Home About us Contact
|
Home About us Contact | ||
|
|
||
Morphological Characteristics (morphological + characteristic)
Selected AbstractsFrequencies of Morphological Characteristics in Two Contemporary Forensic Collections: Implications for Identification,JOURNAL OF FORENSIC SCIENCES, Issue 5 2006Debra Komar Ph.D. ABSTRACT: Positive identification relies on comparison of antemortem and postmortem data. Some identifications are based on morphological features such as fracture, pathological condition, and surgical hardware, despite little literature indicating the frequencies of such traits. This study examines whether such features are sufficiently rare as to be deemed individualizing. Data were collected on two modern North American skeletal collections (N=482 individuals). Presence/absence of features was scored by skeletal element and side. Results indicate that frequencies vary by geographic region (higher frequency of fractures and pathological conditions in New Mexico while individuals in Tennessee were more likely to have surgical interventions), many features such as fractures are remarkably common and that even suites of traits may not be individualizing. Caution is warranted when using written data rather than radiographic comparisons as the primary source of identification. The implications of these findings to missing person databases are also discussed. [source] Morphological Characteristics of C1 and C2 Adrenergic Neurone Groups in Marmoset Monkey Brainstem by using Antibody against Phenylethanolamine-N-methyltransferaseANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2002Y.-G. Jeong Summary This work describes a mapping study of phenylethanolamine-N-methyltransferase (PNMT) immunoreactive neurones and fibres in the medulla oblongata of the marmoset monkey, Callithrix jacchus. Two groups of PNMT-immunoreactive neurones were found in the marmoset monkey medulla oblongata: a ventrolateral (C1 group) and a dorsomedial PNMT-immunoreactive cells group (C2 group). The PNMT-immunoreactive cells in the ventrolateral group C1 were found to be located around the lateral reticular nucleus. The PNMT-immunoreactive somata within the ventrolateral medulla are round to oval, and mostly multipolar with branched processes. In the dorsomedial group C2, PNMT-immunoreactive cell bodies appeared near the obex. The majority of the dorsomedial PNMT-immunoreactive neurones were observed in the nucleus tractus solitarius; although some were present in the dorsal motor nucleus of the vagus. The PNMT-immunoreactive somata in the dorsomedial medulla were small and round or ovoid. These results provide information upon the adrenergic system in the medulla oblongata of a species that presents a useful model of a small primate brain, the marmoset monkey. [source] Simulated microgravity activates MAPK pathways in fibroblasts cultured on microgrooved surface topographyCYTOSKELETON, Issue 2 2008W. A. Loesberg Abstract This study evaluated in vitro the differences in morphological behaviour between fibroblast cultured on smooth and microgrooved substrata (groove depth: 0.5 ,m, width: 1 ,m), which were subjected to simulated microgravity. The aim of the study was to clarify which of these parameters was more dominant to determine cell behaviour. Morphological characteristics were investigated using scanning electron microscopy and fluorescence microscopy in order to obtain qualitative information on cell alignment. Expression of collagen type I, and ,1-, ,1-, ,3-integrin were investigated by QPCR. Finally, immunoblotting was applied to visualise MAPK signalling pathways. Microscopy and image analysis showed that the fibroblasts aligned along the groove direction on all textured surfaces. On the smooth substrata, cells had spread out in a random fashion. The alignment of cells cultured on grooved surfaces under simulated microgravity, after 48 h of culturing appeared similar to those cultured at 1g, although cell shape was different. Analysis of variance proved that all main parameters: topography, gravity force, and time were significant. In addition, gene levels were reduced by simulated microgravity particularly those of ,3-integrin and collagen, however alpha-1 and beta-1 integrin levels were up-regulated. ERK1/2 was reduced in RPM, however, JNK/SAPK and p38 remained active. The members of the small GTPases family were stimulated under microgravity, particularly RhoA and Cdc42. The results are in agreement that application of microgravity to fibroblasts promotes a change in their morphological appearance and their expression of cell-substratum proteins through the MAPK intracellular signalling pathways. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] The effect of combined simulated microgravity and microgrooved surface topography on fibroblastsCYTOSKELETON, Issue 3 2007W. A. Loesberg Abstract This study evaluated in vitro the differences in morphological behaviour between fibroblast cultured on smooth and microgrooved substrata (groove depth: 0.5 ,m, width: 1, 2, 5, and 10 ,m), which were subjected to simulated microgravity. The aim of the study was to clarify which of these parameters was more dominant to determine cell behaviour. Morphological characteristics were investigated using scanning electron microscopy and fluorescence microscopy in order to obtain qualitative information on cell alignment and area. Confocal laser scanning microscopy visualised distribution of actin filaments and focal adhesion points. Finally, expression of collagen type I, fibronectin, and ,1- and ,1-integrin were investigated by PCR. Microscopy and image analysis showed that the fibroblasts aligned along the groove direction on all textured surfaces. On the smooth substrata, cells had spread out in a random fashion. The alignment of cells cultured on grooved surfaces decreased under simulated microgravity, especially after 24 h of culturing. Cell surface area on grooved substrata were significantly smaller than on smooth substrata, but simulated microgravity on the grooved groups resulted in an enlargement of cell area. ANOVA was performed on all main parameters: topography, gravity force, and time. In this analysis, all parameters proved significant. In addition, gene levels were reduced by microgravity particularly those of ,1-integrin and fibronectin. From our data it is concluded that the fibroblasts primarily adjust their shape according to morphological environmental cues like substratum surface whilst a secondary, but significant, role is played by microgravity conditions. