Discrete Areas (discrete + area)

Distribution by Scientific Domains


Selected Abstracts


Intracardiac echogenic focus and fetal outcome

JOURNAL OF CLINICAL ULTRASOUND, Issue 9 2010
Geetika Gupta MS
Abstract Background To study the outcome of the fetuses with intracardiac echogenic focus (ICEF). Methods All patients who were found to have one or more ICEF on sonographic (US) examination at our center from January 2007 through January 2009 were included in this retrospective study. ICEF was defined as a discrete area of echogenicity noted in the left or right ventricle, which was as bright as bone. Patients were followed up to know pregnancy outcome. Results Of 762 fetuses evaluated by US, 48 (6.3%) were found to have an ICEF. Thirty-one of these 48 fetuses had an isolated ICEF; 11 had associated major malformations, and the remaining 6 had no major US abnormalities but were found to have other soft markers. Invasive prenatal testing was done in 21 cases for risk factors other than ICEF and was found to be abnormal in two cases. Seven pregnancies were terminated due to associated major malformations. Conclusion The prevalence of ICEF was 6.3%. Of 31 fetuses with an isolated ICEF, outcomes of 28 fetuses are known and all neonates were reported to be normal at birth. Thus we infer that the presence of an isolated ICEF has no adverse effect on outcome of the neonate. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010 [source]


A LIKELIHOOD FRAMEWORK FOR INFERRING THE EVOLUTION OF GEOGRAPHIC RANGE ON PHYLOGENETIC TREES

EVOLUTION, Issue 11 2005
Richard H. Ree
Abstract At a time when historical biogeography appears to be again expanding its scope after a period of focusing primarily on discerning area relationships using cladograms, new inference methods are needed to bring more kinds of data to bear on questions about the geographic history of lineages. Here we describe a likelihood framework for inferring the evolution of geographic range on phylogenies that models lineage dispersal and local extinction in a set of discrete areas as stochastic events in continuous time. Unlike existing methods for estimating ancestral areas, such as dispersal-vicariance analysis, this approach incorporates information on the timing of both lineage divergences and the availability of connections between areas (dispersal routes). Monte Carlo methods are used to estimate branch-specific transition probabilities for geographic ranges, enabling the likelihood of the data (observed species distributions) to be evaluated for a given phylogeny and parameterized paleogeographic model. We demonstrate how the method can be used to address two biogeographic questions: What were the ancestral geographic ranges on a phylogenetic tree? How were those ancestral ranges affected by speciation and inherited by the daughter lineages at cladogenesis events? For illustration we use hypothetical examples and an analysis of a Northern Hemisphere plant clade (Cercis), comparing and contrasting inferences to those obtained from dispersal-vicariance analysis. Although the particular model we implement is somewhat simplistic, the framework itself is flexible and could readily be modified to incorporate additional sources of information and also be extended to address other aspects of historical biogeography. [source]


Oral myofibromatosis: an unusual cause of gingival overgrowth

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2002
Case report, review of the literature
Abstract Background:, This case report describes a rare benign tumour, which presented as discrete areas of gingival hyperplasia affecting both the mandible and the maxilla. Method:, Surgical excision of the lesions was carried out under local anaesthetic. Histopathological examination confirmed the diagnosis of oral myofibromatosis. Results: The condition responded to surgical excision and appears to have limited growth potential. It affects a wide spectrum of ages and can be alarming due to rapid enlargement and ulceration, so careful diagnosis is important to avoid unnecessary aggressive treatment. Zusammenfassung Orale Myofibromatose: eine ungewöhnliche Ursache einer gingivalen HyperplasieFallbericht und Literaturüberblick Hintergründe: In dem vorliegenden Fallbericht wird ein seltener benigner Tumor, der sich als klar abgegrenzte Bereiche einer gingivalen Hyperplasie darstellte und durch den sowohl Mandibula als auch Maxilla betroffen waren, beschrieben. Methodik: Unter lokaler Betäubung wurde eine operative Exzision der Läsionen vorgenommen. Eine histopathologische Untersuchung bestätigte die Diagnose einer oralen Myofibromatose. Ergebnisse: Die Erkrankung sprach auf die operative Exzision an und scheint lediglich über begrenztes Wachstumspotential zu verfügen. Eine breites Spektrum an Altergruppen ist betroffen und die Störung kann aufgrund einer rapiden Vergrösserung und Ulzerierung alarmierend sein. Um unnötige aggressive Therapien zu vermeiden ist eine sorgfältige Diagnose erforderlich. Résumé Myofibromatose buccale : une cause inhabituelle d'hypertrophie gingivale. Rapport d'un cas et revue de la littérature Les myofibromatoses sont des néoplasmes bénins rares qui peuvent se présenter soit de maničre solitaire soit en lésions multiples. Un diagnostic attentif de cette tumeur bénigne est important pour éviter une thérapie aggressive non-nécessaire. Avec un traitement chirurgical conservateur, le pronostic est excellent. [source]


