Kojima, Ikuho; Sakamoto, Maya; Kobayashi, Akane; Ikeda, Hidetoshi; Sasano, Takashi

2012-01-01

74

Morphological and electrophysiological characteristics of neurons within identified subnuclei of the lateral habenula in rat brain slices.  

PubMed

Based on the specificity of its inputs and targets, the lateral habenular complex (LHb) constitutes a pivotal motor-limbic interface implicated in various cerebral functions particularly in regulating monoamine transmission. Despite its functional significance, cellular characteristics underlying LHb functionality have not been examined systematically. The present study aimed to correlate morphological and electrophysiological properties of neurons within the different subnuclei of the LHb using whole-cell recording and neurobiotin labeling in rat slice preparations. Morphological analysis revealed a heterogeneous population of projection neurons randomly distributed throughout the LHb. According to somatodendritic characteristics four main categories were classified including spherical, fusiform, polymorphic and vertical cells. Electrophysiological characterization of neurons within the different categories demonstrated homologous profiles and no significant differences between groups. Typically, LHb neurons possessed high input resistances and long membrane time constants. They also displayed time-dependent inward rectification and distinct afterhyperpolarization. A salient electrophysiological feature of LHb neurons was their ability to generate rebound bursts of action potentials in response to membrane hyperpolarization. Based on the pattern of spontaneous activity, neurons were classified as silent, tonic or bursting. The occurrence of distinctive firing modes was not related to topographic allocation. The patterns of spontaneous firing and evoked discharge were highly sensitive to alterations in membrane potential and merged upon de- and hyperpolarizing current injection and synaptic stimulation. Besides projection neurons, recordings revealed the existence of a subpopulation of cells possessing morphological and physiological properties of neocortical neurogliaform cells. They were considered to be interneurons. Our data suggest that neurons within the different LHb subnuclei behave electrophysiologically more similar than expected, considering their morphological heterogeneity. We conclude that the formation of functional neuronal entities within the LHb may be achieved through defined synaptic inputs to particular neurons, rather than by individual neuronal morphologies and intrinsic membrane properties. PMID:20974229

Weiss, T; Veh, R W

2010-10-23

75

Morphological and functional damage of the retina caused by intravitreous indocyanine green in rat eyes  

Microsoft Academic Search

Background: This study was designed to investigate the influence of intravitreal indocyanine green (ICG) on retinal morphology and function. Methods: Brown Norway rats eyes (n=24) were vitrectomized by the injection of 0.05 ml of 100% SF6 gas. Two weeks later, ICG solution was injected into the vitreous cavity of vitrectomized eyes at a dose of 25 mg\\/ml, 2.5 mg\\/ml, 0.25

Hiroshi Enaida; Taiji Sakamoto; Toshio Hisatomi; Yoshinobu Goto; Tatsuro Ishibashi

2002-01-01

76

Morphology and mechanical behavior of TTCP-derived calcium phosphate cement subcutaneously implanted in rats  

Microsoft Academic Search

A pre-hardened, TTCP-derived CPC was immersed in Hanks’ solution as well as subcutaneously implanted into abdomen of rats.\\u000a The implant-soft tissue interfacial morphology was examined and properties of the CPC were evaluated and compared under in vitro\\u000a and in vivo conditions. The results indicate that the surface of immersed samples appeared rougher and more porous than that\\u000a of implanted samples and was

C. H. Tsai; C. P. Ju; J. H. Chern Lin

2008-01-01

77

Morphological alterations in retinal neurons in the S334ter-line3 transgenic rat  

Microsoft Academic Search

The S334ter-line-3 rat is a transgenic model of retinal degeneration developed to express a rhodopsin mutation similar to\\u000a that found in human retinitis pigmentosa (RP) patients. Previous studies have focused on physiological changes in retinal\\u000a cells and higher centers of the visual system with this model of retinal degeneration. However, little is known about the\\u000a morphological changes in retinal cells

Aditi Ray; Gerald J. Sun; Leanne Chan; Norberto M. Grzywacz; James Weiland; Eun-Jin Lee

2010-01-01

78

Chronic constriction model of rat sciatic nerve: nerve blood flow, morphologic and biochemical alterations  

Microsoft Academic Search

We evaluated the nerve blood flow (NBF), light and electron microscopy, and adrenergic innervation of rat sciatic nerve at\\u000a 2–45 days after the application of four loose ligatures. Ischemia developed at the lesion edge, creating an endoneurial dam.\\u000a Calcitonin gene-related peptide, norepinephrine and NBF were increased within the lesion. Morphologic alterations consisted\\u000a of early endoneurial edema, followed by myelinated fiber

Hideyuki Sasaki; Mikihiro Kihara; Paula J. Zollman; Kim K. Nickander; Inge L. Smithson; James D. Schmelzer; Catherine L. Willner; Eduardo E. Benarroch; Phillip A. Low

1996-01-01

79

[Morphological studies on Jensen sarcoma in the rat under artificial short-term hyperglycemia].  

PubMed

Possible actions of artificial short-time hyperglycaemia, which is tested as an adjunctive measure in various therapeutical concepts of tumours (for instance in combination with oncolytic apathogenic Clostridia), were checked by histomorphological investigations in Jensen sarcoma of rats. The glucose-induced hyperglycaemia caused a considerable increase of the extend of necrosis in the whole tumour. These morphological findings gave evidence of the high tumour selectivity of the provable effects of artificial short-time hyperglycaemia. PMID:6525021

Hoffmann, F A; Hambsch, K; Haupt, R; Ludewig, R

1984-01-01

80

Dendritic morphology of neurons in medial prefrontal cortex and hippocampus in 2VO rats.  

PubMed

Cerebral ischemia is the main cause of cognitive impairment. Changes in dendritic morphology and spines have been shown to occur with synaptic plasticity and cognitive function. Bilateral occlusion of the common carotid arteries (2VO) in rats was an effective model of chronic cerebral ischemia. In this experiment, SD rats were divided into model group (2VO) and sham-operated group. At 2, 4, 8 and 16 weeks, rats were tested in Morris water maze to observe learning and memory abilities, and then the brain tissue was stained by Golgi method to investigate the morphology of dendrites of pyramidal neurons under light microscope. Dendritic length and arborization and spine density of pyramidal neurons in medial prefrontal cortex (mPFC) and hippocampal CA1 were analyzed by ImageJ. Progressive learning and memory deficits appeared since 2 weeks. Compared to the sham-operated group, the dendritic length and arborization significantly decreased in the model group at 4, 8 and 16 weeks after 2VO in CA1, while there was no significant difference in mPFC. Dendritic spine density in hippocampal CA1 of the model group significantly decreased after 2 weeks, and it was decreased after 8 weeks in mPFC. The results suggest that under the condition of chronic cerebral ischemia, the alteration of dendritic morphology and spine density underlay cognitive impairment. PMID:22218811

Jia, He; Zhang, Xiao Min; Zhang, Bo Ai; Liu, Yu; Li, Jun Min

2012-01-05

81

BIOCHEMICAL, FUNCTIONAL AND MORPHOLOGICAL INDICATORS OF NEUROTOXICITY: EFFECTS OF ACUTE ADMINISTRATION OF TRIMETHYLTIN TO THE DEVELOPING RAT  

EPA Science Inventory

The neurotoxic organometal, trimethyltin (TMT), was administered to rats on postnatal day (PND)5. Neurotoxicity was assessed throughout subsequent development using morphological, biochemical and functional endpoints. These consisted of brain weight measures and histology (morpho...

82

A mechanism of rat vibrissal movement based on actual morphology of the intrinsic muscle using three-dimensional reconstruction.  

PubMed

The vibrissal capsular muscle (VCM) of the rat is known to differ from the arrector pili muscle. The purpose of the present study was to characterize the rat VCM morphologically using three-dimensional reconstruction. The rat snout skin was fixed, processed with routine histological methods, sectioned serially at a thickness of 10 µm, and then stained with Masson's trichrome. The sectioned images were reconstructed three-dimensionally using 'Reconstruct' software. The findings confirmed that the VCM is a skeletal muscle attached to the vibrissal follicle such that the latter is rooted within the former. The VCM encircles the follicle almost entirely, from base to apex, and hooks around the follicle caudally. Each one of these capsular muscles is connected to two adjacent follicles in the same row. They overlap each other in the lower part, as the rostral follicular muscle that surrounds the caudal follicle. The present findings suggest that the vibrissae are able to move more freely (under voluntary control) than other general arrector pili muscles, in line with their sensory function. PMID:22722709

Kim, Jeong-Nam; Yoo, Ja-Young; Lee, Ju-Young; Koh, Ki-Seok; Song, Wu-Chul

2012-06-19

83

Morphological, functional and biochemical characterization of canine gingival fibroblasts.  

PubMed

As dogs are good models for in vivo studies, it is interesting to evaluate the behavior of canine gingival fibroblasts (CGF) in vitro, so that these cells could be seeded on a matrix and later studied in vivo. The aim of this study was to perform a morphological, functional and biochemical analysis of CGF, comparing it with human gingival fibroblasts (HGF), as well as to evaluate the change of their characteristics over several passages. Using gingival fibroblasts from 3 dogs and 3 humans in the subculture (Sub), first (P1), third (P3), fifth (P5) and seventh (P7) passages, the following parameters were assessed: cell morphology, spreading, adhesion, viability and total protein content. The results showed no major differences between the passages in terms of morphology and spreading, and a tendency of greater adhesion and viability for HGF when compared with CGF. The total protein content was significantly higher for HGF. HGF exhibited greater functional and biochemical activity in vitro compared to CGF. Higher numbers at Sub were observed for both CGF and HGF in all evaluated parameters. The differences do not prevent the use of CGF for tissue engineering, but its use seems to be more appropriate in the subculture or first passage. PMID:23780356

Pelegrini, Camila Bonvicino; Maia, Luciana Prado; de Souza, Sérgio Luís Scombatti; Taba, Mário; Palioto, Daniela Bazan

2013-01-01

84

Repeated stress alters dendritic spine morphology in the rat medial prefrontal cortex.  

PubMed

Anatomical alterations in the medial prefrontal cortex (mPFC) are associated with hypothalamopituitary adrenal (HPA) axis dysregulation, altered stress hormone levels, and psychiatric symptoms of stress-related mental illnesses. Functional imaging studies reveal impairment and shrinkage of the mPFC in such conditions, and these findings are paralleled by experimental studies showing dendritic retraction and spine loss following repeated stress in rodents. Here we extend this characterization to how repeated stress affects dendritic spine morphology in mPFC through the utilization of an automated approach that rapidly digitizes, reconstructs three dimensionally, and calculates geometric features of neurons. Rats were perfused after being subjected to 3 weeks of daily restraint stress (6 hours/day), and intracellular injections of Lucifer Yellow were made in layer II/III pyramidal neurons in the dorsal mPFC. To reveal spines in all angles of orientation, deconvolved high-resolution confocal laser scanning microscopy image stacks of dendritic segments were reconstructed and analyzed for spine volume, surface area, and length using a Rayburst-based automated approach (8,091 and 8,987 spines for control and stress, respectively). We found that repeated stress results in an overall decrease in mean dendritic spine volume and surface area, which was most pronounced in the distal portion of apical dendritic fields. Moreover, we observed an overall shift in the population of spines, manifested by a reduction in large spines and an increase in small spines. These results suggest a failure of spines to mature and stabilize following repeated stress and are likely to have major repercussions on function, receptor expression, and synaptic efficacy. PMID:18157834

Radley, Jason J; Rocher, Anne B; Rodriguez, Alfredo; Ehlenberger, Douglas B; Dammann, Mark; McEwen, Bruce S; Morrison, John H; Wearne, Susan L; Hof, Patrick R

2008-03-01

85

Are morphologic and functional consequences of status epilepticus in infant rats progressive?  

PubMed

The present study examined whether status epilepticus (SE) induced by LiCl-pilocarpine in immature rats (postnatal day [P]12) interferes with normal development; leads to progressive epileptogenesis, or cognitive decline and to pathology similar to that seen in human temporal lobe epilepsy. We correlated the extent of pathologic changes with the severity of functional alterations or epilepsy. SE-induced changes were compared with those of rats with SE induced at P25. Animals of both ages were exposed to a battery of behavioral tests for up to 3months after SE. Rats with SE at P12 showed mild retardation of psychomotor development and delayed habituation, whereas rats with SE at P25 showed no habituation. Assessment in adulthood using the Morris water maze test revealed that SE at both P12 and P25 led to cognitive impairment and that the severity of the impairment increased with age. A handling test revealed increased aggression in rats with SE at P25, but not in rats with SE at P12. Epilepsy was diagnosed with continuous video-electroencephalographic (EEG) monitoring for up to 7d. P25 rats were monitored at 5months after SE and seizures were detected in 83.3% of animals. P12 animals were divided into two groups and monitored at 5 or 7months after SE. Both the severity and incidence of spontaneous recurrent seizures tended to progress with time, and their incidence increased from 50% to 87.5% at 5 and 7months, respectively. Morphometric analysis and stereologic assessment of hilar neurons performed after video-EEG monitoring revealed atrophy of temporal brain structures, enlargement of lateral ventricles, and loss of hilar neurons in both age groups. In P12 rats, morphologic damage also tended to progress over time. Performance of animals in the Morris water maze correlated with the severity of damage, but not with seizure parameters. PMID:23305765

Kubová, H; Mareš, P

2013-01-07

86

Faceted Surface Grain Morphology of Rapidly Solidified Alumina: Characterization and Potential Applications  

SciTech Connect

This communication reports on the characterization of novel surface microstructure formed in rapidly solidified porous alumina ceramic. Advanced characterization techniques such as Orientation Imaging Microscopy (OIM) and Atomic Force Microscopy (AFM) are used to understand the crystallographic and morphological aspects of the resultant microstructure. Potential applications of laser surface modified alumina ceramics are presented.

Harimkar, Sandip [Oklahoma State University; Kenik, Edward A [ORNL; Shim, Sanghoon [University of Tennessee, Knoxville (UTK); Dahotre, Narendra B [University of Tennessee, Knoxville (UTK)

2009-01-01

87

Effects of Fixatives and Buffers upon the Morphology of Heart and Skeletal Muscle Mitochondria from Exhausted Rats.  

ERIC Educational Resources Information Center

|This study describes the effects of several fixatives and buffers on the morphology of mitochondria from resting and exhausted rats. Rats were run to exhaustion and adjacent portions from the left ventricle or from the soleus were treated with the following fixation procedures: (a) glutaraldehyde buffered with cacodylate, S-collidine, or…

Gale, James B.

88

The morphology and connectivity of dissociated and reaggregated fetal tectal tissue transplanted to the midbrain of newborn rats  

Microsoft Academic Search

Tectal tissue from E15 or E16 Wistar rat embryos was dissociated and reaggregated (DR) prior to transplantation on to the midbrain of newborn host rats. We wished to determine how complete disruption of the donor tissue (i) affected the subsequent morphological development of the grafts in the host brain, and (ii) whether this procedure affected the selectivity with which host

Brett M. Bairstow; Alan R. Harvey

1992-01-01

89

Effect of prenatal and perinatal acrylamide on the biochemical and morphological changes in liver of developing albino rat  

Microsoft Academic Search

Acrylamide has been employed as an experimental probe to investigate biochemical and morphological changes in developing rat\\u000a liver following toxin administration in pregnant rats. Non-anesthetized pregnant rats were given acrylamide by gastric intubation\\u000a at a dose of 10 mg\\/kg\\/day. The pups were divided into three groups: Group A, mothers were treated with saline (control group);\\u000a Group B, mothers were treated with

Ahmed Aly Allam; Abdel Whaab El-Ghareeb; Manal Abdul-Hamid; Ahlam El Bakery; Mammoun Gad; Mohammad Sabri

2010-01-01

90

Morphology, response properties, and collateral projections of trigeminothalamic neurons in brainstem subnucleus interpolaris of rat  

Microsoft Academic Search

Intracellular recording, electrical stimulation and horseradish peroxidase (HRP) injection techniques were used to delineate the structural and functional characteristics of trigeminothalamic projection neurons in subnucleus interpolaris of the trigeminal brainstem nuclear complex in rat. Eleven such neurons were successfully characterized and recovered. All were medium to large multipolar neurons in the ventral part of interpolaris and all except one also

M. F. Jacquin; R. D. Mooney; R. W. Rhoades

1986-01-01

91

The effects of Creatine Long-Term Supplementation on Muscle Morphology and Swimming Performance in Rats  

PubMed Central

Abstract Creatine (Cr) has been shown to increase the total muscle mass. The purpose of this study was to investigate the effect of Cr supplementation on muscle morphology and swimming performance, using an animal model. Each rat was subjected to exercise 15-minute period daily for the 12 weeks. The rats were randomly divided into four groups: no Cr supplementation (CON), no Cr supplementation and incomplete food intake (lacking lysine and methionine in diet for rats) (INCO), Cr supplementation 1 g·kg-1·day-1 (CREAT-I) and Cr supplementation 2 g·kg-1·day-1 (CREAT-II). Three months later, all groups adult rats exercised in swimming pool chambers. Swimming time was recorded as minute for each rat. Following swimming performance period, the animals were killed by cervical dislocation and the gastrocnemius and diaphragm muscles were dissected. Serial slices of 5-7 ?m were allocated paraffin wax and histochemical staining procedure of cross-sections was carried out with heamatoxylin-eosin technics. All groups gained body weight at the end of 12 weeks but there was no statistical difference among them. Swimming time values were statistical difference between CREAT-II and CON group as well as between CREAT-I and CON group (p < 0.05). In the INCO group was determined increased connective tissue cell of the muscle sample. In contrast, in the CREAT-I and CREAT-II group, the basic histological changes were large-scale muscle fibers and hypertrophic muscle cells. These results suggest that long-term creatine supplementation increased the number of muscle fibers and enhanced endurance swimming performance in rats. Key points There is no study about the effects of creatine long-term supplementation on muscle morphology and swimming performance in rats. Long-term creatine supplementation increase muscle hypertrophy (but not body weight) and enhance endurance swimming performance in rats. The quantitative analysis indicated that the number of muscle fibers per defined area increased in creatine supplementation groups.

Yildiz, Ahmet; Ozdemir, Ercan; Gulturk, Sefa; Erdal, Sena

2009-01-01

92

MORPHOLOGICAL CHANGES IN THE LUNGS OF RATS LIVING UNDER COMPRESSED AIR CONDITIONS.  

PubMed

1. The alveolar cells in the lungs of young rats are greater in number and size than in old rats, a gradual transition to the state in the latter occurring from about the 4th to the 6th months of life. 2. On prolonged exposure to an environment having an 83.6 per cent oxygen tension, the cellularity of the alveoli is increased in both young and old animals, so that after 2 to 3 weeks it is impossible to distinguish them by morphological differences. Numerous mitotic figures are present in the alveolar cells. This hyperplasia and hypertrophy is a change which persists for months after the rats return to normal air. 3. Young rats do not develop the symptoms of acute oxygen poisoning, although some perivascular edema and dilatation of the lymphatics results on the 4th day of exposure, when intense acute pulmonary edema is present in old rats. 4. The mortality of acute oxygen poisoning is directly proportional to the age of the animals, although the majority of rats under 6 months of age survive this state and continue in apparent good health for as long as 72 days. All deaths during the acute stage in an 83.6 per cent oxygen tension occur on the 4th day of exposure. 5. After 1 month of exposure lesions are to be seen in the small arterioles of the lungs, consisting of a thickening and hyalinization of the walls with ultimate thrombosis of many. These vascular changes are identical with those seen in the arterioles of the kidney in chronic vascular nephritis. 6. Around the 45th day of exposure the large pulmonary arteries contain lesions in the media. The walls become loose meshed, thickened, and hyalinized, and hyaline cartilage formation is associated with these changes. 7. Reexposure of animals following an interval of 40 days in normal air subsequent to the first exposure of 72 days, does not produce any clinical or pathological changes. An adaptation to this toxic oxygen tension is produced during the first exposure, so that oxygen poisoning does not occur on second exposure. The increased cellularity of the alveolar walls persists. 8. The similarity in the morphological structure of the alveoli in young rats and in previously exposed old rats has a definite relationship to the adaptation that occurs to an oxygen tension of 83.6 per cent, preventing the development of acute oxygen poisoning on reexposure. PMID:19870056

Smith, F J; Bennett, G A; Heim, J W; Thomson, R M; Drinker, C K

1932-06-30

93

Morphologic, cytochemical and neurochemical characterization of the human medulloblastoma cell line TE671  

Microsoft Academic Search

Medulloblastoma cell line TE671 was characterized by morphologic, cytochemical, neurochemical, and growth criteria. In contrast to the uniform, in vivo histopathologic appearance of the tumor, TE671 in vitro exhibits six morphologic subtypes (Types I–VI) in varying percentages over 14 days in culture. TE671 grows as a monolayer by the merging of separate foci. Cells were positive for Periodic acid Schiff

Paul M. Zeltzer; Sandra L. Schneider; Daniel D. Von Hoff

1984-01-01

94

Synthesis, Characterization (Molecular-Morphological) and Theoretical Morphology Predictions of Poly(cyclohexadiene) Containing Linear Triblock Terpolymers  

SciTech Connect

The synthesis via anionic polymerization of six linear triblock terpolymers with various sequences of blocks such as PS (polystyrene), PB (polybutadiene), PI (polyisoprene) and PCHD (poly(1,3-cyclohexadiene)) is reported. The synthesis of the terpolymers was accomplished by the use of anionic polymerization with high vacuum techniques and sequential monomer addition. Molecular characterization of the samples was performed via size exclusion chromatography and membrane osmometry to measure polydispersity indices and the number-average molecular weights, respectively. Proton nuclear magnetic resonance spectroscopy was adopted to verify the type of microstructure for the polydienes as well as to calculate the molar composition. Structural characterization was performed via transmission electron microscopy and small angle X-ray scattering and several morphologies were observed including one which has not been reported previously. Real-space self-consistent field theory (SCFT) without a priori knowledge about the symmetry of the periodic structures was used to elucidate the thermodynamics of the synthesized triblock copolymers.

Kumar, Rajeev [ORNL; Dadmun, Mark D [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [ORNL; Avgeropoulos, Apostolos [University of Athens, Athens, Greece; Zafeiropoulos, N.E. [University of Athens, Athens, Greece; Misichoronis, K. [University of Athens, Athens, Greece; Rangou, S. [University of Athens, Athens, Greece; Ashcraft, E. [University of Tennessee, Knoxville (UTK)

2013-01-01

95

Characterization of the vasculature supplying the genital tissues in female rats  

PubMed Central

Introduction The internal pudendal arteries are the key resistance vessels controlling the peripheral circulatory component of sexual responses in both male and females. Previous studies in the male rat demonstrated that this vessel has markedly heightened susceptibility to vascular damage compared to other vessels in the body. Evidence suggests that the female may also be susceptible to vascular pathologies contributing to sexual dysfunction. Aim To characterize the anatomical, morphological and functional properties of the pudendal artery in female rats. Methods The pelvic arteries in young Sprague-Dawley female rats were dissected to generate a composite representation of the vascular gross anatomy. Morphometry was performed on perfusion-fixed pudendal arteries whereas others were mounted in a wire myograph to assess responses to vasoactive drugs. These measures were contrasted with a previous study examining male rats. Main Outcomes Measured Gross anatomy, lumen diameter, wall thickness, cross sectional area and contractile responses in the internal pudendal artery. Results The gross anatomy of the pudendal artery in female rats appears to parallel that found in male rats; acting as the primary feeder vessel of the clitoral, labial and vaginal tissue. Compared to the male rat, the female pudendal artery has a smaller lumen diameter (169±5.7 vs 303±13.8um), wall thickness (14±0.7 vs 47±2.2um) and cross-sectional area (8±0.4 vs 52±3.4×103 ?m2). These structural differences also translate into a decreased contractile capacity of the pudendal arteries from female rats vs. males (8.1±2.7 vs 20±1.4mN). Conclusions Although the gross anatomical features of the vasculature tree supplying the genital tissue in male and female rats appears to have similarities, the tissue specific properties of the vessel itself has a very different structure-function balance. We hypothesize this discordance likely reflects the very different sex-specific roles of this vessel in regulating blood flow during arousal.

Hannan, Johanna L.; Cheung, Geoffrey L.; Blaser, Mark C.; Pang, Judith J.; Pang, Stephen C.; Webb, R. Clinton; Adams, Michael A.

2011-01-01

96

Loading effects on rat craniomandibular morphology: a system for gravity studies  

NASA Astrophysics Data System (ADS)

Gravity effects on muscle and bone are a major impediment to long-term space travel. We introduce a model for studying these effects, the craniomandibular system. Some advantages of this system include: (1) craniomandibular morphology is determined by epigenetic factors including gravity, (2) relatively light forces can significantly alter its morphology, and (3) soft diet and tooth loss produce effects that are similar to those produced in lower limbs by weightlessness. In the study, implants made either of gold (experimental group) or lightweight acrylic (controls) were attached to adult rats' mandibles. After 13 weeks, the animals' skulls and mandibles were dissected. Pair-wise comparisons indicated that the experimental animals showed significantly shortened and narrowed cranial bases, and significant changes in the posterior zygomatic arch region. These results indicate that simulated macrogravity influences bone remodeling in the adult craniomandibular system.

Singh, Ranbir; Carvalho, Thais; Gerstner, Geoffrey E.

2005-02-01

97

Loading effects on rat craniomandibular morphology: a system for gravity studies.  

PubMed

Gravity effects on muscle and bone are a major impediment to long-term space travel. We introduce a model for studying these effects, the craniomandibular system. Some advantages of this system include: (1) craniomandibular morphology is determined by epigenetic factors including gravity, (2) relatively light forces can significantly alter its morphology, and (3) soft diet and tooth loss produce effects that are similar to those produced in lower limbs by weightlessness. In the study, implants made either of gold (experimental group) or lightweight acrylic (controls) were attached to adult rats' mandibles. After 13 weeks, the animals' skulls and mandibles were dissected. Pair-wise comparisons indicated that the experimental animals showed significantly shortened and narrowed cranial bases, and significant changes in the posterior zygomatic arch region. These results indicate that simulated macrogravity influences bone remodeling in the adult craniomandibular system. PMID:15754474

Singh, Ranbir; Carvalho, Thais; Gerstner, Geoffrey E

2005-02-01

98

Morphology of Pyramidal Neurons in the Rat Prefrontal Cortex: Lateralized Dendritic Remodeling by Chronic Stress  

PubMed Central

The prefrontal cortex (PFC) plays an important role in the stress response. We filled pyramidal neurons in PFC layer III with neurobiotin and analyzed dendrites in rats submitted to chronic restraint stress and in controls. In the right prelimbic cortex (PL) of controls, apical and distal dendrites were longer than in the left PL. Stress reduced the total length of apical dendrites in right PL and abolished the hemispheric difference. In right infralimbic cortex (IL) of controls, proximal apical dendrites were longer than in left IL, and stress eliminated this hemispheric difference. No hemispheric difference was detected in anterior cingulate cortex (ACx) of controls, but stress reduced apical dendritic length in left ACx. These data demonstrate interhemispheric differences in the morphology of pyramidal neurons in PL and IL of control rats and selective effects of stress on the right hemisphere. In contrast, stress reduced dendritic length in the left ACx.

Perez-Cruz, Claudia; Muller-Keuker, Jeanine I. H.; Heilbronner, Urs; Fuchs, Eberhard; Flugge, Gabriele

2007-01-01

99

Morphology and Electrical Characterization of Reduced Epitaxial Graphene Oxide  

NASA Astrophysics Data System (ADS)

We present results for on-chip oxidation of epitaxial graphene and sequential reduction of the insulating graphene oxide layers. In our previous work , we have used the Hummer's method to oxidize epitaxial graphene and used electron beam exposure and heat treatment to reduce the epitaxial graphene oxide (EGO) band gap by changing the degree of oxidation. Here we further explore various oxidation and reduction methods on epitaxial graphene. EGO is characterized by atomic force microscopy, low-energy electron diffraction, ellipsometry, and Raman Spectrometry. Mobility measurements of patterned structures are presented where epitaxial graphene layers pads are seamlessly connected to EGO ribbons.

Hu, Yike; Wu, Xiaosong; Sprinkle, Michael; Madiomanana, Nerasoa; Ruan, Ming; Berger, Claire; de Heer, Walter

2009-03-01

100

Administration of Dexamethasone to Neonatal Rats Induces Hypomyelination and Changes in the Morphology of Oligodendrocyte Precursors  

PubMed Central

To examine whether hypomyelination in neonatal rats might be related to apoptosis of oligodendrocyte progenitors, we administered dexamethasone (0.5 mg/kg SC) to neonatal rats on postnatal (P) days 1 through 5. Immunofluorescent staining and Western blotting for myelin basic protein (MBP) were performed on P14. Morphologic changes associated with apoptotic death of oligodendrocyte progenitors were assessed by using immunofluorescent staining on P5 of surface markers present at different developmental stages of oligodendrocyte progenitors (O4 and O1) and by double-staining with terminal deoxynucleotidyl transferase-mediated digoxigenin–dUTP nick end-labeling (TUNEL) and O4 or O1. Administration of dexamethasone to neonatal rats reduced the expression of MBP in the white matter by P14. In addition, dexamethasone reduced the expression of O4-positive cells, presumably preoligodendrocytes, in the corpus callosum and induced degenerative changes, such as cytoplasmic condensation and fragmented, tortuous processes, in oligodendrocyte progenitors, and increased the number of TUNEL-positive pyknotic nuclei of oligodendrocyte progenitors. These findings suggest that the dexamethasone-induced decreased expression of MBP in the cerebral hemispheres of the neonatal rats is due to apoptotic degeneration of oligodendrocyte progenitors. Administration of dexamethasone during the critical period of brain development may increase the risk of apoptosis in oligodendrocyte progenitors, subsequently resulting in hypomyelination.

Kim, Jong-Wan; Kim, Young J; Chang, Young P

2013-01-01

101

Bioenergetic, functional and morphological consequences of postinfarct cardiac remodeling in the rat.  

PubMed

Despite recent advances in the treatment, severe chronic heart failure (CHF) remains a syndrome associated with high mortality. Therefore, the search for new agents to improve both patient symptoms and survival, as well as the pursuit for detailed knowledge about pathophysiology of the failing heart, will continue to depend on relevant animal models. Large acute myocardial infarction (MI) initiates complex changes in the geometrical, structural, and biochemical architecture of both infarcted and non-infarcted regions of ventricular myocardium, which can profoundly affect left ventricular function and prognosis. In this paper we present a new model for non-invasive cardiac (31)P MRS in the rat. Volume-selective (31)P magnetic resonance spectroscopy and echocardiography were used for evaluation of myocardial energy metabolism, cardiac morphology and function in rats 3 days and 3 weeks after induction of large MI. The phosphocreatine:adenosine triphosphate (PCr:ATP) ratio was decreased in rats with MI comparing with controls both at 3 days (1.6+/-0.06 vs 2.7+/-0.04; mean+/-s.e.m. P<0.0001) and 3 weeks (1.6+/-0.07 v 2.7+/-0.02 P<0.0001) postinfarct. The results from the study demonstrate that postinfarct cardiac remodeling is a rapid process of changes not only in cardiac geometry, structure and function but also in myocardial energy metabolism after large transmural MI in the rat. PMID:10471352

Omerovic, E; Bollano, E; Basetti, M; Kujacic, V; Waagstein, L; Hjalmarson, A; Waagstein, F; Soussi, B

1999-09-01

102

Administration of dexamethasone to neonatal rats induces hypomyelination and changes in the morphology of oligodendrocyte precursors.  

PubMed

To examine whether hypomyelination in neonatal rats might be related to apoptosis of oligodendrocyte progenitors, we administered dexamethasone (0.5 mg/kg SC) to neonatal rats on postnatal (P) days 1 through 5. Immunofluorescent staining and Western blotting for myelin basic protein (MBP) were performed on P14. Morphologic changes associated with apoptotic death of oligodendrocyte progenitors were assessed by using immunofluorescent staining on P5 of surface markers present at different developmental stages of oligodendrocyte progenitors (O4 and O1) and by double-staining with terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick end-labeling (TUNEL) and O4 or O1. Administration of dexamethasone to neonatal rats reduced the expression of MBP in the white matter by P14. In addition, dexamethasone reduced the expression of O4-positive cells, presumably preoligodendrocytes, in the corpus callosum and induced degenerative changes, such as cytoplasmic condensation and fragmented, tortuous processes, in oligodendrocyte progenitors, and increased the number of TUNEL-positive pyknotic nuclei of oligodendrocyte progenitors. These findings suggest that the dexamethasone-induced decreased expression of MBP in the cerebral hemispheres of the neonatal rats is due to apoptotic degeneration of oligodendrocyte progenitors. Administration of dexamethasone during the critical period of brain development may increase the risk of apoptosis in oligodendrocyte progenitors, subsequently resulting in hypomyelination. PMID:23561937

Kim, Jong-Wan; Kim, Young J; Chang, Young P

2013-02-01

103

Protective Effects of Iganidipine on Morphological and Functional Changes of Arteries in Hypertensive Dahl Rats.  

PubMed

BACKGROUND: This study was performed to examine the protective effects of iganidipine, a new water-soluble calcium antagonist, on the morphological and functional changes of arteries in Dahl salt-sensitive (Dahl-S) rats. METHODS AND RESULTS: Vehicle and iganidipine were administered orally to Dahl-S rats fed a high-salt diet (HSD) for 8 weeks. Aorta, superior mesenteric arteries (SMA), and peripheral mesenteric arteries (PMA) were examined light-microscopically or electon-microscopically. Relaxant responses of isolated aorta and SMA were recorded isometrically. In rats fed HSD, blood pressure was markedly increased. Light microscopy showed intimal and medial hypertrophy, periarteritis, and narrowed arterial lumen in the PMA. Transmission and scanning electron microscopy or light microscopy showed medical thickness in the aorta and SMA and hypertrophy of endothelial cells and dilatation of the subendothelial space only in the aorta. In the SMA, both endothelium-dependent relaxation (EDR) and endothelium-independent relaxations (EIR) were reduced to a similar extent. In the aorta, the EDR was more markedly attenuated than the EIR. Iganidipine at 3 mg/kg/day showed a 24-h sustained hypotensive effect and completely prevented the morphological and functional changes in both arteries. Iganidipine at 1 mg/kg/day, which lowered blood pressure only for several hours, decreased the injuries in PMA and aortic endothelium and moderately restored the EDR in the aorta. Iganidipine at 0.3 mg/kg/day had no effects. CONCLUSIONS: In Dahl-S rats fed an HSD, iganidipine completely prevented all the changes at a sustained-hypotensive dose and prevented the injuries of PMA and aortic endothelium and the reduction of EDR in the aorta at a nonsustained hypotensive dose. Nonhemodynamic effects of iganidipine may be partly involved in its protective effects against arterial injuries. PMID:10684492

Shirahase; Uehara; Kanda; Wada; Ichikawa; Kobayashi; Funahashi

1998-04-01

104

TOPOGRAPHY CHARACTERIZATION OF ENGINEERING SURFACES USING MATHEMATICAL MORPHOLOGY Application to the characterization of wear in internal combustion engine cylinder liners  

Microsoft Academic Search

A state of the art of 3D surface characterization techniques in the au- tomotive and steel industries is presented, and links with mathematical morphology are highlighted. A surface topography decomposition method is described. It decom- poses a surface into three elements:reference surface (waviness and form), superficial roughness (related to friction and wear) and valleys (related to lubricant circulation and reservoirs).

E. Decenciere; D. Jeulin

105

Morphological characterization of carbon-nanofiber-reinforced epoxy nanocomposites using ultra-small angle scattering  

SciTech Connect

Studies of the properties of nanocomposites reinforced with vapor-grown carbon nanofibers (VGCFs) can be found throughout the literature. Electrical, mechanical, viscoelastic, and rheological properties are just a few of the characteristics that have been well discussed. Although these properties depend on morphology, morphological characterization is rare. Due to its 2-dimensional nature, microscopy is of limited value when analyzing network morphologies. This work will show how the characterization of the three-dimensional geometry and network formation of VGCFs can be determined using ultra-small angle scattering techniques. Ultra-small angle x-ray and neutron scattering (USAXS and USANS) were used to characterize the morphology of carbon nanofibers suspended in epoxy. Using a simplified tube model, we estimate the dimensions of suspended fibers. The assumption of tubular fibers accounts for the increased surface area observed with USAXS that is not accounted for using a solid rod model. Furthermore, USANS was used to search for a structural signature associated with the electrical percolation threshold. USANS extends to longer dimensional scales than USAXS, which measures a smaller range of momentum transfer. To determine the electrical percolation threshold, AC impedance spectroscopy was employed to verify that an electrically conductive, percolated network forms at VGCNF loadings of 0.8% < CNF wt% < 1.2%. These values correlate with the USANS data, where a morphological transition is seen at {approx}1.2% loading.

Justice, R.S.; Anderson, D.P.; Brown, J.M.; Arlen, M.J.; Colleary, A.J.; Lafdi, K.; Schaefer, D.W. (UCIN); (AFRL)

2010-07-01

106

Synthesis And Characterization Of Silver Sulfide Nanoparticles Of Various Morphologies Using Chitosan As Stabilizer  

NASA Astrophysics Data System (ADS)

Synthesis of Silver Sulfide nanoparticles of various morphologies were successfully done through colloidal synthesis technique at relatively low temperature using Chitosan bio polymer as stabilizer. The effect of change in stabilizer concentration, reagent concentrations and reaction temperature at constant pH on morphology and optical properties of synthesized products are also studied. It was found that reagent concentration and temperature both played important role in change in morphology of synthesized product. The crystal structure studies of synthesized products were carried out by powder X-ray diffraction technique which reveals the formation of Acanthite monoclinic Ag2S crystal structure and SAD was taken for only two samples whose analysis using XRD was difficult. The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements. Morphologies obtained were characterized by SEM. Further the functionality and effectiveness of stabilization process were established by Fourier transform infrared spectroscopy.

Hashmi, Lubna; Malik, M. M.; Qureshi, M. S.; Dubey, R. N.; Alim, Ishrat; Siddiqui, A. H.

2010-10-01

107

The role of morphology in combination with ploidy analysis in characterizing early gestational abortion.  

PubMed

Morphology in combination with flow cytometry is an inexpensive and fast tool to characterize important reasons for early gestational loss. Early partial hydatidiform moles are especially difficult to identify as not all have developed the typical histological features of central cistern formation and trophoblastic hyperplasia of the chorionic villi. Angiomatoid formation of the blood vessels, irregular chorionic villi, diffuse villous stromal fibrosis, trophoblastic pseudoinclusions, and pleomorphic trophoblast at the implantation site have therefore been proposed as additional morphological criteria. In our study, we investigated the correlation between morphological features and results of ploidy analysis to assess the additional criteria for practical use. Morphological features of the placentas of up to 13 weeks of gestation were evaluated on hematoxylin and eosin sections. Ploidy analysis was performed by flow cytometry on formalin-fixed, paraffin-embedded tissue. Statistical analysis was performed by binary logistic regression. One hundred fifty samples were included in the study. Of the samples, 23 were triploid, 19 were tetraploid, and the remaining ones were diploid. Statistical analysis showed a poor predictive power based on all morphological criteria alone. The most important result of this study was the identification of five triploid placentas that showed diffuse fibrosis of the chorionic villi, angiomatoid changes of the blood vessels, trophoblastic pseudoinclusions, and focal pleomorphic changes at the implantation site, but none of the classical morphological features of triploid pregnancies were identified. Our study demonstrates that the use of additional morphological criteria increases the number of missed abortions with identified causes for pregnancy loss. PMID:23262783

Grinschgl, Isabella; Mannweiler, Sebastian; Holzapfel-Bauer, Margit; Pferschy, Ulrich; Hoefler, Gerald; Guertl, Barbara

2012-12-21

108

Cell morphological changes in venous remodeling induced by arteriovenous grafting in rat limb.  

PubMed

Vascular remodeling induced in rat limb by arteriovenous (AV) shunting was investigated by evaluating changes in vascular diameter and cell morphology. In Wistar rats, a vein graft was implanted in situ in the hind limb. Flow-rate in the grafted vein was assessed by measuring flow in the common femoral artery using an ultrasonic flowmeter. Nuclei and actin filaments of the venous wall were stained with propidium iodine and phalloidine-FITC, and the samples were observed using confocal laser microscopy. The grafted veins became circular in cross-section with increase in diameter during two weeks after AV shunting. Owing to the increase in diameter, the estimated wall shear stress was not increased so much as the flow-rate. The confocal laser microscopic observation showed that endothelial cells (ECs) and smooth muscle cells (SMCs) in the grafted veins were either aligned well (2 out of 8 samples), or ECs were denudated and SMCs were disrupted (in 6 out of 8 samples). The cell density of ECs was unchanged from the control level. In conclusion, the grafted vein was remodeled with morphological changes in ECs and SMCs during 2 weeks after AV shunting. PMID:15894823

Komai, Yutaka; Nakano, Atushi; Seki, Junji; Niimi, Hideyuki

2005-01-01

109

Morphologic investigation of injury caused by locally applied negative pressure in a rat model.  

PubMed

Although some previous studies have reported patients who developed compartment syndrome or died because of locally applied negative pressure, no detailed investigation of pathologic changes caused by negative pressure-induced injury has been reported in the literature. The main purpose of this study was to examine the morphologic characteristics of injury caused by local negative pressure and correlate these with systemic changes. A total of 30 male Wister rats were used. Animals were randomly assigned to 6 groups. Negative pressure was applied to the right hindlimb of each animal in each group for periods of 0 (sham-operated), 30, 60, 90, 120, or 180 min using a vacuum pump. Macroscopic and microscopic changes induced by local negative pressure were already observed after 30 min and were exacerbated with time. The proportion of muscle degeneration was highest in the deep tissues, irrespective of exposure time. The observed increase in the weight of the injured hindlimb at 180 min was caused by an approximately 30% fluid shift to the hindlimb, demonstrating that the application of negative pressure to the hindlimb of rats can induce hypovolemic shock. We here reveal the morphologic changes induced by local negative pressure and discuss possible mechanisms of negative pressure-induced injury. PMID:22204931

Kenji, Ninomiya; Ihama, Yoko; Fukasawa, Maki; Nagai, Takumi; Fuke, Chiaki; Miyazaki, Tetsuji

2011-12-26

110

Derivation and characterization of embryonic stem cells lines derived from transgenic Fischer 344 and Dark Agouti rats.  

PubMed

Rat embryonic stem cell (ESC) lines are not widely available, and there are only 2 lines available for distribution. Here, ESC lines were derived and characterized from Fischer 344 (F344) rats that express marker transgenes either ?-galactosidase or human placental alkaline phosphatase (AP), nontransgenic F344 rats, and from Dark Agouti (DA) rats. The ESC lines were maintained in an undifferentiated state as characterized by colony morphology, expression of Oct4, Nanog, Sox-2, Cdx2, and Stella, staining for AP, and stage-specific embryonic antigen-1. Pluripotency was demonstrated in vitro by differentiation to embryoid bodies, followed by embryonic monsters. The Cdx2 expression by ESCs was unexpected and was confirmed via reverse transcriptase-polymerase chain reaction, immunocytochemistry. Pluripotency of ESCs was demonstrated in vivo by production of teratoma after an injection into F344 nontransgenic rats, and by an injection of male DA ESCs into F344 or Sprague-Dawley rat blastocysts and the generation of chimeric rats and germline contribution. ESCs from both F344 and DA contributed to chimeric rats, and one DA ESC line was proved to be germline competent. ESC sublines were created by transfection with a plasmid expressing enhanced green fluorescent protein (eGFP) under the control of a beta actin promoter and cytomegalovirus enhancer (pCX-eGFP) or by transfection with a plasmid expressing GFP under the control of a 3.1 kb portion of the rat Oct4 promoter (pN1-Oct4-GFP). In pN1-Oct4-GFP sublines, GFP gene expression and fluorescence were shown to be correlated with endogenous Oct4 gene expression. Therefore, these new ESC lines may be useful for tissue engineering and transplantation studies or for optimizing culture conditions required for self-renewal and differentiation of rat ESCs. While they made chimeric rats, further work is needed to confirm whether the transgenic F344 rat ESCs described here are germline-competent ESCs. PMID:21995453

Hong, James; He, Hong; Weiss, Mark L

2011-11-22

111

Derivation and Characterization of Embryonic Stem Cells Lines Derived from Transgenic Fischer 344 and Dark Agouti Rats  

PubMed Central

Rat embryonic stem cell (ESC) lines are not widely available, and there are only 2 lines available for distribution. Here, ESC lines were derived and characterized from Fischer 344 (F344) rats that express marker transgenes either ?-galactosidase or human placental alkaline phosphatase (AP), nontransgenic F344 rats, and from Dark Agouti (DA) rats. The ESC lines were maintained in an undifferentiated state as characterized by colony morphology, expression of Oct4, Nanog, Sox-2, Cdx2, and Stella, staining for AP, and stage-specific embryonic antigen-1. Pluripotency was demonstrated in vitro by differentiation to embryoid bodies, followed by embryonic monsters. The Cdx2 expression by ESCs was unexpected and was confirmed via reverse transcriptase-polymerase chain reaction, immunocytochemistry. Pluripotency of ESCs was demonstrated in vivo by production of teratoma after an injection into F344 nontransgenic rats, and by an injection of male DA ESCs into F344 or Sprague-Dawley rat blastocysts and the generation of chimeric rats and germline contribution. ESCs from both F344 and DA contributed to chimeric rats, and one DA ESC line was proved to be germline competent. ESC sublines were created by transfection with a plasmid expressing enhanced green fluorescent protein (eGFP) under the control of a beta actin promoter and cytomegalovirus enhancer (pCX-eGFP) or by transfection with a plasmid expressing GFP under the control of a 3.1?kb portion of the rat Oct4 promoter (pN1-Oct4-GFP). In pN1-Oct4-GFP sublines, GFP gene expression and fluorescence were shown to be correlated with endogenous Oct4 gene expression. Therefore, these new ESC lines may be useful for tissue engineering and transplantation studies or for optimizing culture conditions required for self-renewal and differentiation of rat ESCs. While they made chimeric rats, further work is needed to confirm whether the transgenic F344 rat ESCs described here are germline-competent ESCs.

Hong, James; He, Hong

2012-01-01

112

A bone replaceable artificial bone substitute: morphological and physiochemical characterizations.  