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] The effect of combined hypergravity and microgrooved surface topography on the behaviour of fibroblastsCYTOSKELETON, Issue 7 2006W. A. Loesberg Abstract This study evaluated in vitro the differences in morphological behaviour between fibroblast cultured on smooth and microgrooved substrata (groove depth: 1 ,m, width: 1, 2, 5, 10 ,m), which undergo artificial hypergravity by centrifugation (10, 24 and 50 g; or 1 g control). The aim of the study was to clarify which of these parameters was more important to determine cell behaviour. Morphological characteristics were investigated using scanning electron microscopy and fluorescence microscopy in order to obtain qualitative information on cell spreading and alignment. Confocal laser scanning microscopy visualised distribution of actin filaments and vinculin anchoring points through immunostaining. Finally, expression of collagen type I, fibronectin, and ,1 - and ,1 -integrin were investigated by PCR. Microscopy and image analysis showed that the fibroblasts aligned along the groove direction on all textured surfaces. On the smooth substrata (control), cells spread out in a random fashion. The alignment of cells cultured on grooved surfaces increased with higher g-forces until a peak value at 25 g. An ANOVA was performed on the data, for all main parameters: topography, gravity force, and time. In this analysis, all parameters proved significant. In addition, most gene levels were reduced by hypergravity. Still, collagen type 1 and fibronectin are seemingly unaffected by time or force. From our data it is concluded that the fibroblasts primarily adjust their shape according to morphological environmental cues like substratum surface whilst a secondary, but significant, role is played by hypergravity forces. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] Root and butt rot of Todo fir (Abies sachalinensis) caused by Heterobasidion annosum s.l. in Hokkaido, JapanFOREST PATHOLOGY, Issue 3 2007S. Tokuda Summary The occurrence and symptoms of root and butt rot were examined in a 35 × 30 m plot of 68-year-old Todo fir plantation in Hokkaido, Japan. Forty-seven percent of the cut stumps were decayed and 52% of the decayed stumps showed similar decay characteristics with yellowish orange to light brown colouration and expanded pockets in the heartwood. Morphological characteristics of the pure cultures isolated from the decay were similar to the cultures isolated from basidiocarps of Heterobasidion annosum sensu lato, found on fallen logs outside of the research site. Also DNA analysis based on the combined data set of three gene loci (glyceraldehyde 3-phosphate dehydrogenase, heat shock protein 80,1 and elongation factor 1-alpha genes) showed that the isolates from the decay are included in the same clade with the Japanese H. annosum s.l. isolates. They form a subclade to H. parviporum (the European S group of H. annosum s.l.). This is the first report of molecular determination of H. annosum s.l. isolated from root and butt rot in a plantation in Japan. [source] Paleoindian environmental change and landscape response in Barger Gulch, Middle Park, ColoradoGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2005James H. Mayer Middle Park, a high-altitude basin in the Southern Rocky Mountains of north-central Colorado, contains at least 59 known Paleoindian localities. At Barger Gulch Locality B, an extensive Folsom assemblage (,10,500 14C yr B.P.) occurs within a buried soil. Radiocarbon ages of charcoal and soil organic matter, as well as stratigraphic positions of artifacts, indicate the soil is a composite of a truncated, latest-Pleistocene soil and a younger mollic epipedon formed between ,6000 and 5200 14C yr B.P. and partially welded onto the older soil following erosion and truncation. Radiocarbon ages from an alluvial terrace adjacent to the excavation area indicate that erosion followed by aggradation occurred between ,10,200 and 9700 14C yr B.P., and that the erosion is likely related to truncation of the latest-Pleistocene soil. Erosion along the main axis of Barger Gulch occurring between ,10,000 and 9700 14C yr B.P. was followed by rapid aggradation between ,9700 and 9550 14C yr B.P., which, along with the erosion at Locality B, coincides with the abrupt onset of monsoonal precipitation following cooling in the region ,11,000,10,000 14C yr B.P. during the Younger Dryas oscillation. Buried soils dated between ,9500 and 8000 14C yr B.P. indicate relative landscape stability and soil formation throughout Middle Park. Morphological characteristics displayed by early Holocene soils suggest pedogenesis under parkland vegetation in areas currently characterized by sagebrush steppe. The expansion of forest cover into lower elevations during the early Holocene may have resulted in lower productivity in regards to mammalian fauna, and may partly explain the abundance of early Paleoindian sites (,11,000,10,000 14C yr B.P., 76%) relative to late Paleoindian sites (,10,000,8000 14C yr B.P., 24%) documented in Middle Park. © 2005 Wiley Periodicals, Inc. [source] Phylogenetic study on Shiraia bambusicola by rDNA sequence analysesJOURNAL OF BASIC MICROBIOLOGY, Issue 5 2004Tian-Fan Cheng In this study, 18S rDNA and ITS-5.8S rDNA regions of four Shiraia bambusicola isolates collected from different species of bamboos were amplified by PCR with universal primer pairs NS1/NS8 and ITS5/ITS4, respectively, and sequenced. Phylogenetic analyses were conducted on three selected datasets of rDNA sequences. Maximum parsimony, distance and maximum likelihood criteria were used to infer trees. Morphological characteristics were also observed. The positioning of Shiraia in the order Pleosporales was well supported by bootstrap, which agreed with the placement by Amano (1980) according to their morphology. We did not find significant inter-hostal differences among these four isolates from different species of bamboos. From the results of analyses and comparison of their rDNA sequences, we conclude that Shiraia should be classified into Pleosporales as Amano (1980) proposed and suggest that it might be positioned in the family Phaeosphaeriaceae. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Lateral line system and its innervation in Tetraodontiformes with outgroup comparisons: Descriptions and phylogenetic implicationsJOURNAL OF MORPHOLOGY, Issue 5 2010Masanori Nakae Abstract The lateral line system and its innervation in ten tetraodontiform families and five outgroup taxa were examined. Although some homology issues remained unresolved, tetraodontiforms were characterized by having two types (at least) of superficial neuromasts (defined by the presence or absence of supporting structures) and accessory lateral lines and neuromasts (except Molidae in which "accessory" elements were absent). The preopercular line in Tetraodontiformes was not homologous with that of typical teleosts, because the line was innervated by the opercular ramule that was newly derived from the mandibular ramus, the condition being identical to that in Lophiidae. Within Tetraodontiformes, the number of neuromasts varied between 70 and 277 in the main lines and between 0 and 52 in accessory elements. Variations were also recognized in the presence or absence of the supraorbital commissure, mandibular line, otic line, postotic line, ventral trunk line, and some lateral line nerve rami, most notably the dorsal branch of the opercular ramule, being absent in Aracanidae, Ostraciidae, Tetraodontidae, Diodontidae, and Molidae. Morphological characteristics derived from the lateral line system and its innervation provided some support for a sister relationship of tetraodontiforms with lophiiforms. J. Morphol., 2010. © 2009 Wiley-Liss, Inc. [source] Air-liquid interface (ALI) culture of human bronchial epithelial cell monolayers as an in vitro model for airway drug transport studiesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2007Hongxia Lin Abstract Serially passaged normal human bronchial epithelial (NHBE) cell monolayers were established on Transwell® inserts via an air-liquid interface (ALI) culture method. NHBE cells were seeded on polyester Transwell® inserts, followed by an ALI culture from day 3, which resulted in peak TEER value of 766,±,154 ,,×,cm2 on the 8th day. Morphological characteristics were observed by light microscopy and SEM, while the formation of tight junctions was visualized by actin staining, and confirmed successful formation of a tight monolayer. The transepithelial permeability (Papp) of model drugs significantly increased with the increase of lipophilicity and showed a good linear relationship, which indicated that lipophilicity is an important factor in determining the Papp value. The expression of P-gp transporter in NHBE cell monolayers was confirmed by the significantly higher basolateral to apical permeability of rhodamine123 than that of reverse direction and RT-PCR of MDR1 mRNA. However, the symmetric transport of fexofenadine,·,HCl in this NHBE cell monolayers study seems to be due to the low expression of P-gp transporter and/or to its saturation with high concentration of fexofenadine,·,HCl. Thus, the development of tight junction and the expression of P-gp in the NHBE cell monolayers in this study imply that they could be a suitable in vitro model for evaluation of systemic drug absorption via airway delivery, and that they reflect in vivo condition better than P-gp over-expressed cell line models. ©2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96:341,350, 2007 [source] Dynamic mechanical study of clay dispersion in maleated polypropylene/organoclay nanocompositesPOLYMER COMPOSITES, Issue 9 2009Yeh Wang Morphological characteristics and the dynamic mechanical properties of maleic anhydride grafted polypropylene (PPgMA) and its clay-filled nanocomposites with different degrees of clay exfoliation have been investigated. Fully and partially exfoliated samples were prepared through powered sonication and melt blending, respectively. Our results indicated that both mechanical , and , relaxations can be identified. The glass (,) transition of the nanocomposites shifted to slightly lower temperatures for nearly all formulations because of reduced chain cooperative motion. However, the broad , transition became more distinct with increasing clay loading for sonicated nanocomposites, and shifted to higher temperatures due to chain confinement of amorphous polymer chains in the crystalline region. The reinforcement in the glassy storage modulus E, of PPgMA was examined by the Halpin,Tsai theory. The high aspect ratio of clay stacks in the fully exfoliated nanocomposites resulted in a significant increase in reinforcing efficiency. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Modeling particle inflation from poly(amic acid) powdered precursors.POLYMER ENGINEERING & SCIENCE, Issue 5 2007Morphological characteristics of polyimide microstructures obtained by solid-state powder foaming determine the geometric properties of the unit cell, in polyimide foams prepared by this process. Morphological analysis of precursor particles has shown that particle size and shape, as well as the presence of embedded microvoids, exert a strong influence on the final microstructure morphology. Of equal importance in the morphological development are processing conditions such as heating rate and primary blowing agent content in the particles, prior to thermal treatment. In the present paper, the first of two numerical schemes is presented. A numerical model has been developed to study the preliminary stages that lead to particle inflation. Based on this model, a parametric analysis is performed for pertinent governing parameters, with the purpose of determining their effect on the onset of particle inflation and the potential morphological characteristics of polyimide microstructures. It has been found that precursor particle morphology and nuclei density are the key parameters in determining the potential morphology of the microstructures, by limiting the number of bubbles that grow within each particle. POLYM. ENG. SCI., 47:560,571, 2007. © 2007 Society of Plastics Engineers. [source] The Restoration of Phytophagous Beetles in Species-Rich Chalk GrasslandsRESTORATION ECOLOGY, Issue 5 2010Ben A. Woodcock This study focuses on the restoration of chalk grasslands over a 6-year period and tests the efficacy of two management practices, hay spreading and soil