Serotonergic and Catecholaminergic Interactions with Co-Localised Dopamine-Melatonin Neurones in the Hypothalamus of the Female Turkey

JOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2009
S. W. Kang
Serotonin and catecholamines (dopamine, norepinephrine, epinephrine) have important roles as neurotransmitters in avian reproduction, but their anatomical relationship to the neuroendocrine circuitry that regulates reproduction is poorly understood. Our previous studies have shown that co-localised dopamine-melatonin (DA-MEL) neurones in the avian premammillary nucleus (PMM) are active during periods of photoresponsiveness and, therefore, are potentially photosensitive neurones. Because serotonergic and catecholaminergic neurotransmitters are important regulators of reproductive function in the female turkey, we hypothesised that the serotonergic/catecholaminergic neurones within the brainstem might interact with PMM DA-MEL neurones and constitute an important circuit for reproductive function. To examine this possible interaction, the retrograde fluorescent tract tracer, 1,1,dioctadecyl-3,3,3,3,-tetramethyleindocarbocyanine perchlorate (DiI) was injected into the PMM, and combined with serotonin, tyrosine hydroxylase (TH), dopamine ,-hydroxylase (DBH) and phenyl N -methyltransferse (PNMT) immunocytochemistry to reveal neuroanatomical connections. Changes in the activities of serotonergic, dopaminergic, adrenergic and noradrenergic neuronal systems projecting to the PMM were measured at different reproductive states with in situ hybridisation (ISH) techniques, using tryptophan hydroxylase 2 (TPH2) and TH mRNA expression, respectively. Cells labelled with DiI were found in anatomically discrete areas in or near the hypothalamus and the brainstem. Double immunocytochemistry confirmed that there were serotonin, DBH and PNMT fibres in close apposition to DA-MEL neurones. TPH2 mRNA expression in serotonin neurones was found in several nuclei, and its most abundant mRNA expression was seen in the nucleus Locus ceruleus of laying and incubating hens. TH mRNA expression levels in the six catecholaminegic areas labelled with DiI was measured across the different reproductive states. In the nucleus tractus solitarius (adrenergic), the highest level of TH mRNA expression was found in photorefractory hens and the lowest level in incubating hens. These observed patterns of serotonin/catecholamine neuronal distribution and their variable interactions with PMM DA-MEL neurones during different reproductive states may offer a significant neuroanatomical basis for understanding the control of avian reproductive seasonality. [source]


Victorian Psychology and the Novel

LITERATURE COMPASS (ELECTRONIC), Issue 3 2008
Anne Stiles
Over the last three decades, literary critics have evinced growing interest in nineteenth-century psychology and its reciprocal relationship with the Victorian novel. The resulting body of interdisciplinary scholarship has yielded insight into how early and mid-Victorian psychological movements (moral management, associationism, evolutionary psychology, and so forth) left their mark on realist authors like George Eliot and writers of sensation fiction such as Wilkie Collins or Mary Elizabeth Braddon. But these scholarly works have dealt less comprehensively with the psychological significance of late Victorian genres like the romance and neo-Gothic novel. Moreover, literary critics are only beginning to explore the ways in which psychology subtly shaded into physiology during the late Victorian era. This materialist shift was felt most strongly after 1870, when cerebral localization experiments by David Ferrier, John Hughlings Jackson, and other neurologists linked specific emotions, faculties, and movements to discrete areas of the brain. These experiments suggested that human behavior amounted to the sum of various neurochemical impulses, a conclusion that raised hackles because it threatened cherished notions of the soul, will, and individual identity. Literary scholars have only recently discussed the ways in which late Victorian novels engaged with these unsettling neurological discoveries. Based on the early promise of these discussions, we might expect to see more work on Victorian brains than Victorian psyches in future literary criticism. [source]


A lethal ovitrap-based mass trapping scheme for dengue control in Australia: II.

MEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2009
Impact on populations of the mosquito Aedes aegypti
Abstract. In Cairns, Australia, the impacts on Aedes aegypti L. (Diptera: Culicidae) populations of two types of ,lure & kill' (L&K) lethal ovitraps (LOs), the standard lethal ovitrap (SLO) and the biodegradable lethal ovitrap (BLO) were measured during three mass-trapping interventions. To assess the efficacy of the SLO, two interventions (one dry season and one wet season) were conducted in three discrete areas, each lasting 4 weeks, with the following treatments: (i) SLOs (>200 traps, ,4/premise), BG-sentinel traps (BGSs; ,15, 1/premise) and larval control (container reduction and methoprene treatment) and (ii) larval control alone, and (iii) untreated control. Female Ae. aegypti populations were monitored for 4 weeks pre- and post-treatment in all three areas using BGSs and sticky ovitraps (SOs) or non-lethal regular ovitraps (ROs). In the dry season, 206 SLOs and 15 BGSs set at 54 and 15 houses, respectively, caught and killed an estimated 419 and 73 female Ae. aegypti, respectively. No significant decrease in collection size of female Ae. aegypti could be attributed to the treatments. In the wet season, 243 SLOs and 15 BGSs killed ,993 and 119 female Ae. aegypti, respectively. The mean number of female Ae. aegypti collected after 4 weeks with SOs and BGSs was significantly less than the control (LSD post-hoc test). The third mass-trapping intervention was conducted using the BLO during the wet season in Cairns. For this trial, three treatment areas were each provided with BLOs (>500, ,4/premise) plus larval control, and an untreated control area was designated. Adult female Ae. aegypti were collected for 4 weeks pre- and post-treatment using 15 BGSs and 20 SOs. During this period, 53.2% of BLOs contained a total of 6654 Ae. aegypti eggs. Over the intervention period, collections of Ae. aegypti in the treatment areas were significantly less than in the control area for BGSs but not SOs. An influx of relatively large numbers of young females may have confounded the measurement of changes in populations of older females in these studies. This is an important issue, with implications for assessing delayed action control measures, such as LOs and parasites/pathogens that aim to change mosquito age structure. Finally, the high public acceptability of SLOs and BLOs, coupled with significant impacts on female Ae. aegypti populations in two of the three interventions reported here, suggest that mass trapping with SLOs and BLOs can be an effective component of a dengue control strategy. [source]


Changes in central steroid receptor expression, steroid synthesis, and dopaminergic activity related to the reproductive cycle of the ring dove

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2001
Robert W. Lea
This review examines possible neural mechanisms involved in the expression of parental behavior in the ring dove, Streptopelia risoria. This avian species has proved an excellent animal model for studies concerning endocrine-behavior interactions for many years. Studies were performed to localize the expression of central androgen and progesterone receptor in both sexes. Expression of androgen receptor (androgen receptor immunoreactivity, AR-ir) was widespread but increased, similarly in both sexes, with increasing day-length. Progesterone receptor-immunoreactivity (PR-ir) was more localized in several discrete areas of the hypothalamus. Similarly, no sex differences were observed in PR-ir, and expression increased in birds maintained on long days. AR-ir demonstrated dramatic changes over the breeding cycle, being greatest in courting birds and almost undetectable in parenting birds of both sexes brooding their young. PR-ir showed a differential expression over the breeding cycle relative to its hypothalamic localization. PR-ir decreased in the tuberal hypothalamic area in brooding birds of both sexes; whereas in the preoptic area, PR-ir was maintained. Significant increases in dopaminergic activity during the parenting phase of the breeding cycle occurred in specific neural regions including the PVM and DMA. Studies demonstrated the ability of the diencephalon of both sexes of the ring dove brain to synthesize progesterone, with indications that in the male brooding dove, synthesis is increased. Finally, a model is presented that proposes a mechanism whereby these central systems may interact to result in the expression of full parental behavior in both sexes of the ring dove. Microsc. Res. Tech. 55:12,26, 2001. © 2001 Wiley-Liss, Inc. [source]