PubMed

A composite material consisting of carbonate apatite (CAp) and type I atelocollagen (AtCol) (88/12 in wt/wt%) was designed for use as an artificial bone substitute. CAp was synthesized at 58 degrees C by a solution-precipitation method and then heated at either 980 degrees C or 1,200 degrees C. In this study, type I AtCol was purified from bovine tail skins. A CAp-AtCol mixture was prepared by centirfugation and condensed into composite rods or disks. The scanning electron-microscopic (SEM) characterization indicated that the CAp synthesized at 58 degrees C displayed a crystallinity similar to that of natural bone and had a high porosity (mean pore size: about 3-10 microns in diameter). SEM also revealed that the CAp heated at 980 degrees C was more porous than that sintered at 1,200 degrees C, and the 1,200 degrees C-heated particles were more uniformly encapsulated by the AtCol fibers than the 980 degrees C-heated ones. A Fourier transformed-infrared spectroscopic analysis showed that the bands characteristic of carbonate ions were clearly observed in the 58 degrees C-synthesized CAp. To enhance the intramolecular cross-linking between the collagen molecules, CAp-AtCol composites were irradiated by ultraviolet (UV) ray (wave length 254 nm) for 4 hours or vacuum-dried at 150 degrees C for 2 hours. Compared to the non cross-linked composites, the UV-irradiated or dehydrothermally cross-linked composites showed significantly (p < 0.05) low collagen degradation and swelling ratio. Preliminary mechanical data demonstrated that the compressive strengths of the CAp-AtCol composites were higher than the values reported for bone. PMID:10992808

Park, J C; Han, D W; Suh, H

2000-08-01

113

Morphological characterization of pecteneal hyalocytes in the developing quail retina  

PubMed Central

The periphery of the vitreous body contains a population of cells termed hyalocytes. Despite the existence for more than one century of publications devoted to the pecten oculi, a convoluted coil of blood vessels that seems to be the primary source of nutrients for the avian avascular retina, little information can be found concerning the pecteneal hyalocytes. These cells are situated on the inner limiting membrane in close relationship with the convolute blood vessels. To characterize the origin and macrophagic activity of pecteneal hyalocytes, we have analysed two different stages of quail eye development using histochemistry and immunohistochemistry. Pecteneal hyalocytes express the QH1 epitope and cKit, confirming that these cells belong to the haematopoietic system. They also express vimentin, an intermediate filament protein present in cells of mesenchymal origin and very important for differentiation of fully active macrophages. However, similarly as described in porcine hyalocytes, pecteneal hyalocytes express the glial fibrillary acidic protein, a recognized neuroglial marker. Pecteneal hyalocytes did not express other neuroglial markers, such as glutamine synthetase or S100. Acidic phosphatase was activated and Lep100 was found in secondary lysosomes, confirming phagocytic activity of pecteneal hyalocytes during ocular development. Pecteneal hyalocytes strongly react with RCA-I, WFA, WGA, PNA, SNA, LEA and SBA lectins, whereas other avian macrophages from thymus and the bursa of Fabricius did not bind PNA, SNA and LEA lectins. Interestingly, WGA lectin reacts with all kinds of avian macrophages, including pecteneal hyalocytes, probably reflecting the specific binding of WGA to components of the phagocytic and endocytic pathways. In conclusion, pecteneal hyalocytes are a special subtype of blood-borne macrophages that express markers not specifically associated with the haematopoietic system.

Llombart, Cristina; Nacher, Victor; Ramos, David; Luppo, Mariana; Carretero, Ana; Navarro, Marc; Melgarejo, Veronica; Armengol, Clara; Rodriguez-Baeza, Alfonso; Mendes-Jorge, Luisa; Ruberte, Jesus

2009-01-01

114

Morphology and x-ray characterization of acenaphthene, fluoranthene, and pyrene crystals grown by sublimation  

Microsoft Academic Search

The preparation of relatively large of acenaphthene, fluoranthene and pyrene crystals grown from vapor phase by plate sublimation method, is described. In order to characterize the intrinsic structure perfection of such grown crystals the X-ray examinations have been performed. The observed morphologies of these crystals have been compared with that predicted from PBC theory by Hartman-Perdok, model growth conditions (vacuum,

Bernard Marciniak; Ewa Rozycka-Sokolowska; A. Balinska; W. Pawliuk

2001-01-01

115

Morphological and cell volume changes in the rat lens during the formation of radiation cataracts  

SciTech Connect

Earlier studies showed that x-irradiation caused an initial increase in early postnatal rat lens epithelial cell volume followed by swelling of the underlying lens fibers. This suggested a correlation between damaged epithelial cell volume regulation and subsequent fiber cell swelling. To test this hypothesis, 4 wk.-old Sprague Dawley rats were injected with ({sup 3}H)-thymidine and, 24 hrs. later, their eyes were irradiated with either 4 or 12 Gy. Lenses were examined with a slit lamp and cataracts were graded on a scale of 1+ to 4+. The surface morphology of these lens fibers and their attachment at the posterior suture were examined by scanning electron microscopy. Lenses were also labeled with ({sup 35}S)-methionine and labeling of their crystalline, cytoskeletal and membrane proteins was examined by SDS-PAGE. Rats exposed to 4 or 12 Gy developed 0.5-1.5+ or 2.5-3.0+ cataracts, respectively, 10 to 16 wks, after x-irradiation. Epithelial and equatorial cells of both groups did not significantly increase in volume during this period. Autoradiography showed that affected fibers had been epithelial cells at the time of x-irradiation.

Bredehoft, C.C.

1985-01-01

116

Rapid morphological brain abnormalities during acute methamphetamine intoxication in the rat: An experimental study using light and electron microscopy  

Microsoft Academic Search

This study describes morphological abnormalities of brain cells during acute methamphetamine (METH) intoxication in the rat and demonstrates the role of hyperthermia, disruption of the blood–brain barrier (BBB) and edema in their development. Rats with chronically implanted brain, muscle and skin temperature probes and an intravenous (i.v.) catheter were exposed to METH (9mg\\/kg) at standard (23°C) and warm (29°C) ambient

Hari S. Sharma; Eugene A. Kiyatkin

2009-01-01

117

Morphological characterization of selected balloon films and its effects on balloon performances  

NASA Astrophysics Data System (ADS)

Morphological characterization of several polyethylene balloon films have been studied using various techniques. The objective is to determine, if any, differentiating structural or morphological features that can be related to the performance of these balloon film materials. The results of the study indicate that the films are composed of either LLDPE or LDPE. A selective examination of these data imply that films with limited degree of branching and larger crystallites size (same % crystallinity) showed good mechanical properties that appear to correlate with their high level of success in balloon flights.

Said, Magdi A.

1994-02-01

118

Tracheal Morphologic and Protein Alterations Following Short-Term Cigarette Mainstream Smoke Exposure to Rats  

PubMed Central

A short-term 5-day nose-only cigarette smoke exposure study was conducted in Fisher 344 rats to identify smoke-induced tracheal protein changes. Groups of 10 male and female 5 week old rats were assigned to 1 of 4 exposure groups. Animals received filtered air, or 75, 200 or 400 mg total particulate matter (TPM)/m3 of diluted 3R4F Kentucky reference cigarette mainstream smoke. Exposures were conducted for 3 hrs/day, for 5 consecutive days. Tracheas from half the rats were processed for pathology, and tracheas from the other half of the rats frozen immediately for proteomics. We hypothesized that smoke will activate tracheal inflammatory, apoptotic, proliferative, and stress-induced pathways. Mucosal epithelial toxicity from the inhaled material was evidenced by cilia shortening and loss of tracheal mucosal epithelium in smoke-exposed animals. Mucosal thinning occurred in all smoke-exposed groups with hyperplastic reparative responses in the 200 and 400 mg TPM/m3 groups. Tracheal lysates from control vs. treated animals were screened for 800 proteins using antibody-based microarray technology and subsequently the most changed proteins evaluated by Western blot. Tracheal proteins expressed at high levels that were markedly increased or decreased by smoke exposure depended on dose and gender and included caspase 5, ERK 1/2 and p38. Signaling pathways common between the morphologic and protein changes were stress, apoptosis, cell cycle control, cell proliferation and survival. Changes in identified proteins affected by smoke exposure were associated with tracheal mucosal pathology, may induce functional tracheal changes, and could serve as early indicators of tracheal damage and associated disease.

Carter, Charleata A.; Misra, Manoj; Maronpot, Robert R.

2012-01-01

119

Correlation of morphologic brain lesions with physiologic alterations and blood-brain barrier impairment in 3-intropropionic acid toxicity in rats  

Microsoft Academic Search

3-Nitropropionic acid (NPA), a toxin which irreversibly inhibits the Krebs cycle enzyme succinate dehydrogenase, causes severe neurologic disease and a specific pattern of morphologic brain damage when given subcutaneously to rats. To determine whether hypotension or hypoxemia were necessary for development of morphologic brain lesions in NPA neurotoxicity, systemic blood pressure and arterial blood gases were measured in NPA-intoxicated rats.

B. F. Hamilton; D. H. Gould

1987-01-01

120

Glomerular dynamics and morphologic changes in the generalized Shwartzman reaction in postpartum rats.  

PubMed Central

The roles of glomerular functional and morphologic changes were examined in the acute renal failure associated with generalized Shwartzman reaction in postpartum Munich Wistar rats. The susceptibility of postpartum rats to acute deterioration in renal function after a 2-h endotoxin infusion was found to be greater than in virgin litter mates: glomerular filtration rate fell by 93% in the former vs. 24% in the latter group (P less than 0.001). In postpartum rats there were marked changes in platelet count and fibrinogen level (P less than 0.025) compatible with consumption coagulopathy. Renal blood flow and glomerular filtration rate fell from 5.5 +/- 0.9 and 0.74 +/- 0.12 to 2.0 +/- 0.7 and 0.12 +/- 0.01 ml/min, respectively (both P less than 0.001). Blood pressure did not change. Results of glomerular dynamics studies showed decreases in single nephron filtration rate from 28 +/- 7 to 6 +/- 4 nl/min and in glomerular plasma flow rate from 77 +/- 26 to 23 +/- 12 nl/min (both P less than 0.001). Afferent net ultrafiltration pressure fell from 20 +/- 3 to 5 +/- 4 mm Hg due to a fall in glomerular capillary hydraulic pressure from 47 +/- 1 to 29 +/- 5 mm Hg (P less than 0.001). There were four- and twofold increases in afferent and efferent arteriolar resistances, respectively. Less than 20% of glomeruli had evidence of fibrin deposition after 2 h of endotoxin infusion, a time when glomerular filtration rate was reduced by greater than 90%. [1-Sar, 5-Ile, 8-Gly] angiotensin II infusion before endotoxin significantly protected glomerular filtration rate, 62 vs. 7% of control in rats with no preinfusion (P less than 0.01) despite consumption coagulopathy and glomerular fibrin deposition similar to rats without pretreatment. These data suggest that the early deterioration in renal function in the generalized Shwartzman reaction in the postpartum rat is due to major changes in glomerular dynamics induced by neurohumoral agents and that glomerular fibrin deposition plays a lesser pathogenetic role at this time in this disorder. The study does not address the pathogenesis of renal failure in pregnancy nor peripartum renal failure in another species. Images

Conger, J D; Falk, S A; Guggenheim, S J

1981-01-01

121

Creation and Characterization of a Renin Knockout Rat  

PubMed Central

The renin-angiotensin system plays an important role in the control of blood pressure (BP) and renal function. To illuminate the importance of renin in the context of a disease background in vivo, we used zinc-finger nucleases (ZFNs) designed to target the renin gene and create a renin knockout in the SS/JrHsdMcwi (SS) rat. ZFN against renin caused a 10-bp deletion in exon 5, resulting in a frameshift mutation. Plasma renin activity was undetectable in the Ren?/? rat, and renin protein was absent from the juxtaglomerular cells in the kidney. Body weight was lower in the Ren?/? rats (than in the Ren+/? or wild-type littermates), and conscious BP on low-salt diet (0.4% NaCl) was 58 ± 2 mm Hg in the Ren?/? male rats versus 117 mm Hg in the Ren+/? littermates, a reduction of almost 50 mm Hg. Blood urea nitrogen (BUN) and plasma creatinine levels were elevated in the Ren?/? strain (BUN 112 ± 7 versus 23 ± 2 mg/dL and creatinine 0.53 ± 0.02 versus 0.26 ± 0.02 mg/dL), and kidney morphology was abnormal with a rudimentary inner renal medulla, cortical interstitial fibrosis, thickening of arterial walls, and abnormally shaped glomeruli. The development of the first rat knockout in the renin-angiotensin system demonstrates the efficacy of the ZFN technology for creating knockout rats for cardiovascular disease on any genetic background and emphasizes the role of renin in BP regulation and kidney function even in the low-renin SS rat.

Moreno, Carol; Hoffman, Mathew; Stodola, Timothy J.; Didier, Daniela N.; Lazar, Jozef; Geurts, Aron M.; North, Paula E.; Jacob, Howard J.; Greene, Andrew S.

2012-01-01

122

Morphological and molecular characterization of Explanatum explanatum from cattle and buffaloes in Myanmar.  

PubMed

A robust molecular marker is needed for discrimination of amphistome species, because identification based on morphology alone requires specialized knowledge and techniques. In this study, we performed morphological and molecular characterization of Explanatum explanatum, a species that causes severe liver damage in definitive host species. Fifty-five adult amphistomes were collected from cattle and water buffaloes in Myanmar. Eighteen of the amphistomes, arbitrarily chosen, were morphologically identified as E. explanatum using sagittal sections. All of the 55 amphistome isolates had identical second internal transcribed spacer (ITS2) of ribosomal DNA sequences; these sequences differed at 7 nucleotide sites from those of the closest species, Paramphistomum leydeni. Our data indicate that the ITS2 sequence could be a useful molecular marker for epidemiological studies on E. explanatum. PMID:23117826

Ichikawa, Madoka; Kondoh, Daisuke; Bawn, Saw; Maw, Ni Ni; Htun, Lat Lat; Thein, Myint; Gyi, Aung; Sunn, Kyaw; Katakura, Ken; Itagaki, Tadashi

2012-10-30

123

Characterization of Nanocomposite filler Morphology using Ultra Small-Angle X-ray Scattering  

SciTech Connect

Loading polymer matrices with nanoscale fillers is widely believed to have the potential to push polymer properties to extreme values. Realization of anticipated properties, however, has proven elusive. Recent nanocomposite research suggests better characterization of the large-scale morphology will provide insight explaining these shortfalls. This work will present ultra-small angle X-ray scattering as a viable tool for elucidating the hierarchical filler morphology that exists within polymer nanocomposites. Scattering analysis tools developed by our group will be applied to scattering data from nanocomposites filled with carbon nanotubes, layered silicates, and colloidal silica. The relationship between imaging data and scattering data will be discussed in the context of filler dispersion. Finally, the impact of large-scale filler morphology on mechanical and electrical properties will be discussed.

Justice, Ryan S.; Schaefer, Dale W. (UCIN); (AFRL)

2010-10-22

124

Morphology and distribution of neurons expressing serotonin 5-HT1A receptors in the rat hypothalamus and the surrounding diencephalic and telencephalic areas.  

PubMed

Disorders of serotonergic neurotransmission are involved in disturbances of numerous hypothalamic functions including circadian rhythm, mood, neuroendocrine functions, sleep and feeding. Among the serotonin receptors currently recognized, 5-HT(1A) receptors have received considerable attention due to their importance in the etiology of mood disorders. While previous studies have shown the presence of 5-HT(1A) receptors in several regions of the rat brain, there is no detailed map of the cellular distribution of 5-HT(1A) receptors in the rat diencephalon. In order to characterize the distribution and morphology of the neurons containing 5-HT(1A) receptors in the diencephalon and the adjacent telencephalic areas, single label immunohistochemistry was utilized. Large, multipolar, 5-HT(1A)-immunoreactive (IR) neurons were mainly detected in the magnocellular preoptic nucleus and in the nucleus of diagonal band of Broca, while the supraoptic nucleus contained mainly fusiform neurons. Medium-sized 5-HT(1A)-IR neurons with triangular or round-shaped somata were widely distributed in the diencephalon, populating the zona incerta, lateral hypothalamic area, anterior hypothalamic nucleus, substantia innominata, dorsomedial and premamillary nuclei, paraventricular nucleus and bed nucleus of stria terminalis. The present study provides schematic mapping of 5-HT(1A)-IR neurons in the rat diencephalon. In addition, the morphology of the detected 5-HT(1A)-IR neural elements is also described. Since rat is a widely used laboratory animal in pharmacological models of altered serotoninergic neurotransmission, detailed mapping of 5-HT(1A)-IR structures is pivotal for the neurochemical characterization of the neurons containing 5-HT(1A) receptors. PMID:20080175

Marvin, Eric; Scrogin, Karie; Dudás, Bertalan

2010-01-18

125

Morphological and functional characteristics of rat steady state peritoneal dendritic cells.  

PubMed

Dendritic cells (DC) are present in lymphoid organs and also in many non-lymphoid tissues. In this study, DC in the steady state peritoneal cavity of rats were identified morphologically and functionally. Approximately 1% of the peritoneal cells are DC. On cytocentrifuge preparations these cells had the same characteristics as lymph node and spleen DC: they had an irregular outline, all were strongly MHC class II positive and had acid phosphatase activity in a spot in a juxtanuclear position. Also ultrastructurally, peritoneal DC were similar to DC isolated from lymph node and spleen. Enrichment of peritoneal DC, using overnight culture and a Nycodenz gradient, resulted in a highly purified DC fraction. Functionally, peritoneal DC appeared to be very potent antigen-presenting cells, far more potent than peritoneal macrophages, which had an inhibitory rather than an accessory function. PMID:1800309

van Vugt, E; Arkema, J M; Verdaasdonk, M A; Beelen, R H; Kamperdijk, E W

1991-12-01

126

Effect of quercetine on survival and morphological properties of cultured embryonic rat spinal motoneurones.  

PubMed

Quercetine a flavonoid compound present in many plants and in the extract of Ginkgo biloba was shown to enhance the survival of purified rat spinal embryonic motoneurones, sampled at day embryonic 15 and maintained in culture for several days. Survival of embryonic spinal motoneurones is dose dependent and concentrations of quercetine ranging from 1 to 10 microM increase by 25% the number of living motoneurones in the culture. Excepted a slight significant decrease in the number of branches at day 3 and a small reduction of total neuritic length, no drastic changes in the motoneurones morphologies were observed in presence of quercetine. Results are discussed in term of neuronal protective effect of quercetine. PMID:12377378

Ternaux, Jean-Pierre; Portalier, Paule

2002-10-25

127

Characterization of the rat developmental liver transcriptome.  

PubMed

Gene regulation and transcriptome studies have been enabled by the development of RNA-Seq applications for high-throughput sequencing platforms. Next generation sequencing is remarkably efficient and avoids many issues inherent in hybridization-based microarray methodologies including the exon-specific dependence of probe design. Biologically relevant transcripts including messenger and regulatory RNAs may now be quantified and annotated regardless of whether they have previously been observed. We used RNA-Seq to investigate global patterns of gene expression in early developing rat liver. Liver samples from timed-pregnant Lewis rats were collected at six fetal and neonatal stages [embryonic day (E)14, E16, E18, E20, postnatal day (P)1, P7], transcripts were sequenced using an Illumina HiSeq 2000, and data analysis was performed with the Tuxedo software suite. Genes and isoforms differing in abundance were queried for enrichment within functionally related gene groups using the Functional Annotation Tool of the DAVID Bioinformatics Database. While hematopoietic gene expression is initiated by E14, hepatocyte maturation is a gradual process involving clusters of genes responsible for response to nutrients and enzymes responsible for glycolysis and fatty acid catabolism. Following birth, a large cluster of differentially abundant genes was enriched for mitochondrial gene expression and cholesterol synthesis indicating that by 1 wk of age, the liver is engaged in lipid sensing and bile production. Clustering results for differentially abundant genes and isoforms were similar with the greatest difference for the E14/E16 comparison. Finally, a bioinformatic approach was used to annotate 1,307 novel liver transcripts assembled from sequences that aligned to intergenic regions of the rat genome. PMID:23429212

Chapple, Richard H; Tizioto, Polyana C; Wells, Kevin D; Givan, Scott A; Kim, JaeWoo; McKay, Stephanie D; Schnabel, Robert D; Taylor, Jeremy F

2013-02-19

128

Characterization of the rat developmental liver transcriptome  

PubMed Central

Gene regulation and transcriptome studies have been enabled by the development of RNA-Seq applications for high-throughput sequencing platforms. Next generation sequencing is remarkably efficient and avoids many issues inherent in hybridization-based microarray methodologies including the exon-specific dependence of probe design. Biologically relevant transcripts including messenger and regulatory RNAs may now be quantified and annotated regardless of whether they have previously been observed. We used RNA-Seq to investigate global patterns of gene expression in early developing rat liver. Liver samples from timed-pregnant Lewis rats were collected at six fetal and neonatal stages [embryonic day (E)14, E16, E18, E20, postnatal day (P)1, P7], transcripts were sequenced using an Illumina HiSeq 2000, and data analysis was performed with the Tuxedo software suite. Genes and isoforms differing in abundance were queried for enrichment within functionally related gene groups using the Functional Annotation Tool of the DAVID Bioinformatics Database. While hematopoietic gene expression is initiated by E14, hepatocyte maturation is a gradual process involving clusters of genes responsible for response to nutrients and enzymes responsible for glycolysis and fatty acid catabolism. Following birth, a large cluster of differentially abundant genes was enriched for mitochondrial gene expression and cholesterol synthesis indicating that by 1 wk of age, the liver is engaged in lipid sensing and bile production. Clustering results for differentially abundant genes and isoforms were similar with the greatest difference for the E14/E16 comparison. Finally, a bioinformatic approach was used to annotate 1,307 novel liver transcripts assembled from sequences that aligned to intergenic regions of the rat genome.

Chapple, Richard H.; Tizioto, Polyana C.; Wells, Kevin D.; Givan, Scott A.; Kim, JaeWoo; McKay, Stephanie D.; Schnabel, Robert D.

2013-01-01

129

Effects of Butyrate on Epidermal Growth Factor Receptor Binding, Morphology, and DNA Synthesis in Cultured Rat Hepatocytes1  

Microsoft Academic Search

We have examined the effect of butyrate on morphology, DNA syn thesis, and epidermal growth factor (EGF) receptor binding in primary cultures of rat hepatocytes. Butyrate added 2 h after plating retarded the flattening and maintained the polyhedral shape of the hepatocytes in culture. Both insulin- and EGF-stimulated DNA syntheses were slightly stimulated by butyrate at 1 HIMbut strongly inhibited

Ivar P. Gladhaug; Magne Refsnes; Tor-Erik Sand; Thoralf Christoffersen

1988-01-01

130

Characterization and control of fungal morphology for improved production performance in biotechnology.  

PubMed

Filamentous fungi have been widely applied in industrial biotechnology for many decades. In submerged culture processes, they typically exhibit a complex morphological life cycle that is related to production performance--a link that is of high interest for process optimization. The fungal forms can vary from dense spherical pellets to viscous mycelia. The resulting morphology has been shown to be influenced strongly by process parameters, including power input through stirring and aeration, mass transfer characteristics, pH value, osmolality and the presence of solid micro-particles. The surface properties of fungal spores and hyphae also play a role. Due to their high industrial relevance, the past years have seen a substantial development of tools and techniques to characterize the growth of fungi and obtain quantitative estimates on their morphological properties. Based on the novel insights available from such studies, more recent studies have been aimed at the precise control of morphology, i.e., morphology engineering, to produce superior bio-processes with filamentous fungi. PMID:22771505

Krull, Rainer; Wucherpfennig, Thomas; Esfandabadi, Manely Eslahpazir; Walisko, Robert; Melzer, Guido; Hempel, Dietmar C; Kampen, Ingo; Kwade, Arno; Wittmann, Christoph

2012-07-04

131

Morphological characterization and viability assessment of Trichoderma reesei by image analysis.  

PubMed

The production of cellulase from the filamentous fungus Trichoderma reesei is a critical step in the industrial process leading to cellulose ethanol. As a result of the lack of quantitative analysis tools, the intimate relationship that exists between the morphological and physiological states of the microorganism, the shear field in the bioreactor, and the process performance is not yet fully understood. A semiautomatic image analysis protocol was developed to characterize the mycelium morphology and to estimate its percentage viability during the fermentation process based on four morphological types (unbranched, branched, entangled, and clumped microorganisms). Pictures taken under bright field microscopy combined with images of fluorescein diacetate stained fungi were used to assess the morphological parameters and the percentage viability of microorganisms simultaneously. The method was tested during the course of fed-batch fermentation in a reciprocating plate bioreactor. The use of the image analysis protocol was found to be successful in quantifying the variations in the morphology and the viability of T. reesei throughout the fermentation. PMID:17373824

Lecault, Véronique; Patel, Nilesh; Thibault, Jules

2007-03-21

132

Biochemical and morphological perturbations in rat erythrocytes exposed to ethion: protective effect of vitamin E.  

PubMed

Erythrocyte membranes are an excellent model system to study interaction of pro-oxidants with membranes. The aim of the present study is to examine the effect of vitamin E on ethion-induced biochemical and morphological alterations in erythrocytes. Ethion was administered to the rats orally at a daily dose of 2.7 mg/kg body weight for a period of 7, 14, 21 and 28 days. The results from the present study show that administration of ethion resulted in oxidative damage to erythrocyte membranes as evident by increased lipid peroxidation and decreased phospholipid content. This was accompanied by decrease in membrane cholesterol levels. In addition, ethion exposure inhibited the activities of membrane bound enzymes; Na+ K+ ATPase and Mg2+ATPase. Scanning electron micrographs of erythrocytes from animals exposed to ethion revealed morphological changes. Supplementation of vitamin E (50 mg/kg body weight) to ethion exposed animals ameliorated the ethion-induced oxidative stress, restored membrane lipid composition and activity of membrane bound enzymes along with erythrocyte shape. The results clearly demonstrate that ethion-induced damage involves increase in oxidative stress that results in alterations in erythrocyte membrane structure and function. Furthermore, supplementation with vitamin E reversed ethion induced alterations suggesting its beneficial role in individuals exposed to ethion. PMID:21366965

Bhatti, G K; Bhatti, J S; Kiran, R; Sandhir, R

2011-02-12

133

Chronic administration of risperidone in a rat model of schizophrenia: a behavioural, morphological and molecular study.  

PubMed

In the present work we analyzed the effect of the chronic administration of risperidone (2mg/kg over 65 days) on behavioural, morphological and molecular aspects in an experimental model of schizophrenia obtained by bilateral injection of ibotenic acid into the ventral hippocampus of new-born rats. Our results show that during their adult lives the animals with hippocampal lesions exhibit different alterations, mainly at behavioural level and in the gene expression of dopamine D(2) and 5-HT(2A) receptors. However, at morphological level the study performed on the prefrontal cortex did not reveal any alterations in either the thickness or the number of cells immunoreactive for c-Fos, GFAP, CBP or PV. Overall, risperidone administration elicited a trend towards the recovery of the values previously altered by the hippocampal lesion, approaching the values seen in the animals without lesions. It may be concluded that the administration of risperidone in the schizophrenia model employed helps to improve the altered functions, with no significant negative effects. PMID:23291154

Castellano, O; Arji, M; Sancho, C; Carro, J; Riolobos, A S; Molina, V; Gómez-Nieto, R; de Anchieta de Castro E Horta, José; Herrero-Turrión, M J; López, D E

2013-01-04

134

Morphology and x-ray characterization of acenaphthene, fluoranthene, and pyrene crystals grown by sublimation  

NASA Astrophysics Data System (ADS)

The preparation of relatively large of acenaphthene, fluoranthene and pyrene crystals grown from vapor phase by plate sublimation method, is described. In order to characterize the intrinsic structure perfection of such grown crystals the X-ray examinations have been performed. The observed morphologies of these crystals have been compared with that predicted from PBC theory by Hartman-Perdok, model growth conditions (vacuum, temperature gradient) effect have been assessed.

Marciniak, Bernard; Rozycka-Sokolowska, Ewa; Balinska, A.; Pawliuk, W.

2001-04-01

135

Morphological, physiological, and molecular characterization of actinomycetes isolated from dry soil, rocks, and monument surfaces  

Microsoft Academic Search

In an extended study on the biodiversity of rock-dwelling bacteria, the colony and cell morphology, physiology, protein patterns,\\u000a and 16S rDNA sequences of 17 bacterial strains isolated from different surfaces of rocks, stones, and monuments and from various\\u000a geographical locations were characterized. All except one strain, which was found to be a Bacillus, were members of the order Actinomycetales. The

Martin Eppard; Wolfgang E. Krumbein; Cathrin Koch; Erhard Rhiel; James T. Staley; Erko Stackebrandt

1996-01-01

136

Morphological and anatomical characterization of six jojoba clones at saline and non-saline sites  

Microsoft Academic Search

Various jojoba (Simmondsia chinensis (Link) Schneider) clones have been demonstrated to differ in their susceptibility to salinity in northern Chile. Our objective was to characterize the anatomical and morphological response of six of these clones when grown under saline and non-saline conditions. Two of these clones are resistant to soil salinity (4.11.32 and Mirov), based on previous field evaluations, and

Claudia Botti; David Palzkill; Diego Muñoz; Loreto Prat

1998-01-01

137

Preparation and structural characterization of bismuth ferrite crystals of different morphological types  

Microsoft Academic Search

We have studied conditions for bismuth ferrite, BiFeO3, crystallization from off-stoichiometric Bi2O3-Fe2O3 melts, obtained crystals of different morphological types (dendritic and faceted pseudocubic) up to 3 mm in size, and characterized\\u000a them by a variety of techniques (X-ray diffraction, IR spectroscopy, differential thermal analysis, X-ray structure analysis,\\u000a and X-ray microanalysis).

L. P. Kozeeva; M. Yu. Kameneva; N. V. Podberezskaya; A. I. Smolentsev; V. E. Fedorov

2011-01-01

138

Morphological characterization of soot aerosol particles during LACIS Experiment in November (LExNo)  

Microsoft Academic Search

Combined mobility and aerodynamic measurements were used to characterize the morphology of soot particles in an experimental campaign on the hygroscopic growth and activation of an artificial biomass burning aerosol. A custom-made, single-stage low-pressure impactor and two aerosol mass spectrometers (AMS) operating in the free molecular regime were used to measure the vacuum aerodynamic diameter of mobility-selected artificial soot particles

A. Kiselev; C. Wennrich; F. Stratmann; H. Wex; S. Henning; T. F. Mentel; A. Kiendler-Scharr; J. Schneider; S. Walter; I. Lieberwirth

2010-01-01

139

Effects of long-term nitrogen dioxide exposure on rat lung: morphological observations.  

PubMed Central

Rats continuously exposed to NO2 at 0.04, 0.4, and 4.0 ppm for as long as 27 months were submitted to morphological observation and electronmicroscopic morphometry of the lung. At 4 ppm exposure for 9 months, bronchial epithelium showed typical proliferation, which progressed further at 18 months. At this stage, proliferation of type II alveolar epithelium and edematous extension of interstitial tissue were evident and yielded fibrosis at 27 months. At 0.4 ppm, morphological changes in 18-month specimens were still ambiguous, although a tendency toward epithelial changes, as well as interstitial edema of the alveolar wall, was noticed under the electron microscope. Slight but definite alteration of the epithelium became evident after 27 months. At 0.04 ppm there were no remarkable changes throughout the entire exposure period. The morphometry revealed concentration- and duration-dependent increases in arithmetic mean thickness (AMT) of the alveolar wall. At 4 ppm, increase of AMT started as early as 9 months, became significant at 18 months, and showed a slight decrease at 27 months. This decrease was interpreted as a recovery of alveolar epithelium and decreased amount of septal edema, which in turn led to fibrosis. At 0.4 ppm, a slight increase of AMT started at 18 months and extended significantly in 27 months. A similar but insignificant tendency was found even at 0.04 ppm. The morphological alterations were parallel to the concentration and duration of exposure. These findings suggested that an intensive study should be conducted to confirm whether alterations were due to prolonged exposure and/or due to elevated sensitivity of the aged lung. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 12. A FIGURE 12. B FIGURE 13. FIGURE 15.

Kubota, K; Murakami, M; Takenaka, S; Kawai, K; Kyono, H

1987-01-01

140

Effect of the environment on the dendritic morphology of the rat auditory cortex  

PubMed Central

The present study aimed to identify morphological correlates of environment-induced changes at excitatory synapses of the primary auditory cortex (A1). We used the Golgi-Cox stain technique to compare pyramidal cells dendritic properties of Sprague-Dawley rats exposed to different environmental manipulations. Sholl analysis, dendritic length measures, and spine density counts were used to monitor the effects of sensory deafness and an auditory version of environmental enrichment (EE). We found that deafness decreased apical dendritic length leaving basal dendritic length unchanged, whereas EE selectively increased basal dendritic length without changing apical dendritic length. On the contrary, deafness decreased while EE increased spine density in both basal and apical dendrites of A1 layer 2/3 (LII/III) neurons. To determine whether stress contributed to the observed morphological changes in A1, we studied neural morphology in a restraint-induced model that lacked behaviorally relevant acoustic cues. We found that stress selectively decreased apical dendritic length in the auditory but not in the visual primary cortex. Similar to the acoustic manipulation, stress-induced changes in dendritic length possessed a layer specific pattern displaying LII/III neurons from stressed animals with normal apical dendrites but shorter basal dendrites, while infragranular neurons (layers V and VI) displayed shorter apical dendrites but normal basal dendrites. The same treatment did not induce similar changes in the visual cortex, demonstrating that the auditory cortex is an exquisitely sensitive target of neocortical plasticity, and that prolonged exposure to different acoustic as well as emotional environmental manipulation may produce specific changes in dendritic shape and spine density.

Bose, Mitali; Munoz-Llancao, Pablo; Roychowdhury, Swagata; Nichols, Justin A.; Jakkamsetti, Vikram; Porter, Benjamin; Byrapureddy, Rajasekhar; Salgado, Humberto; Kilgard, Michael P.; Aboitiz, Francisco; Dagnino-Subiabre, Alexies; Atzori, Marco

2010-01-01

141

Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats  

PubMed Central

Background Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats. Methods Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF) stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB) at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed en bloc and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 ?m wide peri-implant volume of interest (VOI). Results Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (P < .05). Differences in trabecular-thickness and -separation around implants in all groups were similar (P > .05) while the difference in trabecular-number among test and control groups was significant in all VOIs (P < .05). Conclusion Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.

Akca, Kivanc; Sarac, Ebru; Baysal, Ugur; Fanuscu, Mete; Chang, Ting-Ling; Cehreli, Murat

2007-01-01

142

Maternal postnatal high-fat diet, rather than gestational diet, affects morphology and mTOR pathway in skeletal muscle of weaning rat.  

PubMed

The positive regulation of insulin pathway in skeletal muscle results in increased activity of the mammalian target of rapamycin (mTOR), a positive effector of mRNA translation rate and protein synthesis. Studies that assess the activity of this protein in response to chronic high-fat diet (HFD) are scarce and controversial, and to date, there are no studies evaluating the mTOR pathway in infants exposed to gestational and postgestational HFD. This study investigated the effect of maternal HFD on skeletal muscle morphology and on phosphorylation of proteins that comprise the intracellular mTOR signaling pathway in soleus muscle of offspring at weaning. For this purpose, 10 days prior to conception, 39 female Wistar rats were randomly assigned to either control diet (CTL) or HFD. Later, rats were distributed into four groups according to gestational and postpregnancy diet: CTL/CTL (n=10), CTL/HF (n=11), HF/HF (n=10) and HF/CTL (n=8). After 21 days of lactation, pups were killed, and blood samples and soleus and gastrocnemius skeletal muscle were collected for analysis. We observed an influence of maternal postgestational diet, rather than gestational diet, in promoting an obese phenotype, characterized by body fat accumulation, insulin resistance and high serum leptin, glucose, triglycerides and cholesterol levels (P<.05). We have also detected alterations on skeletal muscle morphology--with reduced myofiber density--and impairment on S6 kinase 1 and 4E binding protein-1 phosphorylation (P<.05). These results emphasize the importance of maternal diet during lactation on muscle morphology and on physiological adaptations of infant rats. PMID:23333087

Pantaleão, Lucas C; Teodoro, Gabriela F R; Torres-Leal, Francisco L; Vianna, Daiana; de Paula, Tatyana D; de Matos-Neto, Emídio M; Trindade, Michele C C; Rogero, Marcelo M; Bueno, Carlos R; Tirapegui, Julio

2013-01-17

143

Species identification of Hypoderma affecting domestic and wild ruminants by morphological and molecular characterization.  

PubMed

Cuticular structures and the sequence of the cytochrome oxidase I gene were compared for Hypoderma bovis (Linnaeus), Hypoderma lineatum (De Villers), Hypoderma actaeon Brauer, Hypoderma diana Brauer and Hypoderma tarandi (Linnaeus) (Diptera, Oestridae). Third-stage larvae of each species were examined by scanning electron microscopy revealing differences among species in the pattern and morphology of spines on the cephalic and thoracic segments, by spine patterns on the tenth abdominal segment, and by morphology of the spiracular plates. The morphological approach was supported by the molecular characterization of the most variable region of the cytochrome oxidase I (COI) gene of these species, which was amplified by polymerase chain reaction and analysed. Amplicons were digested with the unique restriction enzyme, BfaI, providing diagnostic profiles able to simultaneously differentiate all Hypoderma species examined. These findings confirm the utility of morphological characters for differentiating the most common Hypoderma larvae and reconfirm the power of the COI gene for studying insect identification and systematics. PMID:12941017

Otranto, D; Colwell, D D; Traversa, D; Stevens, J R

2003-09-01

144

Characterization of Gastric Na +\\/I ?Symporter of the Rat  

Microsoft Academic Search

Characterization of gastric Na+\\/I?symporter (NIS) of the rat was carried out. Sequencing of the open reading frame of gastric NIS mRNA showed only three nucleotide changes when compared with FRTL-5 NIS cDNA, and two of these changes led to amino acid changes. The results of Northern blot analysis showed that abundant NIS mRNA was expressed in the stomach when compared

Tomio Kotani; Yoshikazu Ogata; Ikuo Yamamoto; Yatsuki Aratake; Jun-Ichi Kawano; Tatsuo Suganuma; Sachiya Ohtaki

1998-01-01

145

Development and characterization of new rat monoclonal antibodies for procalcitonin  

Microsoft Academic Search

The development of selective and sensitive biological recognition elements, e.g., antibodies, for the detection of relevant\\u000a blood markers is a great challenge in the field of biosensors. In this context, five new rat monoclonal antibodies (mAbs)\\u000a for procalcitonin (PCT), a marker for bacterial infection and sepsis, were developed and characterized. One mAb, PROC1 3G3,\\u000a was used as capture antibody. Four

Petra M. Krämer; Marie-Françoise Gouzy; Melanie Keß; Ulrike Kleinschmidt; Elisabeth Kremmer

2008-01-01

146

Determination and Characterization of a Cannabinoid Receptor in Rat Brain  

Microsoft Academic Search

SUMMARY The determination and characterization of a cannabinoid receptor from brain are reported. A biologically active bicyclic cannabinoid analgetic CP-55,940 was tntium-Iabeled to high specific activity. Conditions for binding to rat brain P2 membranes and synapto- somes were established. The pH optimum was between 7 and 8, and specific binding could be eliminated by heating the mem- branes to 60#{176}.

WILLIAM A. DEVANE; FRANCIS A. DYSARZ; M. ROSS JOHNSON III; LAWRENCE S. MELVIN; ALLYN C. HOWLETT

147

Morphological characterization of the progenitor blood cells in canine and feline umbilical cord.  

PubMed

The umbilical cord blood (UCB) is an important source of hematopoietic stem cells with great deal of interest in regenerative medicine. The UCB cells have been extensively studied as an alternative to the bone marrow transplants. The challenge is to define specific methods to purify and characterize these cells in different animal species. This study is aimed at morphological characterization of progenitor cells derived from UCB highlighting relevant differences with peripheral blood of adult in dog and cats. Therefore, blood was collected from 18 dogs and 5 cats' umbilical cords from fetus in various developmental stages. The mononuclear cells were separated using the gradient of density Histopaque-1077. Characterization of CD34+ cells was performed by flow cytometric analysis and transmission electron microscopy. Granulocytes (ancestry of the basophiles, eosinophiles, and neutrophiles) and agranulocytes (represented by immature lymphocytes) were identified. We showed for the first time the ultrastructural features of cat UCB cells. PMID:22131289

Brólio, Marina P; Vidane, Atanásio S; Zomer, Helena D; Wenceslau, Cristiane V; Ozório, Juliana J; Martins, Daniele S; Miglino, Maria A; Ambrósio, Carlos E

2011-12-01

148

Mathematical morphology: detection and characterization of directed axonal growth in vitro  

NASA Astrophysics Data System (ADS)

Neurite growth in vitro, neuritogenesis, is a widespread methodology in the field of developmental neurobiology. Morphological analysis of growing neurites is usually a difficult task because of their thinness and their low contrast that makes it difficult to observe clearly their shape, number, length and spatial orientation. This paper presents the use of the granulometric size distribution function to obtain, automatically, information about the shape, size and spatial orientation of growing axons in tissue cultures. The results presented show the efficiency of the granulometric size distribution for this application. The automatic detection of growing axons and the precise characterization of a relevant parameter, indicative of the axonal growth spatial orientation, was obtained by this morphological tool. The developed algorithms facilitates the analysis of these images by automatically quantifying the angle of deviation of the direction of growth, which is important given the large number of images that need to be processed for this type of study.

Gonzalez, M. A.; Ballarin, V. L.; Rapacioli, M.; Rodríguez Celín, A.; Sánchez, V.; Flores, V.

2011-12-01

149

A comprehensive physico-chemical, mineralogical and morphological characterization of Indian mineral wastes.  

PubMed

This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy-energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies. PMID:23255170

Gedam, Vidyadhar V; Jha, Rajesh; Labhasetwar, Pawan; Engelsen, Christian J

2012-12-20

150

Low-level phenolic estrogen pollutants impair islet morphology and ?-cell function in isolated rat islets.  

PubMed

Phenolic estrogen pollutants, a class of typical endocrine-disrupting chemicals, have attracted public attention due to their estrogenic activities of imitating steroid hormone 17?-estradiol (E(2)) effects. Exposure to these pollutants may disrupt insulin secretion and be a risk factor for type 2 diabetes. In this study, we investigated the direct effects of phenolic estrogen diethylstilbestrol (DES), octylphenol (OP), nonylphenol (NP), and bisphenol A (BPA) on rat pancreatic islets in vitro, whose estrogenic activities were DES>NP>OP>BPA. Isolated ?-cells were exposed to E(2), DES, OP, NP, or BPA (0, 0.1, 0.5, 2.5, 25, and 250??g/l) for 24?h. Parameters of insulin secretion, content, and morphology of ?-cells were measured. In the glucose-stimulated insulin secretion test, E(2) and DES increased insulin secretion in a dose-dependent manner in a 16.7?mM glucose condition. However, for BPA, NP, or OP with lower estrogenic activity, the relationship between the doses and insulin secretion was an inverted U-shape. Moreover, OP, NP, or BPA (25??g/l) impaired mitochondrial function in ?-cells and induced remarkable swelling of mitochondria with loss of distinct cristae structure within the membrane, which was accompanied by disruption of mRNA expression of genes playing a key role in ?-cell function (Glut2 (Slc2a2), Gck, Pdx1, Hnf1?, Rab27a, and Snap25), and mitochondrial function (Ucp2 and Ogdh). Therefore, these phenolic estrogens can disrupt islet morphology and ?-cell function, and mitochondrial dysfunction is suggested to play an important role in the impairment of ?-cell function. PMID:22946080

Song, Liqiong; Xia, Wei; Zhou, Zhao; Li, Yuanyuan; Lin, Yi; Wei, Jie; Wei, Zhengzheng; Xu, Bing; Shen, Jie; Li, Weiyong; Xu, Shunqing

2012-09-03

151

Electrophysiological and morphological properties of neurons in layer 5 of the rat postrhinal cortex.  

PubMed

The postrhinal (POR) cortex of the rat is homologous to the parahippocampal cortex of the primate based on connections and other criteria. POR provides the major visual and visuospatial input to the hippocampal formation, both directly to CA1 and indirectly through connections with the medial entorhinal cortex. Although the cortical and hippocampal connections of the POR cortex are well described, the physiology of POR neurons has not been studied. Here, we examined the electrical and morphological characteristics of layer 5 neurons from POR cortex of 14- to 16-day-old rats using an in vitro slice preparation. Neurons were subjectively classified as regular-spiking (RS), fast-spiking (FS), or low-threshold spiking (LTS) based on their electrophysiological properties and similarities with neurons in other regions of neocortex. Cells stained with biocytin included pyramidal cells and interneurons with bitufted or multipolar dendritic patterns. Similarity analysis using only physiological data yielded three clusters that corresponded to FS, LTS, and RS classes. The cluster corresponding to the FS class was composed entirely of multipolar nonpyramidal cells, and the cluster corresponding to the RS class was composed entirely of pyramidal cells. The third cluster, corresponding to the LTS class, was heterogeneous and included both multipolar and bitufted dendritic arbors as well as one pyramidal cell. We did not observe any intrinsically bursting pyramidal cells, which is similar to entorhinal cortex but unlike perirhinal cortex. We conclude that POR includes at least two major classes of neocortical inhibitory interneurons, but has a functionally restricted cohort of pyramidal cells. PMID:22522564

Sills, Joseph B; Connors, Barry W; Burwell, Rebecca D

2012-04-23

152

Metabolic compartmentation of glutamate and glutamine: morphological evidence obtained by quantitative immunocytochemistry in rat cerebellum.  

PubMed

An electron microscopic, double-labelling immunocytochemical procedure was used to assess the level of fixed glutamate and glutamine in different cell profiles in ultrathin sections of rat cerebellar cortex. The procedure was based on sequential immunolabelling with two rabbit antisera, using gold particles of different sizes as markers and formaldehyde vapour as a means to avoid interference between the two incubations. Model sections containing a series of known concentrations of the respective amino acids (aldehyde--fixed to rat brain protein) were incubated together with the tissue material. These revealed a close to linear relationship between gold particle density and antigen concentration throughout the range of biological relevance. The ratio between the density of the two categories of gold particles was calculated for the individual profile types. This ratio showed a 20-fold variation, with the highest glutamate/glutamine ratios obtained for putative excitatory terminals (terminals of parallel fibres in the outer part of the molecular layer, followed by mossy and climbing fibre boutons) and the lowest for glial cells (Bergmann glia, astrocytes in the granule cell layer, and oligodendrocytes). Granule cell bodies and dendrites, and cell bodies and processes of putative GABAergic cells (Purkinje, basket and Golgi cells) displayed intermediate ratios. The ratios corresponded to millimolar ratios (mM fixed glutamate/mM fixed glutamine) ranging from 4.5 to 0.2, tentatively assessed by adjusting for differences in labelling efficiency of the two antigens. Our results show that the compartmentation of glutamate and glutamine, an issue previously addressed mainly in the test tube, can be studied in morphologically intact preparations at a resolution that matches the complexity of CNS tissue. The data indicate that glutamate is effectively converted to glutamine in all categories of glial cells, and that glutamate synthesis prevails in each of the three types of excitatory terminals in the cerebellar cortex. Terminals of putative GABAergic cells form a distinct low glutamate/low glutamine compartment. PMID:1347649

Ottersen, O P; Zhang, N; Walberg, F

1992-01-01

153

Preliminary Morphological and Immunohistochemical Changes in Rat Hippocampus Following Postnatal Exposure to Sodium Arsenite  

PubMed Central

The effects of arsenic exposure during rapid brain growth period (RBGP) (postnatal period 4-11) on pyramidal neurons of cornu ammonis (specifically CA1 and CA3 regions) and granule cells of dentate gyrus (DG) of rat hippocampus were studied. Wistar rat pups, subdivided into the control (group I) and the experimental groups (group II, III, and IV), received distilled water and sodium arsenite (aqueous solution of 1.0, 1.5, and 2.0 mg/kg body weight, respectively) by intraperitoneal (i.p.) route. On postnatal day (PND) 12, the animals were sacrificed and brain tissue obtained. Paraffin sections (8 ?m thick) stained with Cresyl Violet (CV) were observed for morphological and morphometric parameters. Arsenic induced programmed cell death (apoptosis) was studied using Terminal deoxyribonucleotidyl transferase mediated dUTP biotin Nick End Labeling (TUNEL) technique on the paraffin sections. Microscopy revealed decreased number and isolation of pyramidal neurons in superficial layers, misalignments of pyramidal cells in stratum pyramidale (SP) of CA1 and CA3 in experimental group III and IV, and presence of polymorphic cells in subgranular zone of ectal limb of dentate gyrus (suggestive of arsenic induced proliferation and migration of granule cells in the dentate gyrus). Morphometric assessments quantified and confirmed the microscopic findings. The mean nuclear area of pyramidal cells was increased and cell density was decreased in the CA1, CA3, and DG of experimental groups in comparison to the control group. Increase in the TUNEL positive cells in DG was observed in the experimental group IV, suggestive of increased apoptosis. These observations confirm vulnerability of pyramidal (CA1, CA3) and granule cells (DG) of hippocampus during RBGP.