disturbance, in promoting this process for phytophagous beetles. Restoration success for the beetles, measured as similarity to target species,rich chalk grassland, was not found to be influenced by either management practice. In contrast, restoration success for the plants did increase in response to hay spreading management. Although the presence of suitable host plants was considered to dictate the earliest point at which phytophagous beetles could successfully colonized, few beetle species colonized as soon as their host plants became established. Morphological characteristics and feeding habits of 27 phytophagous beetle species were therefore tested to identify factors that limited their colonization and persistence. The lag time between host plant establishment and colonization was greatest for flightless beetles. Beetles with foliage-feeding larvae both colonized at slower rates than seed-, stem-, or root-feeding species and persisted within the swards for shorter periods. Although the use of hay spreading may benefit plant communities during chalk grassland restoration, it did not directly benefit phytophagous beetles. Without techniques for overcoming colonization limitation for invertebrate taxa, short-term success of restoration may be limited to the plants only. [source] Cerebral developmental venous anomalies: Current concepts,ANNALS OF NEUROLOGY, Issue 3 2009Diego San Millán Ruíz MD Cerebral developmental venous anomalies are the most frequently encountered cerebral vascular malformation, and as such, are frequently reported as fortuitous findings in computed tomography (CT) and magnetic resonance imaging (MRI) studies. Developmental venous anomalies (DVAs) are generally considered extreme anatomical variations of the cerebral vasculature, and follow a benign clinical course in the vast majority of cases. Here we review current concepts on DVAs with the aim of helping clinicians understand this complex entity. Morphological characteristics that are necessary to conceptualize DVAs are discussed in depth. Images modalities used in diagnosing DVAs are reviewed, including new MRI or CT techniques. Clinical presentation, association with other vascular malformations and cerebral parenchymal abnormalities, and possible physiopathological processes leading to associated imaging or clinical findings are discussed. Atypical forms of DVAs are also reviewed and their clinical significance discussed. Finally, recommendations as to how to manage asymptomatic or symptomatic patients with a DVA are advanced. Ann Neurol 2009;66:271,283 [source] Morphological characteristics of on-farm water storages and their similarity to natural water bodies in the Border Rivers Catchment, AustraliaAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2010Susan Lutton Abstract 1.Natural wetlands throughout the world are under threat from water resource development required to support an ever increasing population. In the Border Rivers Catchment in Queensland, Australia, a large irrigation industry and highly variable flow regime have necessitated the building of large on-farm water storages. With the decline in number and size of natural wetlands, the presence of these storages on the floodplain has raised the question of their suitability as alternative habitat for aquatic fauna. This paper explores the variety of water storage types in the Border Rivers Catchment and how their morphology compares with that of natural wetlands , in particular, factors likely to influence aquatic biodiversity. 2.Storages and natural wetlands formed two distinct groups based on morphology. Storages tended to be large, deep structures with a more regular shape while natural wetlands were irregular and shallow with large perimeters. Although there was a degree of variability amongst the storage sites, a large proportion fell into one group and were considered ,typical storages'. Typical storages contained tailwater and had the following characteristics: situated 3,km from the source river, 10 years old, embankment height of 5,m, area of 400,000,m2, perimeter of 2.5,km and capacity of 1,700,000,m3. 3.Due to their uniform structure we believe that most on-farm storages are unlikely to support as diverse or abundant an aquatic population as natural wetlands. The presence of tailwater and associated chemicals is also likely to reduce the aquatic biodiversity of storages compared with natural wetlands. While they may be unsuitable as replacement wetlands, given their numbers they could provide significant aquatic habitat across the landscape, if managed effectively. Copyright © 2009 John Wiley & Sons, Ltd. [source] Influence of point-source sediment-supply on modern shelf-slope morphology: implications for interpretation of ancient shelf marginsBASIN RESEARCH, Issue 5 2009Cornel Olariu ABSTRACT Present sea-floor bathymetry indicates that the continental-shelf and shelf-break morphology have some unique and predictable characteristics in areas with and without high sediment supply. Using a global bathymetry dataset in open shelf areas in front of rivers that discharge over 25 × 106 tons of sediment per year, five distinct accretionary types of shelf-break are distinguished based on along-shelf gradient variability and inferred shelf-break trajectory. Morphological characteristics of river-mouth shelves (compared with adjacent areas lateral to the immediate fairway of the river) are: (1) an overall lower gradient and greater width, and (2) a relatively high slope gradient/shelf gradient ratio. The exceptions are shelves with active shelf-edge deltas; these are narrower, steeper and have an attenuated shelf break in front of rivers. These observations are at seismic scale and have direct implications for the recognition and positioning of principal cross-shelf, supply fairways on ancient shelves or shelf margins, and therefore the potential by-pass routes for deepwater sands. Higher slope/shelf gradient ratios in areas of actively accreting margins, where the shelf-break is more prominent and easier to recognize on seismic data compared with adjacent areas, predict areas with high sediment supply. Along-strike morphological changes on supply-dominated shelves suggest that identification of the sediment-feed route and depocenter relative to the shelf break during a relative sea level cycle are critical for understanding/predicting