Infection of Arabidopsis thaliana leaves with Albugo candida (white blister rust) causes a reprogramming of host metabolism

MOLECULAR PLANT PATHOLOGY, Issue 2 2000
Hsueh-Mei Chou
Albugo candida (Pers.) (O.) Kunze is a biotrophic pathogen which infects the crucifer Arabidopsis thaliana (L.) Heynh forming discrete areas of infection. Eight days after inoculation of leaves, white blisters became visible on the under surface of the leaf although no symptoms were apparent on the upper surface. By day 14, the region of leaf invaded by fungal mycelium had become chlorotic. Recently it has been hypothesized that an accumulation of soluble carbohydrates, following an increase in invertase activity, may trigger sugar signal transduction pathways leading to the repression of photosynthetic gene expression and to the induction of defence proteins. This hypothesis was investigated by quantifying localized changes in carbohydrate and photosynthetic metabolism and the expression of genes encoding photosynthetic and defence proteins. Quantitative imaging of chlorophyll fluorescence revealed that the rate of photosynthesis declined progressively in the invaded regions of the leaf. However, in uninfected regions of the infected leaf the rate of photosynthesis was similar to that measured in the control leaf until late on during the infection cycle when it declined. Images of nonphotochemical fluorescence quenching (NPQ) suggested that the capacity of the Calvin cycle had been reduced in infected regions and that there was a complex metabolic heterogeneity within the infected leaf. A. candida also caused localized changes in the carbohydrate metabolism of the leaf; soluble carbohydrates accumulated in the infected region whereas the amount of starch declined. The reverse was seen in uninfected regions of the infected leaf; carbohydrates did not accumulate until late on during infection and the amount of starch increased as the infection progressed. There was an increase in the activity of invertases which was confined to regions of the leaf invaded by the fungal mycelium. The increase in apoplastic invertase activity was of host origin, as mRNA levels of the AT,FRUCT1 gene (measured by semiquantitative RT-PCR) increased 40-fold in the infected region. The increase in soluble invertase activity resulted from the appearance of a new isoform in the invaded region of the leaf. Current evidence suggests that this was of fungal origin. Northern blot analysis of cab and rbcS showed that photosynthetic gene expression was repressed in the infected leaf from 6 days after inoculation (DAI) when compared to control leaves. In contrast, there was no detectable induction of defence proteins in the infected leaf. These data are discussed in the context of the sugar-sensing hypothesis presented above. [source]


Magnetic resonance imaging as a tool to examine the neuropathology of multiple sclerosis

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2004
L. Bö
Magnetic resonance imaging (MRI) has significantly extended the understanding of multiple sclerosis (MS), owing to its ability to sensitively depict the dynamics of the disease process in vivo. The subject of this review is the use of MRI in the post-mortem setting, with emphasis on how it may be used to improve the specimen selection process at autopsy. Lesions with active demyelination are highly interesting in the study of MS pathogenesis, but are rare in a typical autopsy material of chronic MS. The yield of MS lesions in autopsy specimen selection can be increased by the use of MRI-guided tissue sampling, as a significant proportion of abnormalities detected by post-mortem MRI are not macroscopically visible/palpable. The majority of these MRI abnormalities have been found to represent either discrete areas of microglial activation with no demyelination (so-called (p)reactive lesions), or active demyelinating MS lesions by further histopathological examination. The presence and extent of MS pathology outside of the focal demyelinated lesions is more readily appreciated by MRI-guided specimen sampling, as has been shown in the study of extensive areas of partial myelin loss in the spinal cord. A further advantage of MRI-guided specimen sampling is the ability to use three-dimensional and quantitative measures. The potential of correlating these with histopathological data may be further exploited in the future. The technical procedure for MRI-guided tissue sampling at autopsy is presented, and the limitations of the technique are discussed. [source]


Porokeratotic Eccrine Ostial and Dermal Duct Nevus

PEDIATRIC DERMATOLOGY, Issue 5 2006
M.B.Ch.B., M.R.C.P., R. B. Warren B.Sc.
We describe a 6-year-old boy who had the typical palmar involvement and small discrete areas involving the midline of his back. [source]