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Diffuse
Terms modified by Diffuse Selected AbstractsSeverity of cerebral white matter lesions and infarcts in patients with transient or moderately disabling cerebral ischaemia: reproducibility of grading by neurologistsEUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2006E. L. L. M. De Schryver Diffuse or multifocal ischaemic white matter lesions increase the risk of intracranial haemorrhage in patients using oral anticoagulants for secondary prevention after cerebral ischaemia of arterial origin. We studied whether neurologists could reliably assess the presence of these white matter abnormalities. As part of the European/Australian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT), the severity of white matter lesions and presence of ischaemic lesions were twice assessed in a consensus meeting of three neurologists (from a pool of nine) as absent, moderate or severe, in a sample of 126 randomly selected CT or MRI scans. The neurologists were not aware of the duplicate grading. The degree of agreement between the first and second observation was calculated with kappa statistics. The kappa value for agreement between the first and second assessment of white matter lesions was 0.58 (95% CI 0.40,0.76). The kappa value for the presence of clinically relevant and/or irrelevant ischaemic lesions was 0.68 (95% CI 0.58,0.78). Clinicians can assess the presence of white matter lesions with sufficient reliability. Such assessment may prevent unnecessary risk with oral anticoagulation in secondary prevention after cerebral ischaemia of arterial origin, of which the efficacy is currently being assessed in ESPRIT. [source] Plasmablastic lymphomas with light chain restriction , plasmablastic extramedullary plasmacytomas?JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2010Sonja C. Boy J Oral Pathol Med (2010) 39: 435,439 Background:, It is diagnostically difficult to differentiate plasmablastic lymphomas (PBLs) from plasma cell neoplasms with plasmablastic differentiation. Plasmablastic lymphomas are currently classified as ,PBL of the oral mucosa' and ,PBL with plasmacytic differentiation'. Methods:, Forty-five cases of PBL were retrieved from the Departments of Oral Pathology of the Universities of Pretoria and Limpopo, South Africa. Clinical features and HIV status were recorded and each case was classified as ,PBL of the oral mucosa type' or as ,PBL with plasmacytic differentiation'. Immunohistochemistry included: CD45, CD3, CD20, CD79a, CD38, CD138, MUM1, Ki-67 and kappa and lambda light chains. Positivity was recorded based on the percentage of positive staining cells as focal (5,20%); intermediate (20,70%) or diffuse (>70%). In situ hybridization was performed for Epstein,Barr virus (EBV) and HHV-8. Results were recorded as positive or negative. Results:, All cases showed some degree of plasmacytic differentiation. All were negative for CD20 with reactive T cells detected with CD3. Diffuse and strong positive staining was found with Ki-67 and MUM1, but variable immunoreactivity was found with CD79a, CD45, CD38 and CD138. Twenty cases (47%) showed light chain restriction. Epstein,Barr virus was detected in 44/45 cases and HHV-8 in none. Conclusions:, The morphological classification of PBLs is not valid as all cases showed some degree of plasmacytic differentiation. We propose that PBLs with light chain restriction be reclassified as ,plasmablastic extramedullary plasmacytomas' and managed accordingly. The rest represents true PBLs. The true nature of these neoplasms as an entity should be further investigated with molecular and genetic studies. [source] Protein partitioning and transport in supported cationic acrylamide-based hydrogelsAICHE JOURNAL, Issue 5 2003Shawn M. Russell The partitioning and transport of myoglobin in cationic, acrylamide-based hydrogels are studied by a microscopic visualization method. Homogeneous cationic gels are synthesized inside fused-silica capillaries with a square section, which allow a direct determination of protein concentration profiles during transient adsorption and desorption. Diffuse, self-similar profiles are observed and used to determine the equilibrium protein binding capacity and the protein diffusivity in the gel. Mass-transfer rates are found to be essentially independent of the external solution concentration, but to vary dramatically with the gel polymer concentration. A Fickian diffusion model with a flux based on the adsorbed-phase concentration gradient is consistent with the experimentally determined concentration profiles for both positive and negative protein concentration steps. The equilibrium and rate parameters determined for the capillary-supported gels also compare favorably with those obtained from macroscopic measurements using composite ion-exchange media comprising similar gels held within the pores of porous silica particles. [source] Diffuse scattering from large-angle, thermally induced, orientational disorder in molecular crystalsACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2007John Reid Large-angle rotational motion (libration) characteristic of molecular solids has not been properly