the 3-D architecture of the shelf-slope-basin floor clinoform. [source] Retinal capillary basement membrane thickness in diabetic mice genetically modified at the haptoglobin locusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2007Rachel Miller-Lotan Technion Faculty of Medicine Abstract Background Individuals with diabetes mellitus (DM) homozygous for the haptoglobin (Hp) 1 allele are at decreased risk of retinopathy as compared to DM individuals with the Hp 2 allele. We sought to recapitulate these findings in DM mice genetically modified at the Hp locus. Methods An early morphological characteristic of the microangiopathy seen in diabetic retinal disease is retinal capillary basement membrane (RCBM) thickening. RCBM thickness as assessed by electron microscopy was performed on a total of 12 eyes taken from three mice in each of the four study groups (three eyes from C57Bl/6 Hp 1 and C57Bl/6 Hp 2 mice with and without streptozotocin-induced diabetes). Results The non-parametric Kruskal,Wallis ANOVA test demonstrated that there was a highly significant difference between the four groups of mice (P < 0.0001). Mann,Whitney tests for specific pair-wise comparisons demonstrated that there was no significant difference in the RCBM thickness between Hp 1 and Hp 2 mice (p = 0.70) or between DM Hp 1 and non-DM Hp 1 mice (p = 0.42). However, induction of diabetes resulted in a marked increase in RCBM thickness in Hp 2 mice compared to non-DM Hp 2 mice (p = 0.0004) and compared to DM Hp 1 mice (p = 0.0005). Conclusions A highly significant increase in RCBM thickness was observed in DM mice with the Hp 2 genotype. These data provide important support for association studies done in humans showing an increased prevalence of diabetic retinopathy in individuals with the Hp 2 genotype. Copyright © 2006 John Wiley & Sons, Ltd. [source] The latex capacity of opium poppy capsules is fixed early in capsule development and is not a major determinant in morphine yieldANNALS OF APPLIED BIOLOGY, Issue 2 2009T. Harvest Abstract This study found that the latex capacity (mg latex mg,1 dry weight capsule) of opium poppy capsules is fixed early in capsule development. Latex capacity, which represents the proportion of the capsule wall allocated to laticifers (specialised cells for latex storage), had peaked in the capsule at 1 week after flowering. In contrast, the morphine content of capsules continued to increase with capsule development until commercial harvest. Morphine content was correlated with capsule mass and total latex mass, but there was no correlation between latex capacity and morphine yield. The most important morphological characteristic in terms of morphine end yield (commercial harvest stage) was capsule mass. The findings of this study demonstrate that although latex yield per plant is a highly heritable morphological characteristic, it may have limited potential for use in a breeding strategy aimed at increasing the morphine yield from capsules. [source] Infertility observed in female rats treated with N-acetyl-L-cysteine: Histopathological examination of ovarian follicles and recovery of fertilityCONGENITAL ANOMALIES, Issue 3 2003Miwa Harada ABSTRACT, We previously reported infertility in female rats that received N,acetyl-L-cysteine (NAC) intravenously at a dosage of 1000 mg/kg/day. Unfertilized oocytes and gestation day 1 and 2 embryos were assessed morphologically, and the results suggested that absence or thinning of the zona pellucida (ZP) is related to infertility. However, the morphological characteristics of oocytes before ovulation and recovery from the effects of NAC were not clarified. In the present study, the ovarian follicles were histopathologi,cally examined and the recovery of reproductive function was evaluated to investigate the effects of NAC. Female Sprague-Dawley rats at 10 weeks of age received NAC intravenously at 1000 mg/kg/day for more than 1 week. Thinning of the ZP was observed in the ovarian follicles in all stages of growth by light microscopy. Outflow of the components of the ZP between the corona radiata and disarrangement of the corona radiata were more pronounced in growing follicles than in large secondary follicles. Similar findings were observed by electron microscopy, and the effects of NAC were limited to the ZP. Infertility and thinning of the ZP were observed in the no,recovery NAC group, but not in the recovery NAC group, in which animals recovered within four estrous cycles after NAC administration. It has been reported that the ZP is expressed by oocytes or by both oocytes and granulosa cells, but no changes were noted in these cells. The present findings suggest that NAC affects the ZP directly and that reproductive function may recover from the effects of NAC. [source] Models of white matter injury: Comparison of infectious, hypoxic-ischemic, and excitotoxic insultsDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2002Henrik Hagberg Abstract White matter damage (WMD) in preterm neonates is strongly associated with adverse outcome. The etiology of white matter injury is not known but clinical data suggest that ischemia-reperfusion and/or infection-inflammation are important factors. Furthermore, antenatal infection seems to be an important risk factor for brain injury in term infants. In order to explore the pathophysiological mechanisms of WMD and to better understand how infectious agents may affect the vulnerability of the immature brain to injury, numerous novel animal models have been developed over the past decade. WMD can be induced by antenatal or postnatal administration of microbes (E. coli or Gardnerella vaginalis), virus (border disease virus) or bacterial products (lipopolysaccharide, LPS). Alternatively, various hypoperfusion paradigms or administration of excitatory amino acid receptor agonists (excitotoxicity models) can be used. Irrespective of which insult is utilized, the maturational age of the CNS and choice of species seem critical. Generally, lesions with similarity to human WMD, with respect to distribution and morphological characteristics, are easier to induce in gyrencephalic species (rabbits, dogs, cats and sheep) than in rodents. Recently, however, models have been developed in rats (PND 1,7), using either bilateral carotid occlusion or combined hypoxia-ischemia, that produce