Kaler, Saroj; Dhar, Pushpa; Bhattacharya, Arnab; Mehra, Raj D.

2013-01-01

154

Comparative metabolism, thermoregulation and morphology in two populations of vlei rats (Otomys irroratus).  

PubMed

The Hogsback (32 degrees 33S 26 degrees 57E) and Alice (32 degrees 47S 26 degrees 50E), Eastern Cape, South Africa, are separated by only 24 km but by 1000 m in altitude and fall into different climatic regions. Thermal responses (energy expenditure and body temperature) to ambient temperature were measured in a population of vlei rats (Otomys irroratus) from each of the two localities. We predicted that animals from the colder Hogsback would show differences in their thermal physiology and morphology consistent with better cold-resistance. Basal metabolic rates of the Hogsback population were slightly, but not significantly, higher than the Alice population (23.9 J g-1 h-1 vs 22.3 J g-1 h-1), but the slope of the regression between energy expenditure and ambient temperature below the thermal neutral zone was significantly lower (-1.28 vs -1.60). Body temperature, although quite variable in both populations, was not significantly influenced by ambient temperature in the Hogsback population, whereas that of Alice animals was. Fur length was longer and relative size of the ears and tail was smaller in the Hogsback population, which probably accounted for the slightly lower minimum thermal conductance (1.79 J g-1 h-1 degree C-1 vs 1.91 J g-1 h-1 degree C-1) in the Hogsback population. Vlei rats from the two sites also have different karyotypes that correlate with climate but there is insufficient evidence at present to suggest that the different karyotypes and the physiological parameters measured are adaptive. PMID:10093904

Brown, C R; Everitt, V J; Baxter, R M

1999-02-01

155

Alterations in Rat Fetal Morphology Following Abuse Patterns of Toluene Exposure  

PubMed Central

Toluene is a commonly abused organic solvent. Inhalant abusers are increasingly women in their prime childbearing years. Children born to mothers who abused solvents during pregnancy may exhibit characteristics of a “fetal solvent syndrome” which may include dysmorphic features. This study examined the teratological effects of an abuse pattern of binge toluene exposure during gestation on skeletal and soft tissue abnormalities, body weight, and body size in fetal rats. Pregnant Sprague–Dawley rats were exposed for 30 min, twice daily, from gestational day (GD) 8 through GD20 to either air (0 ppm), 8,000 ppm, 12,000 ppm, or 16,000 ppm toluene. Two-thirds of each litter was prepared for skeletal examination using Alizarin Red S staining while the remaining third of each litter was fixed in Bouin’s solution for Wilson’s soft tissue evaluation. Exposure to toluene at all levels significantly reduced growth, including decreases in placental weight, fetal weight, and crown-rump length. In addition, numerous gross morphological anomalies were observed such as short or missing digits and missing limbs. Skeletal examination revealed that ossification of the extremities was significantly reduced as a result of toluene exposure at all levels. Specific skeletal defects included misshapen scapula, missing and supernumerary vertebrae and ribs, and fused digits. Soft tissue anomalies were also observed at all toluene levels and there was a dose-dependent increase in the number of anomalies which included cryptorchidism, displaced abdominal organs, gastromegaly, distended/hypoplastic bladder, and delayed cardiac development, among others. These results indicate that animals exposed prenatally to levels and patterns of toluene typical of inhalant abuse are at increased risk for skeletal and soft tissue abnormalities.

Bowen, Scott E.; Irtenkauf, Susan; Hannigan, John H.; Stefanski, Adrianne L.

2009-01-01

156

Beneficial effects of ventromedial hypothalamus (VMH) lesioning on function and morphology of the liver after hepatectomy in rats.  

PubMed

Liver has a high regenerative capacity and restores its mass and function shortly after partial hepatectomy through increased proliferation and metabolic modification of hepatocytes. The proliferation of hepatocytes can be triggered by its mass reduction after hepatectomy or by the neural factors including lesioning of the ventromedial hypothalamus (VMH). In the present study, we examined the effect of VMH lesioning on liver regeneration in hepatectomized rats by evaluating liver function and morphology. We found that functional deficits caused by partial hepatectomy [prolonged prothrombin time (PT), increased indocyanine green (ICG) retention, and decrease in PAS (periodic Acid-Schiff staining)-positive hepatocytes] were restored by VMH lesioning at 1 week after the surgery, whereas these alterations disappeared at 4 weeks. Morphologically, lipid microdroplets, which are considered to be important for maintaining contiguous liver function via supplying fuel for cell proliferation, were found to accumulate in hepatocytes of the hepatectomized rats at early period (1 day) after partial hepatectomy. Interestingly, such lipid microdroplets were also detected in the VMH lesioned rats and the more abundantly in the VMH lesioned, hepatectomized rats up to 1 week after the surgery. In conclusion, our results suggest that VMH lesioning in rats promotes recovery of liver anatomically and functionally after partial hepatectomy by promoting cell proliferation process. PMID:21962532

Lee, Eun Young; Inoue, Shuji; Senoo, Akira; Shimizu, Hiroyuki; Suzuki, Yoko; Ishizuka, Noriko; Imazeki, Nobuo; Sasaki, Kahoru; Kako, Masako; Osaka, Toshimasa; Miki, Takashi

2011-09-14

157

The morphological and developmental changes of the anterior commissure of male Wistar rats submitted to protein malnutrition in the postnatal period.  

PubMed

The aim of this project was to study the effects of protein malnutrition in the anterior commissure of male albino Wistar rats, submitted to diets with different levels of protein to evaluate the possible morphological and developmental changes of the myelinated nervous fibers and glial cells of this important neural structure during the postnatal period until 120 days of age. In this study the animals (dams and pups) were divided into three groups: the control group which received a commercial diet from the laboratory (22% protein); the nourished group which received a diet of 16% of protein (casein); and the malnourished group which received a diet of 6% of protein (casein). Rat pups were fed by lactating females during the lactation period. After weaning the pups received the same diet until 120 days of age. The results obtained showed that the malnourished animals presented less body and brain growth and important morphological changes in the anterior commissure such as the retard in the myelination, damaged myelinic nervous fibers, and the increase of the interstitial space characterizing edema and vacuolization. The current study shows that the effects of protein malnutrition in the anterior commissure cause a bigger alteration in the posterior limb of the referred commissure, indicating that it is more vulnerable to malnutrition and more susceptible to damages of the anterior limb. PMID:22889551

Pacagnella, Patrícia Aparecida Pereira; Parpinelli, Patrícia Maria Santos D'Andrea; Lachat, João-José

2012-08-08

158

Electrophysiological and morphological characteristics of three subtypes of rat globus pallidus neurone in vitro.  

PubMed

Neurones of the globus pallidus (GP) have been classified into three subgroups based on the visual inspection of current clamp electrophysiological properties and morphology of biocytin-filled neurones. Type A neurones (132/208; 63 %) were identified by the presence of the time- and voltage-dependent inward rectifier (Ih) and the low-threshold calcium current (It) giving rise to anodal break depolarisations. These cells were quiescent or fired regular spontaneous action potentials followed by biphasic AHPs. Current injection evoked regular activity up to maximum firing frequency of 350 Hz followed by moderate spike frequency adaptation. The somata of type A cells were variable in shape (20 x 12 micrometer) while their dendrites were highly varicose. Type B neurones (66/208; 32 %) exhibited neither Ih nor rebound depolarisations and only a fast monophasic AHP. These cells were spontaneously active while current injection induced irregular patterns of action potential firing up to a frequency of 440 Hz with weak spike frequency adaptation. Morphologically, these cells were the smallest encountered (15 x 10 micrometer), oval in shape with restricted varicose dendritic arborisations. Type C neurones were much rarer (10/208; 5 %). They were identified by the absence of Ih and rebound depolarisations, but did possess a prolonged biphasic AHP. They displayed large A-like potassium currents and ramp-like depolarisations in response to step current injections, which induced firing up to a maximum firing frequency of 310 Hz. These cells were the largest observed (27 x 15 micrometer) with extensive dendritic branching. These results confirm neuronal heterogeneity in the adult rodent GP. The driven activity and population percentage of the three subtypes correlates well with the in vivo studies (Kita & Kitai, 1991). Type A cells appear to correspond to type II neurones of Nambu & Llinas (1994, 1997) while the small diameter type B cells display morphological similarities with those described by Millhouse (1986). The rarely encountered type C cells may well be large cholinergic neurones. These findings provide a cellular basis for the study of intercellular communication and network interactions in the adult rat in vitro. PMID:10970430

Cooper, A J; Stanford, I M

2000-09-01

159

Characterization and subcellular distribution of somatogenic receptor in rat liver  

SciTech Connect

Binding of (/sup 125/I)iodobovine GH ((/sup 125/I)iodo-bGH) to rat liver microsomes and Golgi/endosomal fractions isolated from male and female rats has been characterized. Binding of bGH to a pure somatogenic site was suggested by the finding that 50% inhibition of (/sup 125/I)iodo-bGH binding required 5-130 ng bGH, rGH, or hGH/incubation, while around 500 ng rat PRL/incubation were needed to obtain the same effect. Binding of (/sup 125/I)iodo-bGH to microsomes and Golgi/endosomes was time, temperature, and protein dependent. Maximal specific binding occurred at 15-16 and 15-20 h at 22 C in Golgi and microsomal membranes, respectively. Subcellular distribution studies demonstrated in the Golgi/endosomal fractions compared to the total particulate fraction, while residual microsomes devoid of Golgi/endosomal-derived components were approximately 2-fold enriched. Low levels of somatogenic receptors were detected in lysosome-enriched fractions. Removal of endogenous ligand by treating Golgi/endosomal membranes with 3M MgCl/sub 2/ increased specific binding of bGH about 2- to 3-fold. These results indicate that approximately 50% of specific somatogenic binding sites in the low density fractions represent internalized ligand-receptor complexes. The level of rat liver somatogenic receptors did not show a pronounced sex differentiation; however, an endocrine dependence of somatogenic receptor levels is suggested by the finding that livers from rats in the late stages of pregnancy had a level of somatogenic receptors exceeding that of nonpregnant rats.

Husman, B.; Andersson, G.; Norstedt, G.; Gustafsson, J.A.

1985-06-01

160

Functional and molecular characterization of rat intestinal prolidase.  

PubMed

Genetic deficiency of prolidase can lead to severe problems in child development, including mental retardation. However, the exact pathogenesis of the disease is unclear. To understand the enzyme's physiologic functions, we studied the regulation of rat intestinal prolidase. The results indicated that 1) the activities of intestinal prolidase and its kinetic parameters (Km and Vmax) are site-dependent; 2) the jejunal prolidase activity was the most sensitive to the dietary restriction, and the duodenal and jejunal but not colonic kinetic parameters changed with dietary restriction; 3) the pH activity profile of jejunal prolidase at 24 h postfeeding was different from that at 48 h postfeeding, whereas the inhibition profiles of prolidase were qualitatively independent of dietary restriction; and 4) old-aged rats have lower prolidase activities in the small intestine. We also purified rat intestinal prolidase I to homogeneity. The characterization study indicated that the purified rat intestinal prolidase I is fairly similar to prolidase I from other species with a molecular weight of 116,000, which consisted of two monomers, 58,000 D each. The purified prolidase I has a Km value of 178 microM and a Vmax value of 601 micromol x min-1. mg protein-1. Screening of a rat intestinal cDNA library produced a 1.8-kb fragment that encodes the rat intestinal prolidase. This enzyme has 494 deduced amino acid sequence, which is 96% or 86% identical to mouse or human erythrocyte prolidase I. This represents the first report of a successful attempt to purify and clone an intestinal prolidase and of investigation to study prolidase regulation by diet. PMID:12646727

Hu, Ming; Cheng, Zhengqi; Zheng, Lixing

2003-03-19

161

Morphology and Physiology of Excitatory Neurons in Layer 6b of the Somatosensory Rat Barrel Cortex.  

PubMed

Neocortical lamina 6B (L6B) is a largely unexplored layer with a very heterogeneous cellular composition. To date, only little is known about L6B neurons on a systematic and quantitative basis. We investigated the morphological and electrophysiological properties of excitatory L6B neurons in the rat somatosensory barrel cortex using whole-cell patch-clamp recordings and simultaneous biocytin fillings. Subsequent histological processing and computer-assisted 3D reconstructions provided the basis for a classification of excitatory L6B neurons according to their structural and functional characteristics. Three distinct clusters of excitatory L6B neurons were identified: (C1) pyramidal neurons with an apical dendrite pointing towards the pial surface, (C2) neurons with a prominent, "apical"-like dendrite not oriented towards the pia, and (C3) multipolar spiny neurons without any preferential dendritic orientation. The second group could be further subdivided into three categories termed inverted, "tangentially" oriented and "horizontally" oriented neurons. Furthermore, based on the axonal domain two subcategories of L6B pyramidal cells were identified that had either a more barrel-column confined or an extended axonal field. The classification of excitatory L6B neurons provided here may serve as a basis for future studies on the structure, function, and synaptic connectivity of L6B neurons. PMID:22944531

Marx, Manuel; Feldmeyer, Dirk

2012-09-01

162

Morphology and mechanical behavior of TTCP-derived calcium phosphate cement subcutaneously implanted in rats.  

PubMed

A pre-hardened, TTCP-derived CPC was immersed in Hanks' solution as well as subcutaneously implanted into abdomen of rats. The implant-soft tissue interfacial morphology was examined and properties of the CPC were evaluated and compared under in vitro and in vivo conditions. The results indicate that the surface of immersed samples appeared rougher and more porous than that of implanted samples and was covered with a layer of fine apatite crystals. The CPC samples implanted for 4 weeks or longer were surrounded by a layer of fibrous tissue, which was further surrounded by a soft tissue capsule comprising numerous fat cells. The soft tissue capsule had a non-uniform distribution in thickness, which increased most significantly between 4 weeks and 12 weeks after implantation. None of polymorphic cells, osteoblast cells or bone cells adjacent to the implant were observed. The majority of original TTCP powder was transformed into apatite after 1 day of either immersion in Hanks' solution or implantation. The average porosity values of samples immersed in Hanks' solution for 4 weeks or longer were significantly larger than those immersed for 1 day or 1 week. The porosity values of samples implanted for different times were not significantly different. The DTS values of Hanks' solution-immersed samples largely decreased after a few weeks of immersion. The implanted samples maintained their strengths throughout the study. PMID:18185915

Tsai, C H; Ju, C P; Chern Lin, J H

2008-01-10

163

Morphological and molecular changes in aging rat prelimbic prefrontal cortical synapses.  

PubMed

Age-related impairments of executive functions appear to be related to reductions of the number and plasticity of dendritic spine synapses in the prefrontal cortex (PFC). Experimental evidence suggests that synaptic plasticity is mediated by the spine actin cytoskeleton, and a major pathway regulating actin-based plasticity is controlled by phosphorylated LIM kinase (pLIMK). We asked whether aging resulted in altered synaptic density, morphology, and pLIMK expression in the rat prelimbic region of the PFC. Using unbiased electron microscopy, we found an approximate 50% decrease in the density of small synapses with aging, while the density of large synapses remained unchanged. Postembedding immunogold revealed that pLIMK localized predominantly to the postsynaptic density where it was increased in aging synapses by approximately 50%. Furthermore, the age-related increase in pLIMK occurred selectively within the largest subset of prelimbic PFC synapses. Because pLIMK is known to inhibit actin filament plasticity, these data support the hypothesis that age-related increases in pLIMK may explain the stability of large synapses at the expense of their plasticity. PMID:22727942

Bloss, Erik B; Puri, Rishi; Yuk, Frank; Punsoni, Michael; Hara, Yuko; Janssen, William G; McEwen, Bruce S; Morrison, John H

2012-06-22

164

The ameliorating effect of dantrolene on the morphology of urinary bladder in spinal cord injured rats.  

PubMed

In animal models of spinal cord injury (SCI), the urinary bladder can undergo significant structural and physiological alterations. Dantrolene has been shown to be neuroprotective by reducing neuronal apoptosis after SCI. Furthermore, in addition to its anti-inflammatory and antioxidant properties, it appears to have a beneficial action on voiding, once this drug acts on the external urethral sphincter relaxation. In the present study, we investigated the effects of dantrolene on urinary bladder injury that follows experimental SCI. Forty-six male Wistar rats were laminectomized at T13, and a compressive trauma was performed to induce SCI. After euthanasia, the urinary bladder was removed for gross and histological evaluation. Traumatized animals showed urinary retention with severe hemorrhagic cystitis. Injured animals treated with dantrolene had less bladder hemorrhage and inflammatory infiltrate than those treated with placebo (p<0.05). Our results demonstrate that dantrolene may protect against urinary bladder lesions that follow SCI. Treating spinal cord-injured patients with this agent may be a promising additional therapeutic strategy to alleviate the accompanying inflammatory process. The results of the current study show that dantrolene has protective effects on spinal cord contusion-induced urinary bladder injury. The impaired integrity of bladder morphology was ameliorated by dantrolene treatment. PMID:22075388

Torres, Bruno; Serakides, Rogéria; Caldeira, Fátima; Gomes, Mardelene; Melo, Eliane

2011-11-08

165

Corticosterone treatment impairs auditory fear learning and the dendritic morphology of the rat inferior colliculus.  

PubMed

Stress leads to secretion of the adrenal steroid hormone corticosterone (CORT). The aim of this study was to determine the effects of chronic CORT administration on auditory and visual fear conditioning. Male Sprague-Dawley rats received CORT (400 mg/ml) in their drinking water for 10 consecutive days; this treatment induces stress levels of serum CORT. CORT impaired fear conditioning (F((1,28)) = 11.52, p < 0.01) and extinction (F((1,28)) = 4.86, p < 0.05) of auditory fear learning, but did not affect visual fear conditioning. In addition, we analyzed the CORT effects on the neuronal morphology of the inferior colliculus (flat neurons, auditory mesencephalon, a key brain area for auditory processing) and superior colliculus (wide-field neurons, related to visual processing) by Golgi stain. CORT decreased dendritic arborization of inferior colliculus neurons by approximately 50%, but did not affect superior colliculus neurons. Thus, CORT had more deleterious effects on the auditory fear processing than the visual system in the brain. PMID:23088831

Dagnino-Subiabre, Alexies; Pérez, Miguel Ángel; Terreros, Gonzalo; Cheng, Michelle Y; House, Patrick; Sapolsky, Robert

2012-10-23

166

Morphologic and morphometric evaluation of experimental acute crush injuries of the sciatic nerve of rats.  

PubMed

In order to qualify and quantify nerve fiber lesion following an acute crush injury, a morphologic and morphometric study was carried out in 25 Wistar rats divided into five groups of five animals each according to the crushing load applied, i.e., 500, 1,000, 5,000, 10,000, and 15,000 g. The injury was produced under general anesthesia on a 5mm-long intermediate segment of the right sciatic nerve for 10 min using a dead-weight machine. The animals were killed with an excessive dose of anesthetics 72 h later and submitted to perfusion with a fixing solution through the abdominal aorta immediately after death. Both the right and left sciatic nerves were removed and prepared for histologic and morphometric examinations; 5 microm-thick sections stained with 1% Toluidine blue were examined under a light microscope equipped with a video camera linked to a computer loaded with a graphic program (KS 400). The morphometric studies included measuring total number of fibers, fiber density, fiber diameter, myelin fiber area, axon diameter, axon area and G ratio. The results showed that damage to the nerve fibers began to appear as early as with the 500 g load and was similar in all groups despite the load applied, increasing with the 10,000 and 15,000 g loads, although the external supporting tissues and small diameter fibers were preserved. The predominant type of lesion produced was axonotmesis. PMID:18644327

Mazzer, Patrícia Yume Cantalejo Nagima; Barbieri, Cláudio Henrique; Mazzer, Nilton; Fazan, Valéria Paula Sassoli

2008-07-01

167

Effect of sulfur dioxide on the morphology and mucin biosynthesis by the rat trachea  

SciTech Connect

Specific-pathogen-free rats were exposed to 400 ppM sulfur dioxide daily for up to 7 weeks. At intervals during exposure, tracheas were removed and incubated in vitro in culture medium containing radioactive glycoprotein precursors. The most prominent histological changes due to SO/sub 2/ were progressive hypertrophy and hyperplasia of the submucosal mucous glands accompanied by a flattening of the epithelium with eventual recovery. Uptake of radioactive precursors into a highly purified mucin fraction correlated with these histological changes in the submucosal mucous glands, increasing progressively up to 4 times that of control. Uptake of precursors into specific mucins purified by DEAE-Sephacel showed that uptake into the 0.2 and 0.3 M NaCl fractions was stimulated several fold by SO/sub 2/, and uptake into more highly acidic fractions, which was nearly absent in the control, was also greatly increased. Two weeks following the last exposure of the tracheas to SO/sub 2/, their morphological and mucus-secreting properties showed signs of returning to that of the control.

Clark, J.N.; Dalbey, W.E.; Stephenson, K.B.

1980-01-01

168

Morphology of the decrementing expiratory neurons in the brainstem of the rat.  

PubMed

In anesthetized and artificially-ventilated rats, the morphological properties of decrementing expiratory (E-DEC) neurons were studied using intracellular recording and labeling with Neurobiotin. Sixteen E-DEC neurons were successfully labeled; ten of which were cranial motoneurons located in the facial (FN) and ambiguus (NA) nuclei. Two interneurons were labeled in the Bötzinger complex (BOT) and the ventral respiratory group (VRG) rostral to the obex, and the remaining four in the VRG caudal to the obex. All the interneurons had extensive intramedullary collaterals within the ventrolateral medulla. Terminal-like boutons were distributed ventral to the NA at the level of the BOT, both ventral to and within the NA at the level rostral to the obex and largely within the cell column tentatively designed as the ambiguous-retroambiguus complex (NA/NRA) caudal to the obex. The four interneurons in the NA/NRA had axons projecting to the spinal cord as well. The extensive intramedullary projections suggest that these E-DEC interneurons of the BOT and the VRG play a significant role in respiration. The simultaneous projections from the caudal E-DEC neurons to both the spinal cord and the NA suggest that these neurons also play integrative roles in non-respiratory behaviors including vocalization, swallowing and defecation. PMID:12354629

Saito, Yoshiaki; Tanaka, Ikuko; Ezure, Kazuhisa

2002-10-01

169

Morphological characterization of cells in concentrated suspensions using multispectral diffuse optical tomography  

PubMed Central

Based on a non-spherical model of particle scattering, we investigate the capabilities and limitations of a T-matrix based inverse algorithm to morphologically characterize cells in concentrated suspensions. Here the cells are modeled as randomly orientated spheroidal particles with homogenous dielectric properties and suspended in turbid media. The inverse algorithm retrieves the geometrical parameters and the concentration of cells simultaneously by inverting the reduced scattering coefficient spectra obtained from multispectral diffuse optical tomography (MS-DOT). Both round and spheroidal cells are tested and the role of multiple and higher order scattering of particles on the performance of the algorithm is evaluated using different concentrations of cells.

Hajihashemi, Mohammad Reza; Li, Xiaoqi; Jiang, Huabei

2013-01-01

170

Structure, characterization, and expression of the rat oxytocin receptor gene.  

PubMed Central

The multiple hormonal and neurotransmitter functions of the nonapeptide oxytocin are mediated by specific oxytocin receptors (OTRs). In most target tissues, the number of OTRs is strongly regulated. Specifically, in the uterus, a dramatic OTR upregulation precedes the onset of parturition. To study the molecular mechanisms underlying OTR regulation, we have isolated and characterized recombinant bacteriophage lambda EMBL3 genomic clones containing the rat OTR gene, using sequence information derived from a human myometrial OTR cDNA. The rat OTR gene spans > 20 kb and contains three exons. A 97-bp intron is in the 5' untranslated region and a > 12-kb intron interrupts the coding region between transmembrane domains 6 and 7. The promoter region lacks an apparent TATA or CCAAT box but contains multiple putative interleukin-response elements [six NF-IL6 (C/EBP beta) and four APRF (STAT3) binding motifs], supporting the notion that interleukins may mediate labor induction via transcriptional activation of the OTR gene. The predicted amino acid sequence is 93% identical to the human OTR sequence but only 48% and 38% identical to the rat V1 and V2 vasopressin receptor sequences, respectively. At parturition, the OTR gene is highly expressed in the rat uterus and gives rise to at least three transcripts (2.9, 4.8, and 6.7 kb) which differ in the length of their 3' untranslated regions. Images Fig. 3 Fig. 4 Fig. 5

Rozen, F; Russo, C; Banville, D; Zingg, H H

1995-01-01

171

Gonadal morphology and sex hormones in male and female Wistar rats after long-term lamotrigine treatment  

Microsoft Academic Search

Drug-induced disturbances in reproductive hormones and gonadal morphology have been observed both in patients with epilepsy and in non-epileptic animals. Less is known about the influence of newer antiepileptic drugs including lamotrigine on reproduction. Lamotrigine is now increasingly used both in epilepsy and psychiatric disorders. Sixty-five Wistar rats were fed by gastric tube either 5mgkg?1 lamotrigine solution (males=15, females=20) or

LINE SVEBERG RØSTE; ERIK TAUBØLL; JOUKO I. T ISOJÄRVI; AASMUND BERNER; KJELL ANDERSEN BERG; ARTO J PAKARINEN; ILPO T HUHTANIEMI; MIKAEL KNIP; LEIF GJERSTAD

2003-01-01

172

Open access high-resolution 3D morphology models of cat, gerbil, rabbit, rat and human ossicular chains.  

PubMed

High-resolution 3D morphology models of cat, gerbil, rabbit, rat and human ossicular chains are presented. The models are based on high-resolution CT measurements. The resolution of the CT images, from which the models are segmented, varies from 5.6 to 33.5 ?m. Models are freely available in different formats at our website (http://www.ua.ac.be/bimef/models) for research and educational purposes. PMID:22186087

Salih, Wasil H M; Buytaert, Jan A N; Aerts, Johan R M; Vanderniepen, Pieter; Dierick, Manuel; Dirckx, Joris J J

2011-12-13

173

Morphologic effects of subtoxic neonatal chlorpyrifos exposure in developing rat brain: regionally selective alterations in neurons and glia  

Microsoft Academic Search

The widely used organophosphate insecticide, chlorpyrifos (CPF), elicits neurobehavioral teratogenesis with exposure windows ranging from the embryonic neural tube stage through postnatal development. To explore the morphologic changes occurring in late-stage exposure, newborn rats were given 5 mg\\/kg of CPF s.c. daily on postnatal days (PN) 11–14, a regimen that is devoid of systemic toxicity, but that elicits long-term cognitive

Tara Sankar Roy; Frederic J. Seidler; Theodore A. Slotkin

2004-01-01

174

Morphologic and histochemical studies on the differing radiosensitivity of ductular and acinar cells of the rat submandibular gland  

Microsoft Academic Search

Summary  The submandibular glands of male rats were exposed to 50 Gy X-irradiation as a single dose, with or without pre-treatment\\u000a with either alpha-adrenergic agonists (noradrenaline, phenylephrine) or a cholinergic antagonist (atropine). The effects were\\u000a analyzed by morphometric, cytochemical and biophysical methods. When X-irradiated without drug pre-treatment, many serous\\u000a epithelial cells of the intralobular convoluted ducts displayed morphologic evidence of irreversible

Kisia Abok; Ulf Brunk; Bo Jung; Jan Ericsson

1984-01-01

175

Optical, morphological and structural characterization of Langmuir-Schaefer films of a functionalized copper phthalocyanine.  

PubMed

Langmuir-Schaefer (LS) films of copper(II) tetrakis-(isoprpoxy-carbonyl)-phthalocyanine (TiPCuPc) have been deposited onto various solid supports. Its floating film have been characterized at the air-water interface by means of Brewster Angle Microscopy and Langmuir curves. Vibrational modes of multilayer transferred LS film have been studied by Raman spectroscopy and the optical parameters (refractive index n and extinction coefficient k) have been determined in the visible range of the electromagnetic spectrum. Linearly polarized light absorbance measurements have been performed at room temperature in the 400-800 nm spectral range and the average orientation of the phthalocyanine rings have been estimated. Transmission electron microscopy has been also used to characterize the morphological properties of the LS film and a close packed arrangement of the deposited molecules has been observed. PMID:21794870

Giancane, Gabriele; Filippo, Emanuela; Manno, Daniela; Serra, Antonio; Valli, Ludovico

2011-06-30

176

Morphological characterization of the ovarian preantral follicle population of collared peccaries (Tayassu tajacu Linnaeus, 1758).  

PubMed

The aim of this research was to characterize the preantral ovarian follicular population in collared peccaries (Tayassu tajacu) using light and electron microscopy. Ovaries from six mature females were collected and further fixed for histological and ultrastructural analysis. A total of 33273.45 ± 5789.99 preantral follicles (PFs) were estimated for the population in each ovary. Most preantral follicles were primordial (91.56%), followed by primary (6.29%) and secondary (2.15%) ones. Most PFs were morphologically normal (94.4%), and only a few were atretic (5.6%). At histology assessment, amounts of lipid droplets were observed into the oocyte cytoplasm, which was confirmed through ultrastructural analysis. This work characterizes for the first time the ovarian population of preantral follicles, total and per category, in collared peccaries (Tayassu tajacu). The general follicles featured at primordial, primary and secondary categories are very similar to those described for other species. PMID:23278244

Lima, G L; Santos, E A A; Luz, V B; Rodrigues, A P R; Silva, A R

2012-12-19

177

Cloning and characterization of rat casein kinase 1epsilon.  

PubMed

Genes differentially expressed in the subjective day and night in the rat suprachiasmatic nucleus (SCN) were surveyed by differential display. A gene homologous to human casein kinase 1epsilon (CK1epsilon) was isolated, which initially appeared to be expressed in the suprachiasmatic nucleus (SCN) in a circadian manner. We here describe the cDNA cloning of the rat CK1epsilon and characterization of the protein products. The rCK1epsilon is predominantly expressed in the brain including the SCN, binds and phosphorylates mPer1, mPer2, and mPer3 in vitro, and translocates mPer1 and mPer3, but not mPer2, to the cell nucleus depending on its kinase activity when coexpressed with these Per proteins in COS-7 cells. PMID:10899319

Takano, A; Shimizu, K; Kani, S; Buijs, R M; Okada, M; Nagai, K

2000-07-14

178

Cloning and characterization of rat cysteine sulfinic acid decarboxylase.  

PubMed

Cysteine sulfinic acid decarboxylase (CSAD) is a key enzyme in taurine biosynthesis. CSAD activity and enzyme protein concentration are both repressed by the action of the steroid family hormones triiodothyronine and estrogen. To characterize this suppression, a cDNA clone for CSAD was isolated from a rat liver cDNA expression library using polyclonal antibodies to CSAD. The cDNA was sequenced in its entirety and confirmed to be a clone of CSAD. In a Northern blot comparing liver and kidney RNA of male and female rats, the CSAD cDNA probe detected a 2.5 kb mRNA band which was present at levels corresponding to the concentration of enzyme protein. Hyperthyroidism decreased CSAD mRNA as compared to euthyroid controls, providing evidence that negative regulation of CSAD activity occurs at the level of mRNA. PMID:7772604

Kaisaki, P J; Jerkins, A A; Goodspeed, D C; Steele, R D; Kaisakia, P J

1995-05-17

179

The Effect of Cochinchina momordica Seed Extract on Gastric Acid Secretion and Morphologic Change in Aged Rat Stomach  

PubMed Central

Background/Aims Cochinchina momordica seed extract (SK-MS10) has a gastric protective effect. We aimed to assess the effect of SK-MS10 on gastric acid secretion with morphologic changes in the aged rat. Methods Acid secretions were evaluated in the male F344 rats of four different ages (6-, 31-, 74-week, and 2-year). The 31-week-old rats were divided to three groups and continuously administered chow containing vehicle, SK-MS10 and lansoprazole, respectively. At the age of 74 weeks and 2 years, basal and stimulated acid was measured and the expression of mRNA and protein of H+-K+-ATPase were determined. The area of connective tissue of lamina propria was measured. Results Basal and stimulated gastric acid significantly decreased and connective tissue of lamina propria increased with age. The expression of mRNA and protein of H+-K+-ATPase significantly decreased with age. However, 74-week-old rats in the SK-MS10 group had higher stimulated gastric acid secretion than those in the vehicle and lansoprazole groups. In 2-year-old rats of SK-MS10 group, there was no increase of connective tissue. Conclusions As SK-MS10 kept the capacity of acid secretion as well as connective tissue area to comparable to young rats, it might valuable to perform further research regarding mechanism of SK-MS10 as an antiaging agent in the stomach.

Jo, Hyun Jin; Nam, Ryoung Hee; Chang, Hyun; Kim, Joo-Hyon; Park, Ji Hyun; Kang, Jung Mook; Lee, Dong Ho; Jung, Hyun Chae

2013-01-01

180

3D Reconstruction and Standardization of the Rat Vibrissal Cortex for Precise Registration of Single Neuron Morphology  

PubMed Central

The three-dimensional (3D) structure of neural circuits is commonly studied by reconstructing individual or small groups of neurons in separate preparations. Investigation of structural organization principles or quantification of dendritic and axonal innervation thus requires integration of many reconstructed morphologies into a common reference frame. Here we present a standardized 3D model of the rat vibrissal cortex and introduce an automated registration tool that allows for precise placement of single neuron reconstructions. We (1) developed an automated image processing pipeline to reconstruct 3D anatomical landmarks, i.e., the barrels in Layer 4, the pia and white matter surfaces and the blood vessel pattern from high-resolution images, (2) quantified these landmarks in 12 different rats, (3) generated an average 3D model of the vibrissal cortex and (4) used rigid transformations and stepwise linear scaling to register 94 neuron morphologies, reconstructed from in vivo stainings, to the standardized cortex model. We find that anatomical landmarks vary substantially across the vibrissal cortex within an individual rat. In contrast, the 3D layout of the entire vibrissal cortex remains remarkably preserved across animals. This allows for precise registration of individual neuron reconstructions with approximately 30 µm accuracy. Our approach could be used to reconstruct and standardize other anatomically defined brain areas and may ultimately lead to a precise digital reference atlas of the rat brain.

Egger, Robert; Narayanan, Rajeevan T.; Helmstaedter, Moritz; de Kock, Christiaan P. J.; Oberlaender, Marcel

2012-01-01

181

Distinguishing rat brainstem reticulospinal nuclei by their neuronal morphology. I. Medullary nuclei.  

PubMed

While cytoarchitectonic and hodological investigations suggest that the brainstem reticulospinal nuclei (BRN) are complexly organized, previous Golgi studies claimed that BRN comprise a homogeneous population with respect to neuronal morphology. To determine whether this is indeed the case, neurons of the various BRN of adult albino or hooded rats were either backfilled with horseradish peroxidase (HRP) from spinal injections, stained with a Nissl method or impregnated with a Golgi-Kopsch variant. The results suggest that at least thirteen BRN can be distinguished in the medulla. Some medullary BRN contain neurons whose dendritic arborizations (DA) are radially symmetric (e.g., nucleus reticularis (NR) ventralis pars beta (RVb), NR gigantocellularis (RGc) and nucleus raphe magnus (RaM]. Some BRN contain neurons whose DA exhibit a pronounced dorsomedial to ventrolateral slant (e.g., NR dorsalis (RD) and NR parvocellularis (RPc). The DA of NR paragigantocellularis dorsalis (RPgcd) neurons tend to course dorsally. The DA of nucleus raphe obscurus (RaO) neurons course vertically, while those of NR magnocellularis pars alpha (RMca) and NR magnocellularis pars beta (RMcb) course horizontally. The DA of NR ventralis pars alpha (RVa) may be oriented horizontally also, but sometimes slant from dorsolateral to ventromedial. The DA of NR paramedianus neurons (RPm) are cruciform. The neurons of NR paragigantocellularis lateralis (RPgcl) and of the nucleus raphe pallidus (RaP) exhibit a variety of DA patterns. The neurons of RD, RVa, RMcb and RMca project to the spinal cord with a strong ipsilateral predominance, while those of RVb, RPgcl and RGc project to the spinal cord with a weak ipsilateral predominance. The axons of RPc, RaO, RaP, and RaM neurons exhibit no lateral predominance. RPm neurons project to the cord with a weak contralateral predominance, and RPgcd neurons project to the cord with a strong contralateral predominance. Most medullary BRN project to the spinal cord via the medial longitudinal fasciculus (mlf) and sulcomarginal fasciculus. However, RPgcl, RMca and RMcb also project to the spinal cord via the lateral funiculus. The neurons of RD, RPm and RaM project to the spinal cord exclusively via the lateral or dorsolateral funiculus. Since the various medullary BRN are distinguishable on the basis of neuronal morphology, they may play distinct roles in brainstem modulation of spinal motor, sensory or autonomic activity. PMID:2410489

Newman, D B

1985-01-01

182

Characterization of nonlymphoid cells derived from rat peripheral lymph  

PubMed Central

Mesenteric lymphadenectomy in rats is followed by union of peripheral and central lymphatics, allowing the collection of intestine-derived peripheral lymph cells via the thoracic duct for several days. These cells include a proportion of nonlymphoid cells (NLC) that show irregular and heterogeneous surface morphology including long pseudopodia and veils. They stain variably for nonspecific esterase and acid phosphatase and are ATPase-positive. Their nuclei are irregular and some contain cytoplasmic inclusions, some of which show peroxidase activity and/or contain DNA. NLC have a range of densitites generally lower than that of lymphocytes. Freshly collected NLC express the leukocyte-common antigen (defined by monoclonal antibody MRC Ox 1) and Ia antigens (I-A and I-E subregion products defined by monoclonal antibodies) but they show a relative lack of other surface markers normally found on rat B or T lymphocytes (W3/13, W3/25, MRC Ox 12 (sIg), MRC Ox 19) or rat macrophages (FcR, C’R, mannose R, W3/25). In general NLC are only weakly adherent to glass or plastic. Although a subpopulation of NLC appear to have had a phagocytic past, freshly collected NLC fail to phagocytose a variety of test particles in vitro. NLC also appear incapable of pinocytosis in vitro. This heterogeneity may represent distinct subpopulations of NLC or different stages in the development of a single cell lineage. Direct cannulation of mesenteric lacteals shows that the majority of NLC are derived from the small intestine and their precursors appear to be present both in lamina propria and Peyer's patches. Kinetic studies, following irradiation or intravenous tritiated thymidine, show that the majority of NLC turn over rapidly in the intestine with a modal time of 3-5 d. Studies with bone marrow chimeras show that they are derived from a rapidly dividing precursor present in normal bone marrow. NLC occur at very low frequencies in normal thoracic duct lymph at all times following cannulation. The evidence presented suggests that NLC closely resemble mouse lymphoid dendritic cells. This conclusion is supported by evidence already obtained showing that NLC are potent stimulators of the semi-allogeneic rat primary mixed leukocyte reaction. In addition to the ceils resembling dendritic cells rare monocytoid cells are found in thoracic duct lymph of lymphadenectomized specific pathogen-free rats. The proportion of these cells increases greatly when the animals are conventionally housed. It seems probable that the physiological function of NLC is to act as accessory cells in the lymph nodes to which they normally drain. Methods for enriching NLC and thus facilitating analysis of their functions are discussed.

Pugh, CW; MacPherson, GG; Steer, HW

1983-01-01

183

Characterization of three newly established rat sarcoma cell clones.  

PubMed

Establishment of new animal models using selected cell lines with different behaviour is very important for cancer investigations. In this study, we describe three morphologically distinct rat sarcoma clones-C4, C7 and D6-isolated from the R5-28 cell line. Cells of all clones expressed vimentin, fibronectin, laminin, collagen IV and matrix metalloproteinases 2 and 9. However, desmin, cytokeratins 8 and 18, ZO-1 and desmoplakins I and II were not detected. Significant proliferative capacity was documented by proliferating cell nuclear antigen expression and BrdU positivity. Karyotype of the C4, C7 and D6 cells greatly differed from diploid chromosome number of normal rat somatic cells. High expression of three cytokines-monocyte chemoattractant protein 1, tissue inhibitor of metalloproteinases 1 and vascular endothelial growth factor-was observed in all three clones. However, they varied in concentration of chemokines associated with neutrophil migration and activation-cytokine induced neutrophil chemoattractant 2 and lipopolysaccharide induced CXC chemokine. The C4 clone showed spontaneous tumour regression in vivo that was associated with significant changes in lymphocyte subpopulations. PMID:23150138

Holubova, Monika; Leba, Martin; Sedmikova, Markéta; Vannucci, Luca; Horak, Vratislav

2012-11-13

184

Pathogenesis of the Lethal Effect of Anthrax Toxin in the Rat. Ii. Morphologic Studies.  

National Technical Information Service (NTIS)

Intravenous injections of anthrax toxin consistently produce pulmonary edema, cyanosis, and death in Fischer 344 rats. A light and electron microscopic study of the lungs of rats sacrificed serially after injections of toxin revealed diffuse pulmonary ede...

F. A. Beall F. G. Dalldorf

1965-01-01

185

Morphological and membrane properties of rat magnocellular basal forebrain neurons maintained in culture.  

PubMed

Morphological and electrophysiological characteristics of magnocellular neurons from basal forebrain nuclei of postnatal rats (11-14 days old) were examined in dissociated cell culture. Neurons were maintained in culture for periods of 5-27 days, and 95% of magnocellular (>23 micron diam) neurons stained positive with acetylcholinesterase histochemistry. With the use of phase contrast microscopy, four morphological subtypes of magnocellular neurons could be distinguished according to the shape of their soma and pattern of dendritic branching. Corresponding passive and active membrane properties were investigated with the use of whole cell configuration of the patch-clamp technique. Neurons of all cell types displayed a prominent (6-39 mV; 6.7-50 ms duration) spike afterdepolarization (ADP), which in some cells reached firing threshold. The ADP was voltage dependent, increasing in amplitude and decreasing in duration with membrane hyperpolarization with an apparent reversal potential of -59 +/- 2.3 (SE) mV. Elevating [Ca2+]o (2.5-5.0 mM) or prolonging spike repolarization with 10 mM tetraethylammonium (TEA) or 1 mM 4-aminopyridine (4-AP), potentiated the ADP while it was inhibited by reducing [Ca2+]o (2.5-1 mM) or superfusion with Cd2+ (100 microM). The ADP was selectively inhibited by amiloride (0.1-0.3 mM or Ni2+ 10 microM) but unaffected by nifedipine (3 microM), omega-conotoxin GVIA (100 nM) or omega-agatoxin IVA (200 nM), indicating that Ca2+ entry was through T-type Ca2+ channels. After inhibition of the ADP with amiloride (300 microM), depolarization to less than -65 mV revealed a spike afterhyperpolarization (AHP) with both fast and slow components that could be inhibited by 4-AP (1 mM) and Cd2+ (100 microM), respectively. In all cell types, current-voltage relationships exhibited inward rectification at hyperpolarized potentials >/=EK (approximately -90 mV). Application of Cs+ (0.1-1 mM) or Ba2+ (1-10 microM) selectively inhibited inward rectification but had no effect on resting potential or cell excitability. At higher concentrations, Ba2+ (>10 microM) also inhibited an outward current tonically active at resting potential (VH -70 mV), which under current-clamp conditions resulted in small membrane depolarization (3-10 mV) and an increase in cell excitability. Depolarizing voltage commands from prepulse potential of -90 mV (VH -70 mV) in the presence of tetrodotoxin (0.5 microM) and Cd2+ (100 microM) to potentials between -40 and +40 mV cause voltage activation of both transient A-type and sustained delayed rectifier-type outward currents, which could be selectively inhibited by 4-AP (0.3-3 mM) and TEA (1-3 mM), respectively. These results show that, although acetylcholinesterase-positive magnocellular basal forebrain neurons exhibit considerable morphological heterogeneity, they have very similar and characteristic electrophysiological properties. PMID:9772229

Sim, J A; Allen, T G

1998-10-01

186

Effects of a Saturated Fat and High Cholesterol Diet on Memory and Hippocampal Morphology in the Middle-Aged Rat  

PubMed Central

Diets rich in cholesterol and/or saturated fats have been shown to be detrimental to cognitive performance. Therefore, we fed a cholesterol (2%) and saturated fat (hydrogenated coconut oil, Sat Fat 10%) diet to 16-month old rats for 8 weeks to explore the effects on the working memory performance of middle-aged rats. Lipid profiles revealed elevated plasma triglycerides, total cholesterol, HDL, and LDL for the Sat-Fat group as compared to an iso-caloric control diet (12% soybean oil). Weight gain and food consumption were similar in both groups. Sat-Fat treated rats committed more working memory errors in the water radial arm maze, especially at higher memory loads. Cholesterol, amyloid-? peptide of 40 (A?40) or 42 (A?42) residues, and nerve growth factor in cortical regions was unaffected, but hippocampal Map-2 staining was reduced in rats fed a Sat-Fat diet, indicating a loss of dendritic integrity. Map-2 reduction correlated with memory errors. Microglial activation, indicating inflammation and/or gliosis, was also observed in the hippocampus of Sat-Fat fed rats. These data suggest that saturated fat, hydrogenated fat and cholesterol can profoundly impair memory and hippocampal morphology.

Granholm, Ann-Charlotte; Bimonte-Nelson, Heather A.; Moore, Alfred B.; Nelson, Matthew E.; Freeman, Linnea R.; Sambamurti, Kumar

2009-01-01

187

Pore-scale Characterization of Organic Immiscible-Liquid Morphology in Natural Porous Media Using Synchrotron X-Ray Microtomography  

Microsoft Academic Search

The objective of this study was to quantitatively characterize the pore-scale morphology of organic immiscible liquid (chlorinated solvents) residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of solid and liquid phases in packed columns. The image data were processed to generate quantitative measurements of organic-liquid blob morphology. Several porous media, comprising a range

G. Schnaar; M. L. Brusseau

2005-01-01

188

Characterization of cell types during rat liver development.  

PubMed

Hepatic stem cells have been identified in adult liver. Recently, the origin of hepatic progenitors and hepatocytes from bone marrow was demonstrated. Hematopoietic and hepatic stem cells share the markers CD 34, c-kit, and Thy1. Little is known about liver stem cells during liver development. In this study, we investigated the potential stem cell marker Thy1 and hepatocytic marker CK-18 during liver development to identify putative fetal liver stem cell candidates. Livers were harvested from embryonic and fetal day (ED) 16, ED 18, ED 20, and neonatal ED 22 stage rat fetuses from Sprague-Dawley rats. Fetal livers were digested by collagenase-DNAse solution and purified by percoll centrifugation. Magnetic cell sorting (MACS) depletion of fetal liver cells was performed using OX43 and OX44 antibodies. Cells were characterized by immunocytochemistry for Thy1, CK-18, and proliferating cell antigen Ki-67 and double labeling for Thy1 and CK-18. Thy1 expression was found at all stages of liver development before and after MACS in immunocytochemistry. Thy1 positive cells were enriched after MACS only in early developmental stages. An enrichment of CK-18 positive cells was found after MACS at all developmental stages. Cells coexpressing Thy1 and CK-18 were identified by double labeling of fetal liver cell isolates. In conclusion, hepatic progenitor cells (CK-18 positive) in fetal rat liver express Thy1. Other progenitors express only CK-18. This indicates the coexistence of different hepatic cell compartments. Isolation and further characterization of such cells is needed to demonstrate their biologic properties. PMID:12500199

Fiegel, Henning C; Park, Jonas J h; Lioznov, Michael V; Martin, Andreas; Jaeschke-Melli, Stefan; Kaufmann, Peter M; Fehse, Boris; Zander, Axel R; Kluth, Dietrich

2003-01-01

189

Morphological and Phylogenetic Characterizations of Freshwater Thioploca Species from Lake Biwa, Japan, and Lake Constance, Germany  

PubMed Central

Filamentous, gliding, sulfide-oxidizing bacteria of the genus Thioploca were found on sediments in profundal areas of Lake Biwa, a Japanese freshwater mesotrophic lake, and were characterized morphologically and phylogenetically. The Lake Biwa Thioploca resembled morphologically Thioploca ingrica, a brackish water species from a Danish fjord. The diameters of individual trichomes were 3 to 5.6 ?m; the diameters of complete Thioploca filaments ranged from 18 to 75 ?m. The cell lengths ranged from 1.2 to 3.8 ?m. In transmission electron microscope specimens stained with uranyl acetate, dense intracellular particles were found, which did not show any positive signals for phosphorus and sulfur in an X-ray analysis. The 16S rRNA gene of the Thioploca from Lake Biwa was amplified by using newly designed Thioploca-specific primers (706-Thioploca, Biwa160F, and Biwa829R) in combination with general bacterial primers in order to avoid nonspecific amplification of contaminating bacterial DNA. Denaturing gradient gel electrophoresis (DGGE) analysis of the three overlapping PCR products resulted in single DGGE bands, indicating that a single 16S rRNA gene had been amplified. With the same method, the Thioploca from Lake Constance was examined. The 16S rRNA sequence was verified by performing fluorescence in situ hybridization targeted at specific motifs of the Lake Biwa Thioploca. Positive signals were obtained with the bacterial probe EUB-338, the ?-proteobacterial probe GAM42a, and probe Biwa829 targeting the Lake Biwa Thioploca. Based on the nearly complete 16S rRNA sequence and on morphological similarities, the Thioploca from Lake Biwa and the Thioploca from Lake Constance are closely related to T. ingrica and to each other.