included in many scattering calculations because of the need to develop scattering theory through small-angle approximations. A simple but effective approach to calculating the influence of large-angle librations on the thermal disorder scattering given by molecular solids is to treat the molecules as independent librators, each in a harmonic potential well, using the mathematics appropriate for large-angle rotations. The resulting probability distribution for angular misorientations is Gaussian and this distribution can be used to smear the molecular form factor, enabling the librational influence on the scattering to be calculated. It is shown how to apply this direct approach quite generally and by way of examples the technique is used with the molecular solids sulfur hexafluoride (SF6), adamantane (C10H16) and buckminsterfullerene (C60). For these materials, the molecular Fourier transform (i.e. the molecular form factor) have been calculated in selected planes in reciprocal space, followed by the separate effects of librational and translational smearing. It is found that the librational smearing produces a large effect on the form factor, particularly at larger scattering vectors, that is not sensitive to approximations in the argument. Additionally, the Debye,Waller effect of vibrational motion is included in the calculations, showing quantitatively the decreasing influence of vibrations on the scattering with increasing scattering vector. Both effects illustrate with pedagogic clarity how different processes modify the basic molecular scattering. [source] Focal C4d+ in Renal Allografts Is Associated with the Presence of Donor-Specific Antibodies and Decreased Allograft SurvivalAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009R. L. Kedainis Diffuse peritubular capillary C4d deposition in renal allograft biopsies is associated with donor-specific antibodies (DSA) and graft failure. The significance of focal C4d+ is unclear. We reviewed 368 biopsies from 301 patients performed for renal dysfunction or proteinuria over 5 years. Diffuse C4d+, focal C4d+ and C4d- detected by immunofluorescence occurred in 9.5%, 20.9% and 69.4% of biopsies, respectively. Patients were similar in gender, age, cause of renal disease, donor source, HLA mismatch, serum creatinine at baseline and interval from transplantation to biopsy. Diffuse and focal C4d+ were associated with acute cellular rejection (p < 0.001). Transplant glomerulopathy was associated with diffuse C4d+. DSA at the time of biopsy, were positive in 79.3% of diffusely C4d+ patients, 68.8% of those with focal C4d+ (p = 0.27) and 9.9% of patients with C4d- (p < 0.001, compared to either the focal or diffuse groups, respectively). Allograft survival at 40 months was lower in diffuse C4d+ compared to the C4d- group (p = 0.014), but not when compared to the focal C4d+ group. There was a clear trend toward worse graft survival in patients with focal C4d+ in this time interval, but focal C4d+ compared to both diffuse C4d+ and C4d-groups was not statistically significant (p = 0.08). [source] Diffuse (anergic) cutaneous leishmaniasis responding to amphotericin BCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 4 2010B. Morrison Summary American cutaneous leishmaniasis is an important endemic zoonotic disease in the New World that comprises a spectrum of clinical manifestations. Diffuse cutaneous leishmaniasis (DCL) is a rare form of the disease characterized by antigen-specific immunodeficiency that often presents with multiple disfiguring non-ulcerated confluent nodules or plaques that involve large areas of the skin, resembling lepromatous leprosy. Relapse is invariable in advanced stages, despite aggressive chemotherapy, and a plethora of drugs has been tested with unchanging results. We report on a severe an exceptional case that resolved after treatment with amphotericin B, a drug considered only mildly effective, and discuss the therapeutic approach to this disease. [source] Incremental Updates for Rapid Glossy Global IlluminationCOMPUTER GRAPHICS FORUM, Issue 3 2001Xavier Granier We present an integrated global illumination algorithm including non-diffuse light transport which can handle complex scenes and enables rapid incremental updates. We build on a unified algorithm which uses hierarchical radiosity with clustering and particle tracing for diffuse and non-diffuse transport respectively. We present a new algorithm which chooses between reconstructing specular effects such as caustics on the diffuse radiosity mesh, or special purpose caustic textures, when high frequencies are present. Algorithms are presented to choose the resolution of these textures and to reconstruct the high-frequency non-diffuse lighting effects. We use a dynamic spatial data structure to restrict the number of particles re-emitted during the local modifications of the scene. By combining this incremental particle trace with a line-space hierarchy for incremental update of diffuse illumination, we can locally modify complex scenes rapidly. We also develop an algorithm which, by permitting slight quality degradation during motion, achieves quasi-interactive updates. We present an