predominantly white matter lesions. LPS is the infectious agent most often used to produce WMD in immature dogs, cats, or fetal sheep. The mechanism whereby LPS induces brain injury is not completely understood but involves activation of toll-like receptor 4 on immune cells with initiation of a generalized inflammatory response resulting in systemic hypoglycemia, perturbation of coagulation, cerebral hypoperfusion, and activation of inflammatory cells in the CNS. LPS and umbilical cord occlusion both produce WMD with quite similar distribution in 65% gestational sheep. The morphological appearance is different, however, with a more pronounced infiltration of inflammatory cells into the brain and focal microglia/macrophage ("inflammatory WMD") in response to LPS compared to hypoperfusion evoking a more diffuse microglial response usually devoid of cellular infiltrates ("ischemic WMD"). Furthermore, low doses of LPS that by themselves have no adverse effects in 7-day-old rats (maturation corresponding to the near term human fetus), dramatically increase brain injury to a subsequent hypoxic-ischemic challenge, implicating that bacterial products can sensitize the immature CNS. Contrary to this finding, other bacterial agents like lipoteichoic acid were recently shown to induce tolerance of the immature brain suggesting that the innate immune system may respond differently to various ligands, which needs to be further explored. MRDD Research Reviews 2002;8:30,38. © 2002 Wiley-Liss, Inc. [source] Adult neurogenesis in the crayfish brain: Proliferation, migration, and possible origin of precursor cellsDEVELOPMENTAL NEUROBIOLOGY, Issue 7 2009Yi Zhang Abstract The birth of new neurons and their incorporation into functional circuits in the adult brain is a characteristic of many vertebrate and invertebrate organisms, including decapod crustaceans. Precursor cells maintaining life-long proliferation in the brains of crayfish (Procambarus clarkii, Cherax destructor) and clawed lobsters (Homarus americanus) reside within a specialized niche on the ventral surface of the brain; their daughters migrate to two proliferation zones along a stream formed by processes of the niche precursors. Here they divide again, finally producing interneurons in the olfactory pathway. The present studies in P. clarkii explore (1) differential proliferative activity among the niche precursor cells with growth and aging, (2) morphological characteristics of cells in the niche and migratory streams, and (3) aspects of the cell cycle in this lineage. Morphologically symmetrical divisions of neuronal precursor cells were observed in the niche near where the migratory streams emerge, as well as in the streams and proliferation zones. The nuclei of migrating cells elongate and undergo shape changes consistent with nucleokinetic movement. LIS1, a highly conserved dynein-binding protein, is expressed in cells in the migratory stream and neurogenic niche, implicating this protein in the translocation of crustacean brain neuronal precursor cells. Symmetrical divisions of the niche precursors and migration of both daughters raised the question of how the niche precursor pool is replenished. We present here preliminary evidence for an association between vascular cells and the niche precursors, which may relate to the life-long growth and maintenance of the crustacean neurogenic niche. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source] Activity-dependent formation and functions of chondroitin sulfate-rich extracellular matrix of perineuronal netsDEVELOPMENTAL NEUROBIOLOGY, Issue 5 2007Alexander Dityatev Abstract Extracellular matrix molecules,including chondroitin sulfate proteoglycans, hyaluronan, and tenascin-R,are enriched in perineuronal nets (PNs) associated with subsets of neurons in the brain and spinal cord. In the present study, we show that similar cell type-dependent extracellular matrix aggregates are formed in dissociated cell cultures prepared from early postnatal mouse hippocampus. Starting from the 5th day in culture, accumulations of lattice-like extracellular structures labeled with Wisteria floribunda agglutinin were detected at the cell surface of parvalbumin-expressing interneurons, which developed after 2,3 weeks into conspicuous PNs localized around synaptic contacts at somata and proximal dendrites, as well as around axon initial segments. Physiological recording and intracellular labeling of PN-expressing neurons revealed that these are large fast-spiking interneurons with morphological characteristics of basket cells. To study mechanisms of activity-dependent formation of PNs, we performed pharmacological analysis and found that blockade of action potentials, transmitter release, Ca2+ permeable AMPA subtype of glutamate receptors or L-type Ca2+ voltage-gated channels strongly decreased the extracellular accumulation of PN components in cultured neurons. Thus, we suggest that Ca2+ influx via AMPA receptors and L-type channels is necessary for activity-dependent formation of PNs. To study functions of chondroitin sulfate-rich PNs, we treated cultures with chondroitinase ABC that resulted in a prominent reduction of several major PN components. Removal of PNs did not affect the number and distribution of perisomatic GABAergic contacts but increased the excitability of interneurons in cultures, implicating the extracellular matrix of PNs in regulation of interneuronal activity. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Study of a Catalytic Mechanism in Additive Differential Pulse TechniquesELECTROANALYSIS, Issue 4 2003Angela Molina Abstract The new electrochemical double pulse technique, known as additive differential normal pulse voltammetry (ADNPV) when there is no restriction on the duration of both pulses, and additive differential pulse voltammetry (ADPV) when t2,t1, has been applied to a pseudo-first-order catalytic mechanism. The expressions obtained here are applicable to planar and spherical electrodes, of any radius. This is of great interest since the size of the electrode plays an important role in the preponderating of diffusive and kinetics processes. The signal obtained with this technique presents the same morphological characteristics as the triple pulse technique, double differential pulse voltammetry (DDPV) and is more advantageous than DDPV and than the double pulse one, differential pulse voltammetry (DPV). [source] Morphological variation in relation to flower use in bumblebeesENTOMOLOGICAL SCIENCE, Issue 2 2006Maki N. INOUE Abstract To understand resource partitioning in a bumblebee community, we analyzed various morphological characters. A total of 1269 individuals of six bumblebee species, Bombus ardens, B. hypocrita, B. diversus, B. ignitus, B. honshuensis and B. beaticola, were examined and principal component analysis showed that the bumblebee species were clearly differentiated. Glossa, prementa and head lengths were positively correlated with the second component, and a longer proboscis was associated with a narrower body, which may help bees to intrude into and access deep-lying nectar sources. Bombus diversus, with a long proboscis and narrow body, preferred flowers with a long corolla tube, whereas B. hypocrita and B. ignitus, which have short proboscises and wide bodies, visited flowers with short corollas or dish-shaped flowers. Two pairs of consubgeneric species that have similar morphological characteristics, B. ardens and B. beaticola, and B. hypocrita and B. ignitus, divided flower resources by habitat selection and seasonal partitioning. For resource partitioning among bumblebee species, not only morphology but also other factors, such as habitat and seasonal preference, flower use, foraging behavior, and interspecific interactions, are responsible. [source] A novel case of haemoglobin H disease associated with clinical and morphological characteristics of congenital dyserythropoietic anaemia type IEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2002M. Antonelou Abstract: We report, for the first time, an unusual case of congenital anaemia with the clinical diagnosis of haemoglobin H disease complicated by morphological features at the light and electron microscopy level very similar to those of CDA-I. The red cell indices and the globin chain biosynthetic ratio were not characteristic of the defective haemoglobin genotype. The haematological, clinical and morphological data strongly suggest the novel coexistence of the two defects in a patient. The disease is characterised by a unique dyserythropoietic phenotype of diagnostic importance, which possibly brings new data regarding the reciprocal interaction between the two diseases, especially concerning a specific abnormality in globin chain synthesis in CDA-I, as previously suggested. [source] CD34+ cells derived from fetal liver contained a high proportion of immature megakaryocytic progenitor cellsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2000Dong-Chu Ma Abstract: Endoreplication and maturation of the megakaryocyte (MK) may be retarded or delayed during ontogenesis. In this study, CD34+ cells were isolated from both human fetal liver and adult bone marrow and incubated with thrombopoietin (TPO). The cell number, morphological characteristics, platelet-associated antigen phenotype, maturation stage and DNA ploidy of CD41+cells were examined from day 0 to day 12 in culture. 1) TPO stimulated the proliferation of fetal liver (FL)-derived CD34+ cells with a mean 73.14-fold increase of CD41+ cells after 12 d in culture. Adult BM-derived CD34+ cells increased only slightly, with a mean 8.18-fold increase of CD41+ cells. 2) Although the membrane phenotype of both FL CD34+ -derived MKs and BM CD34+ -derived MKs analyzed with CD41a, CD42a, CD61 and CD34 were similar, all FL CD34+ -derived MKs were in maturation stage I and II and in low ploidy (<4N) class. By comparison, BM CD34+ MKs possessed 15% MKs in maturation stage III and IV and with 23% MKs in high ploidy class (>4N). 3) Most of cultured FL-derived CD34+ cells did not have a well developed demarcation system (DM) and numerous ,-granules after 12 d incubation. von Willebrand factor (vWF) appeared earlier on the cultured BM-derived CD34+ cells than on FL-derived CD34+ cells. 4) The expression of both cyclin E and cyclin B1 progressively increased in FL CD34+cells induced by TPO during 12 d in culture. 5) The expression of cyclin D1 gradually decreased in FL CD34+cells induced by TPO over 12 d incubation. 6) Immunocytochemical analysis showed that cyclin D3 was detected only in cytoplasm of cultured FL-derived CD34+ cells, whereas in both cytoplasm and nuclei of cultured BM-derived CD34+ cells. These data suggest that FL-derived CD34+ cells contain a high proportion of immature megakaryocytic progenitor cells. It further suggests that TPO can push these progenitor cells into proliferation by upregulating the expression of cyclins B1 and E, and drive a high proportion of cells into megakaryocytic lineage. [source] New taxonomic concepts for the important forest pathogen Cryphonectria parasitica and related fungiFEMS MICROBIOLOGY LETTERS, Issue 2 2006Marieka Gryzenhout Abstract Species of Cryphonectria include some of the world's most important and devastating tree pathogens. Largely through the application of DNA sequence phylogenies, the taxonomy of these fungi has undergone major changes in recent years. Cryphonectria, including the chestnut blight pathogen Cryphonectria parasitica, has been restricted to species that have semi-immersed stromata, orange and pulvinate conidiomata, and one-septate ascospores. Other species of Cryphonectria with different morphological characteristics have been transferred to new genera that are strongly supported by phylogenetic data. This review represents a summary of the taxonomic changes to species of Cryphonectria sensu lato, and we discuss the impact that these changes might have on the understanding of their ecology, pathology and worldwide distribution. [source] Comparative study and molecular characterization of ectomycorrhizas in Tilia americana and Quercus pubescens with Tuber brumaleFEMS MICROBIOLOGY LETTERS, Issue 1 2002G Giomaro Abstract Mycorrhizas of Tuber brumale on Quercus pubescens and Tilia americana were obtained in vitro using micropropagated plantlets. Mycelium pure cultures were used for inoculation. Both the mycelium used for the inoculations, as well as the mycorrhizas which were obtained, were identified using several molecular approaches: analysis of the ITS region, polymerase chain reaction (PCR) specific primers and sequencing. The mycorrhizas were described from a morphological standpoint. Some of their biometric characteristics