Kojima, Hisaya; Teske, Andreas; Fukui, Manabu

2003-01-01

190

Effects of Trypanosoma cruzi infection on myocardial morphology, single cardiomyocyte contractile function and exercise tolerance in rats  

PubMed Central

The aim of this study was to investigate the effects of Trypanosoma cruzi (T. cruzi) infection on myocardial morphology, single cardiomyocyte contractile function and exercise tolerance in rats. Adult Wistar rats were randomized into control (n = 14) and infected (n = 14) groups. Infected animals were inoculated with T. cruzi Y strain (300,000 trypomastigotes/50 g body weight). After 9 weeks, the animals were subjected to a treadmill running protocol. Then, the right atrium (RA) and left ventricle (LV) were removed for morphological and cell contractile evaluation. The infected animals exhibited a significant reduction in distance travelled, total time to fatigue and workload. In addition, these animals had hypertrophy, increased myocardial cellularity, and an increase in the proportion of collagen and blood vessels. RA and LV myocytes from infected animals showed marked contractile dysfunction under basal conditions and a reduced contractile response to ?-adrenergic stimulation. The workload of infected animals was correlated closely with the amplitude of cell shortening of RA and LV myocytes. T. cruzi infection influenced the myocardial morphology and the mechanical properties of RA and LV single myocytes negatively and reduced exercise tolerance. Single cardiomyocyte contractile dysfunction could constitute an additional mechanism of cardiac impairment and reduced exercise tolerance in this infection.

Novaes, Romulo D; Penitente, Arlete R; Goncalves, Reggiani V; Talvani, Andre; Neves, Clovis A; Maldonado, Izabel R S C; Natali, Antonio J

2011-01-01

191

Trypanosoma cruzi infection alters glucose metabolism at rest and during exercise without modifying the morphology of pancreatic islets in rats.  

PubMed

This study investigated the effects of Trypanosoma cruzi infection on pancreatic morphology and glucose metabolism at rest and during exercise. Wistar rats were randomized into control (CG=10) and infected (IG=10) groups. The IG animals were inoculated with T. cruzi Y strain (300,000 trypomastigotes/50 g). After 9 weeks, the animals were subjected to glucose (OGTT) and insulin (ITT) tolerance tests and a treadmill running protocol. Blood glucose, lactate and time to fatigue were determined. After euthanasia, the pancreases were removed for morphological and biochemical analyses. The IG presented abnormal glucose kinetics in OGTT and a similar glucose curve in ITT compared to the CG. During the exercise test, the IG showed anticipation of time to fatigue. At the point of fatigue, no difference was found in blood glucose and lactate between the groups. There was a significant correlation between lactate levels and the time to fatigue. The IG presented marked pancreatic inflammation, fibrosis and protein oxidation. The number of ? cells in the IG animals was not reduced. T. cruzi infection impaired pancreas morphology and glucose metabolism at rest and during exercise in rats, which could constitute an additional mechanism in the induction of exercise intolerance in Chagas' disease. PMID:22749578

Novaes, Rômulo D; Gonçalves, Reggiani V; Penitente, Arlete R; Talvani, André; Neves, Clóvis A; Natali, Antônio J; Maldonado, Izabel R S C

2012-07-01

192

New insights into the morphology, molecular characterization and identification of Baylisascaris transfuga (Ascaridida, Ascarididae).  

PubMed

Species ranked within the genus Baylisascaris (Ascaridida, Ascarididae) have been implicated in clinical and subclinical intestinal diseases in their natural hosts (e.g., raccoons and bears) as well as in life-threatening larva migrans syndromes in a number of incidental hosts, including humans. Following the diagnosis of Baylisascaris transfuga infestation in two captive polar bears, living in the zoo park of Pistoia (Tuscany, Italy), nematodes (n=300; both sexes) have been characterized by morphological and molecular methods by sequencing and analysing ribosomal (large ribosomal DNA (28S) and internal transcribed spacer region 1 and 2 (ITSs)) and mitochondrial (cytochrome c oxidase subunit 1 (cox1) and cytochrome c oxidase subunit 2 (cox2)) target regions. In addition, seven faecal samples were collected from the animal enclosure and submitted to copromicroscopic and molecular examination. All nematodes were morphologically identified as B. transfuga and their main distinctive features are here presented. No variation in size and nucleotide polymorphisms was detected within each target sequence among all samples analysed. These data contribute to facilitate an accurate diagnosis of this little known nematode infestation in order to apply appropriate anthelmintic strategies. PMID:20947254

Testini, G; Papini, R; Lia, R P; Parisi, A; Dantas-Torres, F; Traversa, D; Otranto, D

2010-09-22

193

Morphological and molecular characterization of a fungus, Hirsutella sp., isolated from planthoppers and psocids in Argentina.  

PubMed

A mycosed planthopper, Oliarus dimidiatus Berg (Hemiptera: Cixiidae), and two psocids, Heterocaecilius sp. (Psocodea: Pseudocaeciliidae) and Ectopsocus sp. (Ectopsocidae), were collected from Los Hornos and La Plata, Buenos Aires, Argentina between February and September 2007. Observations of mycelia growing on the host revealed that the putative fungal parasite had synnemata supporting monophialidic conidiogenous cells. Likewise, in vitro fungal cultures presented characteristics typical of the fungus Hirsutella citriformis Speare (Ascomycota: Hypocreales: Clavicipitaceae). The identity of the isolated fungi characterized based on morphological aspects was complemented by means of the internal transcribed spacer sequences. The sequences of both isolates were highly homologous to those of Cordyceps sp. (Fries) Link and Ophiocordyceps sinensis (Berkely) G.H. Sung, J.M. Sung, Hywel-Jones, and Spatafora (Ophiocordycipitaceae). We additionally confirmed that both isolates had the ability to infect and kill adults of Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) after 10 days. Therefore, based on the morphology of the isolated fungi, their ribosomal internal transcribed spacer sequence, and their ability to parasite insects, we conclude that the fungi isolated belong to the genus Hirsutella and might have biotechnological potential. PMID:23885970

Toledo, Andrea V; Simurro, María E; Balatti, Pedro A

2013-01-01

194

Morphological and Molecular Characterization of a Fungus, Hirsutella sp., Isolated from Planthoppers and Psocids in Argentina  

PubMed Central

A mycosed planthopper, Oliarus dimidiatus Berg (Hemiptera: Cixiidae), and two psocids, Heterocaecilius sp. (Psocodea: Pseudocaeciliidae) and Ectopsocus sp. (Ectopsocidae), were collected from Los Hornos and La Plata, Buenos Aires, Argentina between February and September 2007. Observations of mycelia growing on the host revealed that the putative fungal parasite had synnemata supporting monophialidic conidiogenous cells. Likewise, in vitro fungal cultures presented characteristics typical of the fungus Hirsutella citriformis Speare (Ascomycota: Hypocreales: Clavicipitaceae). The identity of the isolated fungi characterized based on morphological aspects was complemented by means of the internal transcribed spacer sequences. The sequences of both isolates were highly homologous to those of Cordyceps sp. (Fries) Link and Ophiocordyceps sinensis (Berkely) G.H. Sung, J.M. Sung, Hywel-Jones, and Spatafora (Ophiocordycipitaceae). We additionally confirmed that both isolates had the ability to infect and kill adults of Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) after 10 days. Therefore, based on the morphology of the isolated fungi, their ribosomal internal transcribed spacer sequence, and their ability to parasite insects, we conclude that the fungi isolated belong to the genus Hirsutella and might have biotechnological potential.

Toledo, Andrea V.; Simurro, Maria E.; Balatti, Pedro A.

2013-01-01

195

Morphological Characterization of Elastin-Mimetic Block Copolymers Utilizing Cryo- and Cryoetch-HRSEM  

NASA Astrophysics Data System (ADS)

Elastin-mimetic block copolymers were produced by genetic engineering. Genetically driven synthesis permitted control of the final physiochemical characteristics of the block copolymers. We designed BB and BAB block copolymers in which the A-block was hydrophilic and the B-block was hydrophobic. By designing the copolymers in this manner, it was proposed that they would self-assemble into micellar aggregates that, at high concentration, would form thermoreversible hydrogels. To analyze the three-dimensional fine surface morphology of the copolymers, to the resolution level of a few nanometers, we employed cryo-HRSEM. This method provided vast expanses of the specimen in its frozen hydrated state for survey. In our initial cryo-HRSEM studies, we observed the protein filaments and micelles surrounded by lakes of vitreous ice. Upon examination at low and intermediate magnifications, there was an extensive honeycomb-like filamentous network. To delineate the fine morphology of the hydrogel network at high magnification and to greater depths, we cryoetched away unbound water from the sample surface, in high vacuum, prior to chromium deposition. By using this technique, we were able to visualize for characterization purposes the fine fibril networks formed from the micellar aggregates over the surface of the hydrogel.

Wright, Elizabeth R.; Conticello, Vincent P.; Apkarian, Robert P.

2003-06-01

196

Characterization and Genetic Analysis of a Mutant of Escherichia coli K-12 with Rounded Morphology  

PubMed Central

A morphological mutant of Escherichia coli K-12 that grows as round cells at 30, 37, or 42 C in a variety of complex and synthetic media has been isolated and characterized. The gene concerned, designated rodA, has been shown to be on the chromosome between the purE and pyrC loci and to be located at about minute 15. The rodA gene has been found to be co-transducible with the lip gene at a frequency of 95%. The rodA mutant showed an increased resistance to ultraviolet irradiation and a changed sensitivity to drugs. The resistance to ultraviolet irradiation and mitomycin C appears to be co-transducible with the rodA gene. Images

Matsuzawa, Hiroshi; Hayakawa, Kou; Sato, Tetsuji; Imahori, Kazutomo

1973-01-01

197

Morphological and mineralogical characterizations of oolitic iron ore in the Exi region, China  

NASA Astrophysics Data System (ADS)

The morphological and mineralogical characterizations of a Chinese oolitic iron ore (Exi deposit) were studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy in this work. It is shown that the Exi ore is mainly composed of hematite, quartz, apatite, and chlorite. The hematite is present as the oolitic layers and in the spaces between the aggregated ooids; quartz exists as granular particles in the spaces and as nucleuses in ooids; the harmful mineral, apatite, is associated with hematite as the oolitic layers, fine dissemination, granular particles in the spaces, and nucleuses in ooids. From the viewpoint of mineral beneficiation, it is hard to separate apatite and chlorite but easy to separate quartz from hematite in the Exi iron ore in recovering the iron values.

Song, Shao-xian; Campos-Toro, Ernesto Fabian; Zhang, Yi-min; Lopez-Valdivieso, Alejandro

2013-02-01

198

Morphological and molecular characterization of Pratylenchus lentis n. sp. (Nematoda: Pratylenchidae) from Sicily  

PubMed Central

Pratylenchus lentis n. sp. parasitizing roots of lentil in Sicily, Italy, is described and illustrated. The new species is characterized by a relatively high lip region with three annuli, mean stylet length of 16 ?m, with anteriorly flattened knobs, cylindrical body with a relatively anterior vulva, large and ovoid spermatheca full of sperm, plump tail with truncate, irregularly annulated terminus, and by the presence of males. Molecular ITS-RFLP and sequencing analyses of the new species showed clear differences from other most morphologically similar species, such as P. thornei and P. mediterraneus. Preliminary host range tests revealed that chickpea, pea, faba bean and durum wheat are good hosts of P. lentis n. sp., whereas common bean, alfalfa and barley are less robust hosts and tomato, bell pepper, eggplant, melon and sunflower are poor hosts for the nematode.

De Luca, F.; Handoo, Z. A.; Di Vito, M.

2008-01-01

199

Blast exposure in rats with body shielding is characterized primarily by diffuse axonal injury.  

PubMed

Blast-induced traumatic brain injury (TBI) is the signature insult in combat casualty care. Survival with neurological damage from otherwise lethal blast exposures has become possible with body armor use. We characterized the neuropathologic alterations produced by a single blast exposure in rats using a helium-driven shock tube to generate a nominal exposure of 35 pounds per square inch (PSI) (positive phase duration ? 4 msec). Using an IACUC-approved protocol, isoflurane-anesthetized rats were placed in a steel wedge (to shield the body) 7 feet inside the end of the tube. The left side faced the blast wave (with head-only exposure); the wedge apex focused a Mach stem onto the rat's head. The insult produced ? 25% mortality (due to impact apnea). Surviving and sham rats were perfusion-fixed at 24 h, 72 h, or 2 weeks post-blast. Neuropathologic evaluations were performed utilizing hematoxylin and eosin, amino cupric silver, and a variety of immunohistochemical stains for amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba1), ED1, and rat IgG. Multifocal axonal degeneration, as evidenced by staining with amino cupric silver, was present in all blast-exposed rats at all time points. Deep cerebellar and brainstem white matter tracts were most heavily stained with amino cupric silver, with the morphologic staining patterns suggesting a process of diffuse axonal injury. Silver-stained sections revealed mild multifocal neuronal death at 24 h and 72 h. GFAP, ED1, and Iba1 staining were not prominently increased, although small numbers of reactive microglia were seen within areas of neuronal death. Increased blood-brain barrier permeability (as measured by IgG staining) was seen at 24 h and primarily affected the contralateral cortex. Axonal injury was the most prominent feature during the initial 2 weeks following blast exposure, although degeneration of other neuronal processes was also present. Strikingly, silver staining revealed otherwise undetected abnormalities, and therefore represents a recommended outcome measure in future studies of blast TBI. PMID:21449683

Garman, Robert H; Jenkins, Larry W; Switzer, Robert C; Bauman, Richard A; Tong, Lawrence C; Swauger, Peter V; Parks, Steven A; Ritzel, David V; Dixon, C Edward; Clark, Robert S B; Bayir, Hülya; Kagan, Valerian; Jackson, Edwin K; Kochanek, Patrick M

2011-06-01

200

[Morphological characterization of experimental parodontitis during its treatment with a phyto-preparation uno de gato].  

PubMed

Examination of new methods of treatment of parodontitis is stipulated by the significant increase in the number of patients with parodontitis. Experiments were conducted on white outbred male rats weighing 150-200 gr, which were divided into three groups. The first group was a reference one (n=20). The second group includes induced parodontitis (n=15) and the third group includes induced parodontitis with the treatment of uno de gato (n=19). We simulated parodontitis in the following way: on the lower nippers in the field of a neck we attached a ligature causing mechanical damage. We used a intramuscular injection of Nembutal as a means of narcotization (0.1 ml-10 g per mass). The present work is dedicated to morphological studies of the structures of damaged parodontium during its treatment with a phyto-preparation uno de gato. The undertaken treatment has demonstrated partial restoration of the mucous tunic of the gum. Newly formed capillaries were found in the connective tissue. The fibroblasts are mostly mature and collagen-producing. Thus, the study has demonstrated that there is a certain tendency of the tissue restoration and the treatment has produced the best therapeutic results. PMID:17660608

Miminoshvili, Sh M; Gvamichava, T A; Mdinaradze, N L

2007-06-01

201

Characterization of Cyclic Adenosine 3':5'-Monophosphate-dependent Protein Kinase Isozymes in Normal and Neoplastic Fetal Rat Brain Cells1  

Microsoft Academic Search

Fetal brain cells from rats given a transplacental pulse of W- ethyl-N-nitrosourea progressively acquire malignant characteris tics and differentiate when grown in vitro. One aspect of this differentiation is a decreased morphological response to cyclic adenosine 3':5'-monophosphate (cAMP). In the present study, we have characterized and compared the isozymes (I, II) of cAMP-dependent protein kinase in fetal brain cells and

Roald Ekanger; Ola Evjen; Olav Vintermyr; Ole Didrik Laerum; Stein Ove Doskeland

202

Morphological and Metabolic Changes in the Nigro-Striatal Pathway of Synthetic Proteasome Inhibitor (PSI)-Treated Rats: A MRI and MRS Study  

PubMed Central

Systemic administration of a Synthetic Proteasome Inihibitor (PSI) in rats has been described as able to provide a model of Parkinson’s disease (PD), characterized by behavioral and biochemical modifications, including loss of dopaminergic neurons in the substantia nigra (SN), as assessed by post-mortem studies. With the present study we aimed to assess in-vivo by Magnetic Resonance (MR) possible morphological and metabolic changes in the nigro-striatal pathway of PSI-treated rats. 10 animals were subcutaneously injected with PSI 6.0 mg/kg dissolved in DMSO 100%. Injections were made thrice weekly over the course of two weeks. 5 more animals injected with DMSO 100% with the same protocol served as controls. The animals underwent MR sessions before and at four weeks after the end of treatment with either PSI or vehicle. MR Imaging was performed to measure SN volume and Proton MR Spectroscopy (1H-MRS) was performed to measure metabolites changes at the striatum. Animals were also assessed for motor function at baseline and at 4 and 6 weeks after treatment. Dopamine and dopamine metabolite levels were measured in the striata at 6 weeks after treatment. PSI-treated animals showed volumetric reduction of the SN (p<0.02) at 4 weeks after treatment as compared to baseline. Immunofluorescence analysis confirmed MRI changes in SN showing a reduction of tyrosine hydroxylase expression as compared to neuron-specific enolase expression. A reduction of N-acetyl-aspartate/total creatine ratio (p?=?0.05) and an increase of glutamate-glutamine-? amminobutirrate/total creatine were found at spectroscopy (p?=?0.03). At 6 weeks after treatment, PSI-treated rats also showed motor dysfunction compared to baseline (p?=?0.02), accompanied by dopamine level reduction in the striatum (p?=?0.02). Treatment with PSI produced morphological and metabolic modifications of the nigro-striatal pathway, accompanied by motor dysfunction. MR demonstrated to be a powerful mean to assess in-vivo the nigro-striatal pathway morphology and metabolism in the PSI-based PD animal model.

Delli Pizzi, Stefano; Rossi, Cosmo; Di Matteo, Vincenzo; Esposito, Ennio; Guarnieri, Simone; Mariggio, Maria Addolorata; Franciotti, Raffaella; Caulo, Massimo; Thomas, Astrid; Onofrj, Marco

2013-01-01

203

Characterization of deltamethrin metabolism by rat plasma and liver microsomes  

SciTech Connect

Deltamethrin, a widely used type II pyrethroid insecticide, is a relatively potent neurotoxicant. While the toxicity has been extensively examined, toxicokinetic studies of deltamethrin and most other pyrethroids are very limited. The aims of this study were to identify, characterize, and assess the relative contributions of esterases and cytochrome P450s (CYP450s) responsible for deltamethrin metabolism by measuring deltamethrin disappearance following incubation of various concentrations (2 to 400 {mu}M) in plasma (esterases) and liver microsomes (esterases and CYP450s) prepared from adult male rats. While the carboxylesterase metabolism in plasma and liver was characterized using an inhibitor, tetra isopropyl pyrophosphoramide (isoOMPA), CYP450 metabolism was characterized using the cofactor, NADPH. Michaelis-Menten rate constants were calculated using linear and nonlinear regression as applicable. The metabolic efficiency of these pathways was estimated by calculating intrinsic clearance (Vmax/Km). In plasma, isoOMPA completely inhibited deltamethrin biotransformation at concentrations (2 and 20 {mu}M of deltamethrin) that are 2- to 10-fold higher than previously reported peak blood levels in deltamethrin-poisoned rats. For carboxylesterase-mediated deltamethrin metabolism in plasma, Vmax = 325.3 {+-} 53.4 nmol/h/ml and Km = 165.4 {+-} 41.9 {mu}M. Calcium chelation by EGTA did not inhibit deltamethrin metabolism in plasma or liver microsomes, indicating that A-esterases do not metabolize deltamethrin. In liver microsomes, esterase-mediated deltamethrin metabolism was completely inhibited by isoOMPA, confirming the role of carboxylesterases. The rate constants for liver carboxylesterases were Vmax = 1981.8 {+-} 132.3 nmol/h/g liver and Km = 172.5 {+-} 22.5 {mu}M. Liver microsomal CYP450-mediated biotransformation of deltamethrin was a higher capacity (Vmax = 2611.3 {+-} 134.1 nmol/h/g liver) and higher affinity (Km = 74.9 {+-} 5.9 {mu}M) process than carboxylesterase (plasma or liver) detoxification. Genetically engineered individual rat CYP450s (Supersomes) were used to identify specific CYP450 isozyme(s) involved in the deltamethrin metabolism. CYP1A2, CYP1A1, and CYP2C11 in decreasing order of importance quantitatively, metabolized deltamethrin. Intrinsic clearance by liver CYP450s (35.5) was more efficient than that by liver (12.0) or plasma carboxylesterases (2.4)

Anand, Sathanandam S. [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States)]. E-mail: sanand@rx.uga.edu; Bruckner, James V. [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States); Haines, Wendy T. [Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Curriculum in Toxicology, UNC-CH, NC 27514 (United States); Muralidhara, Srinivasa [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States); Fisher, Jeffrey W. [Department of Environmental Health Science, School of Public Health, University of Georgia, Athens, GA 30602 (United States); Padilla, Stephanie [Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

2006-04-15

204

Morphological and biological characterization of cell line developed from bovine Echinococcus granulosus.  

PubMed

The taeniid tapeworm Echinococcus granulosus is the causative agent of echinococcal disease, a major zoonosis with worldwide distribution. Several efforts to establish an in vitro model of E. granulosus have been undertaken; however, many of them have been designed for Echinococcus multilocularis. In the present study, we have described and characterized a stable cell line obtained from E. granulosus bovine protoscoleces maintained 3 yr in vitro. Growth characterization, morphology by light, fluorescent and electronic microscopy, and karyotyping were carried out. Cell culture origin was confirmed by immunofluorescent detection of AgB4 antigen and by PCR for the mitochondrial cytochrome c-oxidase subunit 1 (DCO1) gene. Cells seeded in agarose biphasic culture resembled a cystic structure, similar to the one formed in secondary hosts. This cell line could be a useful tool to research equinococcal behavior, allowing additional physiological and pharmacological studies, such as the effect of growth factors, nutrients, and antiparasitic drugs on cell viability and growth and on cyst formation. PMID:20844980

Echeverría, Claudia I; Isolabella, Dora M; Prieto Gonzalez, Elio A; Leonardelli, Araceli; Prada, Laura; Perrone, Alina; Fuchs, Alicia G

2010-09-16

205

Neurochemical characterization of individual vulnerability to addictive drugs in rats.  

PubMed

Rats exposed to a low-light, low-noise, novel environment exhibit differences in individual locomotor response to the novelty stressor. The categorization of rats in a locomotor screening procedure as low- (LR) or high-responders (HR), where LRs are in the low locomotor range while HRs belong to the high locomotor range, is significant in that HRs show higher activity in mesencephalic dopaminergic projection neurons, and also show a higher propensity to self-administer psychostimulants and other drugs of abuse compared with LRs. In this study, we examined the neurobiological basis of dopaminergic hyperactivity by comparing in HRs and LRs the steady-state differences in regulatory inputs to mesencephalic (substantia nigra and ventral tegmental area: VTA) dopaminergic neurons. In particular, using in situ hybridization, we studied levels of mRNA for tyrosine hydroxylase (TH) and cholecystokinin (CCK) in the mesencephalon, and for preprodynorphin (DYN), preproenkephalin (PPE), and preprotachykinin (PPT) in the striatum and nucleus accumbens (Acb). We also evaluated TH levels by radioimmunocytochemistry (TH-RIC) in striatal, accumbal and mesencephalic regions. HRs versus LRs had lower levels of neurochemicals belonging to the intrinsic inhibitory input to dopaminergic neurons in the VTA, e.g. lower TH-RIC (-25%) and CCK-mRNA (-48%). In contrast, HRs showed higher levels of parameters belonging to extrinsic facilitating inputs, e.g. higher PPE-mRNA (+37%). In addition, HRs had higher DYN-mRNA in Acb (+61%), which has been shown to be positively correlated with higher dopaminergic activity. These results enhance our knowledge of the neurobiological correlates of individual rats' propensities to develop drug-intake and provide some putative mechanisms for the dopaminergic hyperactivity that characterizes drug-prone animals. PMID:9786209

Lucas, L R; Angulo, J A; Le Moal, M; McEwen, B S; Piazza, P V

1998-10-01

206

GLUTAMATE NEUROTOXICITY IN THE DEVELOPING RAT COCHLEA: PHYSIOLOGICAL AND MORPHOLOGICAL APPROACHES  

EPA Science Inventory

The neurotoxic effects of exogenous glutamate were studied in the rat cochlea. lutamate-treated rats (4g/kg/day ip, postnatal days 2 through 9) exhibited electrophysiologically-measured elevations in high frequency thresholds usually associated with hair cell loss in the basal re...

207

Early biochemical and morphological changes of the rat adrenal medulla induced by xylitol  

Microsoft Academic Search

Long-term administration of high doses of xylitol and other polyols in rats has been associated with an increase in adrenal medullary hyperplasia and neoplasia. In order to exclude age-related factors and to differentiate between unspecific stress reactions and direct effects of the compound administered, a model was developed for quantifying early adrenomedullary responses. Male SD rats were fed xylitol (10%

Urs A. Boelsterli; Gerhard Zbinden

1985-01-01

208

Morphologic and histologic abnormalities in female and male rats treated with anabolic steroids  

Microsoft Academic Search

A two-part study was performed to determine the ef fects of high doses of anabolic steroids on weight, appetite, and organ histology. Initially, 30 white Wistar rats, 15 males and 15 females, were treated weekly with either 0.52 cc of physiologic saline or nandrolone decanoate. After 6 weeks, female treated and control rats had comparable weight gains, but male treated

Janet A. Yu-Yahiro; Roger H. Michael; David V. Nasrallah; Brian Schofield

1989-01-01

209

Comparison of functional and morphological deficits in the rat after gestational exposure to ionizing radiation  

Microsoft Academic Search

Ionizing radiation is a precise tool for altering formation of the developing cerebral cortex of the fetal rat. Whole body exposure of the pregnant rat on gestational day 13, 15 or 17 to 1.0 Gy of gamma radiation resulted in maximum thinning of the cortex on days 15 and 17. In the preweaning period, functional tests (negative geotaxis, reflex suspension,

S. Norton; B. F. Kimler

1988-01-01

210

Early Changes in the Tensile Strength and Morphology of Primary Sutured Skin Wounds in Rats  

Microsoft Academic Search

The specific aim of this study was to measure the TS of rat skin wounds during the first week follow- ing surgical injury. Biomechanical and histological data were collected daily (days 1 to 7 following surgery) from separate groups of Sprague-Dawley rats (N = 12) each with two 3 cm long parallel skin incisions on the back. The wounds were

P. GÁL; T. TOPORCER; B. VIDINSKÝ; M. MOKRÝ; M. NOVOTNÝ; R. KILÍK; K. SMETANA JR; T. GÁL; J. SABO

211

Morphological and morphometric studies of the dysmyelinating mutant, the Long Evans shaker rat  

Microsoft Academic Search

The Long Evans shaker (les) rat is a recently identified CNS myelin mutant with an autosomal recessive mode of inheritance. Although scattered myelin sheaths are present in some areas of the CNS, most notably the ventral spinal cord in the young neonatal rat, this myelin is gradually lost, and 8-12 weeks little myelin is present throughout the CNS. Despite this

J. M. Kwiecien; L. T. O'Connor; B. D. Goetz; K. H. Delaney

1998-01-01

212

Effect of antiprogestagen RU486 on both natural and prolactin-induced morphological luteolysis in rat..  

PubMed

Adult female cyclic rats were hypophysectomized and their pituitary glands autotransplanted beneath the left kidney capsule (Aptr) on day 1 (metestrus). To induce the luteolytic effect of prolactin (PRL) the rats were injected s.c. with 0.4 mg of 2-bromo-alpha-ergocryptine (CB154) on cycle days 12, 13 and 14. Other groups of Aptr rats were injected daily with CB154 or ethanol vehicle from day 12 to day 23. To study the role of progesterone (P) on the luteotrophic effect of PRL as well as on the natural and on the PRL-induced luteolysis, rats without CB154 treatment or with long or short CB154 treatment were injected s. c. with 2 mg of the antiprogestagen RU486 or 0.1 ml oil from day 1 to day 23. From each rat the mean weight of the corpus luteum (CL) was noted on day 24. The serum PRL level rose from day 1 to day 12 and fell thereafter by day 15 in CB154-treated rats. The serum level of PRL rose again in short term CB154-treated rats, and remained low in long term CB154-treated rats. No effect of RU486 on serum PRL levels was noted in any group. The serum P level fell rapidly as the treatment with CB154 began after day 12. Neither the rise in serum PRL after day 15 in short term CB154-treated rats nor RU486 treatment affected the P level. Treatment with RU486 did not affect the CL weight on day 24 in ethanol vehicle injected rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7800920

Sánchez-Criado, J E; Ruiz, A; Tébar, M

1994-06-01

213

Physiological and morphological characterization of GABAergic neurons in the medial amygdala.  

PubMed

GABAergic neurons in the medial amygdala (MeA) have been indicated in information processing in reproductive behavior and fear/anxiety. However, basic knowledge of their physiological and morphological properties is still very limited, probably due to the technical challenge to selectively record the GABAergic neurons. In this study, I characterized properties of the MeA GABAergic neurons by performing whole-cell patch clamp recordings from brain slices of adult knock-in mice selectively expressing green fluorescence protein (GFP) in GABAergic neurons. The majority (73%) of GABAergic neurons exhibiting low threshold calcium spike were classified as type I neurons, with morphological properties of being bitufted or stellate, and dendrites either aspiny or covered by various shapes of spines. Axonal collaterals of some neurons were observed near somata as well as in other amygdaloid nuclei. Neurons incapable of generate low threshold calcium spikes were divided into two types. Type II neurons (11%) exhibited hyperpolarization-activated sag and higher input resistance (>400 M?). Most Type II neurons exhibited asymmetric dendritic trees extending towards the superficial layer covered with long neck dendritic spines. The axons of type II neurons formed large collaterals and projected to other amygdaloid nuclei. Type III neurons (16%) lack prominent hyperpolarization-activated sag and possessed lower input resistance (<400 M?). These neurons were local interneurons with smooth multipolar dendritic trees. Since both MeA and nearby amygdaloid nuclei are involved in fear/anxiety processing, two types of MeA GABAergic projection neurons and a third type of interneurons that might participate in anxiety-related behavior were revealed by my present study. PMID:23524192

Bian, Xiling

2013-03-20

214

Bioethanol-gasoline fuel blends: exhaust emissions and morphological characterization of particulate from a moped engine.  

PubMed

This study was aimed at evaluating the effects of gasoline-ethanol blends on the exhaust emissions in a catalyst-equipped four-stroke moped engine. The ethanol was blended with unleaded gasoline in at percentages (10, 15, and 20% v/v). The regulated pollutants and the particulate matter emissions were evaluated over the European ECE R47 driving cycle on the chassis dynamometer bench. Particulate matter was characterized in terms of total mass collected on filters and total number ofparticles in the range 7 nm-10 microm measured by electrical low-pressure impactor (ELPI). In addition, particle-phase polycyclic aromatic hydrocarbons (PAHs) emissions were evaluated to assess the health impact of the emitted particulate. Finally, an accurate morphological analysis was performed on the particulate by high-resolution transmission electron microscope (TEM) equipped with a digital image-processing/data-acquisition system. In general, CO emission reductions of 60-70% were obtained with 15 and 20% v/v ethanol blends, while the ethanol use did not reduce hydrocarbon (HC) and NOx emissions. No evident effect of ethanol on the particulate mass emissions and associated PAHs emissions was observed. Twenty-one PAHs were quantified in the particulate phase with emissions ranging from 26 to 35 microg/km and benzo[a]pyrene equivalent (BaPeq) emission factors from 2.2 to 4.1 microg/km. Both particulate matter and associated PAHs with higher carcinogenic risk were mainly emitted in the submicrometer size range (<0.1 microm). On the basis of the TEM observations, no relevant effect of the ethanol use on the particulate morphology was evidenced, showing aggregates composed ofprimary particles with mean diameters in the range 17.5-32.5 nm. PMID:22916436

Seggiani, Maurizia; Prati, M Vittoria; Costagliola, M Antonietta; Puccini, Monica; Vitolo, Sandra

2012-08-01

215

Phase separation in thermal systems: a lattice Boltzmann study and morphological characterization.  

PubMed

We investigate thermal and isothermal symmetric liquid-vapor separations via a fast Fourier transform thermal lattice Boltzmann (FFT-TLB) model. Structure factor, domain size, and Minkowski functionals are employed to characterize the density and velocity fields, as well as to understand the configurations and the kinetic processes. Compared with the isothermal phase separation, the freedom in temperature prolongs the spinodal decomposition (SD) stage and induces different rheological and morphological behaviors in the thermal system. After the transient procedure, both the thermal and isothermal separations show power-law scalings in domain growth, while the exponent for thermal system is lower than that for isothermal system. With respect to the density field, the isothermal system presents more likely bicontinuous configurations with narrower interfaces, while the thermal system presents more likely configurations with scattered bubbles. Heat creation, conduction, and lower interfacial stresses are the main reasons for the differences in thermal system. Different from the isothermal case, the release of latent heat causes the changing of local temperature, which results in new local mechanical balance. When the Prandtl number becomes smaller, the system approaches thermodynamical equilibrium much more quickly. The increasing of mean temperature makes the interfacial stress lower in the following way: ?=?(0)[(T(c)-T)/(T(c)-T(0))](3/2), where T(c) is the critical temperature and ?(0) is the interfacial stress at a reference temperature T(0), which is the main reason for the prolonged SD stage and the lower growth exponent in the thermal case. Besides thermodynamics, we probe how the local viscosities influence the morphology of the phase separating system. We find that, for both the isothermal and thermal cases, the growth exponents and local flow velocities are inversely proportional to the corresponding viscosities. Compared with the isothermal case, the local flow velocity depends not only on viscosity but also on temperature. PMID:22181315

Gan, Yanbiao; Xu, Aiguo; Zhang, Guangcai; Li, Yingjun; Li, Hua

2011-10-31

216

Morphological characterization of high surface area mesoporous micropheres of platinum and platinum/ruthenium  

NASA Astrophysics Data System (ADS)

Mesoporous microspheres of Pt and Pt/Ru have been electrodeposited into a carbon black layer on a silicon/gold electrode surface and characterized for coulombic deposition efficiency, physical morphology, particle size and dispersion, electrochemically available surface area, and activity toward methanol oxidation. The target applications for these deposits are catalyst materials in a polymer electrolyte membrane fuel cell. Coulombic efficiency was measured simultaneously with coulombic charge data using an in-situ liquid phase quartz crystal microbalance. Deposition efficiency varied from near unity to under 30%, depending on precursor salt concentration and applied deposition potential. The effect of chloride ion concentration on kinetic rates under various deposition conditions is also discussed. In general, more negative applied potential and lower precursor salt concentrations showed higher deposition efficiencies. Pt/Ru deposits showed similar trends to Pt deposits, albeit at lower efficiency. Microsphere morphology was evaluated for electrochemically available surface area through hydrogen adsorption/desorption (Pt) and carbon monoxide stripping voltammetry (Pt/Ru). Mass specific surface area rose rapidly at low loading and remained relatively constant thereafter at 40-50 m 2/g for Pt and 60-70 m2/g for Pt/Ru. Particle size analysis of the growth process revealed electrochemically available surface area may penetrate up to 80 rim below the microsphere's surface for loadings of 3.000 coulombs, which had an average diameter of 250 nm. Applied deposition potential and precursor salt concentration have shown a modest effect on Pt surface area and a stronger effect on Pt/Ru surface area. More positive potential and higher precursor concentration resulted in the greatest surface area for both compositions. The effect on morphology of the catalyst pore structure and distribution of growth centers throughout the carbon layer are discussed in terms of kinetic impact on nucleation and growth processes in the presence of chloride ions. Methanol oxidation current response was evaluated for Pt/Ru samples. Normalized oxidation current was highest at very low catalyst loading and became constant at higher loading. Deposition potential did not have a meaningful effect on catalyst activity, while precursor concentration showed a modest effect. Oxidation currents ranged from 52 MA/m2 at high precursor concentration to 30 mA/m2 at low concentration.

Knutson, Trevor Lawrence

217

Morphology-tunable synthesis and characterizations of Mg(OH) 2 films via a cathodic electrochemical process  

Microsoft Academic Search

An electrodeposition route for preparation of well-controlled magnesium hydroxide nanostructure using sodium acetate as structure-directing agent was presented. The magnesium hydroxide thin films were characterized by XRD, SEM and TEM. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide thin films deposited from nitrate bath was investigated, such as concentration of sodium acetate additive and

Guanglong Zou; Weixiang Chen; Run Liu; Zhude Xu

2008-01-01

218

The shrinkage compensation of unsaturated polyester resins — polyvinyl acetate blends polymerization proceeds through fractal morphologies: characterization and simulation  

Microsoft Academic Search

Blends of unsaturated polyester, styrene and polyvinyl acetate are hot cured either between glass plates or under pressure in a molding simulator. The morphologies of the products are observed using microscopy and show their usual aspects. They are characterized according to fractal concepts by image processing; the influence of mixture composition, pressure and temperature is investigated. Based on the hypothesis

M. Ruffier; G. Merle; J. P. Pascault; H. Bouleçane; N. Vincent

1996-01-01

219

Morphological characterization and functional immune response of the carpet shell clam ( Ruditapes decussatus) haemocytes after bacterial stimulation  

Microsoft Academic Search

The morphology and functionality of Ruditapes decussatus haemocytes have been characterized by light microscopy and flow cytometry, leading to the identification of three different cellular subpopulations. Granulocytes were the largest cells, the hyalinocytes were smaller and contained fewer granules and the intermediate cells showed a size similar to hyalinocytes and a higher number of granules. The phagocytosis of different particles

M. Prado-Alvarez; A. Romero; P. Balseiro; S. Dios; B. Novoa; A. Figueras

220

Effects of raftilose on serum biochemistry and liver morphology in rats fed with normal or high-fat diet.  

PubMed

Non-alcoholic fatty liver disease is the leading cause of chronic liver injury in developed countries. Oligofructose (OFS) is a prebiotic with proven benefits for health. The aim of the study is to evaluate the effect of 10% OFS on hepatic morphology and lipid metabolism in Wistar Kyoto rats submitted to normal diet (ND) or high-fat diet (FD). Animals were treated for 7 weeks. Lipid profile and serum alkaline phosphatase (ALP) activity were measured and liver histology evaluated at the end of the study. Ten percent OFS reduced triglyceride (TAG) levels when added to any of the diet regimens; 10% OFS decreased plasmatic urea in ND and plasmatic and urinary urea levels in FD; ND + 10% OFS treated rats showed lower ALP activity than controls. FD increased ALP activity, an effect not reversed by OFS. Animals submitted to FD have microscopic hepatic changes: marked steatosis with disarranged centrilobular zone structure; enlarged sinusoids; enlarged mitochondria and an increase in number and volume of adiposomes. Supplementation with 10% OFS in FD reversed those effects. In conclusion, 10% OFS supplementation prevented deleterious effects of FD such as alterations on lipid profile (TAG elevation) and hepatic morphologic changes. OFS decreased ALP activity in animals subjected to ND, which may have contributed to the differences on lipid metabolism. PMID:23653231

Correia-Sá, Inês; de-Sousa-Lopes, Hugo; Martins, Maria J; Azevedo, Isabel; Moura, Eduardo; Vieira-Coelho, Maria A

2013-05-08

221

Chemical, dimensional and morphological ultrafine particle characterization from a waste-to-energy plant  

SciTech Connect

Highlights: > Particle size distributions and total concentrations measurement at the stack and before the fabric filter of an incinerator. > Chemical characterization of UFPs in terms of heavy metal concentration through a nuclear method. > Mineralogical investigation through a Transmission Electron Microscope equipped with an Energy Dispersive Spectrometer. > Heavy metal concentrations on UFPs as function of the boiling temperature. > Different mineralogical and morphological composition amongst samples collected before the fabric filter and at the stack. - Abstract: Waste combustion processes are responsible of particles and gaseous emissions. Referring to the particle emission, in the last years specific attention was paid to ultrafine particles (UFPs, diameter less than 0.1 {mu}m), mainly emitted by combustion processes. In fact, recent findings of toxicological and epidemiological studies indicate that fine and ultrafine particles could represent a risk for health and environment. Therefore, it is necessary to quantify particle emissions from incinerators also to perform an exposure assessment for the human populations living in their surrounding areas. To these purposes, in the present work an experimental campaign aimed to monitor UFPs was carried out at the incineration plant in San Vittore del Lazio (Italy). Particle size distributions and total concentrations were measured both at the stack and before the fabric filter inlet in order to evaluate the removal efficiency of the filter in terms of UFPs. A chemical characterization of UFPs in terms of heavy metal concentration was performed through a nuclear method, i.e. Instrumental Neutron Activation Analysis (INAA), as well as a mineralogical investigation was carried out through a Transmission Electron Microscope (TEM) equipped with an Energy Dispersive Spectrometer (EDS) in order to evaluate shape, crystalline state and mineral compound of sampled particles. Maximum values of 2.7 x 10{sup 7} part. cm{sup -3} and 2.0 x 10{sup 3} part. cm{sup -3} were found, respectively, for number concentration before and after the fabric filter showing a very high efficiency in particle removing by the fabric filter. With regard to heavy metal concentrations, the elements with higher boiling temperature present higher concentrations at lower diameters showing a not complete evaporation in the combustion section and the consequent condensation of semi-volatile compounds on solid nuclei. In terms of mineralogical and morphological analysis, the most abundant compounds found in samples collected before the fabric filter are Na-K-Pb oxides followed by phyllosilicates, otherwise, different oxides of comparable abundance were detected in the samples collected at the stack.

Buonanno, Giorgio, E-mail: buonanno@unicas.it [University of Cassino, via G. Di Biasio 43, 03043 Cassino (Italy); Stabile, Luca [University of Cassino, via G. Di Biasio 43, 03043 Cassino (Italy); Avino, Pasquale [DIPIA, INAIL (ex-ISPESL), via Urbana 167, 00184 Rome (Italy); Belluso, Elena [Dipartimento di Scienze Mineralogiche e Petrologiche, University of Torino and Institute of Geosciences and Earth Resources, CNR-Unita di Torino, via Valperga Caluso 35, 10125 Torino (Italy)

2011-11-15

222

HemoHIM improves ovarian morphology and decreases expression of nerve growth factor in rats with steroid-induced polycystic ovaries.  

PubMed

Estradiol valerate (EV)-induced polycystic ovaries (PCOs) in rats cause the anovulation and cystic ovarian morphology. We investigated whether treatment with HemoHIM influences the ovarian morphology and the expression of nerve growth factor (NGF) in an EV-induced PCO rat model. PCO was induced by a single intramuscular injection of EV (4 mg, dissolved in sesame oil) in adult cycling rats. HemoHIM was either administered orally (100 mg/kg of body weight/day) for 35 consecutive days or injected intraperitoneally (50 mg/kg of body weight) every other day after EV injection. Ovarian morphology was almost normalized, and NGF was normalized in the PCO + HemoHIM group. HemoHIM lowered the high numbers of antral follicles and increased the number of corpora lutea in PCOs. The results are consistent with a beneficial effect of HemoHIM in the prevention and treatment of PCO syndrome. PMID:20041792

Kim, Sung Ho; Lee, Hae June; Kim, Joong Sun; Moon, Changjong; Kim, Jong Choon; Bae, Chun Sik; Park, Hae Ran; Jung, Uhee; Jo, Sung Kee

2009-12-01

223

Morphological Study of Early Changes in Rat Bones in Simulated Weightlessness.  

National Technical Information Service (NTIS)

By histomorphometric methods tibial bones and lumbar vertebrae of rats exposed for 7 days to hypokinesia or head-down suspension were investigated. Both hypokinesia and suspension led to osteoporosis of the tibial metaphyseal spongiosa which was primarily...

A. S. Kaplanskiy Z. F. Sakharova Y. I. Ilyinakakuyeva G. N. Durnova

1988-01-01

224

Morphologic Analysis Correlates with Gene Expression Changes in Cultured F344 Rat Mesothelial Cells  

Microsoft Academic Search

The gene expression pattern of mesothelial cells in vitro was determined after 4 or 12 h exposure to the rat mesothelial, kidney, and thyroid carcinogen and oxidative stressor potassium bromate (KBrO3). Gene expression changes observed using cDNA arrays indicated oxidative stress, mitotic arrest, and apoptosis in treated immortalized rat peritoneal mesothelial cells. Increases occurred in oxidative stress responsive genes HO-1,

L. M. Crosby; K. S. Hyder; A. B. DeAngelo; T. B. Kepler; B. Gaskill; G. R. Benavides; L. Yoon; K. T. Morgan

2000-01-01

225

Dietary fat saturation, mortality and heart and lung morphology of rats  

Microsoft Academic Search

Rats of both sexes were fed diets containing 21% (wt) fat as beef tallow (BT), safflower oil (SO), or a 60:40 BT:SO mix (M).\\u000a Some of each group were killed at 9, 12, 15, 18, and 21 months of age. Death by 15 months was significantly (P<.001) greater\\u000a in SO rats than in other groups. Mortality in SO females was

Audrey A. Spindler; Jacqueline Dupont; Melvin M. Mathias

1978-01-01

226

Chlorphentermine-induced lipidosis in the rat retina: a functional and morphological study  

Microsoft Academic Search

Chronic administration of the cationic amphiphilic anorexigenic drug chlorphentermine to rats has previously been shown to induce extraocular and ocular lipidosis: large numbers of lipidosis —related cytoplasmic inclusions can be found in the pigment epithelium and smaller numbers in the neuroretina. In the present study, female albino Wistar rats were treated orally with chlorphentermine (30–45 mg\\/kg body weight) for 4–16

Gernot Duncker; Timm Bredehorn

1994-01-01

227

Biochemical and morphological changes in the digestive tract of rats after prenatal and postnatal malnutrition13  

Microsoft Academic Search

Six-week-old rats subjected to prenatal and postnatal dietary restriction (ma- ternal and weanling intake = 50% that of controls) were studied. Compared with controls, malnourished rats not only had reduced body (78 ± 12 vs 187 ± 2 1 g) and organ weights (small intestine: 4.5 1 ± 0.46 vs 9.89 ± 0.6 1 g; colon: 0.75 ± 0.08 vs

Agus Firmansyah; Laurentius Suwandito; Duna Penn; Emanuel Lebenthal

228

Effect of dichloromethylene diphosphonate on morphology, enzyme activity, and ash content of bones of thyroparathyroidectomized rats  

Microsoft Academic Search

Summary Dichloromethylene diphosphonate (Cl2MDP) was given at doses of 4 mg\\/kg and 10 mg\\/kg daily for 7 days to adult thyroparathyroidectomized rats fed a low calcium diet. Primary metaphyseal trabeculae in Cl2MDP-treated rats were more numerous and longer than in controls. The light and electron microscopic appearance of osteoblasts, osteocytes and osteoclasts were unaltered by Cl2MDP. Bone alkaline phosphatase was

Steven E. Weisbrode; Charles C. Capen; Charles B. Pendley II

1978-01-01

229

Effect of prenatal and perinatal acrylamide on the biochemical and morphological changes in liver of developing albino rat.  