implementation of our new method and its application to indoors and outdoors scenes. [source] Singlet states open the way to longer time-scales in the measurement of diffusion by NMR spectroscopyCONCEPTS IN MAGNETIC RESONANCE, Issue 1 2008Simone Cavadini Abstract Nuclear magnetic resonance is a powerful nonintrusive technique for measuring diffusion coefficients through the use of pulsed field gradients. The main limitation to the application range of this method is imposed by the relaxation time constants of the magnetization. The recently introduced singlet-state spectroscopy affords obtaining relaxation time constants for pairs of coupled spins which can be longer by more than an order of magnitude than the spin-lattice relaxation time constants. We review in this paper the advantages that are offered by these long relaxation time constants for diffusion measurements. Using experiments that combine singlet-state and diffusion spectroscopy, slower diffusion constants can be determined. The coupling of the two methods constitutes an alternative to the use of special probes equipped with strong gradients for the study of large molecules that diffuse slowly in solution. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 68,78, 2008. [source] P45 Neomycine sulfate patch testsCONTACT DERMATITIS, Issue 3 2004Bolli Bjarnason Objective:, The purpose of this study is to investigate if patients with neomycin sulfate allergy may develop test responses that are unclassifiable by commonly used assessment scales but which should be considered positive. Materials:, 16 patients who tested positive to neomycin sulfate patch tests are retested with different dose levels and application times. Test areas are assessed visually up to 11 days. Results:, Three types of reactions were observed. The first type was characterized by erythema and diffuse infiltrate. Some of these had in addition either discrete papules or both papules and vesicles on their surface. The second type of reaction initially developed large perifollicular papules which later developed into coalescent erythema and diffuse infiltrate. The third type of reaction exhibited perifollicular papules only which declined over time. This type was unclassifiable by commonly used assessment scales. All types of reactions were of clinical significance. Conclusion:, The results support that universal assessment scales for patch-test responses due to different test agents may be inappropriate for assessment of neomycin sulfate patch tests. The clinician should only consider assessment scales as an aid in the assessment of test responses and be aware that morphology of test responses may differ between test agents and test techniques. [source] The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smearsCYTOPATHOLOGY, Issue 1 2010M. Uke M. Uke, B. Rekhi, D. Ajit and N. A. Jambhekar The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smears Objectives:, A diagnosis in pulmonary onco-cytopathology primarily necessitates distinguishing small cell carcinoma (SCLC) from non-small cell carcinoma (NSCLC), which includes squamous cell carcinoma and adenocarcinoma. Lately, p63 antibody has been used for distinguishing squamous cell carcinoma from SCLC and adenocarcinoma. We present an analysis of p63 expression in cytological smears from 100 bronchial lavage specimens comprising 51 cases of SCLC and 49 cases of NSCLC. Methods:, A single Papanicolaou-stained conventional smear was de-stained and re-fixed with cold acetone and methanol for immunocytochemical staining with p63 antibody. Staining results were graded as 0 (nil), 1+ (focal), 2+ (moderate, diffuse) and 3+ (strong, diffuse). Results:, Out of 100 cases, 21 were cytologically diagnosed as squamous cell carcinoma. Twenty of these showed 2+ or 3+ p63 positivity, whereas one, which was adenocarcinoma on histology, showed 1+ staining. Of seven cases cytologically diagnosed as adenocarcinoma, six showed no p63 staining, whereas one, which was squamous cell carcinoma on histology, showed 1+ staining. All 48 cases cytologically diagnosed as SCLC were confirmed as such on histology and showed no p63 staining. Four cases were cytologically designated as poorly differentiated carcinomas, of which three showed no p63 staining and one showed 3+ staining. The former three were found to be SCLC on histology while the latter was squamous cell carcinoma. The remaining 20 cases were cytologically designated as NSCLC. Of these, eight showed no p63 staining, whereas 10 showed 1+ and two showed 2+ staining. The former eight were adenocarcinoma on histology and the latter two were squamous cell carcinoma. The 10 cases that showed 1+ p63 staining were adenocarcinomas (n = 5), squamous cell carcinoma (n = 4) and NSCLC, not otherwise specified (n = 1). Positive staining was seen in normal basal cells, which acted as an internal control. Overall sensitivity of p63 for squamous cell carcinoma was 100% and specificity was 90.4%. Conclusions:, p63 immunostaining on processed cytology smears can be used to help identify squamous cell carcinoma. Its diffuse expression was specific for squamous cell carcinoma while focal staining was also seen in adenocarcinoma. [source] Steps