were different in bass-wood than they were in oak, thus showing the influence of the host plant on several of the morphological features believed to be necessary for the identification of the species. Considering the variability of their morphological characteristics, molecular analysis proved to be a necessary tool for the recognition of the mycorrhizas of Tuber spp. [source] Sirococcus shoot blight on Picea spinulosa in BhutanFOREST PATHOLOGY, Issue 1 2007T. Kirisits Summary During a recent survey of forest tree diseases in Western and Central Bhutan, Sirococcus shoot blight and an associated Sirococcus sp. were found on saplings and mature trees of Eastern Himalayan spruce (Picea spinulosa). Based on morphological characteristics and DNA sequence comparisons of the ITS region of the rDNA operon, representative isolates from Bhutan were unequivocally identified as Sirococcus conigenus. The DNA sequence data also showed that these isolates belong to the P group of S. conigenus. To our best knowledge, this is the first report of Sirococcus shoot blight from the Himalayas or any other part of Asia. Sirococcus conigenus does not appear to cause dramatic damage at the moment, but this fungus has the potential to cause severe disease problems on P. spinulosa in Bhutan. [source] A combination of baiting and PCR techniques for the detection of Phytophthora quercina and P. citricola in soil samples from oak standsFOREST PATHOLOGY, Issue 2 2001Nechwatal A description is given of the use of a combination of polymerase chain reaction (PCR) and baiting techniques for the specific detection of Phytophthora quercina and Phytophthora citricola from soil around declining oak trees. The soil was flooded with water and subjected to a specific baiting procedure using Quercus robur leaflets as baits. Single round or nested PCR, respectively, with species-specific primers allowed the detection of P. quercina and P. citricola in infected oak leaflets used as baits and in the water from the same bait tests. PCR detection of both fungi was also possible after soil samples had been thoroughly mixed with water and the floating organic debris had been collected. Phytophthora quercina and P. citricola could be readily detected in almost every case in the water from these tests by PCR but less frequently in the organic debris. The identities of P. quercina and P. citricola were confirmed by restriction digests of the corresponding PCR amplicons. The presence of both fungi was also confirmed in parallel in soil samples tested by baiting with oak leaflets. Nested PCR with the primers used allowed the detection of as few as five zoospores of P. citricola and 300 zoospores of P. quercina in a volume of 100 ,l. The methods presented here allow detection and identification of species of Phytophthora in soil without the need for direct extraction of soil samples, and without specific knowledge of the morphological characteristics of the genus. Détection de Phytophthora quercina et de P. citricola dans le sol de chênaies par une méthode combinant le piégeage et la PCR L'article décrit la détection spécifique de Phytophthora quercina et de P. citricola dans le sol prélevé autour de chênes dépérissants, par une méthode combinant les techniques de piégeage et de PCR. Le sol a été immergé dans l'eau et soumis à la procédure du piégeage avec de très jeunes feuilles de Quercus robur. Une amplification par PCR simple ou par PCR gigogne, respectivement, avec des amorces spécifiques des espèces ont permis de détecter P. quercina et P. citricola dans les feuilles-piège infectées, et dans l'eau de piégeage. La détection des deux champignons par PCR a aussi été possible après que les échantillons de sol aient été soigneusement mélangés à de l'eau et que les débris organiques aient été collectés. Phytophthora quercina et P. citricola ont pu être facilement détectés par PCR dans presque tous les cas dans l'eau de piégeage, mais moins fréquemment dans les débris organiques. L'identité de P. quercina et de P. citricola a été confirmée par les profils de restriction des amplifiats obtenus. La présence des deux champignons a aussi été confirmée en parallèle dans des échantillons de sol par piégeage. L'amplification par PCR gigogne avec les amorces utilisées a permis la détection de seulement 5 zoospores de P. citricola et 300 zoospores de P. quercina, dans un volume de 100 ,l. Les méthodes présentées ici permettent la détection et l'identification des espèces de Phytophthora dans le sol en évitant l'extraction directe d'ADN du sol, et sans connaissances spécifiques sur les caractéristiques morphologiques du genre. Eine Kombination von Köder- und PCR-Techniken zum Nachweis von Phytophthora quercina und P. citricola in Bodenproben von Eichenstandorten Es wird der spezifische Nachweis von Phytophthora quercina und P. citricola in Bodenproben von absterbenden Eichen mit Hilfe einer Kombination von PCR- und Baiting-Methoden beschrieben. Die Bodenproben wurden mit Wasser geflutet und Baiting-Tests unterzogen, bei denen junge Blättchen von Quercus robur als Köder zum Einsatz kamen. Einfache oder nested PCR-Reaktionen mit artspezifischen Primern erlaubten den Nachweis von P. quercina und P. citricola in den infizierten Eichenblättchen aus diesen Tests und im jeweiligen ,Baiting-Wasser'. Der PCR-Nachweis beider Erreger war auch möglich, wenn Bodenproben gründlich mit Wasser gemischt wurden, das aufgeschwemmte organische Material abgesammelt und das Wasser abgenommen wurde. P. quercina und P. citricola wurden dabei in nahezu allen Fällen im Wasser, jedoch weniger regelmäßig im organischen Material nachgewiesen. Die Identität der betreffenden Arten wurde zusätzlich durch Restriktions-Analysen der entsprechenden Amplicons bestätigt. Außerdem wurde die Anwesenheit beider Arten in den untersuchten Bodenproben durch klassische Baiting-Methoden nachgewiesen. Nested PCR mit den verwendeten Primerpaaren erlaubte den Nachweis von nur 5 Zoosporen von P. citricola und 300 Zoosporen von P. quercina in einem Gesamt-Volumen von 100 ,l. Die beschriebenen Methoden ermöglichen Nachweis und Identifizierung von Phytophthora-Arten in Bodenproben, ohne die Notwendigkeit einer direkten Extraktion des Bodens und ohne weitreichende Kenntnis der morphologischen Merkmale der Arten dieser Gattung. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||