PubMed

Acrylamide has been employed as an experimental probe to investigate biochemical and morphological changes in developing rat liver following toxin administration in pregnant rats. Non-anesthetized pregnant rats were given acrylamide by gastric intubation at a dose of 10 mg/kg/day. The pups were divided into three groups: Group A, mothers were treated with saline (control group); Group B, mothers were treated with acrylamide from day D7 of gestation till birth (prenatal intoxication); Group C, mothers were treated with acrylamide from D7 of gestation to D28 after birth (perinatal intoxication). Acrylamide-induced biochemical changes (in liver and serum) and morphological changes (in liver) were studied in control and acrylamide-treated developing pups. Prenatally and perinatally administered acrylamide significantly increased lipid peroxidation and reduced glutathione and total thiol levels in liver. Significant inhibition of peroxidase and superoxide dismutase activities was observed in liver tissue. Total lipids including cholesterol and triglycerides were significantly increased in the serum. Acrylamide treatment increased serum alanine aminotransferase and aspartate aminotransferase activities and inhibited alkaline phosphatase activity. Sodium and potassium concentrations were increased, but calcium, phosphorus and iron levels were significantly reduced in the serum. Acrylamide produced significant electrophoretic changes in serum proteins. The most noticeable change was splitting of beta-globulin into beta1- and beta2-globulins. Light microscopy showed acrylamide-induced fatty deposits, congested central vein, vacuolization and chromatolysis in hepatocytes. Ultrastructural studies revealed vacuolated cytoplasm, lipid droplets of variable size and mitochondria with damaged cristae and vacuolization. The nuclei in acrylamide-treated groups showed marked decrease in the staining of nuclear DNA. PMID:19862503

Allam, Ahmed Aly; El-Ghareeb, Abdel Whaab; Abdul-Hamid, Manal; Bakery, Ahlam El; Gad, Mammoun; Sabri, Mohammad

2009-10-28

230

Changes in small intestinal morphology and digestive enzyme activity with oral administration of copper-loaded chitosan nanoparticles in rats.  

PubMed

The experiment was conducted to evaluate the effect of copper-loaded chitosan nanoparticles on the small intestinal morphology and activities of digestive enzyme and mucosal disaccharase in rats. Forty male Sprague-Dawley rats, with average body weight of 82 g, were randomly allotted to five groups (n?=?8). All rats were received a basal diet (control) or the same basal diet added with 80 mg/kg BW CuSO(4), 80 mg/kg BW chitosan (CS-I), 80 mg/kg BW copper-loaded chitosan nanoparticles (CSN-I), 160 mg/kg BW copper-loaded chitosan nanoparticles (CSN-II), respectively. The experiment lasted 21 days. The results showed that the villus heights of the small intestinal mucosa in groups CSN-I and CSN-II were higher than those of the control, group CuSO(4) or CS-I. The crypt depth of duodenum and ileum mucosa in group CSN-I or CSN-II was depressed. Compared with the control, there were no significant effects of CuSO(4) or CS-I on the villus height and crypt depth of small intestinal mucosa. Supplementation with CSN improved the activities of trypsin, amylase and lipase in the small intestinal contents and maltase, sucrase and lactase of duodenum, jejunum, and ileum mucosa while there were no significant effects of CuSO(4) on the digestive enzyme activities of the small content compared with the control. The results indicated that intestinal morphology, activities of digestive enzyme in digesta and mucosal disaccharase were beneficially changed by treatment of copper-loaded chitosan nanoparticles. PMID:21882065

Han, Xin-Yan; Du, Wen-Li; Huang, Qi-Chun; Xu, Zi-Rong; Wang, Yi-Zheng

2011-09-01

231

Longitudinal Characterization of Brain Atrophy of a Huntington Disease Mouse Model by Automated Morphological Analyses of Magnetic Resonance Images  

PubMed Central

Mouse models of human diseases play crucial roles in understanding disease mechanisms and developing therapeutic measures. Huntington’s disease (HD) is characterized by striatal atrophy that begins long before the onset of motor symptoms. In symptomatic HD, striatal volumes decline predictably with disease course. Thus, imaging based volumetric measures have been proposed as outcomes for presymptomatic as well as symptomatic clinical trials of HD. Magnetic resonance imaging of the mouse brain structures is becoming widely available and has been proposed as one of the biomarkers of disease progression and drug efficacy testing. However, three-dimensional and quantitative morphological analyses of the brains are not straightforward. In this paper, we describe a tool for automated segmentation and voxel-based morphological analyses of the mouse brains. This tool was applied to a well-established mouse model of Huntington disease, the R6/2 transgenic mouse strain. Comparison between the automated and manual segmentation results showed excellent agreement in most brain regions. The automated method was able to sensitively detect atrophy as early as 3 weeks of age and accurately follow disease progression. Comparison between ex vivo and in vivo MRI suggests that the ex vivo end-point measurement of brain morphology is also a valid approach except for the morphology of the ventricles. This is the first report of longitudinal characterization of brain atrophy in a mouse model of Huntington’s disease by using automatic morphological analysis.

Zhang, Jiangyang; Peng, Qi; Li, Qing; Jahanshad, Neda; Hou, Zhipeng; Jiang, Mali; Masuda, Naoki; Langbehn, Douglas R.; Miller, Michael I.; Mori, Susumu; Ross, Christopher A.; Duan, Wenzhen

2010-01-01

232

Solid state microcellular foamed poly(lactic acid): morphology and property characterization.  

PubMed

Poly(lactic acid) or PLA is a plant-based biodegrable plastic which exhibits many properties that are equivalent to or better than many petroleum-based plastics. However, there have been few commercial applications due to its lower impact resistance and higher cost than synthetic plastics. In this paper, the concept of creating microcellular foamed structures in PLA as a means to improve its shortcomings is presented. The effect of the foaming conditions (temperature and time) on the void fraction, volume expansion ratio, impact strength and tensile properties of foamed PLA is discussed. Each step of microcellular processing is addressed including: the manufacture of PLA film; the saturation of the samples with gas; the microcellular foaming of PLA; the void fraction determination, volume expansion ratio calculation, impact and tensile property characterization of foamed samples. The microcellular morphologies developed in PLA samples were a strong function of the foaming conditions. Due to the presence of foamed microcells, a twofold expansion ratio and significant improvements in the impact resistance (twofold increase over unfoamed PLA), strain at break (up to twofold increase over unfoamed PLA) and toughness (up to fourfold increase over unfoamed PLA) were achieved in PLA. PMID:17855079

Matuana, L M

2007-09-12

233

Multistep Aggregation Pathway of Human Interleukin-1 Receptor Antagonist: Kinetic, Structural, and Morphological Characterization  

PubMed Central

Abstract The complex, multistep aggregation kinetic and structural behavior of human recombinant interleukin-1 receptor antagonist (IL-1ra) was revealed and characterized by spectral probes and techniques. At a certain range of protein concentration (12–27 mg/mL) and temperature (44–48°C), two sequential aggregation kinetic transitions emerge, where the second transition is preceded by a lag phase and is associated with the main portion of the aggregated protein. Each kinetic transition is linked to a different type of aggregate population, referred to as type I and type II. The aggregate populations, isolated at a series of time points and analyzed by Fourier-transform infrared spectroscopy, show consecutive protein structural changes, from intramolecular (type I) to intermolecular (type II) ?-sheet formation. The early type I protein spectral change resembles that seen for IL-1ra in the crystalline state. Moreover, Fourier-transform infrared data demonstrate that type I protein assembly alone can undergo a structural rearrangement and, consequently, convert to the type II aggregate. The aggregated protein structural changes are accompanied by the aggregate morphological changes, leading to a well-defined population of interacting spheres, as detected by scanning electron microscopy. A nucleation-driven IL-1ra aggregation pathway is proposed, and assumes two major activation energy barriers, where the second barrier is associated with the type I ? type II aggregate structural rearrangement that, in turn, serves as a pseudonucleus triggering the second kinetic event.

Krishnan, Sampathkumar; Raibekas, Andrei A.

2009-01-01

234

High-precision characterization of individual E. coli cell morphology by scanning flow cytometry.  

PubMed

We demonstrate a flow-cytometric method to measure length and diameter of single Escherichia coli cells with sub-diffraction precision. The method is based on the original scanning flow cytometer that measures angle-resolved light-scattering patterns (LSPs) of individual particles. We modeled the shape of E. coli cells as a cylinder capped with hemispheres of the same radius, and simulated light scattering by the models using the discrete dipole approximation. We computed a database of the LSPs of individual bacteria in a wide range of model parameters and used it to solve the inverse light-scattering problem by the nearest-neighbor interpolation. The solution allows us to determine length and diameter of each individual bacterium, including uncertainties of these estimates. The developed method was tested on two strains of E. coli. The resulting precision of bacteria length and diameter measurements varied from 50 nm to 250 nm and from 5 nm to 25 nm, respectively. The measured distributions of samples over length and diameter were in good agreement with measurements performed by optical microscopy and literature data. The described approach can be applied for rapid morphological characterization of any rod-shaped bacteria. PMID:23568828

Konokhova, Anastasiya I; Gelash, Andrey A; Yurkin, Maxim A; Chernyshev, Andrey V; Maltsev, Valeri P

2013-04-08

235

Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering. 1992 Annual summary  

SciTech Connect

This study is aimed at characterizing the influence of aerosol surface structure on the kinetics of gas-aerosol interactions. Changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol are measured with aerosols having different surface properties due to the composition and/or temperature of the material making up the aerosol. The kinetic data generated can be used directly in atmospheric modeling calculations. The surface structure of the aerosol is using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during, the course of the reaction. This dynamics information can be used to generate kinetic data for systems which are similar in nature to those studied, but are not amenable to laboratory investigation. We show here that increased MDSRS sensitivity is achieved by using an excitation laser source that has a narrow linewidth and we have been able to detect sulfate anion concentrations much lower than previously reported. We have shown that the linewidth of the MDSRS mode excited in a droplet is limited by the laser linewidth. This is a positive result for it eases our ability to quantify the MDSRS gain equation. This result also suggests that MDSRS signal size should be independent of droplet size, and preliminary experiments confirm this hypothesis.

Aker, P.M.

1993-01-30

236

Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering  

SciTech Connect

This study is aimed at characterizing the influence of aerosol surface structure on the kinetics of gas-aerosol interactions. Changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol are measured with aerosols having different surface properties due to the composition and/or temperature of the material making up the aerosol. The kinetic data generated can be used directly in atmospheric modeling calculations. The surface structure of the aerosol is using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during, the course of the reaction. This dynamics information can be used to generate kinetic data for systems which are similar in nature to those studied, but are not amenable to laboratory investigation. We show here that increased MDSRS sensitivity is achieved by using an excitation laser source that has a narrow linewidth and we have been able to detect sulfate anion concentrations much lower than previously reported. We have shown that the linewidth of the MDSRS mode excited in a droplet is limited by the laser linewidth. This is a positive result for it eases our ability to quantify the MDSRS gain equation. This result also suggests that MDSRS signal size should be independent of droplet size, and preliminary experiments confirm this hypothesis.

Aker, P.M.

1993-01-30

237

Electrical, Mechanical, and Morphological Characterization of Carbon Nanotube filled Polymeric Nanofibers  

NASA Astrophysics Data System (ADS)

This work focuses on the inclusion of conductive nanotubes into polymeric matrices with the end goal of creating conductive nanocomposites. This investigation has been carried out by uniform dispersion of multi-walled carbon nanotubes in aqueous solutions of polyvinyl alcohol (PVA) and polyethylene oxide (PEO), which are inherently nonconductive polymers. To fabricate these structures we are using the electrospinning process encompassing an array of collection methods including parallel bars and a static plate. Carbon nanotubes are known to have excellent electrical conductivity and mechanical properties. This investigation shows that the inclusion of carbon nanotubes increases the electronic conduction in these polymers and enhances the mechanical properties of the composites. Dispersion of these nanotubes is the key factor in this process; gum Arabic and surfactants have been utilized for the dispersion of these nanotubes. Conductivity measurements have been carried out by two point probe method and by performing sensitive current and conductance measurements with a femtoammeter. Further morphological characterization has been performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).^1 Department of Textile Engineering, Chemistry, and Science ^2 Department of Physics

Gorga, Russell; Clarke, Laura; McCullen, Seth; Ojha, Satyajeet; Roberts, Wesley

2006-03-01

238

Droplet size and morphology characterization for dense sprays by image processing: application to the Diesel spray  

NASA Astrophysics Data System (ADS)

Up to now, measurement of drop size remains difficult in dense sprays such as those encountered in Diesel applications. Commonly used diagnostics are often limited due to multi-scattering effects, high drop velocity and concentration and also nonspherical shapes. The advantage of image-based techniques on the others is its ability to describe the shape of liquid particles that are not fully atomized or relaxed. In the present study, a model is developed to correct the main drawbacks of imaging. It permits to define criteria for the correction of the apparent size of an unfocused drop and to determine a measurement volume independent of the drop size. This considerably reduces the over-estimation of large drops in the drop size distribution. Drop shapes are also characterized by four morphological parameters. The image-based granulometer is satisfactorily compared to a PDPA and a diffraction-based granulometer for measurements on an ultrasonic spray. Then, the new granulometer is applied to a diesel spray. One of the results of the analysis is that even if mean drop size distributions are stable 30 mm downstream from the nozzle outlet, the shape of the drops is still evolving towards the spherical shape. The atomization process is thus not totally established at this position in opposition to what can be deduced from the drop size distribution alone.

Blaisot, J. B.; Yon, J.

2005-12-01

239

Study on silk sericin and chitosan blend film: morphology and secondary structure characterizations.  

PubMed

This study aimed to prepare and characterize silk sericin and chitosan blend film as well as the native silk sericin and chitosan films. The films were observed their morphology using Scanning Electron Microscope (SEM). The secondary structures of the films were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Transparency of the films was investigated with UV-visible spectroscopy. The results found that all of silk films were smooth throughout the film surfaces, including blend film. This showed that silk sericin and chitosan very well compatible. However, phase separation is also being observed. It is show that the interaction between two materials might be miscible together. The FTIR results indicated that the most of films were composed both in random coil and beta-sheet forms which predominantly of the random coil structures. The results suggesting the blend film between sericin and chitosan did not change the intramolecular structure when compared to the native films. The silk sericin and blend films were slightly yellowish color and were higher transparent than chitosan film. However, % transmittance at lamda max of 660 nm showed that all of films have similar values. The result suggested that the transparency of the film did not change even blend together. It is a promising that both silk sericin and chitosan would be blended into many forms for applications in specifically fields. PMID:20180324

Srihanam, P; Simcheur, W; Srisuwan, Y

2009-11-15

240

Molecular and Morphological Characterization of an Unusual Meloidogyne arenaria Population from Traveler's Tree, Ravenala madagascariensis.  

PubMed

An unusual variant of Meloidogyne arenaria was discovered on roots of a traveler's tree (Ravenala madagascariensis) intended for display at a public arboretum in Pennsylvania. The population aroused curiosity by the lack of visible galling on the roots of the infected plant, and the female vulval region was typically surrounded by egg sacs. Most morphometrics of the population fit within the ranges reported for M. arenaria, with a mosaic of features in common with either M. platani or other tropical Meloidogyne spp. Molecular characterization included analysis of four loci. The mitochondrial sequence, extending from cytochrome oxidase II (COII) to the 16S (1RNA) gene, was nearly identical to another M. arenaria population and closely related to sequences from M. morocciensis and M. thailandica. The 28S D2-D3 expansion segment was most similar to those from M. arenaria, M. incognita and M. paranaensis, and the IGS-2 was most related to those from M. thailandica, M. arenaria and M. incognita. Analysis of partial Hsp90 genomic sequences revealed the greatest similarity to M. arenaria, M. thailandica and an Hsp90 haplotype from M. floridensis, and a composite sequence comprised of EST from M. arenaria. No morphological or molecular features clearly distinguished this population as a new species, and, when considered as a whole, the evidence points to its identification as M. arenaria. PMID:19440257

Skantar, Am; Carta, Lk; Handoo, Za

2008-09-01

241

Molecular and Morphological Characterization of an Unusual Meloidogyne arenaria Population from Traveler's Tree, Ravenala madagascariensis  

PubMed Central

An unusual variant of Meloidogyne arenaria was discovered on roots of a traveler's tree (Ravenala madagascariensis) intended for display at a public arboretum in Pennsylvania. The population aroused curiosity by the lack of visible galling on the roots of the infected plant, and the female vulval region was typically surrounded by egg sacs. Most morphometrics of the population fit within the ranges reported for M. arenaria, with a mosaic of features in common with either M. platani or other tropical Meloidogyne spp. Molecular characterization included analysis of four loci. The mitochondrial sequence, extending from cytochrome oxidase II (COII) to the 16S (1RNA) gene, was nearly identical to another M. arenaria population and closely related to sequences from M. morocciensis and M. thailandica. The 28S D2-D3 expansion segment was most similar to those from M. arenaria, M. incognita and M. paranaensis, and the IGS-2 was most related to those from M. thailandica, M. arenaria and M. incognita. Analysis of partial Hsp90 genomic sequences revealed the greatest similarity to M. arenaria, M. thailandica and an Hsp90 haplotype from M. floridensis, and a composite sequence comprised of EST from M. arenaria. No morphological or molecular features clearly distinguished this population as a new species, and, when considered as a whole, the evidence points to its identification as M. arenaria.

Carta, LK; Handoo, ZA

2008-01-01

242

The inhibiting effect of trilostane on adrenal steroid synthesis: Hormonal and morphological alterations induced by subchronic trilostane treatment in normal rats  

Microsoft Academic Search

Summary In adult male rats the effect of a subchronic treatment with trilostane, a new, orally active, competitive inhibitor of 3ß-hydroxysteroid dehydrogenase, on adrenal steroid production and morphology was studied. Rats were treated with 150 mg or 300 mg trilostane\\/kg\\/day for 7 or 14 days and with 150 mg trilostane\\/kg\\/day for 10 days in combination with 75 mg propranolol\\/kg\\/day or

E. Jungmann; W. Magnet; U. Rottmann-Kuhnke; R. Sprey; U. Schwedes; K.-H. Usadel; K. Schöffling

1982-01-01

243

Characterization of metabolites of worenine in rat biological samples using liquid chromatography–tandem mass spectrometry  

Microsoft Academic Search

The in vivo and in vitro metabolites of worenine in rat were identified or characterized using a specific and sensitive liquid chromatography–tandem mass spectrometry (LC–MS\\/MS) method. In vivo samples including rat urine, feces, and plasma samples were collected after ingestion of 25mg\\/kg worenine to healthy rats. The in vivo and in vitro samples were cleaned up by a solid-phase extraction

Huaixia Chen; Jianlin Huang; Juan Li

2010-01-01

244

Characterization of a transformed rat retinal ganglion cell line  

Microsoft Academic Search

The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the ?2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells.

R. R. Krishnamoorthy; P. Agarwal; G. Prasanna; K. Vopat; W. Lambert; H. J. Sheedlo; I.-H. Pang; D. Shade; R. J. Wordinger; T. Yorio; A. F Clark; N. Agarwal

2001-01-01

245

Morphological characterization of the spermatogonial subtypes in the neonatal mouse testis.  

PubMed

Spermatogenesis is the process of differentiation of diploid type A spermatogonia to haploid spermatozoa. Several subtypes of A spermatogonia have been characterized in the adult mouse testis. These include A-single (A(s)), A-paired (A(pr)), A-aligned (A(al)), and A1-A4. However, in the immature testis, very little information is available on subtypes and morphological features of type A spermatogonia. Six-day-old mouse testes, fixed either in Bouin solution or 5% glutaraldehyde, were embedded in paraffin and Epon, respectively. Thick sections (approximately 1 microm) of Epon-embedded tissue were stained with toluidine blue and revealed three subtypes of spermatogonia by light microscopy. The smallest spermatogonia (subtype I) appeared as single cells and exhibited a round or oval flattened nucleus with one or two prominent dense nucleoli and a characteristic unstained round and centrally located vacuole. These cells bound toluidine blue more avidly and appeared darker in comparison with the other cell types. Electron microscopy of thin sections (90 nm) revealed a finely granulated chromatin homogeneously distributed in the nucleus and sparse organelles in the cytoplasm. The second subtype of spermatogonia (subtype II) also displayed dark staining but was larger than subtype I; there was no central vacuole in the nucleus and heterochromatin clumps were observed. The largest subtype of spermatogonia (subtype III) showed large heterochromatin clumps and a pale staining nucleus. Intercellular bridges were noted between subtypes II and III. Based on the dye avidity, the three subtypes were classified as dark, transitional, and pale spermatogonia, respectively. Image analyses of 30 different cells of each subtype revealed a decline in gray-scale intensity from subtype I to III. Five-micrometer sections of paraffin-embedded tissue were immunoassayed with an antibody against the glial cell-derived neurotrophic factor family receptor alpha-1 (GFRalpha-1) receptor, a putative marker for undifferentiated spermatogonia, showing positive reaction only in germ cells. The pattern of GFRalpha-1 expression, coupled to the overall morphology of the cells, indicates that at this stage of development, mouse seminiferous tubules contain essentially A(s), A(pr), and possibly A(al) spermatogonia. Thus, the present study indicates the presence of subtypes of type A spermatogonia in the immature mouse testis similar to that described previously in adult monkey and man. PMID:12855601

Dettin, Luis; Ravindranath, Neelakanta; Hofmann, Marie-Claude; Dym, Martin

2003-07-09

246

Tetrodotoxin suppresses morphological enhancement of the metastatic MAT-LyLu rat prostate cancer cell line.  

PubMed

Voltage-gated Na+ channels are expressed by highly metastatic MAT-LyLu cells, but not by poorly metastatic AT-2 cells, derived from the rodent Dunning model of prostatic cancer. We have investigated the possible involvement of these channels in the morphological development of the cells. Incubation of both the MAT-LyLu and the AT-2 cell line for 24 h with the Na+ channel blocker tetrodotoxin (TTX) at 6 microM altered the morphology only of the MAT-LyLu cell line. TTX produced significant decreases in: (a) cell process length and (b) field diameter, and increases in (c) cell body diameter and (d) process thickness. Importantly, 6 microM TTX had no significant effects on proliferation rates or cellular toxicity. The results suggest that Na+ channel activity plays a significant role in determining the morphological development of MAT-LyLu cells in such a way as to enhance their metastatic potential. PMID:10022970

Fraser, S P; Ding, Y; Liu, A; Foster, C S; Djamgoz, M B

1999-03-01

247

Mammary gland morphology and gene expression differ in female rats treated with 17?-estradiol or fed soy protein isolate.  

PubMed

Soy foods have been suggested to have both positive health benefits and potentially adverse effects as a result of their content of phytoestrogens. However, studies on the estrogenicity of soy foods are lacking. Here we directly compared the effects of soy protein isolate (SPI), the protein in soy infant formula, with those of 17?-estradiol (E2), on global gene expression profiles and morphology in the female rat mammary gland. Rats were fed AIN-93G diets containing casein or SPI beginning on postnatal d 30. Rats were ovariectomized on postnatal d 50 and treated with 5 ?g/kg/d E2 or vehicle for 14 d. Microarray analysis revealed that E2 treatment altered expression of 780 genes more than or equal to 2-fold (P < 0.05), whereas SPI feeding altered expression of only 53 genes more than or equal to 2-fold. Moreover, the groups had only 10 genes in common to increase more than or equal to 2-fold. The combination of SPI feeding and E2 altered expression of 422 genes and reversed E2 effects on many mRNAs, including those involved in the c-myc signaling pathway, cyclin D1, and Ki67. ER? binding to its response element on the Tie-2/Tek and progesterone receptor promoters was increased by E2, but not SPI, and this promoter binding was suppressed by the combination of E2 + SPI for the Tie-2/Tek promoter but increased for the progesterone receptor promoter (P < 0.05). SPI reduced the ratio of epithelial to fat pad area and E2 + SPI reduced both epithelial and fat pad area (P < 0.05). These data suggest that SPI is only minimally estrogenic in the rat mammary gland even in the absence of endogenous estrogens. PMID:23027806

Ronis, Martin J J; Shankar, Kartik; Gomez-Acevedo, Horacio; Hennings, Leah; Singhal, Rohit; Blackburn, Michael L; Badger, Thomas M

2012-10-01

248

Characterization of the estrogen-induced lipoprotein receptor of rat liver  

Microsoft Academic Search

The ethinyl estradiol-induced lipoprotein receptor of rat liver was purified and characterized. Liver membranes were prepared from ethinyl estradiol-treated rats, solubilized, and subjected to DEAE chromatography. A fraction with a high specific activity for low density lipoprotein (LDL) binding was isolated and used to immunize mice. Hybridomas were pre- pared from their spleen cells, and a clone that secreted an

Allen D. Cooper; Rhoda Nutik; Jean Chen

249

Characterization of Contractile Function in Diabetic Hypertensive Cardiomyopathy in Adult Rat Ventricular Myocytes  

Microsoft Academic Search

Diabetes and hypertension both produce myocardial dysfunction that accelerates cardiovascular morbidity and mortality. Coexistence of the two often results in a more severe cardiomyopathy than either process alone. The purpose of this study was to characterize the contractile function of diabetic hypertensive cardiomyopathy at the single myocyte level. Adult spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were made

Loren E. Wold; David P. Relling; Peter B. Colligan; Glenda I. Scott; Kadon K. Hintz; Bonnie H. Ren; Paul N. Epstein; Jun Ren

2001-01-01

250

Identification, culture, and characterization of pancreatic stellate cells in rats and humans  

Microsoft Academic Search

Background & Aims: Until now, the basic matrix-producing cell type responsible for pancreas fibrosis has not been identified. In this report, retinoid-containing pancreatic stellate cells (PSCs) in rat and human pancreas are described, and morphological and biochemical similarities to hepatic stellate cells are shown. Methods: Electron and immunofluorescence microscopy (collagen types I and III, fibronectin, laminin, ?-actin, and desmin) was

Max G. Bachem; Erik Schneider; Hans Groß; Hans Weidenbach; Roland M. Schmid; Andre Menke; Marco Siech; Hans Beger; Adolf Grünert; Guido Adler

1998-01-01

251

Dietary supplementation with ovine serum immunoglobulin attenuates acute effects on growth, organ weights, gut morphology and intestinal mucin production in the growing rat challenged with Salmonella enteritidis.  

PubMed

The aim was to determine the effect of orally administered ovine serum immunoglobulin (Ig) on growth performance, organ weight, gut morphology and mucin production in the Salmonella enteritidis--gavaged growing rat. Four groups consisted of non-gavaged rats fed a casein-based control basal diet (BD) and three groups of rats gavaged with 1×10(7) CFU S. enteritidis and fed a casein-based diet, a diet containing freeze-dried ovine Ig (FDOI) or a casein-based diet containing inactivated ovine Ig (IOI). The rats were randomly allocated to one of the four groups (n=15/group) and received their respective diets for an 18-day experimental study. Gavaging took place on day 15. Average daily gain and body gain : feed ratio (post-gavage, 3 days) were significantly (P<0.05) higher for the Salmonella-challenged rats fed the FDOI diet compared to those fed the BD and IOI diets. At the end of the study, the small intestine and colon were significantly (P<0.05) heavier for the gavaged rats fed the FDOI diet compared to the gavaged rats fed either the BD or IOI diet. Moreover, the relative weights of the caecum, liver and spleen of the gavaged rats fed the BD or IOI diet were significantly (P<0.05) heavier compared to the gavaged rats fed the FDOI diet. Generally, the gavaged rats fed the FDOI diet had significantly (P<0.05) higher goblet cell counts and luminal mucin protein contents than the gavaged rats fed either the BD or IOI diet and had a more functional gut morphology. Overall, the FDOI fraction prevented the acute effects of S. enteritidis. PMID:22440348

Balan, P; Han, K S; Rutherfurd, S M; Singh, H; Moughan, P J

2011-08-01

252

Effects of induced premaxillary suture fusion on the craniofacial morphology in growing rats  

Microsoft Academic Search

ObjectiveDue to premaxillary rapid development and fusion with the maxilla at the fetus stage, the functions of the premaxillary suture still remain unclear. This study was designed to explore the effect of artificial induced premaxillary suture fusion on craniofacial morphology.

Wen-hua Ruan; Julia N. Winger; Jack C. Yu; James L. Borke

2008-01-01

253

Morphological analysis of neovascularization at early stages of rat splenic autografts in comparison with tumor angiogenesis  

Microsoft Academic Search

This study was undertaken to reveal the neovascularization at early stages of splenic autografts three-dimensionally, to illustrate the differences between it and tumor angiogenesis, and to establish its origin. Early vascular formation after transplantation of the rat spleen or Waker tumor into the major omentum was examined by using a video macroscope, vascular casting methods and the organ culture technique.

Katsunori Sasaki; Yoshihiro Kiuchi; Yoji Sato; Shinji Yamamori

1991-01-01

254

Involutive morphological modifications in the rat adrenal glomerular zone after a low-sodium diet  

Microsoft Academic Search

Summary We have studied glomerular zone involution in the rat's adrenal gland after a period of hyperfunction brought about by a low-sodium diet. The changes observed in this zone affect those organoids that are more directly involved in steroid genesis; mitochondria, smooth endoplasmic reticulum and liposomes. The Golgi complexes appear very developed, often, showing, a positive acid phosphatase activity. Lysosomes

G. Palacios

1978-01-01

255

Morphological and functional consequences of chronic epilepsy in rat hippocampal slice cultures  

Microsoft Academic Search

We have developed an in vitro model of chronic epilepsy in order to study the consequences of prolonged periods of epileptic activity. After applying the convulsants bicuculline and\\/or picrotoxin to mature rat hippocampal slice cultures for 3 days, large numbers of swollen and vacuolated cells were observed throughout all hippocampal subfields. The number of dendritic spines of pyramidal cells was

Michael Miiller

1993-01-01

256

Morphological Changes in Locus ceruleus of Albino Rats in Relation to Aging  

Microsoft Academic Search

Comparative studies were carried out under light, fluorescence- and electron-microscopic observations between young, adult and aged groups of albino rats with the following results: the neuronal packing density of locus ceruleus decreases with advanced age. In addition to the senescent loss of nerve cells, the surviving ones showed some shrinkage of perikarya and reduction or loss of Nissl substance. Some

Cui Zhi-tan; Zhang Tie-ming; Su Zhang-hai; William W C. Yen

1988-01-01

257

Structural Characterization and Transport Properties of GaN nanowires in non-serrated and newly discovered serrated morphologies  

NASA Astrophysics Data System (ADS)

We present results on the synthesis, structural characterization and transport properties of single crystal GaN nanowires in two different morphologies (non-serrated and serrated nanowires). The synthesis of these two types of nanowires is carried out in chemical vapor deposition with Au catalysts. Different from the regularly non-serrated GaN nanowires, the GaN nanowires in ``serrated'' morphology have been newly discovered by our group. By controlling the growth conditions, it has been demonstrated that GaN nanowires with regular periodic serrations along the surface of the nanowire can be produced under specific conditions as for large-sized Au catalysts and excess concentration of gallium oxide. Detailed structural and morphological characterization studies reveal interesting features for these two growth modes. In an attempt to understand how these structural and morphological variations impact the electrical properties, transport studies on single GaN nanowires (both serrated and non-serrated) are currently underway. The transport properties, namely current versus voltage will be obtained for such nanowires which in turn will reveal important information on the potential applications of such wires in optoelectronic devices.

Ma, Zheng; Friedman, Adam; Menon, Latika

2013-03-01

258

The brachial plexus branches to the pectoral muscles in adult rats: morphological aspects and morphometric normative data  

PubMed Central

Animal models provide an important tool to investigate the pathogenesis of neuromuscular disorders. In the present study, we analyze fiber composition of the brachial plexus branches to the pectoral muscles: the medial anterior thoracic nerve (MATN) and the lateral anterior thoracic nerve (LATN). The morphological and morphometric characteristics and the percentage of motor fibers within each nerve are here reported, adding information to microscopic anatomy knowledge of the rat brachial plexus. As control, we employed the quadriceps nerve, commonly used for the evaluation of motor fibers at hindlimbs. We demonstrated that the MATN and the LATN are predominantly composed of large motor fibers and therefore could be employed to evaluate the peripheral nervous system (PNS) involvement at forelimbs in neurological diseases models, predominantly affecting the motor fiber compartment.

Riva, Nilo; Domi, Teuta; Lopez, Ignazio Diego; Triolo, Daniela; Fossaghi, Andrea; Dina, Giorgia; Podini, Paola; Comi, Giancarlo; Quattrini, Angelo

2012-01-01

259

Characterization of the major parathyroid hormone target cell in the endosteal metaphysis of rat long bones  

SciTech Connect

The majority of in vivo competitive binding of parathyroid hormone (PTH) in the endosteal metaphysis of rat long bones was recently shown to be localized in the intertrabecular tissue to a cell that is distinct from a differentiated osteoblast. In the present report we have further characterized this cell, termed a parathyroid hormone target (PT) cell, by light and electron microscopy using radioautography and histochemical techniques. These studies demonstrate that the PT cell is a mononuclear cell with a large cell body located at times between clusters of differentiated osteoblasts, as well as in other regions of the intertrabecular tissue. Its long cytoplasmic processes extend from the bone matrix through the intertrabecular region toward vascular structures, interdigitating with various cells of the endosteum. A distinctive tubular structure originating in the Golgi system and often associated with long mitochondria and glycogen particles extends throughout the cytoplasmic processes of the PT cell. Based on its capacity to incorporate ({sup 3}H)thymidine, the PT cell appears to divide rather slowly. The identification of occasional hybrid cells with ultrastructural features of both the PT cell and the differentiated osteoblast and the presence of histochemical evidence for alkaline phosphatase activity suggest that the PT cell is of the osteoblast lineage. These studies therefore morphologically define a major osseous target cell for PTH that, although of the osteoblast lineage, is not a differentiated osteoblast and provide in vivo evidence that characteristics of the 'osteoblast phenotype' are not restricted to a sole osseous cell type.

Rouleau, M.F.; Mitchell, J.; Goltzman, D. (McGill Univ., Montreal, Quebec (Canada))

1990-10-01

260

Characterization of six varieties of Cucumis melo L. based on morphological and physiological characters, including shelf-life of fruit  

Microsoft Academic Search

Seventy-two accessions covering six varieties of Cucumis melo were characterized by using 35 morphological characters with emphasis on shelf-life, and the relationships between shelf-life\\u000a and related characters was investigated. Principal component analysis (PCA) revealed that development period of plant and\\u000a fruit, size of seed and fruit, shelf-life, stem hair, flesh juiciness, netting, abscission of peduncle, rapid yellowing of\\u000a epidermis at

Li Liu; Fumika Kakihara; Masahiro Kato

2004-01-01

261

Quartz crystal microbalance sample stage for in situ characterization of thickness and surface morphology of spin coated polymer films  

SciTech Connect

A miniature spin coating stage is developed for in situ characterization of the thickness and the surface morphology of spin coated polymer films using quartz crystal microbalance (QCM) and atomic force microscopy. The spin coated polystyrene films deposited on gold surfaces from solutions using the stage were found to be uniform; the thickness of the films varied linearly with the polystyrene concentration in solution. The film thickness determined by the QCM agree with that from ellipsometry measurements.

Rao Nanxia; Xie Xin; Wielizcka, David; Zhu Daming [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, Kansas City, Missouri 64110 (United States)

2006-11-15

262

Morphological redescription and molecular characterization of three species of Travassosinematidae (Nematoda: Oxyurida: Thelastomatoidea) from Gryllotalpa africana Beauv (Orthoptera: Gryllotalpidae)  

PubMed Central

Binema mirzaia (Basir, 1942a) Basir, 1956, Cameronia nisari (Parveen and Jairajpuri, 1985) Adamson and Van Waerebeke, 1992a and Mirzaiella meerutensis Singh and Malti, 2003 are redescribed morphologically along with molecular identification from the intestine of mole cricket Gryllotalpa africana. Molecular characterization was carried out using the D2–D3 expansion domains of the 18S ribosomal DNA region. This study first time presents molecular data for the above three nematode species.

Singh, Neetu; Chaudhary, Anshu; Singh, Hridaya Shanker

2013-01-01

263

Morphological redescription and molecular characterization of three species of Travassosinematidae (Nematoda: Oxyurida: Thelastomatoidea) from Gryllotalpa africana Beauv (Orthoptera: Gryllotalpidae).  

PubMed

Binema mirzaia (Basir, 1942a) Basir, 1956, Cameronia nisari (Parveen and Jairajpuri, 1985) Adamson and Van Waerebeke, 1992a and Mirzaiella meerutensis Singh and Malti, 2003 are redescribed morphologically along with molecular identification from the intestine of mole cricket Gryllotalpa africana. Molecular characterization was carried out using the D2-D3 expansion domains of the 18S ribosomal DNA region. This study first time presents molecular data for the above three nematode species. PMID:24143052

Singh, Neetu; Chaudhary, Anshu; Singh, Hridaya Shanker

2013-09-23

264

Dental morphology of the Lesser Bamboo Rat, Cannomys badius (Rodentia, Spalacidae).  

PubMed

Cannomys and Rhizomys are the sole living genera of the tribe Rhizomyini (Rhizomyinae, Spalacidae, Rodentia), known in the fossil record since the Late Miocene. The dental morphology of fossil Rhizomyini has been described in detail but until recently such descriptions were unavailable for extant species. A detailed account of the morphology and dental wear pattern of the cheek teeth of Cannomys badius is provided here based on the examination of museum specimens. Three stages of wear are recognized. Cannomys shares with Rhizomys the synapomorphy of having a mesolophid that is a long continuation of the protoconid on the first lower molar. There are significant differences between these taxa, such as the much smaller size of the cheek teeth and the trilophodont dental pattern of the M2, M3, and m2 in Cannomys. PMID:23166472

López-Antoñanzas, Raquel

2012-10-17

265

Dental morphology of the Lesser Bamboo Rat, Cannomys badius (Rodentia, Spalacidae)  

PubMed Central

Abstract Cannomys and Rhizomys are the sole living genera of the tribe Rhizomyini (Rhizomyinae, Spalacidae, Rodentia), known in the fossil record since the Late Miocene. The dental morphology of fossil Rhizomyini has been described in detail but until recently such descriptions were unavailable for extant species. A detailed account of the morphology and dental wear pattern of the cheek teeth of Cannomys badius is provided here based on the examination of museum specimens. Three stages of wear are recognized. Cannomys shares with Rhizomys the synapomorphy of having a mesolophid that is a long continuation of the protoconid on the first lower molar. There are significant differences between these taxa, such as the much smaller size of the cheek teeth and the trilophodont dental pattern of the M2, M3, and m2 in Cannomys.

Lopez-Antonanzas, Raquel

2012-01-01

266

Tetrodotoxin suppresses morphological enhancement of the metastatic MAT-LyLu rat prostate cancer cell line  

Microsoft Academic Search

Voltage-gated Na+ channels are expressed by highly metastatic MAT-LyLu cells, but not by poorly metastatic AT-2 cells, derived from the rodent\\u000a Dunning model of prostatic cancer. We have investigated the possible involvement of these channels in the morphological development\\u000a of the cells. Incubation of both the MAT-LyLu and the AT-2 cell line for 24 h with the Na+ channel blocker

S. P. Fraser; Y. Ding; A. Liu; C. S. Foster; M. B. A. Djamgoz

1999-01-01

267

Isolation and characterization of rat gastric microvascular endothelial cells as a model for studying gastric angiogenesis in vitro.  

PubMed

We have previously characterized morphologic features of wounding-induced angiogenesis that occurs in response to acute and chronic gastric mucosal injury. As a means of investigating the molecular mechanisms underlying gastric angiogenesis, microvascular endothelial cells were isolated from stomachs of normal (non-injured) rats. The isolation procedure adapted and combined aspects of previous methods and employed positive selection using magnetic beads coated with monoclonal antibody specific for rat CD31 (PECAM-1), a cell surface marker restricted to platelets, monocytes, T lymphocytes and endothelial cells. The isolated microvascular endothelial cells expressed vascular endothelium-specific antigen and the endothelial-specific receptors, Tie2 and flt-1 (VEGFR1). When plated on growth factor-reduced matrigel, the isolated microvascular endothelial cells formed capillary-like structures reflecting in vitro angiogenesis. These cells were also responsive to vascular endothelial growth factor, VEGF, further verifying their endothelial nature. The rat microvascular endothelial cells isolated by this procedure should be useful in delineating molecular mechanisms and regulation of the angiogenesis that is essential for the healing of acute and chronic gastric injury. PMID:11220490

Jones, M K; Wang, H; Tomikawa, M; Szabó, I L; Kawanaka, H; Sarfeh, I J; Tarnawski, A S

2000-12-01

268

[Morphological study of Organum cavum pre-lamina terminalis (OCPLT), implicated in thirst in rats].  

PubMed

It has been shown that micro-injections of angiotensin II in the Organum cavum pre-lamina terminalis (OCPLT) of the rat brain trigger water intake. Our anatomical study shows that the anterior, vertical extension of this Organum corresponds to the anterior inter-hemispheric fissure, and its posterior, horizontal extension to the Cavum septi pellucidi (CSP). Contrary to classical descriptions, the CSP persists in the adult rat, though reduced to one third of its initial antero-posterior extension. It appears rostrally as an opening into the anterior inter-hemispheric fissure. The absence of ependymal cells and of communication with the lateral ventricles points to the fact that this diverticulum is not a median cerebral ventricle. Its pial sheathing and the presence of leptomenix in the cavity confirm its inter-hemispheric origin. The pinocytotic vesicles of the meningeal capillaries suggest an active transfer of substances. Circumstantial evidence suggests circulating angiotensin could be one of them. PMID:9247028

Ronsin, E; Perre, J

1997-06-01

269

Moderate aging does not modulate morphological responsiveness of the neuromuscular system to chronic overload in Fischer 344 rats.  

PubMed

The purpose of this investigation was to determine the effect of aging on neuromuscular adaptations to chronic overload. Eight young adult (8 months old) and eight aged (22 months old) Fischer 344 rats underwent unilateral synergist ablation to overload the plantaris and soleus muscles of that hindlimb and to provide control muscles from the contralateral hindlimb. Cytofluorescent staining and confocal microscopy were used to quantify pre- and post-synaptic features of neuromuscular junctions (NMJs). Histochemical staining and light microscopy were used to assess adaptations of myofibers to chronic overload. Results demonstrate that NMJs of young adult and aged muscles did not undergo morphological remodeling as a result of 4 weeks of chronic overload. In contrast, myofibers of young and aged rats displayed significant (P<0.05), but similar hypertrophy ( approximately 18%) following that 4 week intervention. In both age groups, however, this hypertrophy was detected in the plantaris, but not the soleus. These data indicate that moderate aging (the equivalent of 65 years in human lifetime) does not modify the sensitivity of the neuromuscular system to chronic overload. PMID:17720323

Deschenes, M R; Tenny, K; Eason, M K; Gordon, S E

2007-08-27

270

Adrenalectomy and corticosterone replacement differentially alter CA3 dendritic morphology and new cell survival in the adult rat hippocampus.  

PubMed

Plastic changes in the adult mammal hippocampus can be altered by many factors and perhaps the most well-documented is stress. Stress and elevated corticosterone levels have been shown to decrease hippocampal neurogenesis and decrease the complexity of CA3 pyramidal neurons. However, the extent of these changes in relation to low and moderately elevated levels of corticosterone has yet to be fully investigated. Therefore, the aim of the present study was to determine how low to moderately elevated circulating corticosterone levels affect dendritic morphology of CA3 pyramidal cells and hippocampal neurogenesis in adult male rats. To do this, three groups of adult male Wistar rats were used: (1) Sham-operated, (2) Adrenalectomized (ADX), and (3) ADX+corticosterone replacement. Primary results show that adrenalectomy, but not moderately elevated levels of corticosterone replacement, resulted in significant atrophy of CA3 pyramidal neurons. Interestingly, moderate corticosterone replacement resulted in significantly more surviving new cells in the dentate gyrus when compared to sham controls. This work shows that circulating levels of corticosterone differentially affect plasticity in the CA3 region and the dentate gyrus. PMID:23333161

Martínez-Claros, M; Steinbusch, H W M; van Selm, A; van den Hove, D L A; Prickaerts, J; Pawluski, J L

2013-01-16

271

Morphological and morphometric changes in the cervix uteri of the rat at term pregnancy induced by hyaluronidase.  

PubMed

Intracervix injection of hyaluronidase during pregnancy has been proposed to accelerate cervix ripening. We evaluated the morphological and morphometric changes of the uterine cervix of pregnant rats, caused by the action of this enzyme. Ten female rats were equally divided between an experimental group (G II) and a control group (G I). On the 20th day of pregnancy, under light microscopy, a greater thinning of the superficial muciferous epithelium, with lamina propria rich in blood vessels and in eosinophils was found in G II. The histometric count of G II showed a smaller number of collagen fibers (average 248 vs 552 in the control group) and a greater concentration of eosinophils (average 18.20 vs 9.20 in the control group). The Student's t-test showed a significant difference in collagen fibers (p < 0.0001) and in eosinophils (p < 0.0007). The action of this enzyme caused a predominance of flaccid connective tissue, a lower concentration of collagen fibers and an increased concentration of eosinophils, confirming its utilization in cervix ripening. PMID:15491070

de Souza, G Negrão; Cordioli, E; de Jesus Simões, M; de Souza, E; Kulay, L Júnior; Camano, L

2004-01-01

272

Morphology and proliferation kinetics of early tumor stages induced by dimethylnitrosamine in rat kidneys  

Microsoft Academic Search

Summary  A total of 49 dimethylnitrosamine (DMN)induced rat renal cell tumors were analyzed and classified cytomorphologically at an\\u000a early stage of development. Of these, 17 were basophilictubular tumors, two of which showed a direct transition to proximal\\u000a tubules of the P3segment; 21 lesions were vacuolated and contained glycogen; these were defined cytomorphologically as a separate tumor type\\u000a the histogenetic derivation of

Christof Brummer; Hartmut M. Rabes

1992-01-01

273

Rearrangement of the dendritic morphology in limbic regions and altered exploratory behavior in a rat model of autism spectrum disorder.  

PubMed

Valproic acid (VPA) is a blocker of histone deacetylase widely used to treat epilepsy, bipolar disorders, and migraine; its administration during pregnancy increases the risk of autism spectrum disorder (ASD) in the child. Thus, prenatal VPA exposure has emerged as a rodent model of ASD. In the present study, we aimed to investigate the effect of prenatal administration of VPA (500mg/kg) at E12.5 on the exploratory behavior and locomotor activity in a novel environment, as well as on neuronal morphological rearrangement in the prefrontal cortex (PFC), in the hippocampus, in the nucleus accumbens (NAcc), and in the basolateral amygdala (BLA) at three different ages: immediately after weaning (postnatal day 21 [PD21]), prepubertal (PD35) and postpubertal (PD70) ages. Hyper-locomotion was observed in a novel environment in VPA animals at PD21 and PD70. Interestingly, exploratory behavior assessed by the hole board test at PD70 showed a reduced frequency but an increase in the duration of head-dippings in VPA-animals compared to vehicle-treated animals. In addition, the latency to the first head-dip was longer in prenatal VPA-treated animals at PD70. Quantitative morphological analysis of dendritic spine density revealed a reduced number of spines at PD70 in the PFC, dorsal hippocampus and BLA, with an increase in the dendritic spine density in NAcc and ventral hippocampus, in prenatal VPA-treated rats. In addition, at PD70 increases in neuronal arborization were observed in the NAcc, layer 3 of the PFC, and BLA, with retracted neuronal arborization in the ventral and dorsal hippocampus. Our results extend the list of altered behaviors (exploratory behavior) detected in this model of ASD, and indicate that the VPA behavioral phenotype is accompanied by previously undescribed morphological rearrangement in limbic regions. PMID:23535253

Bringas, M E; Carvajal-Flores, F N; López-Ramírez, T A; Atzori, M; Flores, G

2013-03-25

274

Growth assessment of diabetic rat fetuses under the influence of insulin and melatonin: a morphologic study.  