towards a centralized nervous system in basal bilaterians: Insights from neurogenesis of the acoel Symsagittifera roscoffensisDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2010Henrike Semmler Due to its proposed basal position in the bilaterian Tree of Life, Acoela may hold the key to our understanding of the evolution of a number of bodyplan features including the central nervous system. In order to contribute novel data to this discussion we investigated the distribution of ,-tubulin and the neurotransmitters serotonin and RFamide in juveniles and adults of the sagittiferid Symsagittifera roscoffensis. In addition, we present the expression pattern of the neuropatterning gene SoxB1. Adults and juveniles exhibit six serotonergic longitudinal neurite bundles and an anterior concentration of serotonergic sensory cells. While juveniles show an "orthogon-like" arrangement of longitudinal neurite bundles along the anterior-posterior axis, it appears more diffuse in the posterior region of adults. Commissures between the six neurite bundles are present only in the anterior body region of adults, while irregularly distributed individual neurites, often interconnected by serotonergic nerve cells, are found in the posterior region. Anti-RFamide staining shows numerous individual neurites around the statocyst. The orthogon-like nervous system of S. roscoffensis is confirmed by ,-tubulin immunoreactivity. In the region of highest neurotransmitter density (i.e., anterior), the HMG-box gene SrSoxB1, a transcription factor known to be involved in neurogenesis in other bilaterians, is expressed in juvenile specimens. Accordingly, SoxB1 expression in S. roscoffensis follows the typical pattern of higher bilaterians that have a brain. Thus, our data support the notion that Urbilateria already had the genetic toolkit required to form brain-like neural structures, but that its morphological degree of neural concentration was still low. [source] Abnormal venous and arterial patterning in chordin mutantsDEVELOPMENTAL DYNAMICS, Issue 9 2007Emmanuèle C. Délot Abstract Classic dye injection methods yielded amazingly detailed images of normal and pathological development of the cardiovascular system. However, because these methods rely on the beating heart of diffuse the dyes, the vessels visualized have been limited to the arterial tree, and our knowledge of vein development is lagging. In order to solve this problem, we injected pigmented methylsalicylate resins in mouse embryos after they were fixed and made transparent. This new technique allowed us to image the venous system and prompted the discovery of multiple venous anomalies in Chord,/, mutant mice. Genetic inactivation of Chordin, an inhibitor of the Bone Morphogenetic Protein signaling pathway, results in neural crest defects affecting heart and neck organs, as seen in DiGeorge syndrome patients. Injection into the descending aorta of Chrd,/, mutants demonstrated how a very severe early phenotype of the aortic arches develops into persistent truncus arteriosus. In addition, injection into the atrium revealed several patterning defects of the anterior cardinal veins and their tributaries, including absence of segments, looping and midline defects. The signals that govern the development of the individual cephalic veins are unknown, but our results show that the Bone Morphogenetic Protein pathway is necessary for the process. Developmental Dynamics 236:2586,2593, 2007. © 2007 Wiley-Liss, Inc. [source] Severity of personality disorders and suicide attemptACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009H. Blasco-Fontecilla Objective:, Severity of personality disorders (PDs) may be more useful in estimating suicide risk than the diagnosis of specific PDs. We hypothesized that suicide attempters with severe PD would present more attempts and attempts of greater severity/lethality. Method:, Four hundred and forty-six suicide attempters were assessed. PD diagnosis was made using the International Personality Disorder Questionnaire , Screening Questionnaire. PDs were classified using Tyrer and Johnson's classification of severity (no PD, simple PD, diffuse PD). Severity/lethality of attempts was measured with the Suicide Intent Scale, Risk-Rescue Rating Scale and Lethality Rating Scale. Results:, Attempters with severe (diffuse) PD had more attempts than the other groups. After controlling for age and gender, this difference remained significant only for the younger age group and women. There was no relationship between severity of PDs and severity/lethality of attempts. Conclusion:, Younger female attempters with severe PD are prone to repeated attempts. However, the severity of PD was not related to the severity/lethality of suicide attempts. [source] Acute encephalopathy with biphasic seizures and late restricted diffusion on MRI in a Japanese child living in the USADEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 9 2008David E Traul MD PhD We report an 18-month-old Japanese female living in the USA whose clinical course and radiographic findings were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). She was initially diagnosed with complex febrile