PubMed

Hyperglycemia-induced oxidative stress makes an important contribution to the etiology of diabetic teratogenicity namely fetal growth and congenital dysmorphogenesis. The aim of this study is to evaluate the protective roles of melatonin and insulin against diabetic's embryolethality and teratogenicity. Diabetes was induced to virgin Sprague Dawley albino rats by a single peritoneal injection of alloxan. Thirty pregnant rats were divided equally into 5 groups: 1) Control 2) Diabetic 3) Diabetic insulin 4) Diabetic melatonin 5) Diabetic melatonin-insulin. Insulin and melatonin were administered daily throughout the whole gestational period. Fetuses were collected on day 20 of gestation and were examined for malformations and growth disorders. A significant increase in fetal growth parameters (Macrosomia) were noticed in the diabetic group compared to the control. Melatonin prevents the appearance of soft tissue anomalies, but it leads to fetal growth restriction of diabetic rats (Microsomia). No significant changes were noticed in fetal growth parameters in diabetic insulin or in diabetic melatonin-insulin groups compared to the control. Congenital anomalies were not seen in diabetic insulin and in diabetic melatonin-insulin groups while the rate of resorption was reduced in both groups when compared to the diabetic group. In conclusion, co-administration of melatonin with insulin leads to a slight non significant improvement of the protective role of insulin against diabetic embryolethality, teratogenicity and fetal growth changes. PMID:21452678

Salem, Abdel Halim A; Nosseir, Nermine S; El Badawi, Mohamed G Y; Shoair, Mohamed I; Fadel, Raouf A R

2010-01-01

275

[Characteristics of morphological changes in the myocardium of rats with different degrees of hereditary resistance to hypoxia during the development of adrenaline-induced myocardial dystrophy].  

PubMed

By means of polarizational microscopy method morphological changes of the cardiac muscle have been studied in highly-(HS) and poorly-stable (PS) rats to hypoxia 1 h and 1 day after injection of cardiotoxic dose of adrenaline (1.5 mg/kg of body mass). One hour after injection of adrenaline in PS animals the II-III stages of contractive myofibrillar changes are revealed, while in HS rats--the I-II stages. In 1 day in the myocardium of PS animals contractures of the III-IV degree are observed, more foci of clumping decay and myocytolysis than in HS rats. Severity of the morphological changes of the cardiac muscle after cardiotoxic dose of adrenaline essentially depends on the organism's reactivity. PMID:3447562

Markova, E A; Kvik, I I; Misula, I R

1987-08-01

276

Characterizing Morphology and Erosional Trends of Permafrost Bluffs, Barter Island, Alaska  

NASA Astrophysics Data System (ADS)

Recession of coastal permafrost bluffs along portions of the North Slope of Alaska are highly variable, and recent studies have found increased retreat rates since the early 2000s along the western Beaufort Sea coastline, yet the mechanisms and processes driving the increased retreat rates remain poorly understood. The Native village of Kaktovik and adjacent U.S. Air Force radar site are situated on Barter Island and bound by an eroding coastal bluff where attempts to control bluff erosion with shore protection structures were undertaken more than a decade ago. In an effort to gain insight into the physical controls driving or limiting bluff recession in this region, a suite of field data was collected in August 2010 to characterize the beaches, bluffs, and nearshore setting. Data collected at 13 transect locations along the 3 km section of coastal bluffs include general bluff morphology and stratigraphy, detailed surveys of bluff edge and bluff face morphology, sediment grain size of the fronting beach, water/ice content and sediment grain size of the massive ice within the bluffs, and nearshore bathymetry. The bluffs here range in height from a few meters to more than ten meters and consist of a very complex sequence of material ranging from dense marine clay at the base, sands and gravel thought to be of fluvial origin, massive units of sand of unknown origin, massive ice which has recently been interpreted as buried glacial ice, wedge ice, thermokarst cave ice, aeolian silts and sands, and peat. At one site, thermistor arrays were installed to evaluate temperature gradients in response to solar radiation and heat flux transfers through characteristic bluff material. Aerial lidar DEMs obtained in 2009 (USGS) revealed a rise in bluff elevation across the central portion of the island where field observations of bluff stratigraphy showed multi-layered stratification. At the lower elevation outer flanks the exposed bluff face consisted of homogenous layers of sandy-silt below the surface peat layer. Comparison of historical bluff edge lines (1947, 1987, 2003), 2009 lidar derived bluff lines, and differential GPS surveys collected in August 2010 suggest increased erosion rates of the bluff top in recent years near the topographically-higher central portion of the island. Maximum beach widths were observed at the flanks of the island where east-west trending spits have formed, likely by way of longshore transport driven by variations in wave direction at the terminus of the spits. Beach width ranged from a maximum of 80 m at the eastern boundary of the bluffs to no beach in front of the former radar station landfill where shore protection structures are emplaced. Beach surface material consisted of fine sands in the back beach region and gravels to pebble-sized material in the mid-beach and swash zone areas. Primary failure modes of Barter Island bluffs appear to be a combination of thermal degradation and thawing of permafrost in the exposed bluff face, mechanical and thermal niching at the toe, followed by rotational slumping of the higher bluffs near the central portion of the island and block collapse of the lower bluffs at the flanks of the island.

Gibbs, A.; Erikson, L. H.; Jones, B.; Richmond, B. M.

2010-12-01

277

The influence of chronic fluorosis on mitochondrial dynamics morphology and distribution in cortical neurons of the rat brain.  

PubMed

The present study was designed to evaluate the effects of chronic fluorosis on the dynamics (including fusion and fission proteins), fragmentation, and distribution of mitochondria in the cortical neurons of the rat brain in an attempt to elucidate molecular mechanisms underlying the brain damage associated with excess accumulation of fluoride. Sixty Sprague-Dawley rats were divided randomly into three groups of 20 each, that is, the untreated control group (drinking water naturally containing <0.5 mg fluoride/l, NaF), the low-fluoride group (whose drinking water was supplemented with 10 mg fluoride/l) and the high-fluoride group (50 mg fluoride/l). After 6 months of exposure, the expression of mitofusin-1 (Mfn1), fission-1 (Fis1), and dynamin-related protein-1 (Drp1) at both the protein and mRNA levels were detected by Western blotting, immunohistochemistry, and real-time PCR, respectively. Moreover, mitochondrial morphology and distribution in neurons were observed by transmission electron or fluorescence microscopy. In the cortices of the brains of rats with chronic fluorosis, the level of Mfn1 protein was clearly reduced, whereas the levels of Fis1 and Drp1 were elevated. The alternations of expression of the mRNAs encoding all three of these proteins were almost the same as the corresponding changes at the protein levels. The mitochondria were fragmented and the redistributed away from the axons of the cortical neurons. These findings indicate that chronic fluorosis induces abnormal mitochondrial dynamics, which might in turn result in a high level of oxidative stress. PMID:23007560

Lou, Di-Dong; Guan, Zhi-Zhong; Liu, Yan-Jie; Liu, Yan-Fei; Zhang, Kai-Lin; Pan, Ji-Gang; Pei, Jin-Jing

2012-09-25

278

Characterization of breast lesion morphology with delayed 3DSSMT: An adjunct to dynamic breast MRI  

Microsoft Academic Search

The purpose of the study was to determine the sensitivity and specificity of various morphologic criteria in distin- guishing malignant from benign breast lesions using a new sequence (3DSSMT) performed immediately after dynamic breast MRI. 3DSSMT combines a water-selective spectral- spatial excitation and an on-resonance magnetization transfer pulse with three-dimensional spoiled gradient- echo imaging. Morphologic features of 87 pathologically confirmed

Cindy S. Leong; Bruce L. Daniel; Robert J. Herfkens; Robyn L. Birdwell; Stefanie S. Jeffrey; Debra M. Ikeda; Anne M. Sawyer-Glover; Gary H. Glover

2000-01-01

279

Eccentric exercise-induced morphological changes in the membrane systems involved in excitation-contraction coupling in rat skeletal muscle  

PubMed Central

Physiological evidence suggests that excitation-contraction (E—C) coupling failure results from eccentric contraction-induced muscle injury because of structural and morphological damage to membrane systems directly associated with the E—C coupling processes within skeletal muscle fibres. In this study using rats, we observed the ultrastructural features of the membrane systems of fast-twitch (FT) and slow-twitch (ST) muscle fibres involved in E—C coupling following level and downhill running exercise. Our aim was to find out whether mechanically mediated events following eccentric exercise caused disorder in the membrane systems involved in E—C coupling, and how soon after exercise such disorder occurred. We also compared the morphological changes of the membrane systems between ST and FT muscle fibres within the same muscles. Single muscle fibres were dissected from triceps brachii muscles of male Fischer 344 rats after level or downhill (16 deg decline) motor-driven treadmill running (18 m min?1, 5 min running with 2 min rest interval, 18 bouts). All single muscle fibres were histochemically classified into ST or FT fibres. The membrane systems were visualized using Ca2+–K3Fe(CN)6–OsO4 techniques, and observed by high voltage electron microscopy (120–200 kV). There were four obvious ultrastructural changes in the arrangement of the transverse (t)-tubules and the disposition of triads after the downhill running exercise: (1) an increase in the number of longitudinal segments of the t-tubule network, (2) changes in the direction and disposition of triads, (3) the appearance of caveolar clusters, and (4) the appearance of pentads and heptads (close apposition of two or three t-tubule elements with three or four elements of terminal cisternae of the sarcoplasmic reticulum). The caveolar clusters appeared almost exclusively in the ST fibres immediately after downhill running exercise and again 16 h later. The pentads and heptads appeared almost exclusively in the FT fibres, and their numbers increased dramatically 2–3 days after the downhill running exercise. The eccentric exercise led to the formation of abnormal membrane systems involved in E–C coupling processes. These systems have unique morphological features, which differ between ST and FT fibres, even within the same skeletal muscle, and the damage appears to be concentrated in the FT fibres. These observations also support the idea that eccentric exercise- induced E–C coupling failure is due to physical and chemical disruption of the membrane systems involved in the E–C coupling process in skeletal muscle.

Takekura, Hiroaki; Fujinami, Nahoko; Nishizawa, Tomie; Ogasawara, Hitomi; Kasuga, Norikatsu

2001-01-01

280

Pore-scale Characterization of Organic Immiscible-Liquid Morphology in Natural Porous Media Using Synchrotron X-Ray Microtomography  

NASA Astrophysics Data System (ADS)

The objective of this study was to quantitatively characterize the pore-scale morphology of organic immiscible liquid (chlorinated solvents) residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of solid and liquid phases in packed columns. The image data were processed to generate quantitative measurements of organic-liquid blob morphology. Several porous media, comprising a range of particle-size distributions, were used to evaluate the impact of porous-medium texture on blob morphology. Organic liquid blob morphology was characterized in both two-phase (water-organic liquid) and three-phase (water-organic liquid-air) systems. The sizes and shapes of the organic-liquid blobs varied greatly, ranging from small spherical singlets (as small as 0.03-mm in diameter) to large, amorphous ganglia with mean lengths of 4-5 mm. The majority of the total organic-liquid surface area and volume was associated with the largest blobs. The distribution of blob sizes was greatest for the porous medium with the broadest particle-size and pore-size distributions. A significant portion of the organic liquid in the three-phase systems was observed to exist as lenses and films in contact with air. These features were not observed in the two-phase water-organic liquid systems. Additional studies were conducted to examine changes in blob morphology and associated mass flux due to dissolution induced mass removal. The microtomography method allowed for observations of the dissolution progress of individual organic liquid blobs, as well as changes in global volume, surface area, and water-organic liquid interfacial area.

Schnaar, G.; Brusseau, M. L.

2005-12-01

281

Characterization of serotonin receptors in isolated rat intramyocardial coronary artery.  

PubMed

The purpose of the present study was to characterize the receptor subtypes that mediate serotonin (5-HT)-induced contraction in isolated rat intramyocardial coronary artery. In coronary artery with and without endothelium, only 5-HT and alpha-methylserotonin maleate (5-HT2 agonist) elicited equipotent concentration-dependent contractions. The EC50 values for 5-HT and alpha-methylserotonin maleate in endothelium-intact arteries were 4.7 x 10(-7) and 4.5 x 10(-7) M, respectively, whereas in endothelium-denuded arteries they were 2.8 x 10(-7) and 1.9 x 10(-7) M, respectively. The other subtype agonists, such as (+/-)-8-hydroxy-dipropylaminotetralin hydrobromide (5-HT1A agonist), 1-(3-chlorophenyl)piperazine dihydrochloride and 7-trifluoromethyl-4-(4-methyl-1-piperazinyl)-pyrrolo(1,2-a)quinoxaline (5-HT1B) and 2-methyl-serotonin maleate (5-HT3), only elicited a small percentage of the maximum contraction to 5-HT. In prostaglandin F2 alpha-precontracted coronary arteries with intact endothelium or denuded of endothelium, the addition of 5-HT resulted in a further increase in tension. No relaxation was observed with 5-HT up to 1 x 10(-5) M. The contraction induced by 5-HT in artery both with and without endothelium was inhibited by ketanserin (5-HT2 antagonist) but not by l-propranolol (5-HT1 antagonist) nor by 3-tropanyl-indole-3,5-dichlorobenzoate (5-HT3 antagonist). Ketanserin, the selective 5-HT2 antagonist, effectively antagonized 5-HT-induced contraction by shifting the 5-HT response curve to the right without inhibiting the maximal response in both endothelium-intact and -denuded arteries.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1988655

Lai, F M; Tanikella, T; Cervoni, P

1991-01-01

282

Chemical, dimensional and morphological ultrafine particle characterization from a waste-to-energy plant.  

PubMed

Waste combustion processes are responsible of particles and gaseous emissions. Referring to the particle emission, in the last years specific attention was paid to ultrafine particles (UFPs, diameter less than 0.1 ?m), mainly emitted by combustion processes. In fact, recent findings of toxicological and epidemiological studies indicate that fine and ultrafine particles could represent a risk for health and environment. Therefore, it is necessary to quantify particle emissions from incinerators also to perform an exposure assessment for the human populations living in their surrounding areas. To these purposes, in the present work an experimental campaign aimed to monitor UFPs was carried out at the incineration plant in San Vittore del Lazio (Italy). Particle size distributions and total concentrations were measured both at the stack and before the fabric filter inlet in order to evaluate the removal efficiency of the filter in terms of UFPs. A chemical characterization of UFPs in terms of heavy metal concentration was performed through a nuclear method, i.e., Instrumental Neutron Activation Analysis (INAA), as well as a mineralogical investigation was carried out through a Transmission Electron Microscope (TEM) equipped with an Energy Dispersive Spectrometer (EDS) in order to evaluate shape, crystalline state and mineral compound of sampled particles. Maximum values of 2.7 × 10(7) part. cm(-3) and 2.0 × 10(3) part. cm(-3) were found, respectively, for number concentration before and after the fabric filter showing a very high efficiency in particle removing by the fabric filter. With regard to heavy metal concentrations, the elements with higher boiling temperature present higher concentrations at lower diameters showing a not complete evaporation in the combustion section and the consequent condensation of semi-volatile compounds on solid nuclei. In terms of mineralogical and morphological analysis, the most abundant compounds found in samples collected before the fabric filter are Na-K-Pb oxides followed by phyllosilicates, otherwise, different oxides of comparable abundance were detected in the samples collected at the stack. PMID:21802934

Buonanno, Giorgio; Stabile, Luca; Avino, Pasquale; Belluso, Elena

2011-07-29

283

Immunolocalization and characterization of the rat analogue of human CD59 in kidney and glomerular cells.  

PubMed Central

CD59, a potent inhibitor of the human membrane attack complex (MAC) of complement, is present on many different tissues throughout the body. Recently we identified and characterized the rat analogue of CD59 and produced a number of monoclonal antibodies (mAb). We have now used these antibodies to demonstrate, by immunofluorescence microscopy, that rat CD59 was widely expressed in the rat kidney. Staining of renal sections revealed the presence of rat CD59 in abundance in the glomerulus, collecting ducts and distal tubules. Staining was abolished by treatment of sections with phosphatidylinositol-specific phospholipase C (PIPLC). Rat mesangial cells also stained strongly for rat CD59, giving an intensely granular staining pattern. In complement attack experiments the cultured mesangial cells were rendered more susceptible to lysis by rat or human complement after preincubation with the anti-inhibitor mAb. The results demonstrate that the rat analogue of CD59 is present and functionally active in rat renal tissue. The protective effect of CD59 against MAC-mediated tissue injury can now be examined in rat models of human renal disease. Images Figure 1 Figure 2

Hughes, T R; Meri, S; Davies, M; Williams, J D; Morgan, B P

1993-01-01

284

The influence of vitamin E and methionine on the activity of enzymes and the morphological picture of liver of rats intoxicated with sodium fluoride.  

PubMed

The aim of this study was to investigate the effects of vitamin E and methionine on the activity of enzymes regulating carbohydrate metabolism and enzymes associated with glutathione as well as to examine the morphology of the liver in rats exposed to sodium fluoride. The study was conducted in 18 male rats of Wistar strain. The rats were divided into three groups: a control group, which received distilled water and two experimental groups, which received sodium fluoride (10 mg/kg of body mass/24 h) in water solution. Animals in the second experimental group received 3 mg of vitamin E/rat/24 h and 2 mg methionine/rat/24 h. The experiment lasted 35 days. In supernatants obtained after homogenization of rat liver slices, the activity of the following enzymes was assayed: fructose-1,6-biphosphate aldolase (ALD) malate dehydrogenase (MDH), lactate dehydrogenase (LDH), sorbitol dehydrogenase (SDH) the activity of glutathione peroxidase (GPx), glutathione transferase (GST) and glutathione reductase (GR). Pathomorphological evaluation was conducted on preparations made by standard paraffin method, followed by staining with hematoxylin and eosin. The administration of antioxidants counteracted changes in the activity of the enzymes and the morphological abnormalities of the liver induced by NaF. Antioxidants may be important in preventing toxicity of fluoride compounds. PMID:22266362

Stawiarska-Pi?ta, Barbara; Bielec, Beata; Birkner, Katarzyna; Birkner, Ewa

2012-01-15

285

Functional and morphological changes in the rat kidney after long-term adrenaline application.  

PubMed

A 24 h lasting long term adrenaline application in the form of subcutaneously implanted retard-tablets causes functional and morphological changes in the kidney, which are dose dependent and either reversible or irreversible. Animals in the V 15 group received one 15 mg and in the V 30 group two 15 mg adrenaline tablets resp. The tablets were removed after 24 h and a clearance depot capsule was implanted in the abdominal cavity. The test period extended from 22 h after removal of the retard tabl. to 21 d thereafter. Inulin (except the V 30 grp.), PAH and urea clearance are showing no significant differences. The data of urine gamma-GT activity, urea and urea-N in serum and urine, S-glucose, S-triglycerides, Combur-8-test, Na+ and K+ levels are in normal ranges. Morphological changes were found in the glomerula and tubular regions. Both the number of damaged nephrons and the extent of the damage depend upon the doses of adrenaline given. All glomerula with visible serious changes are irreversibly damaged; this was not true in case of the tubule. In the latter, after 7 d, the fatty deposits had diminished or disappeared. PMID:6144567

Sadjak, A; Egger, G; Kink, E; Korsatko, W

1984-01-01

286

Waking the Dead: Morphological and Molecular Characterization of Extant †Posoniella tricarinelloides (Thoracosphaeraceae, Dinophyceae).  

PubMed

The Thoracosphaeraceae are dinophytes that produce calcareous shells during their life history, whose optical crystallography has been the basis for the division into subfamilies. To evaluate the validity of the classification (mainly applied by palaeontologists), living material of phylogenetic key species is necessary albeit frequently difficult to access for contemporary morphological and molecular analyses. We isolated and established five living strains of the rare fossil-taxon †Posoniella tricarinelloides from different sediment samples collected in the South China Sea, Yellow Sea and in the Mediterranean Sea (west coast off Italy). Here, we provide detailed descriptions of its morphology and conducted phylogenetic analyses based on hundreds of accessions and thousands of informative sites on concatenated rRNA datasets. Within the monophyletic Peridiniales, †P. tricarinelloides was reliably nested in the Thoracosphaeraceae and exhibited two distinct morphological types of coccoid cells. The two morphologies of coccoid cells would have been assigned to different taxa at the subfamily level if found separately in fossil samples. Our results thus challenge previous classification concepts within the dinophytes and underline the importance of comparative morphological and molecular studies to better understand the complex biology of unicellular organisms such as †P. tricarinelloides. PMID:23850812

Gu, Haifeng; Kirsch, Monika; Zinssmeister, Carmen; Soehner, Sylvia; Meier, K J Sebastian; Liu, Tingting; Gottschling, Marc

2013-07-11

287

Effects of ozone and neutrophils on function and morphology of the isolated rat lung  

SciTech Connect

Since whole-animal studies suggest that neutrophils play a role in ozone-induced impairment of pulmonary function and increases in airway reactivity, this study was designed to study more precisely the interaction of neutrophils and ozone using the isolated perfused rat lung. Sprague-Dawley rat lungs (n = 60) were ventilated for 3 h with 95% air and 5% CO2 alone or mixed with 1 ppm ozone and perfused with buffer alone or with neutrophils (8 x 10(7)). RL, Cdyn, Ppa, airway reactivity to methacholine, lung/body weight, bronchoalveolar lavage fluid (BALF) protein concentration, and airway lesions were analyzed using a two-way GLM or Kruskal-Wallis test (p < or = 0.05 significant). Both ozone and neutrophils increased RL and decreased Cdyn. Ozone but not neutrophils increased airway reactivity to methacholine. Neutrophils but not ozone increased lung weight/body weight and BALF protein concentration. Ozone damaged airway epithelium. In distal bronchioles, neutrophils enhanced this damage. We conclude that (1) ozone impaired pulmonary function, increased airway reactivity, and damaged airway epithelium without causing measurable microvascular leak; (2) neutrophils impaired pulmonary function, probably a result of microvascular leak, but did not change airway reactivity or damage airway epithelium; and (3) neutrophils had no effect on ozone-induced airway reactivity but had an additive effect on ozone-induced pulmonary function impairment and a synergistic effect on ozone-induced airway epithelial injury.

Joad, J.P.; Bric, J.M.; Pino, M.V.; Hyde, D.M.; McDonald, R.J. (Univ. of California, Davis (United States))

1993-06-01

288

Comparison of functional and morphological deficits in the rat after gestational exposure to ionizing radiation  

SciTech Connect

Ionizing radiation is a precise tool for altering formation of the developing cerebral cortex of the fetal rat. Whole body exposure of the pregnant rat on gestational day 13, 15 or 17 to 1.0 Gy of gamma radiation resulted in maximum thinning of the cortex on days 15 and 17. In the preweaning period, functional tests (negative geotaxis, reflex suspension, continuous corridor and gait) were most affected by irradiation gestational day 15, as was body weight. When a lower dose of radiation (0.75 Gy) was used on gestational day 15, the damage to the cortex was much less but behavioral changes were still present. Frontal, parietal and occipital areas of the cortex were approximately equally affected. Using stepwise multiple regression analysis, the linkage of functional tests and cortical thickness was examined. Functional variables which were most commonly included as predictors of frontal and parietal cortex were negative geotaxis and continuous corridor. Occipital cortical layers were not predicted by behavioral variables. In predicting function using cortical variables, frontal cortex was better than parietal and occipital cortex was the poorest predictor.

Norton, S.; Kimler, B.F.

1988-07-01

289

Morphological and molecular characterization of Phomopsis vaccinii and additional isolates of Phomopsis from blueberry and cranberry in the eastern United States  

Microsoft Academic Search

Forty isolates of Phomopsis were obtained from twigs and berries of highbush blueberry, Vaccin- ium corymbosum, and cranberry, Vaccinium macrocar- pon, isolated primarily from plants grown in the east- ern United States. They were characterized using conidiomatal morphology, conidial dimensions, col- ony appearance and growth rate, and sequences of ITS rDNA. Based on morphological and molecular similarities, most isolates grouped

David F. Farr; Lisa A. Castlebury; Amy Y. Rossman

2002-01-01

290

Synthesis and characterization of {beta}-MnO{sub 2} single crystals with novel tetragonous morphology  

SciTech Connect

{beta}-MnO{sub 2} single crystals with novel tetragonous morphology have been hydrothermally prepared in an HCl solution at 180 deg. C for 24 h without using templates, catalysts, and organic reagents. The structure of the obtained {beta}-MnO{sub 2} was systematically investigated by X-ray diffraction, SEM and TEM microscopy, FT-IR spectroscopy, DSC-TGA analyses, and chemical compositional analyses. The morphology of {beta}-MnO{sub 2} could be controlled by the hydrothermal treatment temperatures and the hydrothermal reaction times. {beta}-MnO{sub 2} single crystals with diameters 200-600 nm and lengths up to 1-5 {mu}m not only had novel tetragonous morphology, but also had high purity.

Zhang Lichun [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062 (China); Liu Zonghuai [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062 (China)]. E-mail: zhliu@snnu.edu.cn; Tang Xiuhua [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062 (China); Wang Jianfang [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062 (China); Ooi, Kenta [National Institute of Advanced Industrial Science and Technology, 2217-14, Hayashi-cho, Takamatsu, Kagawa 761-0395 (Japan)

2007-08-07

291

Characterization of the morphology of co-extruded, thermoplastic/rubber multi-layer tapes.  

PubMed

Tapes with alternating semi-crystalline thermoplastic/rubber layers with thicknesses varying from 100 nm up to several microm were prepared by multi-layer co-extrusion. The variation in layer thickness was obtained by varying the thermoplastic/rubber feed ratio. A systematic study on the use of various microscopy techniques to visualize the morphology of the layered systems is presented. The relatively large length scales and the sample preparation make optical microscopy (OM) unsuitable to study the morphology of the multi-layer tapes. Although excellent contrast between the thermoplastic and rubber layers can be obtained, the usually applied, relatively large magnifications limit the use of transmission electron microscopy (TEM) and atomic force microscopy (AFM) to small sample areas. The large range of applicable magnifications makes scanning electron microscopy (SEM) the most suitable technique to study the morphology of the multi-layer tapes. The sample preparation for SEM with a secondary electron (SE) detector is often based on the removal of one of the components, which may induce changes in the morphology. SEM with a back-scattered electron (BSE) detector is a very convenient method to study the morphology over a wide range of length scales, where the contrast between the different layers can be enhanced by chemical staining. Finally, the nucleation behavior (homogeneous versus heterogeneous) of the semi-crystalline layers, as probed by differential scanning calorimetry (DSC), provides valuable information on the layered morphology. The use of relatively straightforward DSC measurements shows a clear advantage with respect to the discussed microscopy techniques, since no sample preparation is required and relatively large samples can be studied, which are more representative for the bulk. PMID:19850162

l'Abee, R M A; Vissers, A M J T; Goossens, J G P; Spoelstra, A B; van Duin, M

2009-06-21

292

Characterizing the Morphologies of Mechanically Manipulated Multiwall Carbon Nanotube Films by Small-Angle X-ray Scattering  

SciTech Connect

We used small-angle X-ray scattering (SAXS) to quantitatively characterize the morphological characteristics of pristine and mechanically manipulated multiwall carbon nanotube (MWCNT) films. We determined that CNT diameters measured near the edges of a film were smaller compared to those measured in the interior. Uniaxially compressed MWCNT films exhibited a buckling deformation that was observable both in scanning electron microscopy (SEM) and SAXS. CNT films were also converted into cellular foams of CNTs through capillarity-induced densification. By examining spatially- and time-resolved SAXS data for the cellular foams, we identified low angle features in the scattering curves that correspond to the average spacing between CNTs, demonstrating that SAXS is a useful method for monitoring the packing density of CNTs in a film. For all of the morphologies that were examined (aligned, disordered, compressed, and densified), SAXS data showed good correspondence with SEM images.

Wang,B.; Bennett, R.; Verploegen, E.; Hart, A.; Cohen, R.

2007-01-01

293

Effects of bromoethylamine on antioxidant capacity, lipid peroxidation, and morphological characteristics of rat liver.  

PubMed

Administration of bromoethylamine (BEA, 1.2 mmol/kg) to fed rats induced a significant diminution in the activity of hepatic superoxide dismutase (at 1 h after treatment), catalase, and glutathione peroxidase and in the content of nonprotein sulfhydryls (at 15 h after treatment). The content of thiobarbituric acid reactants by the liver was enhanced by 1.9 times over control values (at 3 h). Light microscopy studies revealed that BEA (72 h after treatment) induced periportal fatty accumulation, focal liver cell necrosis, and diffuse inflammatory infiltrates, in addition to hypertrophic Kupffer cells and mitotic hepatocytes. Also, hypertrophic middle tunic or hypertrophic smooth muscle layers of arterioles was observed in the periportal space, with dilated sinusoidal capillaries and free macrophage infiltration. It is concluded that BEA induces a derangement in the antioxidant status of the liver with the consequent lipid peroxidation response, which may constitute a significant hepatotoxic mechanism of the haloaklylamine. PMID:9890447

Thielemann, L E; Bosco, C; Rodrigo, R; Orellana, M; Videla, L A

1999-01-01

294

Cloning and Pharmacological Characterization of a Rat kappa Opioid Receptor  

Microsoft Academic Search

A full-length cDNA was isolated from a rat striatal library by using low-stringency screening with two PCR fragments, one spanning transmembrane domains 3-6 of the mouse delta opioid receptor and the other unidentified but homologous to the mouse delta receptor from rat brain. The novel cDNA had a long open reading frame encoding a protein of 380 residues with 59%

Fan Meng; Guo-Xi Xie; Robert C. Thompson; Alfred Mansour; Avram Goldstein; Stanley J. Watson; Huda Akil

1993-01-01

295

Prenatal exposure to tobacco extract containing nicotinic alkaloids produces morphological and behavioral changes in newborn rats.  

PubMed

Tobacco exposure is not only a health concern for adults but has also been shown to exert deleterious effects on the health of the fetus, newborn, child, and adolescent. Decreased cognitive function, lower Intellectual Quotient (IQ) and deficits in learning and memory in children have been associated with maternal smoking during pregnancy. In this study, we have studied the effect of a tobacco plant extract on the growth and development in the rat. The extract contained relative proportions of alkaloids, including nicotine, purified by chemical separation. Pregnant rats received oral doses of either control (NaCl) or tobacco extract during the entire gestational period. Offspring length and body weight were measured. Each day, the offspring were observed for the following physical parameters: hair growth, incisor eruption and eye opening. The day of appearance of these developments was recorded. Before weaning, the offspring were examined to test their cliff avoidance response (6 postnatal day (PN)), surface righting reflex (05, 07, 13 postnatal day), swimming development (10, 12 postnatal day), negative geotaxis response (7,9,13 and 17 postnatal day) and jumping down choice cage (15, 17 postnatal day). Administration of tobacco extract to dams during the entire gestation period affects behavior and development in pups. The observed effects were a delay in opening eyes, incisor eruption and hair appearance, behavioral developments and an alteration in the rate of success behavior. However, in the jumping down choice cage test there was no difference compared to control animals. The results suggest that tobacco extract has a significant effect on the development of behavioral patterns, orientation and motor coordination and function. They also suggest significant growth retardation and teratogenic effects. PMID:22306748

Khalki, Hanane; Khalki, Loubna; Aboufatima, Rachida; Ouachrif, Abderrahim; Mountassir, Maryam; Benharref, Ahmed; Chait, Abderrahman

2012-01-31

296

Genistein stimulates the hypothalamo-pituitary-adrenal axis in adult rats: morphological and hormonal study.  

PubMed

Genistein, the soy isoflavone structurally similar to estradiol, is widely consumed for putative beneficial health effects. However, there is a lack of data about the genisteins' effects in adult males, especially its effects on the hipothalamo-pituitary-adrenal (HPA) axis. Therefore, the present study was carried out to investigate the effects of genistein on the HPA axis in orchidectomized adult rats, and to create a parallel with those of estradiol. Changes in the hypothalamic corticotrophin-releasing hormone (CRH) neurons and pituitary corticotrophs (ACTH cells) were evaluated stereologically, while corticosterone and ACTH levels were determined biochemically. Orchidectomy (Orx) provoked the enlargement (p<0.05) of: hypothalamic paraventricular nucleus volume (60%), percentage of CRH neurons (23%), percentage of activated CRH neurons (45%); pituitary weight (15%) and ACTH level (57%). In comparison with Orx, estradiol treatment provoked the enlargement (p<0.05) of: percentage of CRH neurons (28%), percentage of activated CRH neurons (2.7-fold), pituitary weight (131%) and volume (82%), ACTH level (69%), the serum (103%) and adrenal tissue (4.8 fold) level of corticosterone. Clearly, Orx has induced the increase in HPA axis activity, which even augments after estradiol treatment. Also, compared to Orx, genistein treatment provoked the enhancement (p<0.05) of: percentage of activated CRH neurons (2.3-fold), pituitary weight (28%) and volume (21%), total number of ACTH cells (22%) ACTH level (45%), the serum (2.6-fold) and adrenal tissue (2.8 fold) level of corticosterone. It can be concluded that an identical tendency, concerning the HPA axis parameters, follows estradiol and genistein administration to the orchidectomized adult rats. PMID:22419027

Trifunovi?, Svetlana; Manojlovi?-Stojanoski, Milica; Ajdzanovi?, Vladimir; Nestorovi?, Nataša; Risti?, Nataša; Medigovi?, Ivana; Miloševi?, Verica

2012-05-01

297

Morphological and morphometric studies of the dysmyelinating mutant, the Long Evans shaker rat.  

PubMed

The Long Evans shaker (les) rat is a recently identified CNS myelin mutant with an autosomal recessive mode of inheritance. Although scattered myelin sheaths are present in some areas of the CNS, most notably the ventral spinal cord in the young neonatal rat, this myelin is gradually lost, and 8-12 weeks little myelin is present throughout the CNS. Despite this severe myelin deficiency, some mutants may live beyond one year of age. Rare, thin myelin sheaths that are present early in development lack myelin basic protein (MBP) and on ultrastructural examination are poorly compacted and lack a major dense line. Many oligodendrocytes develop an accumulation of vesicles and membranous bodies, but no abnormal cell death is observed. In the optic nerve, cell kinetic studies show an increase in proliferation at early time points in les, while total glial cell counts are also increased in les from 2 months of age. In situ hybridization studies demonstrate that the numbers of mature oligodendrocytes are similar to controls early in life and increase with time compared to controls. There is both a progressive astrocyte hypertrophy and microgliosis. While les has a mutation in the myelin basic protein (mbp) gene, it is dissimilar in both genotype and phenotype to the previously described mbp mouse mutants, shiverer (shi) and shiverer(mld). Unlike shi and its allele, where myelin increases with time and oligodendrocytes become ultrastructurally normal, les oligodendrocytes are permanently disabled, continue to demonstrate cytoplasmic abnormalities, and fail to produce myelin beyond the first weeks of life. PMID:10405025

Kwiecien, J M; O'Connor, L T; Goetz, B D; Delaney, K H; Fletch, A L; Duncan, I D

1998-08-01

298

Phenotypic and Functional Characterization of Vaginal Dendritic Cells in a Rat Model of Candida albicans Vaginitis  

PubMed Central

This study analyzes the phenotype of vaginal dendritic cells (VDCs), their antigenic presentation and activation of T-cell cytokine secretion, and their protective role in a rat model of Candida vaginitis. Histological observation demonstrated a significant accumulation of OX62+ VDCs in the mucosal epithelium of Candida albicans-infected rats at the third round of infection. We identified two subsets of OX62+ VDCs differing in the expression of CD4 molecule in both noninfected and Candida-infected rats. The OX62+ CD4+ subset of VDCs displayed a lymphoid cell-like morphology and expressed the T-cell antigen CD5, whereas the OX62+ CD4? VDC subset exhibited a myeloid morphology and was CD5 negative. Candida infection resulted in VDC maturation with enhanced expression of CD80 and CD134L on both CD4+ and CD4? VDC subsets at 2 and 6 weeks after Candida infection. CD5? CD4? CD86? CD80? CD134L+ VDCs from infected, but not noninfected, rats spontaneously released large amounts of interleukin-12 (IL-12) and tumor necrosis factor alpha, whereas all VDC subsets released comparable levels of IL-10 and IL-2 cytokines. Furthermore, OX62+ VDCs from infected rats primed naïve CD4+ T-cell proliferation and release of cytokines, including gamma interferon, IL-2, IL-6, and IL-10, in response to staphylococcal enterotoxin B stimulation in vitro. Adoptive transfer of highly purified OX62+ VDCs from infected rats induced a significant acceleration of fungal clearance compared with that in rats receiving naive VDCs, suggesting a protective role of VDCs in the anti-Candida mucosal immunity. Finally, VDC-mediated protection was associated with their ability to rapidly migrate to the vaginal mucosa and lymph nodes, as assessed by adoptive transfer of OX62+ VDCs labeled with 5 (and 6-)-carboxyfluorescein diacetate succinimidyl ester.

De Bernardis, Flavia; Lucciarini, Roberta; Boccanera, Maria; Amantini, Consuelo; Arancia, Silvia; Morrone, Stefania; Mosca, Michela; Cassone, Antonio; Santoni, Giorgio

2006-01-01

299

Phenotypic and functional characterization of vaginal dendritic cells in a rat model of Candida albicans vaginitis.  

PubMed

This study analyzes the phenotype of vaginal dendritic cells (VDCs), their antigenic presentation and activation of T-cell cytokine secretion, and their protective role in a rat model of Candida vaginitis. Histological observation demonstrated a significant accumulation of OX62(+) VDCs in the mucosal epithelium of Candida albicans-infected rats at the third round of infection. We identified two subsets of OX62(+) VDCs differing in the expression of CD4 molecule in both noninfected and Candida-infected rats. The OX62(+) CD4(+) subset of VDCs displayed a lymphoid cell-like morphology and expressed the T-cell antigen CD5, whereas the OX62(+) CD4(-) VDC subset exhibited a myeloid morphology and was CD5 negative. Candida infection resulted in VDC maturation with enhanced expression of CD80 and CD134L on both CD4(+) and CD4(-) VDC subsets at 2 and 6 weeks after Candida infection. CD5(-) CD4(-) CD86(-) CD80(-) CD134L(+) VDCs from infected, but not noninfected, rats spontaneously released large amounts of interleukin-12 (IL-12) and tumor necrosis factor alpha, whereas all VDC subsets released comparable levels of IL-10 and IL-2 cytokines. Furthermore, OX62(+) VDCs from infected rats primed naïve CD4(+) T-cell proliferation and release of cytokines, including gamma interferon, IL-2, IL-6, and IL-10, in response to staphylococcal enterotoxin B stimulation in vitro. Adoptive transfer of highly purified OX62(+) VDCs from infected rats induced a significant acceleration of fungal clearance compared with that in rats receiving naive VDCs, suggesting a protective role of VDCs in the anti-Candida mucosal immunity. Finally, VDC-mediated protection was associated with their ability to rapidly migrate to the vaginal mucosa and lymph nodes, as assessed by adoptive transfer of OX62(+) VDCs labeled with 5 (and 6-)-carboxyfluorescein diacetate succinimidyl ester. PMID:16790803

De Bernardis, Flavia; Lucciarini, Roberta; Boccanera, Maria; Amantini, Consuelo; Arancia, Silvia; Morrone, Stefania; Mosca, Michela; Cassone, Antonio; Santoni, Giorgio

2006-07-01

300

Morphological and molecular characterization of Globodera populations from Oregon and Idaho  

Technology Transfer Automated Retrieval System (TEKTRAN)

A new species of Globodera, identified from three potato fields, is described herein as Globodera pseudopallida n. sp. Morphologically, G. pseudopallida n. sp. exhibits some unique features that are not consistent between populations; but molecularly, G. pseudopallida n. sp. is distinct from G. pall...

301

Morphological characterization of steam-exploded hemp fibers and their utilization in polypropylene-based composites  

Microsoft Academic Search

An investigation is described in which the morphology of hemp stem was examined by optical and scanning electron microscopy. We reported the results concerning steam-explosion treatment either on bast fibers impregnated with alkaline liquor or on woody hemp chènevotte samples impregnated under neutral, acidic and alkaline conditions. The influence of steam-explosion treatment parameters were followed by optic and scanning electron

M. R. Vignon; D. Dupeyre; C. Garcia-Jaldon

1996-01-01

302

Morphological characterization of the antennal sensilla of the dogwood borer (Lepidoptera: Sesiidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The external morphology of the dogwood borer antennae and their sensilla was investigated using light and scanning electron microscopy. Male and female antennaes were clavate before tapering to an apical point and consisted of three main segments; the scape, pedicel, and flagellum. Although, there...

303

Morphological characterization of the ovary and vitellogenesis dynamics in the tick Amblyomma cajennense (Acari: Ixodidae)  

Microsoft Academic Search

In this work we describe the internal morphology of the female reproductive system of the cayenne tick Amblyomma cajennense. This system is represented by a panoistic ovary, which lacks nurse cells in the germarium. This ovary consists of a single tube, in which a large number of oocytes develop asynchronously, thus accompanying the processes of yolk deposition in the oocytes.

Sandra Eloisi Denardi; Gervásio Henrique Bechara; Patrícia Rosa de Oliveira; Érika Takagi Nunes; Kelly Cristina Saito; Maria Izabel Camargo Mathias

2004-01-01

304

Single step molecular characterization of morphologically similar black truffle species 1 Accession number AF001010 1  

Microsoft Academic Search

Species-specific internal ITS primers that amplify polymerase chain reaction (PCR) products of different lengths were selected to distinguish the morphologically similar ectomycorrhizal fungi T. melanosporum, T. brumale and T. indicum by aligning their internal transcribed spacer sequences and taking into account any incidence of intraspecific variability. In multiplex PCR experiments, the species-specific primers yielded the expected amplicons on template DNA

Andrea Rubini; Francesco Paolocci; Bruno Granetti; Sergio Arcioni

1998-01-01

305

Molecular and morphological characterization of Tuber magnatum mycorrhizas in a long-term survey  

Microsoft Academic Search

Tuber magnatum Pico is an ectomycorrhizal fungus whose mycorrhizas can be barely distinguished morphologically from those of other related white truffles. Here we describe the use of specific primers based on the T. magnatum ITS sequence for screening mycorrhizas from a large number of growth chambers, greenhouse and nursery samples taken in a long-term survey. This molecular identification technique enabled

Antonietta Mello; Anna Fontana; Francesco Meotto; Ornella Comandini; Paola Bonfante

2001-01-01

306

Morphological and Molecular Characterization of Adult Cardiomyocyte Apoptosis During Hypoxia and Reoxygenation  

Microsoft Academic Search

Apoptosis has been implicated in ischemic heart disease, but its mechanism in cardiomyocytes has not been elucidated. In this study, we investigate the effects of hypoxia and reoxygenation in adult cardiomyocytes and the molecular mechanism involved in cardiomyocyte apoptosis. Morphologically, reoxygenation induced rounding up of the cells, appearance of membrane blebs that were filled with marginated mitochondria, and ultrastructural findings

Peter M. Kang; Armin Haunstetter; Hiroki Aoki; Anny Usheva; Seigo Izumo

307

Characterization of morphological response of red cells in a sucrose solution  

Microsoft Academic Search

The dynamics of red cell shape changes following transfer into sucrose media having a low chloride content was studied. Based on a large number of measurements, six types of morphological response (MR), differing both in the degree of shape changes and the time course of the process, were identified. The most prominent type of response is a triphasic sequence of

Sergey V. Rudenko

2009-01-01

308

Analysis of LiDAR-derived topographic information for characterizing and differentiating landslide morphology and activity  

Microsoft Academic Search

This study used airborne laser altimetry (LiDAR) to examine the surface morphology of two canyon-rim landslides in southern Idaho. The high resolution topographic data were used to calculate surface roughness, slope, semivariance, and fractal dimension. These data were combined with historical movement data (Global Positioning Systems (GPS) and laser theodolite) and field observations for the currently active landslide, and the

Nancy F. Glenn; David R. Streutker; D. John Chadwick; Glenn D. Thackray; Stephen J. Dorsch

2006-01-01

309

Synthesis, characterization and optical properties of ZnO nanoparticles with controlled size and morphology  

Microsoft Academic Search

Zinc oxide monodispersed nanoparticles were synthesized using a modified polyol process without any requirement to use a catalyst or calcination step at high temperature. The morphology and the size of the resulting oxide particles were adjusted by using several synthesis parameters (temperature, alkaline ratio, hydrolysis ratio, etc.). The increasing of the alkaline ratio results in a great change of the

Amel Dakhlaoui; Mouna Jendoubi; Leila Samia Smiri; Andrei Kanaev; Noureddine Jouini

2009-01-01

310

Isolation and characterization of Candida albicans morphological mutants derepressed for the formation of filamentous hypha-type structures  

SciTech Connect

Several Candida albicans morphological mutants were obtained by a procedure based on a combined treatment with nitrous acid plus UV irradiation and a double-enrichment step to increase the proportion of mutants growing as long filamentous structures. Altered cell morphogenesis in these mutants correlated with an altered colonial phenotype. Two of these mutants, C. albicans NEL102 and NEL103, were selected and characterized. Mutant blastoconidia initiated budding but eventually gave rise to filamentous hypha-type formations. These filaments were long and septate, and they branched very regularly at positions near septa. Calcofluor white (which is known to bind chitin-rich areas) stained septa, branching zones, and filament tips very intensely, as observed under the fluorescence microscope. Wild-type hybrids were obtained by fusing protoplasts of strain NEL102 with B14, another morphological mutant previously described as being permanently pseudomycelial, indicating that genetic determinants responsible for the two altered phenotypes are different. The mutants characterized in this work seemed to sequentially express the morphogenic characteristics of C. albicans, from blastoconidia to hyphae, in the absence of any inducer. Further characterization of these strains could be relevant to gain understanding of the genetic control of dimorphism in this species.

Gil, C.; Pomes, R.; Nombela, C. (Universidad Complutense, Madrid (Spain))

1990-05-01

311

Isolation and partial characterization of rat LDH A-genomic sequences  

Microsoft Academic Search

As a part of the study to elucidate the mechanism by which the transcription of LDH A-gene is regulated by cAMP, we aimed\\u000a to isolate rat LDH A gene and characterize cAMP-responsive element (CRE). We have screened 1.2×106 recombinant phages of rat Charon 4A genomic library and isolated 33 positive clones among which we identified 12 different\\u000a LDH A gene-related

Mi Young Lee; Sun Young Yim; Seung Ki Lee

1990-01-01

312

Characterization of nucleotide pyrophosphatase5 as an oligomannosidic glycoprotein in rat brain  

Microsoft Academic Search

Membrane glycoproteins of neural cells play crucial roles in axon guidance, synaptogenesis, and neuronal transmission. We have here characterized membrane glycoproteins containing terminal ?-mannose residues in rat brain membranes. Affinity purification using Galanthus nivalis agglutinin, that is highly specific for terminal ?-mannose residues, revealed a 50-kDa protein as well as 80-kDa SHPS-1 and 45-kDa ?2 subunit of Na,K-ATPase in rat

Yoshihide Ohe; Hiroshi Ohnishi; Hideki Okazawa; Kyoko Tomizawa; Hisae Kobayashi; Katsuya Okawa; Takashi Matozaki

2003-01-01

313

Hepatic morphological alterations, glycogen content and cytochrome P450 activities in rats treated chronically with N ? -nitro-L-arginine methyl ester (L-NAME)  

Microsoft Academic Search

Chronic treatment of rats with N?-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) biosynthesis, results in hypertension mediated\\u000a partly by enhanced angiotensin-I-converting enzyme (ACE) activity. We examined the influence of L-NAME on rat liver morphology,\\u000a on hepatic glycogen, cholesterol, and triglyceride content, and on the activities of the cytochrome P450 isoforms CYP1A1\\/2,\\u000a CYP2B1\\/2, CYP2C11, and CYP2E1. Male Wistar

Christiane Aparecida Badin Tarsitano; Valdemar A. Paffaro; José Rodrigo Pauli; Gustavo Henrique da Silva; Mario J. Saad; Ione Salgado; Maria Alice da Cruz-Höfling; Stephen Hyslop

2007-01-01

314

Characterization of the rat pneumonic plague model: infection kinetics following aerosolization of Yersinia pestis CO92.  