seizures. However, on day 3 of admission, she had a cluster of complex partial seizures and the onset of a global developmental regression. In contrast to the normal magnetic resonance image of the brain obtained on admission, subsequent imaging demonstrated transient subcortical diffusion-weighted abnormalities in the white matter of the bilateral posterosuperior frontal, parietal, temporal, and occipital regions, with sparing of the perirolandic area. One year later, her developmental delay, although improved, persisted and she continued to experience sporadic seizures while being treated with topiramate monotherapy. Repeat imaging showed diffuse, poorly defined, increased T2 signals in the white matter of the posterosuperior frontal, parietal, temporal and occipital regions and diffuse cerebral volume loss. Previous reports of AESD have been limited to children aged under 4 years living in Japan. With the identification of this case, it is important that all physicians, not only those in Japan, who care for children with febrile seizures be aware of AESD and its associated neurological morbidity. [source] A shift from diffuse to focal cortical activity with developmentDEVELOPMENTAL SCIENCE, Issue 1 2006Sarah Durston Recent imaging studies have suggested that developmental changes may parallel aspects of adult learning in cortical activation becoming less diffuse and more focal over time. However, while adult learning studies examine changes within subjects, developmental findings have been based on cross-sectional samples and even comparisons across studies. Here, we used functional MRI in children to test directly for shifts in cortical activity during performance of a cognitive control task, in a combined longitudinal and cross-sectional study. Our longitudinal findings, relative to our cross-sectional ones, show attenuated activation in dorsolateral prefrontal cortical areas, paralleled by increased focal activation in ventral prefrontal regions related to task performance. [source] Effects of aminoguanidine and tolrestat on the development of ocular and renal structural changes in experimental diabetic ratsDIABETES OBESITY & METABOLISM, Issue 1 2002Ö. Azal Studies that researched the role of aminoguanidine and tolestat in the prevention of diabetic retinopathy and nephropathy resulted in conflicting data. We investigated the effects of these agents in the prevention of ocular and renal changes in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ in 30 rats. Ten rats that were not given STZ served as non-diabetic control (Group 1). Ten STZ-diabetic rats that were not given any treatment served as diabetic control (Group 2). Groups 3 and 4 were composed of STZ-induced diabetic rats (10 each) that were given tolrestat and aminoguanidine respectively. Eyes and kidneys were examined at the 24th week under electronmicroscopy. Cataract was observed in all six of the surviving rats in Groups 2 and 4, and in one of 6 surviving rats in group 3. Cataract development was lower in Group 3 than Groups 2 and 4. All retinal samples obtained from group 2 demonstrated a number of structural abnormalities, whereas there were no significant ultrastructural changes in groups 3 and 4. Groups 2 and 3 demonstrated mesangial proliferation and expansion, diffuse glomerular basement membrane (GBM) thickening, and focal GBM thickening in the bulb form. Group 4 demonstrated a normally appearing mesangial space, minimal diffuse but no focal GBM thickening. The urinary albumin excretion (UAE) was lower in Group 4 than the other groups. In conclusion, our results suggest that aminoguanidine may be an important agent for the prevention of renal changes, whereas tolrestat may be effective for the prevention of ocular changes in diabetes mellitus. [source] Cerebral cortical laminar necrosis on diffusion-weighted MRI in hypoglycaemic encephalopathyDIABETIC MEDICINE, Issue 8 2005Y. Yoneda Abstract Background Laminar necrosis of the cerebral cortex characterized neuropathologically by delayed selective neuronal necrosis occurs in hypoglycaemic encephalopathy and other brain diseases. Case report A 37-year-old male with insulin-treated Type 1 diabetes mellitus developed hypoglycaemic encephalopathy associated with respiratory failure. Brain diffusion-weighted MRI during the subacute period demonstrated high signals along the cerebral cortex. Brain single-photon emission computed tomography showed diffuse, severe cerebral hypoperfusion. The patient remained comatose and died 1 month later. Conclusions High signals along the cortical bands on diffusion-weighted MRI suggest cortical laminar necrosis, although a postmortem examination was unavailable. Sustained hypoglycaemic brain injury, possibly associated with respiratory hypoxia, may be the underlying mechanism. [source] ,-Methylacyl-CoA racemase (AMACR) in fine-needle aspiration specimens of prostate lesionsDIAGNOSTIC CYTOPATHOLOGY, Issue 11 2009Gordana Kai, M.D. Abstract The elevated expression of P504S gene and its product ,-methylacyl-CoA racemase (AMACR) can serve as a molecular marker for prostate cancer. The goal of this study is to investigate P504S/AMACR expression in fine-needle aspiration smears and correlate it with cytological diagnosis. Immunocytochemistry was performed in 35 patients with morphological diagnosis of prostate carcinoma (n = 16), atypia (n = 15), and benign hyperplasia (n = 4). Among 16 malignant cases there were two low-grade, eight intermediate, and six high-grade prostate carcinomas. Cytoplasmic positivity is analyzed qualitatively as predominantly diffuse or focal and quantitatively as <5%, 5,50%, and >50% of cells. Benign cases showed no P504S/AMACR expression. Positive staining was recorded in 75% of malignant cases, but in the majority of them it was weak and focal or diffuse and in a small amount of cells. The most intensive staining was seen in low-grade carcinomas and some atypical cases. This observation indicates a correlation between P504S/AMACR expression and differentiation of cells. P504S/AMACR staining might be of great value in cytodiagnosis of prostate lesions as well as an example of the characterization of cells at the molecular level using fresh tissue obtained by fine-needle aspiration. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source] Helicobacter Pylori and Precancerous Gastric LesionsDIGESTIVE ENDOSCOPY, Issue 3 2000Pham Quang Cu Background: To determine the relationship between Helicobacter pylori (H. pylori) infection and the precancerous gastric lesions: atrophic gastritis (AG) and intestinal metaplasia (IM) and dysplasia. Methods: A total of 347 dyspeptic patients, including 141 H. pylori -positive patients and 206 H. pylori -negative patients, were studied alongside age- and sex-matched controls. The patients underwent gastroscopy and endoscopic biopsy for detection of H. pylori, and histological examinations. Helicobacter pylori was detected by a urease test (CLO; Delta West; Bentley, Australia), by histology (H&E stain, Giemsa) and by serology (BioSig; BioMeditech, NJ, USA). Atrophic gastritis, IM and dysplasia were detected by histological examination (Giemsa, H&E stain). Results: There is a higher rate of atrophic gastritis in H. pylori -positive than in H. pylori -negative patients (46 vs 13.5%, odds ratio (OR) = 5.4; P < 0.01). Gastritis in H. pylori -positive patients also has a higher rate of activity than in H. pylori -negative patients. The rate of IM is higher in H. pylori -positive patients than in H. pylori -negative patients (35 vs 11%; OR = 4.3; P < 0.01). Metaplasia is more often diffuse in H. pylori -positive than in H. pylori -negative patients. Dysplasia is more common in H. pylori -positive than in H. pylori -negative patients (12 and 3.8%; OR = 3.3; P < 0.01). Conclusions: This study supports the suggestion of a relationship between H. pylori infection and precancerous gastric lesions. Wherever H. pylori is present, the precancerous lesions are more common and more severe. [source] Spatial dynamics of supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian OceanDIVERSITY AND DISTRIBUTIONS, Issue 1 2006K. L. AbbottArticle first published online: 19 DEC 200 ABSTRACT Key to the management of invasive species is an understanding of the scope of an invasion, the rate of proliferation and the rate at which invaded habitats become degraded. This study examines the spatial dynamics of high-density supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian Ocean, and the associated impacts at their boundaries. Since the early 1990s, A. gracilipes supercolonies have occupied over 30% of the 10,000 ha of rainforest on Christmas Island. Thirty-four discrete high-density supercolonies formed between 1989 and 2003, ranging in size across nearly three orders of magnitude from 0.9 to 787 ha. Supercolonies boundaries are diffuse, and ants were observed in low densities in some cases up to 200 m from the main high-density supercolony. The 13 boundaries examined were all dynamic over a 10,20 observation month period: nine boundaries expanded, and the maximum rate of spread was 0.5 m day,1. Across boundary transition zones, between high-density supercolonies and intact rainforest, yellow crazy ants reduced other ant species richness, occupied red crab burrows and killed resident red crabs, which was the trigger for ,invasional meltdown' on Christmas Island. The highly variable and unpredictable nature of A. gracilipes boundaries poses a challenge for incorporation into a predictive framework, as well as for their management. [source] Gully processes and gully dynamicsEARTH SURFACE PROCESSES AND LANDFORMS, Issue 14 2009M. J. Kirkby Abstract This synthetic review of gully morphology and genesis focuses on incised semi-permanent gully systems rather than on shallow ephemeral gullies. It examines the conditions for gully formation; a sharp step to initiate a headcut, a sufficiently low effective bedload fraction to evacuate eroded material, and the potential to maintain steep sidewalls, usually dominated by mass movement processes. Gully formation is also favoured by an indurated surface layer which maintains steep sideslopes, often with armouring material from the capping layer, and a sharp headcut which does not diffuse away. Two different approaches towards the areal modelling of gully system development agree in treating the ratio of advective (channel) to