PubMed

Yersinia pestis, the causative agent of human bubonic and pneumonic plague, is spread during natural infection by the fleas of rodents. Historically associated with infected rat fleas, studies on the kinetics of infection in rats are surprisingly few, and these reports have focused mainly on bubonic plague. Although the natural route of primary infection results in bubonic plague in humans, it is commonly thought that aerosolized Y. pestis will be utilized during a biowarfare attack. Accordingly, based on our previous characterization of the mouse model of pneumonic plague, we sought to examine the progression of infection in rats exposed in a whole-body Madison chamber to aerosolized Y. pestis CO92. Following an 8.6 LD(50) dose of Y. pestis, injury was apparent in the rat tissues based on histopathology, and chemokines and cytokines rose above control levels (1h post infection [p.i.]) in the sera and organ homogenates over a 72-h infection period. Bacteria disseminated from the lungs to peripheral organs, with the largest increases in the spleen, followed by the liver and blood at 72h p.i. compared to the 1h controls. Importantly, rats were as sensitive to pneumonic plague as mice, having a similar LD(50) dose by the intranasal and aerosolized routes. Further, we showed direct transmission of plague bacteria from infected to uninfected rats. Taken together, the data allowed us to characterize for the first time a rat pneumonic plague model following aerosolization of Y. pestis. PMID:19073275

Agar, Stacy L; Sha, Jian; Foltz, Sheri M; Erova, Tatiana E; Walberg, Kristin G; Baze, Wallace B; Suarez, Giovanni; Peterson, Johnny W; Chopra, Ashok K

2008-12-03

315

A morphological analysis of vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons in the area dentata of the rat brain.  

PubMed

The general distribution and morphology of vasoactive intestinal polypeptide-like immunoreactive (VIP-LI) neurons in the area dentata (AD) have been studied using immunohistochemical methods on thick (70-120 micron) sections from the rat brain. The long (greater than or equal to 72 hours) incubation of free-floating sections in combination with a sensitive immunoperoxidase method resulted in extensive labeling of VIP-positive cell bodies, along with their dendritic and axonal processes in the hippocampal formation, including the area dentata. The VIP-positive cells are found in all parts of the area dentata, and plots of the distribution of individual cells showed that there is a preferential clustering of these neurons within, or in close proximity to, the granule cell layer, while the deep zones in the hilus are almost completely devoid of VIP-LI immunoreactive neurons. Throughout the long axis of the AD the number and relative position of the VIP-LI neurons remains rather constant. Analysis of the size and shape of the VIP-positive neurons in the AD shows a remarkable morphological heterogeneity, with the soma ranging from small (long axis: approximately 10 micron) ovoid or round, to large (long axis: approximately 25 micron) stellate or multipolar; of these the small to medium sized cells predominate. Comparisons between the morphology of neurons visualized with the VIP antibody and sections stained by the rapid Golgi method allow a rather conclusive classification of some of the VIP-stained neurons, while the classification of a majority of the VIP neurons remains tentative, perhaps because of the selective visualization by the rapid Golgi method of only certain cell types in the AD. On the basis of this comparison, several displaced granule cells in the molecular layer, as well as granule cells, small ovoid cells, and pyramidal basket cells in the granule cell layer have been identified as VIP-positive as determined by their somatic shape, dendritic branching pattern, and axonal projections. In addition, several VIP-positive neurons have been identified with less certainty. These include the dentate basket cell of Cajal, certain small cells in the molecular layer, and fusiform cells in the polymorph layer. Taken together the present results demonstrate the usefulness of "Golgi-like" immunoperoxidase staining for detailed classification of chemically defined neurons.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6197428

Köhler, C

1983-12-10

316

An inverse light scattering technique for morphological characterization of irregular particles based on the Gaussian-random-sphere model  

PubMed Central

The Gaussian-random-sphere model is employed for morphological characterization of nonspherical, irregular particles using an inverse light scattering technique. The synthetic measurement data consist of reduced scattering spectra caused by an aggregate of irregular particles randomly oriented in turbid media and are generated using the discrete dipole approximation. The proposed method simultaneously retrieves the concentration and shape parameters of particles using the data collected at multiple wavelengths. The performance of the inverse algorithm is tested using noise-corrupted data, in which up to 50% noise may be added to the observed scattering spectra.

Hajihashemi, M. Reza; Jiang, Huabei

2012-01-01

317

Structural and morphological characterization of molecular beam epitaxy grown Si/Ge multilayer using x-ray scattering techniques  

SciTech Connect

Si/Ge multilayers are of great technological importance as is evident from the research studies of the past two decades. Here, we have presented a method for the morphological and structural characterization of such MBE grown epitaxial Si/Ge superlattice structures using simultaneous analysis of x-ray reflectivity and x-ray diffraction data, respectively. The consistent analysis of the data collected in the Indian Beamline at Photon Factory Synchrotron have allowed for the determination of electron density and strain profile as a function of depth.

Sharma, M.; Sanyal, M. K.; Mukhopadhyay, M. K.; Bera, M. K.; Saha, B.; Chakraborty, P. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

2011-11-15

318

Photochemically induced cystic lesion in the rat spinal cord. I. Behavioral and morphological analysis  

SciTech Connect

The present study describes the production of a spinal cord lesion which is initiated by vascular occlusion resulting from the interaction between the photosensitizing dye erythrosin B and an argon laser beam. The lesion has characteristics similar to those of the central cavity thought to lead to the production of post-traumatic syringomyelia (PTS) in humans. The present study examines the behavioral and morphological characteristics of this injury over a 28-day period. Histological analysis revealed a cavity extending from the dorsal horns to lamina VIII, with some lateral and ventral pathways being spared. The cavity volume reached a maximum 7 days after lesion induction. Behavioral changes were assessed using six different tests of motor and reflex function (motor function, climbing, waterbath, inclined plane, withdrawal to pain, and withdrawal to extension). Lesioned animals exhibited flaccid paralysis for 3-5 days, which resolved afterward. The photochemically induced cavity should provide a reproducible model for examining the effects of cystic spinal cord injury on locomotor and reflex function.

Cameron, T.; Prado, R.; Watson, B.D.; Gonzalez-Carvajal, M.; Holets, V.R. (Univ. of Miami, FL (USA))

1990-08-01

319

Morphological study of the sensory innervation of the rat labial mucosa.  

PubMed

The sensory innervation of the rat labial mucosa was investigated by means of methylene blue vital staining and osmic acid staining. Sensory receptors in this region were of three kinds (free nerve endings, encapsulated corpuscles and bush-like nerve endings) which constituted separate sensory units respectively. The encapsulated corpuscles were observed in the deep part of lamina propria, and distributed mainly in the margin of labial mucosa. Almost all (78.8%) of encapsulated corpuscles were of a simple type which had a non-branched axon terminal. No clew-like type corpuscles or glomerular-Meissner corpuscles were observed. The bush-like nerve endings were located in the lamina propria close to the epithelium, and localized in the central part of labial mucosa where the formation of papillae was remarkable. The density of the encapsulated corpuscles in the entire mucosa was 3.5-5.3/mm2, and that of the bush-like nerve endings in the densely distributed area was 38.9-60.6/mm2. PMID:3961800

Yamamoto, T; Tazaki, M; Sakada, S

1986-02-01

320

The energy costs of sexual dimorphism in mole-rats are morphological not behavioural  

PubMed Central

Different reproductive strategies of males and females may lead to the evolution of differences in their energetic costs of reproduction, overall energetic requirements and physiological performances. Sexual dimorphism is often associated with costly behaviours (e.g. large males might have a competitive advantage in fighting, which is energetically expensive). However, few studies of mammals have directly compared the energy costs of reproductive activities between sexes. We compared the daily energy expenditure (DEE) and resting metabolic rate (RMR) of males and females of two species of mole-rat, Bathyergus janetta and Georychus capensis (the former is sexually dimorphic in body size and the latter is not) during a period of intense digging when males seek females. We hypothesized that large body size might be indicative of greater digging or fighting capabilities, and hence greater mass-independent DEE values in males of the sexually dimorphic species. In contrast to this prediction, although absolute values of DEE were greater in B. janetta males, mass-independent values were not. No differences were apparent between sexes in G. capensis. By comparison, although RMR values were greater in B. janetta than G. capensis, no differences were apparent between the sexes for either species. The energy cost of dimorphism is most likely to be the cost of maintenance of a large body size, and not the cost of behaviours performed when an individual is large.

Scantlebury, M; Speakman, J.R; Bennett, N.C

2005-01-01

321

Effects of auranofin and myochrysine on intestinal transport and morphology in the rat.  

PubMed Central

Auranofin (SKF-D 39162) is an oral gold preparation for the treatment of rheumatoid arthritis. One of its major side effects is diarrhoea. To determine one possible mechanism for this we compared the effects of auranofin and myochrysine on intestinal water and solute transport in the rat. Jejunal perfusion with 2 mM auranofin (n = 5) induced fluid and electrolyte secretion and inhibited glucose absorption (p less than 0.01). Auranofin (0.2 mM) induced fluid secretion in the jejunum (n = 5; p less than 0.01) and colon (n = 6; p less than 0.01). In contrast, 2 mM myochrysine enhanced jejunal water and electrolyte absorption (n = 6; p less than 0.02). Both compounds enhanced absorption of mannitol (p less than 0.01). Perfusion of 0.2 mM auranofin for two hours had no significant effect on mucosal c-AMP levels (n = 4). After perfusion for two hours with 2 mM auranofin the jejunal mucosa showed severe injury by light and scanning electronmicroscopy while myochrysine had no apparent effect. The damage after perfusion with 0.2 mM auranofin for two hours was less severe. Auranofin was more rapidly absorbed than myochrysine (p less than 0.05). These effects provide an explanation for the diarrhoea associated with auranofin therapy. Images Figure

Ammon, H V; Fowle, S A; Cunningham, J A; Komorowski, R A; Loeffler, R F

1987-01-01

322

Isolation and Characterization of Progenitor Cells in Uninjured, Adult Rat Lacrimal Gland  

PubMed Central

Purpose. The purpose of this study was to investigate the presence of progenitor cells in the uninjured, adult rat lacrimal gland (LG). Methods. The presence of progenitor cells was examined in LG sections from male rats using antibodies against selected stem cell markers and ?-smooth muscle actin (SMA), which marks myoepithelial cells (MECs), by immunofluorescence microscopy (IF). Small, immature cells were isolated after digestion of LG with collagenase and culture in RPMI 1640 for 2 weeks. Immature cells were examined for expression of stem cell markers by IF. Immature cell were grown in neuronal, epithelial, and myoepithelial cell media, and examined by light morphology and IF using antibodies to markers of different cell lineages. Results. In the intact LGs, MECs expressed the stem cell markers nestin, Musashi 1, ABCG2, Pax6, Chx 10, ?N p63, and Sox 2. All markers colocalized with SMA. Isolated immature cells contained Ki-67, nestin, Musashi 1, Pax 6, and CHX 10. In neuronal media, immature cells differentiated and assumed a neuronal cell morphology expressing neurofilament 200. In media for human corneal endothelial cells, immature cells differentiated, assumed cobblestone morphology, and labeled with the epithelial marker AE1/AE3. In RPMI media immature cells differentiated into cells with MEC-like morphology, and expressed the MEC markers SMA, ?-actinin, adenylate cyclase II, and vimentin. Conclusions. We conclude that uninjured, adult LG contains progenitor cells that may be MECs, which can be isolated and differentiated into multiple lineages.

Shatos, Marie A.; Haugaard-Kedstrom, Linda; Hodges, Robin R.; Dartt, Darlene A.

2012-01-01

323

Changes in dendritic morphology and spine density in motor cortex of the adult rat after stroke during infancy.  

PubMed

Cognitive and motor deficits are pervasive in children that suffer early brain injury. The aim of this study was to determine the impact that early damage has on dendritic spine density and other aspects of dendritic morphology of neurons in the motor cortex. Also of interest was how changes in dendritic structure evolved across the lifespan. Ischemia was induced in 10-day-old Long Evans rats by injection of Rose Bengal dye and a laser positioned over right motor cortex. Animals were sacrificed at two and six months of age, and brains were processed for Golgi-Cox staining. Animals exposed to early damage exhibited increases in length of basilar dendrites at two months of age, however no differences in spine density were found across groups at this age. At six months of age, injured animals demonstrated an overall decrease in apical and basilar spine density. Our results suggest that the changes in dendritic length and spine density observed after early damage are unable to be maintained as the animal ages. The observation that increases in spine density do not necessarily coincide with increases in dendritic length suggests that the two processes may not be dependent on one another and suggest two independent plasticity processes responding to damage. PMID:20340167

Hartle, Kelly D; Jeffers, Matthew S; Ivanco, Tammy L

2010-08-01

324

Collection and morphological characterization of Lagenaria siceraria germplasm from the Mediterranean region of Turkey  

Microsoft Academic Search

The landraces of Lagenaria siceraria in Turkey show great diversity for morphologic traits, particularly in fruit size and shape even though Turkey is not centre\\u000a of genetic diversity for L. siceraria. In Turkey, L. siceraria is used as food, musical instruments and containers, according to the type and shape of their fruits. Its diversity has been\\u000a gradually declining over the

H. Yeti?ir; M. ?akar; S. Serçe

2008-01-01

325

Molecular Characterization and Morphology of Two Endophytic Peyronellaea Species from Pinus koraiensis in Korea  

PubMed Central

Species of Phoma and its allies were isolated during a survey on the diversity of endophytic fungi associated with pine trees in Korea. Based on the phylogenetic analyses of internal transcribed spacer and ?-tubulin gene sequences, two Phoma-like species from the needles of Pinus koraiensis were identified as Peyronellaea calorpreferens and P. glomerata. They were also morphologically identified based on the previous descriptions. Here, we report P. calorpreferens and P. glomerata being present in Korea as endophytic fungi in Pinus koraiensis.

Deng, Jian Xin; Paul, Narayan Chandra; Li, Mei Jia; Seo, Eun Young; Sung, Gi Ho

2011-01-01

326

Characterization of corneal keratocyte morphology and mechanical activity within 3-D collagen matrices.  

PubMed

The purpose of this study was to assess quantitatively the differences in morphology, cytoskeletal organization and mechanical behavior between quiescent corneal keratocytes and activated fibroblasts in a 3-D culture model. Primary cultures of rabbit corneal keratocytes and fibroblasts were plated inside type I collagen matrices in serum-free media or 10% FBS, and allowed to spread for 1-5 days. Following F-actin labeling using phalloidin, and immunolabeling of tubulin, alpha-smooth muscle actin or connexin 43, fluorescent and reflected light (for collagen fibrils) 3-D optical section images were acquired using laser confocal microscopy. In other experiments, dynamic imaging was performed using differential interference contrast microscopy, and finite element modeling was used to map ECM deformations. Corneal keratocytes developed a stellate morphology with numerous cell processes that ran a tortuous path between and along collagen fibrils without any apparent impact on their alignment. Fibroblasts on the other hand, had a more bipolar morphology with pseudopodial processes (P morphological, cytoskeletal and contractile behavior of corneal keratocytes (i.e. their mechanical phenotype) in a 3-D microenvironment. PMID:20025872

Lakshman, Neema; Kim, Areum; Petroll, W Matthew

2009-12-16

327

Morphological characterization of adult Fascioloides magna (Trematoda: Fasciolidae): first SEM report  

Microsoft Academic Search

Five adult Fascioloides magna specimens were recovered from the livers of naturally infected calves from Texas, USA. Scanning electron microscopy was used\\u000a to study the morphological characteristics of the trematodes. These mature flukes measured 35–100 mm in length by 15–25 mm\\u000a in width and had an oval dorsoventrally flattened body, with no anterior cone. The tegument was armed with sharp spines. Around

Soraya Naem; Christine M. Budke; Thomas M. Craig

328

Biological and morphological characterization of human neonatal fibroblast cell culture B-HNF-1  

Microsoft Academic Search

In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present\\u000a investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics\\u000a of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing\\u000a was also performed. Analysis of chromosomes count showed

Vanda Repiská; Ivan Varga; Ivan Lehocký; Daniel Böhmer; Milan Blaško; Štefan Polák; Marián Adamkov; ?uboš Danišovi?

2010-01-01

329

Molecular and Morphological Characterization of a Taxol-Producing Endophytic Fungus, Gliocladium sp., from Taxus baccata.  

PubMed

The endophytic fungal populations of different tissues of Taxus baccata grown at high altitudes in West Bengal, India were explored. These isolated fungal populations represented different genera, which were screened for taxol production using immunoassay technique. The culture AAT-TS-4(1) that produced taxol was identified as Gliocladium sp. based on its cultural, morphological characteristics, internal transcribed spacer, and 18S rRNA sequence analysis. Kinetics of taxol production as a function of culture growth were investigated. PMID:22783096

Sreekanth, D; Sushim, G K; Syed, A; Khan, B M; Ahmad, A

2011-09-27

330

Molecular and Morphological Characterization of a Taxol-Producing Endophytic Fungus, Gliocladium sp., from Taxus baccata  

PubMed Central

The endophytic fungal populations of different tissues of Taxus baccata grown at high altitudes in West Bengal, India were explored. These isolated fungal populations represented different genera, which were screened for taxol production using immunoassay technique. The culture AAT-TS-41 that produced taxol was identified as Gliocladium sp. based on its cultural, morphological characteristics, internal transcribed spacer, and 18S rRNA sequence analysis. Kinetics of taxol production as a function of culture growth were investigated.

Sushim, G. K.; Syed, A.; Khan, B. M.; Ahmad, A.

2011-01-01

331

Morphological and molecular characterization of different Echinochloa spp. and Oryza sativa populations.  

PubMed

Echinochloa P. Beauv. is an important genus because many of its species are weeds infesting most paddy fields, which can reduce the rice grain production by up to 80%. A controversy exists about the taxonomy of the genus due to the high level of morphological variations found in these species. Cyhalofop-butyl, an aryloxyphenoxy-propionate herbicide, is used to control Echinochloa spp. in paddy fields, although differences in susceptibility were found between different Echinochloa species. E. colona was highly susceptible [ED50= 34 g of active ingredient (ai) ha(-1)]; very similar results were obtained with the remaining species. By contrast, E. oryzicola (170 g of ai ha(-1)) was less sensitive, with the herbicide symptoms appearing later. Because of this differential susceptibility, morphological and molecular studies were carried out. A morphological study, using 21 characters both quantitative and qualitative of spikelets and seedlings, was capable of clearly distinguishing closely related E. crus-galli plants (two populations), E. muricata and E. crus-pavonis, and E. oryzicola, E. utilis, and E. colona species. The resolution of Echinochloa species at the molecular level, based on RAPD analyses, was fairly consistent with morphological analysis results. Among the 60 primers screened, 21 primers exhibited polymorphic bands and produced a total of 136 RAPD markers. Of all the amplified fragments, 90 were found to be polymorphic. E. oryzicola and E. colona were clearly separated, and the RAPD analyses showed that both E. crus-galli populations were 100% related and 51% related to E. utilis, whereas E. crus-pavonis and E. muricata (73% similarity) appeared as being clearly separated from this group. PMID:16478232

Ruiz-Santaella, J P; Bastida, F; Franco, A R; De Prado, R

2006-02-22

332

Genus Coltivirus (family Reoviridae ): genomic and morphologic characterization of Old World and New World viruses  

Microsoft Academic Search

Summary.  ?We report a genomic and morphologic study of the European Eyach (EYA) virus (genus Coltivirus, family Reoviridae) and a comparative analysis with the American Colorado tick fever (CTF) virus (the type species of the genus). The previously\\u000a established, but distant, antigenic relationship between these viruses was strengthened by genetic findings (presence of cognate\\u000a genes, amino acid identity between 55 and

H. Attoui; F. Mohd Jaafar; P. Biagini; J.-F. Cantaloube; P. de Micco; F. A. Murphy; X. de Lamballerie

2002-01-01

333

Molecular and Morphological Characterization of Endophytic Heterobasidion araucariae from Roots of Capsicum annuum L. in Korea.  

PubMed

A species of Heterobasidion was encountered during a diversity study of endophytic fungi from healthy root tissues of chili pepper (Capsicum annuum L.) in Korea. The fungal species (CNU081069) was identified as Heterobasidion araucariae based on phylogenetic analyses of the internal transcribed spacer and translation elongation factor gene sequences. Morphological descriptions of the endophytic isolate matched well with the previous references and supported the molecular identification. The fungus Heterobasidion araucariae CNU081069 is new to Korea. PMID:22870048

Paul, Narayan Chandra; Deng, Jian Xin; Shin, Kyu Seop; Yu, Seung Hun

2012-06-29

334

Molecular and Morphological Characterization of Endophytic Heterobasidion araucariae from Roots of Capsicum annuum L. in Korea  

PubMed Central

A species of Heterobasidion was encountered during a diversity study of endophytic fungi from healthy root tissues of chili pepper (Capsicum annuum L.) in Korea. The fungal species (CNU081069) was identified as Heterobasidion araucariae based on phylogenetic analyses of the internal transcribed spacer and translation elongation factor gene sequences. Morphological descriptions of the endophytic isolate matched well with the previous references and supported the molecular identification. The fungus Heterobasidion araucariae CNU081069 is new to Korea.

Paul, Narayan Chandra; Deng, Jian Xin; Shin, Kyu Seop

2012-01-01

335

Morphological and molecular characterization of Mariannaea aquaticola sp. nov. collected from freshwater habitats  

Microsoft Academic Search

Mariannaea aquaticola sp. nov. is described, illustrated, and compared with closely related taxa. Phylogenetic analysis of rDNA ITS and 28S sequences\\u000a show that Mariannaea aquaticola has affinity with Nectriaceae, which is in agreement with other Mariannaea species. Other morphologically similar genera such as Verticillium and Clonostachys are shown to be phylogenetically distant to Mariannaea. The generic concept of Mariannaea is

Lei Cai; Elvi Kurniawati; Kevin D. Hyde

2010-01-01

336

Characterization of the morphology of co-extruded, thermoplastic\\/rubber multi-layer tapes  

Microsoft Academic Search

Tapes with alternating semi-crystalline thermoplastic\\/rubber layers with thicknesses varying from 100nm up to several ?m were prepared by multi-layer co-extrusion. The variation in layer thickness was obtained by varying the thermoplastic\\/rubber feed ratio. A systematic study on the use of various microscopy techniques to visualize the morphology of the layered systems is presented. The relatively large length scales and the

R. M. A. l’Abee; A. M. J. T. Vissers; J. G. P. Goossens; A. B. Spoelstra; M. van Duin

2009-01-01

337

Characterization of antisera against bovine prolactin for in vivo studies on prolactin function in the rat.  

PubMed Central

The IgG fraction of rabbit antisera to bovine prolactin (PRL), intended for in vivo studies on the role of PRL in the rat, was prepared and characterized in vitro and in vivo. The antibodies showed a strong reaction with bovine PRL in double diffusion, immunoelectrophoresis, radioimmunoassay and passive haemagglutination using bovine PRL-coated erythrocytes. In indirect immunofluorescence on paraffin sections of bovine pituitary glands the antibodies could be used for the detection of PRL-producing cells. Cross-reaction with rat PRL was observed in passive haemagglutination with rat PRL-coated erythrocytes and in indirect immunofluorescence on rat pituitary gland, but not in any of the other test systems. The ability of the antibodies to neutralize homologous, i.e. bovine, PRL was tested in lactating rats depleted of endogenous PRL by bromergocriptin treatment. The impaired lactation performance of such animals can be restored by substitution with bovine PRL. If the bovine PRL used for substitution was complexed with anti-bovine PRL-IgG, it lost its biological activity. On the other hand, injections of even high amounts of the antibodies into lactating rats failed to reveal any effect on lactation. It is concluded that either the antibodies do not cross-react with circulating rat PRL in contrast to pituitary PRL (preprolactin?) or that the cross-reacting antibody-populations(s) lack(s) the ability to neutralize the biological function of rat PRL.

Kofler, R; Tabarelli, M; Schwarz, S; Wolf, H; Loewit, K; Wick, G

1980-01-01

338

Porcine Alveolar Epithelial Cells in Primary Culture: Morphological, Bioelectrical and Immunocytochemical Characterization  

Microsoft Academic Search

Purpose  The purpose of this study was to establish a primary culture of porcine lung epithelial cells as an alternative to the currently existing cell cultures from other species, such as e.g., rat or human. Primary porcine lung epithelial cells were isolated, cultivated and analyzed at distinct time points after isolation.Materials and Methods  The main part of the work focused on the

Anne Steimer; Michael Laue; Helmut Franke; Eleonore Haltner-Ukomado; Claus-Michael Lehr

2006-01-01

339

Isolation, morphological and molecular characterization of phytate-hydrolysing fungi by 18S rDNA sequence analysis  

PubMed Central

Phytate is the primary storage form of phosphate in plants. Monogastric animals like poultry, pigs and fishes have very low or no phytase activities in their digestive tracts therefore, are incapable to efficiently utilize phytate phosphorus from the feed. Phytase from microbial sources are supplemented to feedstuff of these to increase the uptake of phytate phosphorus. In the present work efforts were made to isolate and characterize proficient phytase producing fungi from soil. Phytase producing fungi were isolated using phytate specific medium. Fungal isolates were selected according to their higher phytase activities. These isolates were further characterized and identified by morphological and microscopic analysis and confirmed by amplification of 18S rRNA gene, using specific primers. This gene was subsequently sequenced and phylogenetic affiliations were assigned. Fungal isolates were identified as various species of Aspergillus. Phytases from these fungi could be utilized as a feed additive in poultry and swine industries.

Gontia-Mishra, Iti; Deshmukh, Dhanshree; Tripathi, Niraj; Bardiya-Bhurat, Khushboo; Tantwai, Keerti; Tiwari, Sharad

2013-01-01

340

A LIGHT AND ELECTRON MICROSCOPE STUDY OF THE MORPHOLOGICAL CHANGES INDUCED IN RAT LIVER CELLS BY THE AZO DYE 2-ME-DAB  

Microsoft Academic Search

The cytological changes induced in rat liver cells by the aminoazo dye 2-Me-DAB have been examined by light and electron microscopy. It is observed that this non-carcinogenic com- pound duplicates most of the morphological alterations produced by other hepatotoxins, some of which, such as the closely related aminoazo dye 3~-Me-DAB, are potent carcinogens. These non-specific effects involve both the granular

J. G. Lafontaine; C. ALLARD

1964-01-01

341

Functional and Morphological Reproductive Aspects in Male Rats Exposed to Di-n-Butyl Phthalate (DBP) in Utero and During Lactation  

Microsoft Academic Search

The potential adverse reproductive effects, with emphasis on the epididymis, of in utero and lactational exposure to 100 mg\\/kg\\/d di-n-butyl phthalate (DBP) in adult male rat offspring were investigated. The fetal testis histopathology was also determined. The selected endpoints included reproductive organ weights, sperm motility and morphology, sperm epididymal transit time, sperm quantity in the testis and epididymis, hormonal status,

Wellerson R. Scarano; Fabíola C. Toledo; Marina T. Guerra; Patrícia F. F. Pinheiro; Raquel F. Domeniconi; Sérgio L. Felisbino; Silvana G. P. Campos; Sebastião R. Taboga; Wilma G. Kempinas

2010-01-01

342

Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water  

PubMed Central

This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion-like, gyroid-like, and spherical morphologies having poly(N-isopropylacrylamide) matrix and physically cross-linking polystyrene domains. The particles were dispersed in aqueous media and their behavior in water was studied both below and above the lower critical solution temperature of poly(N-isopropylacrylamide). We found out that the particles with spherical and gyroid-like morphologies swell considerably in water at 20 °C, whereas at 40 °C the particles resemble more of those studied without water treatment. Light scattering experiments showed that the particles gradually aggregate and precipitate with time at 40 °C. Microcalorimetric studies revealed for all three studied morphologies that PNIPAM undergoes a two-step transition due to the different hydration levels of PNIPAM inside and outside the particles. Thicknesses of the PS and PNIPAM layers within the onion-like particles were analyzed using the TEM micrographs by fitting a model of electron density to the integrated electron intensity data. The surface layer of the particles was found out to be PNIPAM, which was supported by light scattering and microcalorimetry. It was also found out from the TEM micrograph analysis that the width of the outmost PS layer is considerably thinner than the one in the dry state prior to immersion in water, and a degradation scheme is proposed to explain these results.

Nykanen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

2012-01-01

343

Prenatal stress and subsequent exposure to chronic mild stress influence dendritic spine density and morphology in the rat medial prefrontal cortex  

PubMed Central

Background Both prenatal stress (PS) and postnatal chronic mild stress (CMS) are associated with behavioral and mood disturbances in humans and rodents. The aim of this study was to reveal putative PS- and/or CMS-related changes in basal spine morphology and density of pyramidal neurons in the rat medial prefrontal cortex (mPFC). Results We show that rats exposed to PS and/or CMS display changes in the morphology and number of basal spines on pyramidal neurons in the mPFC. CMS had a negative effect on spine densities, particularly on spines of the mushroom type, which are considered to form stronger and more stable synapses than other spine types. PS alone did not affect spine densities, but had a negative effect on the ratio of mushroom spines. In addition, PS seemed to make rats less responsive to some of the negative effects of CMS, which supports the notion that PS represents a predictive adaptive response. Conclusion The observed changes may represent a morphological basis of PS- and CMS-related disturbances, and future studies in the field should not only consider total spine densities, but also separate between different spine types.

Michelsen, Kimmo A; van den Hove, Daniel LA; Schmitz, Christoph; Segers, Olivier; Prickaerts, Jos; Steinbusch, Harry WM

2007-01-01

344

Study on morphology and characterization of poly(mphenylene isophtalamide)/multi-walled carbon nanotubes composite nanofibers by electrospinning.  

PubMed

Electrospinning technique is the main method of preparing polymer nanofiber simply, directly and continuously at present. In this work, electrospinning blend solution was prepared by in-situ polymerization using acid-modified multi-walled carbon nanotubes (MWNTs), m-phenylenediamine (MPD) and isophthaloyl chloride (IPC). And then composite nanofibers were prepared by electrospinning. MWNTs played an important role in nanofiber's properties. The effects of MWNTs on the morphology and characterization of the MWNTs/PMIA composite nanofibers were investigated. Scanning electron microscopy (SEM), thermal gravimetric analyzer (TGA), and X-ray diffraction (XRD) were utilized to characterize the MWNTs/PMIA nanofibers morphology and properties. The experimental results indicated that the nanofibers diameter decreased and solution dynamic viscosity increased with increasing MWNTs contents. XRD data demonstrated that PMIA composite nanofibers had the same crystal type as the pure PMIA nanofiber, and crystallinity was improved with increasing MWNTs loading. Transmission electron microscopy (TEM) was used to confirm MWNTs aligned along the axis of composite nanofibers. PMID:21780398

He, Su-Wen; Liu, Li-Qi; Gaol, Bao-Shan; Chen, Lei; Hu, Zu-Ming; Yu, Jun-Rong; Zhu, Jing

2011-05-01

345

Morphological, morphometric, and molecular characterization of Hepatozoon spp. (Apicomplexa, Hepatozoidae) from naturally infected Caudisona durissa terrifica (Serpentes, Viperidae).  

PubMed

Hepatozoon spp. are the most frequent intracellular protozoa in snakes. Considering the variety of parasites infecting specimens of Caudisona durissa terrifica and the divergent data in literature where only two species, Hepatozoon romani and Hepatozoon capsulata, are described, the aim of this study was to morphologically, morphometrically, and molecularly characterize Hepatozoon spp. from some naturally infected specimens of C. durissa terrifica, and observe changes caused by these protozoa in parasitized erythrocytes. Four snakes were examined. Two of them had two morphological distinct gamonts, while the other two had only one type of gamont. The six distinct gamonts were provisionally named gamonts A, B, C, D, E, and F. Statistical analysis, however, confirmed the existence of only four parasite populations, those which were capable of inducing significant alterations in determined red blood cells variables. Attempts to infect Aedes aegypti and Culex quinquefasciatus mosquitoes were done for each snake specimen. Some mosquitoes became infected and oocysts were recovered and measured. The detection of Hepatozoon DNA was obtained with success but the molecular characterization was unable to differentiate species of the samples, with respect to the fragment studied. PMID:21922238

Moço, Tatiana Cristina; da Silva, Reinaldo José; Madeira, Newton Goulart; Dos Santos Paduan, Karina; Rubini, Adriano Stefani; Leal, Denise Dutra Menezes; O'Dwyer, Lucia Helena

2011-09-16

346

Morphological, biochemical, and histopathological indices and contaminant burdens of cotton rats (Sigmodon hispidus) at three hazardous waste sites near Houston, Texas, USA  

USGS Publications Warehouse

Male cotton rats (Sigmodon hispidus) were studied at three industrial waste sites near Houston, Texas, to determine whether various morphological, biochemical, and histopathological indices provided evidence of contaminant exposure and toxic insult. Only modest changes were detected in cotton rats residing at waste sites compared with reference sites. No single parameter was consistently altered, except hepatic cytochrome P-450 concentration which was lower ( [Formula: see text] ) at two waste sites, and tended to be lower ( [Formula: see text] ) at a third waste site. Elevated petroleum hydrocarbon concentrations were detected in rats at one waste site, but contaminant burdens of rats from the other sites were unremarkable. Unlike rats captured in summer, those trapped in winter exhibited hepatocellular hypertrophy and up to a 65% increase in liver: body weight ratio, cytochrome P-450 concentration, and activities of aniline hydroxylase, aryl hydrocarbon hydroxylase, and glutathione S-transferase. Although genotoxicity has been previously documented in cotton rats residing at two of the waste sites, biomarkers in the present study provided little evidence of exposure and damage

Rattner, B. A.; Flickinger, E. L.; Hoffman, D. J.

1993-01-01

347

Characterization of Some Morphological Parameters of Orbicularis Oculi Motor Neurons in the Monkey  

PubMed Central

The primate facial nucleus is a prominent brainstem structure that is composed of cell bodies giving rise to axons forming the facial nerve. It is musculotopically organized, but we know little about the morphological features of its motor neurons. Using the Lucifer yellow intracellular filling method, we examined 17 morphological parameters of motor neurons innervating the monkey orbicularis oculi (OO) muscle, which plays an important role in eye lid closure and voluntary and emotional facial expressions. All somata were multipolar and remained confined to the intermediate subnucleus, as did the majority of its aspiny dendritic branches. We found a mean maximal cell diameter of 54 ?m in the transverse dimension, cell diameter of 60 ?m in the rostrocaudal dimension, somal surface area of 17,500 ?m2 and somal volume of 55,643 ?m3. Eight neurons were used in the analysis of dendritic parameters based upon complete filling of the distal segments of the dendritic tree. We found a mean number of 16 dendritic segments, an average dendritic length of 1,036 ?m, diameter of 7 ?m, surface area of 12,757 ?m2 and total volume of 16,923 ?m3. Quantitative analysis of the dendritic branch segments demonstrated that the average number, diameter and volume gradually diminished from proximal to distal segments. A Sholl analysis revealed that the highest number of dendritic intersections occurred 60 ?m distal to the somal center with a gradual reduction of intersections occurring distally. These observations advance our understanding of the morphological organization of the primate facial nucleus and provide structural features for comparative studies, interpreting afferent influence on OO function and for designing studies pinpointing structural alterations in OO motor neurons that may accompany disorders affecting facial movement.

McNeal, DW; Ge, J; Herrick, JL; Stilwell-Morecraft, KS; Morecraft, RJ

2008-01-01

348

Design and characterization of hybrid morphology nanoarrays as plasmonic Raman probes for antimicrobial detection.  

PubMed

Advances in nanofabrication have allowed the production of new and more reproducible substrates for the Raman detection of trace antimicrobials in water. The superior substrate uniformity combined with the ability to control surface morphology represents a significant step forward in the design of substrates with improved enhancement factors and trace-detection capabilities. The work presented herein successfully combines electron-beam lithography (EBL) and reactive ion-etching (RIE) protocols for the construction, testing, and validation of plasmonic hybrid morphology nanoarrays for the detection of arsenic antimicrobials in water. The fabricated substrates consist of 2500 ?m(2) Ag-coated silicon dioxide (SiO2)/Si pillar nanoarrays of alternating hexagonal and elliptical features. Control of simple fabrication parameters such as inter-particle spacing (gap) and its orientation relative to the laser polarization vector (parallel or orthogonal) result in over a tenfold improvement in the apparent Raman response under optimized conditions. At a 633 nm excitation frequency, the best substrate performance was observed on parallel-oriented features with a 200 nm gap, with over one order of magnitude increase in the apparent surface-enhanced Raman scattering (SERS) signal relative to standard silver-polydimethylsiloxane (Ag-PDMS) nanocomposites. Monitoring of the characteristic As-C stretching band at 594 cm(-1) allowed the detection of arsenic antimicrobials in water well within the parts per million range. Calculated surface-enhancement factors (SEF) for this substrate, employing 532, 785, and 633 nm excitation wavelengths, was within five, six, and seven orders of magnitude, respectively. The effect of substrate morphology and nanofabrication process on the Raman enhancement factor is presented. PMID:24160884

Olavarría-Fullerton, Jenifier; Velez, Raymond A; Wells, Sabrina; Sepaniak, Michael J; Hernández-Rivera, Samuel P; De Jesús, Marco A

2013-11-01

349

Characterization of morphological response of red cells in a sucrose solution.  

PubMed

The dynamics of red cell shape changes following transfer into sucrose media having a low chloride content was studied. Based on a large number of measurements, six types of morphological response (MR), differing both in the degree of shape changes and the time course of the process, were identified. The most prominent type of response is a triphasic sequence of shape changes consisting of a fast transformation into a sphere (phase 1), followed by restoration of the discoid shape (phase 2) and final transformation into spherostomatocytes (phase 3), with individual parameters which could vary significantly. It was found that individual morphological response exhibited day to day variations, depending on the initial state of the red blood cells and the donor, but to a larger extent depended on the composition of the sucrose solution, such as concentration and type of buffers, the presence of EDTA, calcium, as well as very small amounts of extracellular hemoglobin. MR shows strong pH and ionic strength dependence. Low pH inhibited phase 1 and high pH changed dramatically the time course of the response. Increasing ionic strength inhibited all phases of MR, and at concentrations above 10-20 mM NaCl it was fully suppressed. Tris and phosphate were also inhibitory whereas HEPES, MOPS and Tricine were less effective. MR occurred also in hypertonic or hypotonic sucrose solutions, with exception of extreme hypotonicity due to volume restrictions. It is concluded that strong membrane depolarization per se is not a causal factor leading to MR, and its different phases could be regulated independently. For some types of morphological response the fast shape transformation from sphere to disc and back to sphere occurs within a 10 s time interval and could be accelerated several fold in the presence of a small amount of hemoglobin. It is suggested that MR represents a type of general cell reaction that occurs upon exposure to low ionic strength. PMID:19249232

Rudenko, Sergey V

2009-02-26

350

Molecular Characterization and Morphology of Two Endophytic Peyronellaea Species from Pinus koraiensis in Korea.  

PubMed

Species of Phoma and its allies were isolated during a survey on the diversity of endophytic fungi associated with pine trees in Korea. Based on the phylogenetic analyses of internal transcribed spacer and ?-tubulin gene sequences, two Phoma-like species from the needles of Pinus koraiensis were identified as Peyronellaea calorpreferens and P. glomerata. They were also morphologically identified based on the previous descriptions. Here, we report P. calorpreferens and P. glomerata being present in Korea as endophytic fungi in Pinus koraiensis. PMID:22783114

Deng, Jian Xin; Paul, Narayan Chandra; Li, Mei Jia; Seo, Eun Young; Sung, Gi Ho; Yu, Seung Hun

2011-12-07

351

Characterization of Two ENU-Induced Mutations Affecting Mouse Skeletal Morphology  

PubMed Central

Using the N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we have identified two skeletal morphology mutants, Skm1 and Skm2. Positional cloning and candidate gene sequencing localized the causative point mutations within the genes coding for natriuretic peptide receptor C (NPR-C) and filamin b (FLNB), respectively. Mice that carry a mutation in Npr3 exhibit a skeletal overgrowth phenotype, resulting in an elongated body and kyphosis. Skm2 mice, carrying a mutation in Flnb, present with scoliosis and lordosis. These mutant mice will serve as useful models for the study of vertebral malformations.

Dauphinee, Shauna M.; Eva, Megan M.; Yuki, Kyoko E.; Herman, Melissa; Vidal, Silvia M.; Malo, Danielle

2013-01-01

352

Characterization of Two ENU-Induced Mutations Affecting Mouse Skeletal Morphology.  

PubMed

Using the N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we have identified two skeletal morphology mutants, Skm1 and Skm2. Positional cloning and candidate gene sequencing localized the causative point mutations within the genes coding for natriuretic peptide receptor C (NPR-C) and filamin b (FLNB), respectively. Mice that carry a mutation in Npr3 exhibit a skeletal overgrowth phenotype, resulting in an elongated body and kyphosis. Skm2 mice, carrying a mutation in Flnb, present with scoliosis and lordosis. These mutant mice will serve as useful models for the study of vertebral malformations. PMID:23979929

Dauphinee, Shauna M; Eva, Megan M; Yuki, Kyoko E; Herman, Melissa; Vidal, Silvia M; Malo, Danielle

2013-10-03

353

Al3+ doped V2O5 nanostructure: Synthesis and structural, morphological and optical characterization  

NASA Astrophysics Data System (ADS)

AlxV2-xO5(x = 0,2mol%) nanorods were synthesized at room temperature by facile surfactant free non-aqueous route. The phase pure orthorhombic structure and nanorods-like morphology have been studied by X-ray diffraction (XRD) and High resolution scanning electron microscopy. EDXS spectrum confirms the purity and presence of Al into V2O5 lattice. Optical absorption from DRS UV-Vis spectra showed the band gap broadening due to quantum confinement effect. The results ensure that the dopant cation (Al3+) successfully intercalated with the host cation (V5+) and the products are promising for electrochromic and catalytic applications.

Venkatesan, A.; Chandar, N. Krishna; Kumar, M. Krishna; Arjunan, S.; Kumar, R. Mohan; Jayavel, R.

2013-02-01

354

Morphology, mechanical characterization and in vivo neo-vascularization of chitosan particle aggregated scaffolds architectures  

Microsoft Academic Search

The present study intended to evaluate the performance of chitosan-based\\u000d\\u000a scaffolds produced by a particle aggregation method aimed to be used in\\u000d\\u000a tissue engineering applications addressing key issues such as\\u000d\\u000a morphological characteristics, mechanical performance and in vivo\\u000d\\u000a behaviour. It is claimed that the particle aggregation methodology may\\u000d\\u000a present several advantages, such as combine simultaneously a high\\u000d\\u000a interconnectivity with high mechanical

Patricia B. Malafaya; Tircia C. Santos; Martijn van Griensven; Rui L. Reis

2008-01-01

355

Agro-morphological characterization of ovary culture-derived plants of rice (Oryza sativa L.)  

Microsoft Academic Search

Plants derived from unpollinated ovary culture of ten rice genotypes showed significant variability in agro-morphological\\u000a characteristics. The ovary-derived plant (H1) populations were completely haploid, doubled haploid or haploid-doubled haploid\\u000a mixture. Haploids had very drastic reduction in plant height, panicle length, grain length, breadth and number and spikelet\\u000a fertility (0.0%–2.1%). Doubled haploids from the hybrid of UPRI 95–121 UPRI 95–165 were

Li Rongbai; M. P. Pandey; S. K. Pandey; D. K. Dwivedi

1999-01-01

356

Morphological and rheological characterization of multi-walled carbon nanotube\\/PLA\\/PBAT blend nanocomposites  

Microsoft Academic Search

Biodegradable poly (lactic acid) (PLA)\\/poly (butyleneadipate-co-butyleneterephthalate) (PBAT)\\/multi-walled carbon nanotube\\u000a (MWNT) polymer blend nanocomposites were prepared by using a laboratory-scale twin-screw extruder. Fractured surface morphology\\u000a of the polymer blend\\/MWNT nanocomposites were examined via SEM. Furthermore, cross sectioned samples obtained using an ultramicrotome\\u000a was observed via TEM. In addition, effects of both MWNT reinforcement and phase affinity of MWNT on thermal and

S. W. Ko; M. K. Hong; B. J. Park; R. K. Gupta; H. J. Choi; S. N. Bhattacharya

2009-01-01

357

Morphological and Molecular Characterization of Discocriconemella inarata, an Endemic Nematode from North American Native Tallgrass Prairies  

PubMed Central

Discocriconemella inarata, a plant parasitic nematode species originally discovered in a virgin tallgrass prairie in northwest Iowa, was re-examined by molecular and morphological analyses of topotype material. This species has never been recorded in cultivated fields and could potentially serve as an indicator for high quality prairie habitats. DNA sequence from a conserved 3’ portion of the 18S ribosomal gene exhibited an identical match between D. inarata topotype specimens and topotype specimens of Mesocriconema xenoplax from Fresno, California. Higher resolution sequence analyses using the internal transcribed spacer 1 (ITS1) and a portion of the mitochondrial gene cytochrome b (cytb) allowed discrimination of D. inarata apart from M. xenoplax. This pair of species formed a well-supported clade with other Mesocriconema species exclusive of tropical Discocriconemella species. Scanning electron microscopy confirmed the absence of submedian lobes on D. inarata, suggesting a secondary loss of this defining morphological characteristic for Mesocriconema. Observations and measurements of D. inarata juveniles were added for the first time. Surveys of other prairies within the Great Plains expanded the known distribution of this species.

Harris, Timothy; Higgins, Rebecca; Sutton, Lisa; Powers, Kirsten S.

2010-01-01

358

Synthesis and characterization of silver nanowires with zigzag morphology in N,N-dimethylformamide  

NASA Astrophysics Data System (ADS)

Zigzag silver nanowires with a uniform diameter of 20±5 nm were prepared by reducing silver nitrate (AgNO3) with N,N-dimethylformamide (DMF) in the presence of tetrabutyl titanate (TBT) and acetylacetone (AcAc) at 373 K for 18 h. X-ray and selected area electron diffraction (XRD and SAED) patterns reveal that the prepared product is made of pure silver with face centered cubic structure. Transmission electron microscopy (TEM) investigations suggest that the amount of silver nanowires is enhanced with increase in reaction time, and the end-to-end assemblies of silver nanorods are observed during the reaction process. After 18 h reaction, silver nanowires with zigzag morphology are obtained. In this paper, a possible growth process of silver nanowires with this interesting shape is described. Silver nanoparticles with small sizes were obtained by reducing Ag+ ions with DMF, providing seeds for homogeneous growth of silver nanorods. With the extending reaction time, the synthesized silver nanorods were connected in an end-to-end manner, and the interface between the connections of two nanorods gradually disappeared. The final product shows zigzag morphology with various angles. The angles between two connecting straight parts of zigzag nanowires exhibit an alterable range of 74 151°. These silver nanowires show tremendous potential applications in future nanoscale electronic circuits.