diffusive (sideslope) processes as a key determinant of the morphology of a gully system as it evolves. Implications for gully prevention and remediation are briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Turbulent flow over a dune: Green River, ColoradoEARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2005Jeremy G. Venditti Abstract Detailed echo-sounder and acoustic Doppler velocimeter measurements are used to assess the temporal and spatial structure of turbulent flow over a mobile dune in a wide, low-gradient, alluvial reach of the Green River. Based on the geometric position of the sensor over the bedforms, measurements were taken in the wake, in transitional flow at the bedform crest, and in the internal boundary layer. Spatial distributions of Reynolds shear stress, turbulent kinetic energy, turbulence intensity, and correlation coefficient are qualitatively consistent with those over fixed, two-dimensional bedforms in laboratory flows. Spectral and cospectral analysis demonstrates that energy levels in the lee of the crest (i.e. wake) are two to four times greater than over the crest itself, with minima over the stoss slope (within the developing internal boundary layer). The frequency structure in the wake is sharply defined with single, dominant peaks. Peak and total spectral and cross-spectral energies vary over the bedform in a manner consistent with wave-like perturbations that ,break' or ,roll up' into vortices that amalgamate, grow in size, and eventually diffuse as they are advected downstream. Fluid oscillations in the lee of the dune demonstrate Strouhal similarity between laboratory and field environments, and correspondence between the peak frequencies of these oscillations and the periodicity of surface boils was observed in the field. Copyright © 2005 John Wiley & Sons, Ltd. [source] Localization of deposited polycyclic aromatic hydrocarbons in leaves of PlantagoENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Martine I. Bakker Abstract After deposition to foliage, polycyclic aromatic hydrocarbons (PAHs) may remain on the leaf surface, accumulate in the cuticular wax, or diffuse into the remaining interior of the plant. In a field study, the location of deposited PAHs in the leaves of two Plantago species was determined. To this aim, leaves of Plantago major and Plantago media were divided into three fractions. First, the leaves were washed (wash-off fraction), then cuticular wax was extracted (wax fraction). Finally, the remaining leaf material was extracted (interior fraction). The presence of PAHs could be demonstrated in all three fractions. For both plants, the distribution of PAHs over the three fractions changed with molecular weight (mol wt) of the PAHs. The wash-off fraction increased with increasing molecular weight, likely because high molecular-weight PAHs occur predominantly bound to particles, which can be readily washed off from the leaves. In contrast, the amount of PAHs detected in the interior of the leaves decreased with increasing molecular weight. This can be explained by a slow desorption of the PAHs from the particles and a low diffusion rate of the larger molecules. This study shows that washing reduces the amount of high molecular-weight PAHs on plant surfaces. Therefore, washing of leafy vegetables is important to minimize human dietary intake of PAHs. [source] ,-[11C]methyl-L-tryptophan uptake in patients with periventricular nodular heterotopia and epilepsyEPILEPSIA, Issue 5 2008Jun Natsume Summary Background:,-[11C]methyl-L-tryptophan (,-MTrp) positron emission tomography (PET) is a promising tool in the localization of the epileptogenic area in selected group of focal epilepsy patients. Electrophysiological evidence suggests the involvement of the neocortex in periventricular nodular heterotopia (PVNH). Purpose: To determine whether ,-MTrp PET can detect neocortical changes in patients with PVNH. Methods: Four patients (2 male, mean age 28, range 23,35 years) with PVNH and intractable seizures were studied. The functional image in each patient was compared with those from 21 healthy controls (mean age 34.6 ± 14.2 years) by using statistical parametric mapping (SPM). The location of increased ,-MTrp uptake was compared with the location of the EEG focus. A significant cluster was defined as a cluster with a height p = 0.005 and an extent threshold 100. Results:,-MTrp PET revealed increased cortical uptake in two of four patients. The area of increased ,-MTrp uptake in one patient was widespread. In the other patient, the area of increased uptake did not include the region where most seizures were generated on EEG. ,-MTrp PET did not show increased uptake in the heterotopic nodules in any of the patients. Conclusions:,-MTrp PET suggests abnormal metabolism of tryptophan in the neocortex. The increased uptake may be diffuse and may not co-localize with the EEG focus. This preliminary study suggests that ,-MTrp PET may be useful, in conjunction with other evaluations, in localizing epileptic focus in patients with PVNH and refractory seizures. [source] The pathology of bronchointerstitial pneumonia in young foals associated with the first outbreak of