He, Xin; Zhao, Xiujian; Chen, Yunxia; Feng, Jinyang; Sun, Zhenya

2007-08-01

359

Morphological and molecular characterization of Paramecium (Viridoparamecium nov. subgen.) chlorelligerum Kahl (Ciliophora).  

PubMed

We redescribe Paramecium chlorelligerum, a forgotten species, which Kahl (Tierwelt Dtl., 1935, 30:651) briefly but precisely described in the addendum to his ciliate monographs as a Paramecium with symbiotic green algae. The redescription is based on classical morphological methods and the analysis of the small subunit (SSU) rDNA. Morphologically, P. chlorelligerum differs from P. (C.) bursaria, the second green species in the genus, by having a special swimming shape, the length of the caudal cilia, the size of the micronucleus, the size of the symbiotic algae, the contractile vacuoles (with collecting vesicles vs. collecting canals), and the number of excretory pores/contractile vacuole (1 vs. 2-3). The molecular investigations show that P. chlorelligerum forms a distinct branch distant from the P. (Chloroparamecium) bursaria clade. Thus, we classify P. chlorelligerum in a new subgenus: Paramecium (Viridoparamecium) chlorelligerum. The symbiotic alga belongs to the little-known genus Meyerella, as yet recorded only from the plankton of a North American lake. PMID:22827482

Kreutz, Martin; Stoeck, Thorsten; Foissner, Wilhelm

2012-07-24

360

Characterization of Chemically Induced Hepatotoxicity in Collagen Sandwiches of Rat Hepatocytes  

Microsoft Academic Search

It has been shown that hepatocytes cultured in a collagen sandwich configuration maintain cell viability, morphology, and drug metabolizing activities for several weeks. The purpose of this study was to characterize chemically induced general toxicity in this system by exposing hepatocytes to eight different hepato- toxic compounds. Cell function and viability was measured by analyzing the secretions of urea and

Dora Farkas; Steven R. Tannenbaum

2005-01-01

361

Subpopulations of rat cerebellar astrocytes in primary culture: morphology, cell surface antigens and [3H]GABA transport.  

PubMed

Glial fibrillary acidic protein (GFAP)-positive astrocytes in preconfluent cultures derived from postnatal rat cerebellum have been previously shown to display two distinct morphologies, one stellate and the other irregularly epithelioid. The immunofluorescence studies described here showed that these cells also possess unique surface characteristics. In cultures derived from 8-day-old animals stellate cells bound the monoclonal antibody A2B5 whereas the epithelioid cells bound another monoclonal antibody against rat neural antigen-2 (RAN2). Some stellate cells derived from 2-day-old animals also bound tetanus toxin. The A2B5 labelling of the stellate cells made it possible to follow their fate in vitro. In confirmation of previous time-lapse studies, they underwent a shape transformation as confluence was approached, ultimately attaining a form resembling that of the epithelioid cells. Autoradiographic transport studies using two tritiated gamma-aminobutyric acid (GABA) analogues cis-1,3-aminocyclohexane carboxylic acid (ACHC) and beta-alanine revealed further differences between the two types of astrocytes. Whereas [3H]ACHC was taken up solely by the stellate cells [3H]beta-alanine was transported by both cell types. In other experiments in which various inhibitors of [3H]GABA transport were used ACHC virtually eliminated uptake into the stellate astrocyte, but had little effect on the epithelioid ones. The 'neuron-like' [3H]GABA transport process in the stellate astrocytes was confirmed in experiments comparing the effect of another compound which has been proposed as an astrocyte-selective GABA transport inhibitor, 4,5,6,7-tetrahydroisoxazolo-(4,5-C)pyridin-3-ol (THPO). No discrimination was found in its effect on the uptake of [3H]GABA into either neurons or stellate astrocytes. Further autoradiographic studies following the uptake of [3H]GABA by postnatal cerebellar slices showed that astrocytes in all layers of the cerebellar cortex and white matter transported [3H]GABA in contrast to the situation in culture where the amino acid is taken up predominantly by the stellate astrocytes. The possibility is discussed that the stellate astrocytes represent a population of cerebellar fibrous astrocytes whereas the identity of the epithelioid astrocytes is less certain. PMID:2418929

Johnstone, S R; Levi, G; Wilkin, G P; Schneider, A; Ciotti, M T

1986-01-01

362

Characterization of skeletal muscle effects associated with daptomycin in rats.  

PubMed

Daptomycin is a lipopeptide antibiotic with strong bactericidal effects against Gram-positive bacteria and minor side effects on skeletal muscles. The type and magnitude of the early effect of daptomycin on skeletal muscles of rats was quantified by histopathology, examination of contractile properties, Evans Blue Dye uptake, and effect on the patch repair process. A single dose of daptomycin of up to 200 mg/kg had no effect on muscle fibers. A dose of 150 mg/kg of daptomycin, twice per day for 3 days, produced a small number of myofibers (rats. Some fibers were Evans Blue Dye-positive but were not yet infiltrated by neutrophils. This suggests that the sarcolemma may be the primary target for the observed effects. PMID:20544940

Kostrominova, Tatiana Y; Hassett, Cheryl A; Rader, Erik P; Davis, Carol; Larkin, Lisa M; Coleman, Scott; Oleson, Frederick B; Faulkner, John A

2010-09-01

363

The characterization and metabolism of rat hepatic nascent HLD subfractions  

SciTech Connect

Nascent HDL was isolated from recirculating rat liver perfusates and separated by heparin-sepharose chromatography into a non-retained fraction (A) and a fraction (B) that eluted with 0.5 M NaCl. Fractions A and B contained 70% and 30% of the nascent HDL protein, respectively. Livers perfused by the single-pass technique produced fractions A and B in the same ratio as livers perfused by recirculation. The apolipoprotein compositions were similar to those in the recirculating perfusion; however, both fractions A and B had more triglyceride (greater than 50% of total lipid). In a preliminary study designed to investigate whether nascent HDL-apo E was secreted by Kupffer cells or hepatocytes, label was targeted to Kupffer cells by perfusing rat livers with {sup 3}H-acetylated LDL or {sup 3}H-amino acids incorporated into large multilamellar vesicles. For metabolic studies, nascent HDL and nascent VLDL were isolated from rat livers that had been perfused with {sup 3}H-glycerol to label the triglyceride.

Winkler, K.E.

1988-01-01

364

Genomic cloning and characterization of the rat glutathione S-transferase-A3-subunit gene.  

PubMed Central

The rat glutathione S-transferase-A3-subunit (GSTA3) gene is a member of the class Alpha GSTs, which we have previously reported to be overexpressed in anti-cancer-drug-resistant cells. In this study, we report the isolation and characterization of the entire rat GSTA3 (rGST Yc1) subunit gene. The rat GSTA3 subunit gene is approximately 15 kb in length and consists of seven exons interrupted by introns of different lengths. Exon 1, with a length of 219 bp, contains only the 5'-untranslated region of the gene. Each exon-intron splicing junction exhibited the consensus sequence for a mammalian splice site. The transcription start site and exon 1 of rat GSTA3 were characterized by a combination of primer extension and rapid amplification of the cDNA ends. Position +1 was identified 219 bp upstream of the first exon-intron splicing junction. The proximal promoter region of the rat GSTA3 subunit gene does not contain typical TATA or CAAT boxes. A computer-based search for potential transcription-factor binding sites revealed the existence of a number of motifs such as anti-oxidant-responsive element, ras-response element, activator protein-1, nuclear factor-kappaB, cAMP-response-element-binding protein, Barbie box and E box. The functional activity of the regulatory region of the rat GSTA3 subunit gene was shown by its ability to drive the expression of a chloramphenicol acetyltransferase reporter gene in rat mammary carcinoma cells, and its activity was greater in melphalan-resistant cells known to have transcriptional activation of this gene by previous studies. The structure of the gene, with a large intron upstream of the translation-initiation site, may explain why the isolation of this promoter has been so elusive. This information will provide the opportunity to examine the involvement of the rat GSTA3 subunit gene in drug resistance and carcinogenesis.

Fotouhi-Ardakani, N; Batist, G

1999-01-01

365

Genomic cloning and characterization of the rat glutathione S-transferase-A3-subunit gene.  

PubMed

The rat glutathione S-transferase-A3-subunit (GSTA3) gene is a member of the class Alpha GSTs, which we have previously reported to be overexpressed in anti-cancer-drug-resistant cells. In this study, we report the isolation and characterization of the entire rat GSTA3 (rGST Yc1) subunit gene. The rat GSTA3 subunit gene is approximately 15 kb in length and consists of seven exons interrupted by introns of different lengths. Exon 1, with a length of 219 bp, contains only the 5'-untranslated region of the gene. Each exon-intron splicing junction exhibited the consensus sequence for a mammalian splice site. The transcription start site and exon 1 of rat GSTA3 were characterized by a combination of primer extension and rapid amplification of the cDNA ends. Position +1 was identified 219 bp upstream of the first exon-intron splicing junction. The proximal promoter region of the rat GSTA3 subunit gene does not contain typical TATA or CAAT boxes. A computer-based search for potential transcription-factor binding sites revealed the existence of a number of motifs such as anti-oxidant-responsive element, ras-response element, activator protein-1, nuclear factor-kappaB, cAMP-response-element-binding protein, Barbie box and E box. The functional activity of the regulatory region of the rat GSTA3 subunit gene was shown by its ability to drive the expression of a chloramphenicol acetyltransferase reporter gene in rat mammary carcinoma cells, and its activity was greater in melphalan-resistant cells known to have transcriptional activation of this gene by previous studies. The structure of the gene, with a large intron upstream of the translation-initiation site, may explain why the isolation of this promoter has been so elusive. This information will provide the opportunity to examine the involvement of the rat GSTA3 subunit gene in drug resistance and carcinogenesis. PMID:10215608

Fotouhi-Ardakani, N; Batist, G

1999-05-01

366

Characterization of a rat model to study acute neuroinflammation on histopathological, biochemical and functional outcomes  

Microsoft Academic Search

Neuroinflammation is one of the events occurring after acute brain injuries. The aim of the present report was to characterize a rat model to study acute neuroinflammation on the histopathological, biochemical and functional outcomes. Lipopolysaccharide (LPS), known as a strong immunostimulant, was directly injected into the hippocampus. The spatiotemporal evolution of inducible NOS (iNOS) and cell death was studied from

Andrea Ambrosini; Gaëlle Louin; Nicole Croci; Michel Plotkine; Mehrnaz Jafarian-Tehrani

2005-01-01

367

Characterization of Prohibitin in a Newly Established Rat Ovarian Granulosa Cell Line  

Microsoft Academic Search

Prohibitin is an evolutionary conserved protein that is asso- ciated with cellular differentiation, atresia, and luteolysis in the rat ovary. However, the specific cellular location and func- tion of prohibitin in ovarian cells has not been clearly eluci- dated. To characterize the expression of prohibitin during cell proliferation, differentiation, and cell death, we have success- fully established a temperature-sensitive granulosa

WINSTON E. THOMPSON; ALICIA BRANCH; JOSEPH A. WHITTAKER; DEBORAH LYN; MOSHER ZILBERSTEIN; KELLY E. MAYO; KELWYN THOMAS

2010-01-01

368

Characterization of glycoconjugates in developing rat respiratory system by means of conventional and lectin histochemistry  

Microsoft Academic Search

The glycoconjugates of the respiratory system of rats from 15 days of gestation through the adult period have been characterized by means of both conventional and lectin histochemistry. The main changes occurred at 20–21 days of gestation immediately before birth. An increase of acidic groups in the glycoproteins of the lung and airway epithelium was observed by conventional mucin histochemistry.

M. T. Castells; J. Ballesta; J. F. Madrid; M. Aviles; J. A. Martinez-Menarguez

1991-01-01

369

Characterization of permeability and morphological perturbations induced by nisin on phosphatidylcholine membranes.  

PubMed Central

Nisin is an antimicrobial peptide used as food preservative. To gain some insights into the hypothesis that its bactericidal activity is due to the perturbation of the lipid fraction of the bacterial plasmic membrane, we have investigated the effect of nisin on model phosphatidylcholine (PC) membranes. We show that nisin affects the PC membrane permeability, and this perturbation is modulated by the lipid composition. Nisin-induced leakage from PC vesicles is inhibited by the presence of cholesterol. This inhibition is associated with the formation of a liquid ordered phase in the presence of cholesterol, which most likely reduces nisin affinity for the membrane. Conversely, phosphatidylglycerol (PG), an anionic lipid, promotes nisin-induced leakage, and this promotion is associated with an increased affinity of the peptide for the bilayer because nisin is a cationic peptide. When the electrostatic interactions are encouraged by the presence of 70 mol% PG in PC, the inhibitory effect of cholesterol is not observed anymore. Nisin drastically modifies the morphology of the dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) multilamellar dispersion without causing a significant change in the gel-to-liquid crystalline phase transition of the lipid. The morphological changes are observed from (31)P and (2)H NMR and cryo-electron microscopy. From the NMR point of view, the interactions giving rise to a broad signal (quadrupolar interactions and chemical shift anisotropy for (2)H NMR and (31)P NMR, respectively) are partly averaged out in the presence of nisin. This phenomenon is interpreted by the formation of curved lipid planes that lead to the lipid lateral diffusion occurring in the intermediate motional regime. By cryo-electron microscopy, large amorphous aggregates containing small dense globular particles are observed for samples quenched from 25 and 50 degrees C. Long thread-like structures are also observed in the fluid phase. A structural description of DPPC/nisin complex, consistent with the experimental observation, is proposed. The presence of 30 mol% cholesterol in DPPC completely inhibits the morphological changes induced by nisin. Therefore, it is concluded that nisin can significantly perturb PC bilayers from both the permeability and the structural points of view, and these perturbations are modulated by the lipidic species in the bilayer.

El Jastimi, R; Edwards, K; Lafleur, M

1999-01-01

370

Functional and Structural Neural Network Characterization of Serotonin Transporter Knockout Rats  

PubMed Central

Brain serotonin homeostasis is crucially maintained by the serotonin transporter (5-HTT), and its down-regulation has been linked to increased vulnerability for anxiety- and depression-related behavior. Studies in 5-HTT knockout (5-HTT-/-) rodents have associated inherited reduced functional expression of 5-HTT with increased sensitivity to adverse as well as rewarding environmental stimuli, and in particular cocaine hyperresponsivity. 5-HTT down-regulation may affect normal neuronal wiring of implicated corticolimbic cerebral structures. To further our understanding of its contribution to potential alterations in basal functional and structural properties of neural network configurations, we applied resting-state functional MRI (fMRI), pharmacological MRI of cocaine-induced activation, and diffusion tensor imaging (DTI) in 5-HTT-/- rats and wild-type controls (5-HTT+/+). We found that baseline functional connectivity values and cocaine-induced neural activity within the corticolimbic network was not significantly altered in 5-HTT-/- versus 5-HTT+/+ rats. Similarly, DTI revealed mostly intact white matter structural integrity, except for a reduced fractional anisotropy in the genu of the corpus callosum of 5-HTT-/- rats. At the macroscopic level, analyses of complex graphs constructed from either functional connectivity values or structural DTI-based tractography results revealed that key properties of brain network organization were essentially similar between 5-HTT+/+ and 5-HTT-/- rats. The individual tests for differences between 5-HTT+/+ and 5-HTT-/- rats were capable of detecting significant effects ranging from 5.8% (fractional anisotropy) to 26.1% (pharmacological MRI) and 29.3% (functional connectivity). Tentatively, lower fractional anisotropy in the genu of the corpus callosum could indicate a reduced capacity for information integration across hemispheres in 5-HTT-/- rats. Overall, the comparison of 5-HTT-/- and wild-type rats suggests mostly limited effects of 5-HTT genotype on MRI-based measures of brain morphology and function.

van der Marel, Kajo; Homberg, Judith R.; Otte, Willem M.; Dijkhuizen, Rick M.

2013-01-01

371

Spatial and temporal morphological changes in the subarachnoid space after graded spinal cord contusion in the rat.  

PubMed

Spontaneous repair or treatment-induced recovery after spinal cord injury (SCI) is very limited and might be related to extramedullary alterations that have only briefly been documented. Here we report on the morphological changes of the spinal subarachnoid space (SAS) in a clinically relevant model of SCI. Anesthetized rats were subjected either to mild or severe spinal cord contusion at T9. Spine blocks from the site of injury and adjacent segments were harvested at acute (1 h and 1 day [d]), subacute (3 and 7 d), and chronic (1 and 3 months) stages post-injury. Histopathology and morphometry at each decalcified vertebral level were assessed. At acute and subacute stages, reduction of SAS lumen was observed after both mild and severe injuries. Acutely, after severe injuries, SAS occlusion was associated mainly with cord swelling and subarachnoid hematomas; a trend for dural sac constriction was observed for mild injuries. At 7 d, cord swelling diminished in both instances, but dural sac constriction increased for severe injuries. At early stages, in the epicenter and vicinity, histopathology revealed compression of neurovascular elements within the SAS, which was more intense in severe than in mild injuries. In the chronic stage, SAS lumen increased notably, mostly from cord atrophy, despite dural sac constriction. Myelograms complemented observations made on SAS lumen permeability. Post-traumatic arachnoiditis occurred mainly in animals with severe injury. In conclusion, early extramedullary SAS changes described here might be expected to produce alterations in cerebrospinal fluid (CSF) dynamics and cord blood perfusion, thereby contributing to the pathophysiology of SCI and becoming novel targets for treatment. PMID:23472674

Reyes-Alva, Horacio J; Franco-Bourland, Rebecca E; Martinez-Cruz, Angelina; Grijalva, Israel; Madrazo, Ignacio; Guizar-Sahagun, Gabriel

2013-06-15

372

Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering  

SciTech Connect

A research program on the influence of aerosol surface structure on the kinetics of gas-aerosol interactions is proposed. The experiments involve measuring changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol. Aerosols with differing surface properties will be generated by changing the composition and/or temperature of the material making up the aerosol. Kinetic data generated can be used directly in atmospheric modelling calculations. The surface structure of the aerosol will be measured, both before and after reaction, using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Information about the detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during the course of the reaction. Studies will focus on the condensation and oxidation of sulfur species (sulfur dioxide and dimethyl sulfide) on water aerosols.

Aker, P.M.

1992-01-01

373

Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering. Final technical report  

SciTech Connect

A research program on the influence of aerosol surface structure on the kinetics of gas-aerosol interactions is proposed. The experiments involve measuring changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol. Aerosols with differing surface properties will be generated by changing the composition and/or temperature of the material making up the aerosol. Kinetic data generated can be used directly in atmospheric modelling calculations. The surface structure of the aerosol will be measured, both before and after reaction, using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Information about the detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during the course of the reaction. Studies will focus on the condensation and oxidation of sulfur species (sulfur dioxide and dimethyl sulfide) on water aerosols.

Aker, P.M.

1992-12-31

374

Morphological characterization of the ovary and vitellogenesis dynamics in the tick Amblyomma cajennense (Acari: Ixodidae).  

PubMed

In this work we describe the internal morphology of the female reproductive system of the cayenne tick Amblyomma cajennense. This system is represented by a panoistic ovary, which lacks nurse cells in the germarium. This ovary consists of a single tube, in which a large number of oocytes develop asynchronously, thus accompanying the processes of yolk deposition in the oocytes. The oocytes were classified into stages that varied from I to V, according to: cytoplasm appearance, presence of the germ vesicle, presence of yolk granules, and presence of chorion. The study of vitellogenesis dynamics suggest that the yolk elements are deposited in the oocyte following a preferencial sequence, in which the lipids are the first to appear, followed by proteins an finally by the carbohydrates. In this way the yolk of A. cajennense ticks have these three elements that may be free in the cytoplasm or chemically bounded forming glycoprotein or lipoprotein complexes. PMID:15482894

Denardi, Sandra Eloisi; Bechara, Gervásio Henrique; Oliveira, Patrícia Rosa de; Nunes, Erika Takagi; Saito, Kelly Cristina; Mathias, Maria Izabel Camargo

2004-11-10

375

Abnormal Morphology of the Penis in Male Rats Exposed Neonatally to Diethylstilbestrol Is Associated with Altered Profile of Estrogen Receptor-a Protein, but Not of Androgen Receptor Protein: A Developmental and Immunocytochemical Study1  

Microsoft Academic Search

Objectives of the study were to determine developmental changes in morphology and expression of androgen receptor (AR) and estrogen receptor (ER)a in the body of the rat penis exposed neonatally to diethylstilbestrol (DES). Male pups re- ceived DES at a dose of 10 mg per rat on alternate days from Postnatal Day 2 to Postnatal Day 12. Controls received olive

H. O. Goyal; T. D. Braden; C. S. Williams; P. Dalvi; M. M. Mansour; J. W. Williams; F. F. Bartol; A. A. Wiley; L. Birch; G. S. Prins

376

Characterization of collagen precursors found in rat skin and rat bone.  

PubMed

Two genetic types of collagenous proteins, type I and type III, were isolated by extraction and differential salt precipitation from rat skin. The yield of collagen precursors was increased by injecting animals with colchicine 30 min before sacrifice to inhibit secretion of collagen. DEAE-cellulose chromatography was used to separate collagen from collagen precursors. Although these preparations contained more type I collagen than type III collagen, there were always more type III than type I precursors. The precursor chains of type I fractions were separated on CM-cellulose chromatography after denaturation. Three precursor forms were found for each collagen alpha chain, a complete chain (proalpha chain), and a precursor chain with only an amino-terminal (pNalpha chain) and carboxy-terminal extension (pCalpha chain). Species differences were demonstrated between rat collagen precursors and other species using rat calvaria (frontal and parietal) bones extracted with either 0.5 N acetic acid or neutral salt buffers containing protease inhibitors. Native rat procollagen elutes earlier than chicken or human procollagen on DEAE-cellulose chromatography and does not separate significantly from the pC collagen form. The collagenase resistant amino terminal peptides of rat pNalpha1 and pNalpha2 were the same size (16 000) but could be separated by DEAE-cellulose chromatography. PMID:195597

Smith, B D; McKenney, K H; Lustberg, T J

1977-06-28

377

Compositional, morphological, and hysteresis characterization of magnetic airborne particulate matter in Rome, Italy  

Microsoft Academic Search

The magnetic properties of tree leaves may be used to delineate the abundance and dispersal of anthropogenic airborne particulate matter (PM) in urban environments. In the city of Rome, Italy, circulating vehicles are the main source of magnetic PM, already characterized as prevalently low-coercivity, magnetite-like particles. To further constrain the nature and origin of such magnetic particles, we carried out

Leonardo Sagnotti; Jacopo Taddeucci; Aldo Winkler; Andrea Cavallo

2009-01-01

378

CHARACTERIZATION OF FUNGI FROM HYPERSALINE ENVIRONMENTS OF SOLAR SALTERNS USING MORPHOLOGICAL AND MOLECULAR TECHNIQUES  

EPA Science Inventory

The Cabo Rojo Solar Salterns located on the southwest coast of Puerto Rico are composed of two main ecosystems (i.e., salt ponds and microbial mats). Even though these locations are characterized by high solar radiation (mean light intensity of 39 mol photons m-2d-1) they harbor ...

379

Morphological and molecular characterization of Pratylenchus lentis n. sp. (Nematoda: Pratylenchidae) from Sicily  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pratylenchus lentis n. sp. parasitizing roots of lentil in Sicily, Italy, is described and illustrated. The new species is characterized by a high lip region with three annuli, stylet mean length of 16 micrometers with anteriorly flattened knobs, cylindrical body with a relatively anterior vulva, l...

380

MORPHOLOGICAL AND GENOMIC CHARACTERIZATION OF THE POLYDNAVIRUS ASSOCIATED WITH THE PARASITOID WASP, GLYPTAPANTELES INDIENSIS (HYMENOPTERA: BRACONIDAE)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Glyptapanteles indiensis polydnavirus (GiPDV) is essential for successful parasitization of the larval stage of the lepidopteran Lymantria dispar (gypsy moth) by the endoparasitic wasp, Glyptapanteles indiensis. This virus has not been characterized. Ultrastructural studies of GiPDV showed that th...

381

Purification and characterization of flavin-containing monooxygenase isoform 3 from rat kidney microsomes.  

PubMed

Rats are a common animal model for metabolism and toxicity studies. Previously, the enzymatic properties of rat flavin-containing monooxygenase (FMO) 1 purified from hepatic and renal microsomes and that of FMO3 purified from hepatic microsomes were characterized. This study investigated the physical, immunological, and enzymatic properties of FMO3 purified from male rat kidney microsomes and compared the results with those obtained with isolated rat liver FMO3. Renal FMO3 was purified via affinity columns based on the elution of L-methionine (Met) S-oxidase activity and reactivity of the eluted proteins with human FMO3 antibody. In general, Met S-oxidase-specific activity was increased 100-fold through the purification steps. The resulting protein had similar mobility (approximately 56 kDa) as isolated rat liver FMO3 and cDNA-expressed human FMO3 by SDS-polyacrylamide gel electrophoresis. When the isolated kidney protein band was subjected to trypsin digestion and matrix-assisted laser desorption ionization/time of flight mass spectral analysis, 34% of the sequence of rat FMO3 was detected. The apparent K(m) and V(max) values for rat kidney FMO3 were determined using the known FMO substrates Met, seleno-L-methionine, S-allyl-L-cysteine (SAC), and methimazole (N-methyl-2-mercaptoimidazole). The stereoselectivity of the reactions with Met and SAC were also examined using high-performance liquid chromatography. The obtained kinetic and stereoselectivity results were similar to those we obtained in the present study, or those previously reported, for rat liver FMO3. Taken together, the results demonstrate many similar properties between rat hepatic and renal FMO3 forms and suggest that renal FMO3 may play an important role in kidney metabolism of xenobiotics containing sulfur and selenium atoms. PMID:18775983

Novick, Rachel M; Elfarra, Adnan A

2008-09-05

382

Purification and Characterization of Flavin-Containing Monooxygenase Isoform 3 from Rat Kidney Microsomes  

PubMed Central

Rats are a common animal model for metabolism and toxicity studies. Previously, the enzymatic properties of rat FMO1 purified from hepatic and renal microsomes and that of FMO3 purified from hepatic microsomes were characterized. This study investigated the physical, immunological, and enzymatic properties of FMO3 purified from male rat kidney microsomes and compared the results to those obtained with isolated rat liver FMO3. Renal FMO3 was purified via affinity columns based on the elution of L-methionine (Met) S-oxidase activity and reactivity of the eluted proteins with human FMO3 antibody. Typically, Met S-oxidase specific activity was increased 100-fold through the purification steps. The resulting protein had similar mobility (?56 kDa) as isolated rat liver FMO3 and cDNA-expressed human FMO3 by SDS-polyacrylamide gel electrophoresis. When the isolated kidney protein band was subjected to trypsin digestion and MALDI-TOF mass spectral analysis, 34% of the sequence of rat FMO3 was detected. The apparent Km and Vmax values for rat kidney FMO3 were determined using the known FMO substrates Met, seleno-L-methionine (SeMet), S-allyl-L-cysteine (SAC) and methimazole. The stereoselectivity of the reactions with Met and SAC were also examined using HPLC. The obtained kinetic and stereoselectivity results were similar to those we obtained in the present study, or those previously reported, for rat liver FMO3. Collectively, the results demonstrate many similar properties between rat hepatic and renal FMO3 forms and suggest that renal FMO3 may play an important role in kidney metabolism of xenobiotics containing sulfur and selenium atoms.

Novick, Rachel M.

2008-01-01

383

Combining light microscopy, dielectric spectroscopy, MALDI intact cell mass spectrometry, FTIR spectromicroscopy and multivariate data mining for morphological and physiological bioprocess characterization of filamentous organisms.  

PubMed

Along with productivity and physiology, morphological growth behavior is the key parameter in bioprocess design for filamentous fungi. Lacking tools for fast, reliable and efficient analysis however, fungal morphology is still commonly tackled by empirical trial-and-error techniques during strain selection and process development procedures. Bridging the gap, this work presents a comprehensive analytical approach for morphological analysis combining automated high-throughput microscopy, multi-frequency dielectric spectroscopy, MALDI intact cell mass spectrometry and FTIR spectromicroscopy. Industrial fed-batch production processes were investigated in fully instrumented, automated bioreactors using the model system Penicillium chrysogenum. Physiological process characterization was based on the determination of specific conversion rates as scale-independent parameters. Conventional light microscopic morphological analysis was based on holistic determination of time series for more than 30 morphological parameters and their frequency distributions over the respective parameter range by automated high-throughput light microscopy. Characteristic protein patterns enriched in specific morphological and physiological states were further obtained by MALDI intact cell mass spectrometry. Spatial resolution of molecular biomass composition was facilitated by FTIR spectromicroscopy. Real-time in situ monitoring of morphological process behavior was achieved by linking multi-frequency dielectric spectroscopy with above outlined off-line methods. Data integration of complementing orthogonal techniques for morphological and physiological analysis together with multivariate modeling of interdependencies between morphology, physiology and process parameters facilitated complete bioprocess characterization. The suggested approach will thus help understanding morphological and physiological behavior and, in turn, allow to control and optimize those complex processes. PMID:23220594

Posch, Andreas E; Koch, Cosima; Helmel, Michaela; Marchetti-Deschmann, Martina; Macfelda, Karin; Lendl, Bernhard; Allmaier, Günter; Herwig, Christoph

2012-12-06

384

Hydrothermal temperature as a morphological control factor: Preparation, characterization and photocatalytic activity of titanate nanotubes and nanoribbons  

NASA Astrophysics Data System (ADS)

Layered titanate nanotubes (TNTs) and titanate nanoribbons (TNRs) were synthesized via hydrothermal treatment from commercial TiO2. Formation of nanotubes and nanoribbons were monitored by varying the hydrothermal reaction temperature and time. The two parameters hydrothermal reaction temperature and time was 100 °C for 24 h/72 h, 150 °C for 24 h/72 h and 200 °C for 24 h/72 h. The morphology, structure and optical properties were systematically analyzed, with samples are characterized by TEM, XRD, XPS, SEM, N2 adsorption–desorption isotherm (BET) as well as Raman, FT-IR and UV–Vis/DR spectroscopy. The study revealed that reaction temperature is the parameter for morphological control of the product. Structure and physical properties of TNTs and TNRs are summarized. Further, dense products are obtained by increase the reaction time for the same temperature. The photocatalytic activities were assessed under UV light by degradation of rhodamine B aqueous solution. Results revealed that, degradation of TNTs and TNRs was observed, after samples annealed once at 400 °C, which is due to occurrence of phase transformation from titanate to anatase TiO2 and TiO2 (B) respectively.

Thennarasu, S.; Rajasekar, K.; Balkis Ameen, K.

2013-10-01

385

Thymic nurse cells. Lymphoepithelial cell complexes in murine thymuses: morphological and serological characterization.  

PubMed

We describe a new cellular component of normal mouse thymuses, which is isolated by fractionated trypsin dissociation of minced thymus tissue followed by repeated unit gravity sedimentation. These cells are of unusually large size, with diameters of 30 mum and more. They represent cellular complexes of single large cells filled with high numbers of lymphoid cells. The majority of the engulfed lymphoid cells is not only fully intact, as judged by morphological criteria, but, moreover, includes a high proportion of mitotic figures. Electron microscopic investigations reveal the epithelial character of the large thymic nurse cells (TNC). The peripherally situated cytoplasmic tonofilament streams, and characteristic vacuoles filled with coarse, unidentified material, closely resemble cytoplasmic organelles found in the cortical reticuloepithelial cells described in situ. The internalized lymphocytes are located within caveolae lined by plasma membranes. These TNC caveolae are completely sequestered, and have lost any communication with the extracellular space, as demonstrated by the inability of an electrondense marker, cationized ferritin, to diffuse into the perilymphocytic clefts. The structural interactions between the membranes of the engulfed thymocytes with the surrounding TNC caveolar membranes were investigated both in ultrathin sections and in freeze-etch preparates. Two distinct contact types between both membranes were discerned: (a) complete, close contact along the entire lymphocyte circumference, and (b) more frequently, contact restricted to discrete, localized areas. Judging from their size and distribution, the localized contacts could correspond particle aggregates of freeze-etch preparates, which morphologically resemble certain stages of gap junction. Furthermore, we regularly found square arrays of particles of uniform size, which so far have been thought to be typical for cell membranes actively engaged in ion exchange. Tight junction-like particle arrays, which were present on TNC outer membranes, and probably represented disrupted contacts between adjacent TNC in the intact tissue, could not be found on caveolar or lymphocyte membranes. Finally, one of the most conspicuous specializations of the TNC caveolar membrane were membrane invaginations, which were arranged mainly in groups, and which probably reflect endo- or exocytotoxic events. We investigated the surface antigen phenotype of TNC by indirect immunofluorescence, with monoclonal antibodies against determinants of H-2- complex subregions as well as against lymphocyte differentiation markers. Semiquantification was reached with flow cytofluorimetry, followed by morphological control by fluorescence microscopy. The surface antigen formula of TNC is: Ig(-), Thy-l(-), H-2K(++), I-A (++), I-E/C(+), H-D(++), Ly-1(-), Ly-2(-), Qat-4(-), Qat-5(-), and peanut agglutinin (PNA)(-). Thymic macrophages, which were identified by double fluorescence, with rhodamine- coupled zymosan as a phagocytosis marker, were serologically identical with TNC. Free thymocytes, in contrast, had the following antigen formula: Ig(-), Thy-1(++), H-2K(+/-), I-A(-), I-E/C(-), H-2D(+/-), Ly-1(+/-), Ly-2(+), Qat- 4(-), Qat-5(-), and PNA(+). The unprecedented finding of high numbers of dividing thymocytes sojourning within thymic epithelial cells, and the particular specializations of the TNC caveolar membranes surrounding these engulfed thymocytes is the basis of a hypothesis that postulates that an intraepithelial differentiation cycle is one essential step in, intrathymic T lymphocyte generation. PMID:6966312

Wekerle, H; Ketelsen, U P; Ernst, M

1980-04-01

386

Non-invasive characterization of structure and morphology of silk fibroin biomaterials using non-linear microscopy  

PubMed Central

Designing biomaterial scaffolds remains a major challenge in tissue engineering. Key to this challenge is improved understanding of the relationships between the scaffold properties and its degradation kinetics, as well as the cell interactions and the promotion of new matrix deposition. Here we present the use of non-linear spectroscopic imaging as a non-invasive method to characterize not only morphological, but also structural aspects of silkworm silk fibroin-based biomaterials, relying entirely on endogenous optical contrast. We demonstrate that two photon excited fluorescence and second harmonic generation are sensitive to the hydration, overall ? sheet content and molecular orientation of the sample. Thus, the functional content and high resolution afforded by these non-invasive approaches offer promise for identifying important connections between biomaterial design and functional engineered tissue development. The strategies described also have broader implications for understanding and tracking the remodeling of degradable biomaterials under dynamic conditions both in vitro and in vivo.

Rice, William L.; Firdous, Shamaraz; Gupta, Sharad; Hunter, Martin; Foo, Cheryl Wong Po; Wang, Yongzhong; Kim, Hyeon Joo; Kaplan, David L.; Georgakoudi, Irene

2009-01-01

387

Characterizing complex particle morphologies through shape matching: Descriptors, applications, and algorithms  

NASA Astrophysics Data System (ADS)

Many standard structural quantities, such as order parameters and correlation functions, exist for common condensed matter systems, such as spherical and rod-like particles. However, these structural quantities are often insufficient for characterizing the unique and highly complex structures often encountered in the emerging field of nano and microscale self-assembly, or other disciplines involving complex structures such as computational biology. Computer science algorithms known as "shape matching" methods pose a unique solution to this problem by providing robust metrics for quantifying the similarity between pairs of arbitrarily complex structures. This pairwise matching operation, either implicitly or explicitly, lies at the heart of most standard structural characterization schemes for particle systems. By substituting more robust "shape descriptors" into these schemes we extend their applicability to structures formed from more complex building blocks. Here, we describe several structural characterization schemes and shape descriptors that can be used to obtain various types of structural information about particle systems. We demonstrate the application of shape matching algorithms to a variety of example problems, for topics including local and global structure identification and classification, automated phase diagram mapping, and the construction of spatial and temporal correlation functions. The methods are applicable to a wide range of systems, both simulated and experimental, provided particle positions are known or can be accurately imaged.

Keys, Aaron S.; Iacovella, Christopher R.; Glotzer, Sharon C.

2011-07-01

388

Characterization of cadmium proteinuria in man and rat  

SciTech Connect

In workers chronically exposed to cadmium and without signs of renal insufficiency, plasma proteins with molecular weight ranging from 11,800 to 450,000 are excreted in greater amount in urine. Increased urinary excretion of low and high molecular weight proteins can occur independently. Because of its greater stability in urine and provided a sensitive immunological technique is used, the determination of retinol-binding protein is a more practical and realiable test of proximal tubular function than ..beta../sub 2/-microglobulin. The evaluation of renal function of workers removed from cadmium exposure indicates that cadmium-induced renal lesions, albeit of slow progression, are not reversible when exposures ceases. In workers chronically exposed to cadmium or removed from cadmium exposure, metallothionein in urine is directly correlated with cadmium in urine but not with cadmium in blood or years of cadmium exposure. The association between cadmium in urine and metallothionein in urine is independent of the status of renal function and the intensity of current exposure to cadmium. Whereas the repeated IP injection of high doses of cadmium to rat gives rise to a mixed or tubular type proteinuria, the prolonged oral administraitn of cadmium results mainly in the development of a glomerular type proteinuria. The former is usually reversible after cessation of treatment whereas the latter is not. Circulating antiglomerular basement membrane antibodies have been found in man and in rat chronically exposed to cadmium. The pathogenic significance of this finding deserves further investigation. 10 references, 5 figures, 1 table.

Lauwerys, R.R.; Bernard, A.; Roels, H.A.; Buchet, J.P.; Viau, C.

1984-03-01

389

Morphological, ultrastructural, and molecular characterization of Euplotidium rosati n. sp. (Ciliophora, Euplotida) from Guam.  

PubMed

We combined morphological (i.e. live, stained, scanning, and transmission electron microscopy) with morphometric and molecular analysis to describe a ciliate species collected from shallow reefs in Guam, grown, and maintained in our laboratory. The species was recognized as a member of Euplotidium, and compared with established species of the genus: Euplotidium itoi Ito 1958; Euplotidium psammophilus (Vacelet 1961) Borror 1972; Euplotidium arenarium Magagnini and Nobili 1964; Euplotidium helgae Hartwig 1980; Euplotidium prosaltans Tuffrau 1985, and Euplotidium smalli Lei, Choi and Xu, 2002. To obtain more elements to compare the species, new morphometric data and additional SSU rRNA gene sequences of E. itoi and of E. arenarium are reported. On the basis of this comparison, we established the new species Euplotidium rosati that has a cirral pattern composed of 12 frontoventral and six transverse cirri, and lacks the left marginal cirrus. Euplotidium rosati harbors on its dorsal surface epixenosomes, the peculiar extrusive symbionts described in other Euplotidium species. The whole body of our observations together with the analysis of the data available in the literature leads us to propose a redefinition of the genus. The results may also be useful to clarify the tangled relationship between Euplotidium and Gastrocirrhus. PMID:23194274

Modeo, Letizia; Petroni, Giulio; Lobban, Christopher S; Verni, Franco; Vannini, Claudia

2012-11-29

390

Morphological Characterization of Low-Bandgap Crystalline Polymer:PCBM Bulk Heterojunction Solar Cells  

NASA Astrophysics Data System (ADS)

Understanding the morphology of polymer-based bulk heterojunction (BHJ) solar cells is key to improving device efficiencies. Blends of a low-bandgap silole-containing conjugated polymer, poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b;2',3'-d]silole)-2,6-diyl-alt-(4,7-bis(2-thienyl)-2,1,3-benzothiadiazole)-5,5'-diyl] (PSBTBT) with phenyl-C61-butyric acid methyl ester (PCBM) were investigated using different processing conditions. Scanning force microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, dynamic secondary ion mass spectrometry and neutron reflectivity studies showed that thermal annealing did not induce obvious changes in the structure of the active layer. Grazing-incidence X-ray diffraction and small-angle neutron scattering showed that the crystallization of PSBTBT and segregation of PCBM occurred during spin coating, and a brief thermal annealing increased the ordering of PSBTBT and enhanced the segregation of the PCBM, forming domains with 10-nm in size, leading to an improvement in photovoltaic performance.

Lu, Haiyun; Russell, Thomas

2011-03-01

391

Fully cosmological virtual massive galaxies at z = 0: kinematical, morphological and stellar population characterization  

NASA Astrophysics Data System (ADS)

We present the results of a numerical adaptive mesh refinement hydrodynamical and N-body simulation in a ? cold dark matter cosmology. We focus on the analysis of the main properties of massive galaxies (M* > 1011 M?) at z = 0. For all the massive virtual galaxies, we carry out a careful study of their one-dimensional density, luminosity, velocity dispersion and stellar population profiles. In order to best compare with observational data, the method to estimate the velocity dispersion is calibrated by using an approach similar to that performed in the observations, based on the stellar populations of the simulated galaxies. With these ingredients, we discuss the different properties of massive galaxies in our sample according to their morphological types, accretion histories and dynamical properties. We find that the galaxy merging history is the leading actor in shaping the massive galaxies that we see nowadays. Indeed, galaxies having experienced a turbulent life are the most massive in the sample and show the steepest metallicity gradients. Beside the importance of merging, only a small fraction of the final stellar mass has been formed ex situ (10-50 per cent), while the majority of the stars formed within the galaxy. These accreted stars are significantly older and less metallic than the stars formed in situ and tend to occupy the most external regions of the galaxies.

Navarro-González, Javier; Ricciardelli, Elena; Quilis, Vicent; Vazdekis, Alexandre

2013-10-01

392

Main airborne Ascomycota spores: characterization by culture, spore morphology, ribosomal DNA sequences and enzymatic analysis.  

PubMed

The aim of this work was to identify the main allergy-related Ascomycetes fungal spores present in the atmosphere of Porto, using different and complementary techniques. The atmospheric sampling, performed in the atmosphere of Porto (Portugal) from August 2006 to July 2008, indicated Cladosporium, Penicillium, Aspergillus and Alternaria as the main fungal spore taxa. Alternaria and Cladosporium peaks were registered during summer. Aspergillus and Penicillium highest values were registered from late winter to early spring. Additionally, the Andersen sampler allowed the culture and isolation of the collected viable spores subsequently used for different identification approaches. The internal-transcribed spacer region of the nuclear ribosomal repeat unit sequences of airborne Ascomycetes fungi isolates revealed 11 taxonomically related fungal species. Among the identified taxa, Penicillum and Aspergillus presented the highest diversity, while only one species of Cladosporium and Alternaria, respectively, were identified. All selected fungal spore taxa possessed phosphatase, esterase, leucine arylamidase and beta-glucosidase enzymatic activity, while none had lipase, cystine arylamidase, trypsin or beta-glucuronidase activity. The association between the spore cell wall morphology, DNA-based techniques and enzymatic activity approaches allowed a more reliable identification procedure of the airborne Ascomycota fungal spores. PMID:20143229

Oliveira, Manuela; Amorim, M Isabel; Ferreira, Elsa; Delgado, Luís; Abreu, Ilda

2010-02-09

393

Characterization and morphological reconstruction of the Terny impact structure, central Ukraine  

NASA Astrophysics Data System (ADS)

The Terny impact structure, located in central Ukraine, displays a variety of diagnostic indicators of shock metamorphism, including shatter cones, planar deformation features in quartz, diaplectic glass, selective melting of minerals, and whole rock melting. The structure has been modified by erosion and subsequently buried by recent sediments. Although there are no natural outcrops of the deformed basement rocks within the area, mining exploration has provided surface and subsurface access to the structure, exposing impact melt rocks, shocked parautochthonous target rocks, and allochthonous impact breccias, including impact melt-bearing breccias similar to suevites observed at the Ries structure. We have collected and studied samples from surface and subsurface exposures to a depth of approximately 750 m below the surface. This analysis indicates the Terny crater is centered on geographic coordinates 48.13° N, 33.52° E. The center location and the distribution of shock pressures constrain the transient crater diameter to be no less than approximately 8.4 km. Using widely accepted morphometric scaling relations, we estimate the pre-erosional rim diameter of Terny crater to be approximately 16-19 km, making it close in original size to the well-preserved El'gygytgyn crater in Siberia. Comparison with El'gygytgyn yields useful insights into the original morphology of the Terny crater and indicates that the amount of erosion Terny experienced prior to burial probably does not exceed 320 m.

Sharpton, V. L.; Krochuk, R. V.; Herrick, R. R.

2013-05-01

394

Morphological and functional characterization of leech circulating blood cells: role in immunity and neural repair.  

PubMed

Unlike most invertebrates, annelids possess a closed vascular system distinct from the coelomic liquid. The morphology and the function of leech blood cells are reported here. We have demonstrated the presence of a unique cell type which participates in various immune processes. In contrast to the mammalian spinal cord, the leech CNS is able to regenerate and restore function after injury. The close contact of the blood with the nerve cord also led us to explore the participation of blood in neural repair. Our data evidenced that, in addition to exerting peripheral immune functions, leech blood optimizes CNS neural repair through the release of neurotrophic substances. Circulating blood cells also appeared able to infiltrate the injured CNS where, in conjunction with microglia, they limit the formation of a scar. In mammals, CNS injury leads to the generation of a glial scar that blocks the mechanism of regeneration by preventing axonal regrowth. The results presented here constitute the first description of neuroimmune functions of invertebrate blood cells. Understanding the basic function of the peripheral circulating cells and their interactions with lesioned CNS in the leech would allow us to acquire insights into the complexity of the neuroimmune response of the injured mammalian brain. PMID:22159559

Boidin-Wichlacz, Céline; Vergote, David; Slomianny, Christian; Jouy, Nathalie; Salzet, Michel; Tasiemski, Aurélie

2011-12-11

395

Morphologic and molecular characterization of ATRT xenografts adapted for orthotopic therapeutic testing  

PubMed Central

Atypical teratoid rhabdoid tumor (ATRT) is a malignant tumor of the central nervous system that most commonly arises in young children. The aggressive growth and propensity for early dissemination throughout the neuraxis confers a dismal prognosis. Large clinical trials that could test new therapeutic agents are difficult to conduct due to the low incidence of this cancer. For this reason, high throughput preclinical testing with suitable animal models for ATRT would serve a critical need for identifying the most efficacious treatments. In response to this need, we have adapted ATRT cell lines for bioluminescence imaging (BLI) of intracranial (orthotopic) xenografts established in athymic mice. Our results indicate that following supratentorial or infratentorial injection in athymic mice, ATRT cells produce rapidly growing tumors, often with intraventricular spread or neuraxis dissemination. When established as orthotopic xenografts, the tumors predominantly display cells with a rhabdoid-like cellular morphology that show a spectrum of immunophenotypes similar to primary ATRT tumors. To demonstrate the feasibility of this orthotopic ATRT xenograft model for therapeutic testing with correlation to biomarker analysis, we examined the responses of luciferase-modified ATRT cells to temozolomide (TMZ). These xenografts, which highly express MGMT, are resistant to TMZ treatment when compared with an orthotopic glioblastoma xenograft that is MGMT deficient and responsive to TMZ. These data suggest that an orthotopic ATRT xenograft model, in which BLI is used for monitoring tumor growth and response to therapy, should contribute to the identification of effective therapeutics and regimens for treating this highly aggressive pediatric brain tumor.

Hashizume, Rintaro; Gupta, Nalin; Berger, Mitchel S.; Banerjee, Anu; Prados, Michael D.; Ayers-Ringler, Jennifer; James, C. David; VandenBerg, Scott R.