equine influenza in AustraliaEQUINE VETERINARY JOURNAL, Issue 3 2008J. C. PATTERSON-KANE Summary Objectives: The aim of this study was to describe post mortem lesions in EIV-infected foals. Methods: Post mortem examinations were conducted on 11 young foals (age 2,12 days) submitted to the Scone Veterinary Hospital, New South Wales, Australia over a 2-month period in 2007. The foals had presented with or developed fatal pneumonia, and were known or suspected to be EIV-positive. Equine influenza virus nucleic acid was detected in tissue specimens using an influenza A group reactive real-time reverse transcriptase PCR assay. Results: Grossly there was diffuse or extensive pulmonary consolidation. Histological changes included: bronchiolar and alveolar necrosis; neutrophilic infiltration; hyaline membrane formation; and hyperplasia and squamous metaplasia of airway epithelium. Tissues for 10 foals were EIV-positive, with a positive nasal swab from the remaining animal. Conclusions: This is the first detailed pathological description of bronchointerstitial pneumonia associated with EIV infection in young foals. It is also the first series of such cases in which a causative agent has consistently been detected. Potential relevance: Given the findings in this outbreak, and a previous outbreak in the UK in 1965 involving a similarly naive population, veterinary clinicians and pathologists should be aware that EIV can cause fatal bronchointerstitial pneumonia in young foals that do not have maternal immunity. The lesions did not differ from those previously reported in foals of various ages with bronchointerstitial pneumonia of other or undefined causes, indicating that this is most likely to be a stereotypical response to a variety of insults. Therefore, tissue specimens should be obtained from cases of pneumonia in young foals for virological and bacteriological testing. Reasons for performing study: The first outbreak of equine influenza virus (EIV) infection was confirmed in Australia in 2007. Some EIV-positive young foals died with broncho-interstitial pneumonia, a rare disease process in this age group that is often postulated to be caused by viral infection. [source] New concepts in bilirubin encephalopathyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2003J. D. Ostrow Abstract Revised concepts of bilirubin encephalopathy have been revealed by studies of bilirubin toxicity in cultured CNS cells and in congenitally jaundiced Gunn rats. Bilirubin neurotoxicity is related to the unbound (free) fraction of unconjugated bilirubin (Bf), of which the dominant species at physiological pH is the protonated diacid, which can passively diffuse across cell membranes. As the binding affinity of plasma albumin for bilirubin decreases strikingly as albumin concentration increases, previously reported Bf values were underestimated. Newer diagnostic tests can detect reversible neurotoxicity before permanent damage occurs from precipitation of bilirubin (kernicterus). Early toxicity can occur at Bf only modestly above aqueous saturation and affects astrocytes and neurons, causing mitochondrial damage, resulting in impaired energy metabolism and apoptosis, plus cell-membrane perturbation, which causes enzyme leakage and hampers transport of neurotransmitters. The concentrations of unbound bilirubin in the cerebro-spinal fluid and CNS cells are probably limited mainly by active export of bilirubin back into plasma, mediated by ABC transporters present in the brain capillary endothelium and choroid plexus epithelium. Intracellular bilirubin levels may be diminished also by oxidation, conjugation and binding to cytosolic proteins. These new concepts may explain the varied susceptibility of neonates to develop encephalopathy at any given plasma bilirubin level and the selective distribution of CNS lesions in bilirubin encephalopathy. They also can suggest better strategies for predicting, preventing and treating this syndrome. [source] Myotonic dystrophy type 2EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2002J. Finsterer Myotonic dystrophy type 2 (DM2) is a clinically but not genetically heterogeneous, multisystem disorder, that is clinically similar to, but distinct from myotonic dystrophy type 1 (DM1). Initially, different phenotypes of DM2 were described by Ricker (proximal myotonic myopathy, PROMM), Ranum (myotonic dystrophy 2, DM2) and Udd (proximal myotonic dystrophy, PDM). Clinical features these three phenotypes had in common were diffuse, proximal or distal weakness, wasting, myotonia, cataract, cerebral, endocrine and cardiac abnormalities. Initially, the clinical differences between DM1 and PROMM seemed unmistakable, but meanwhile it has become apparent that the clinical differences between these entities are blurring. In 1999, Day et al., Meola et al. and Ricker et al. mapped the mutated gene of all three phenotypes to chromosome 3q. In 2001, the three different phenotypes were found to rely on the same mutation in the ZNF9 gene on chromosome 3q21.3. Although DM2 may be clinically heterogeneous, it is by result of a mutation in a single gene. The mutation responsible for DM2 is a CCTG-repeat expansion of 75,11 000 repeats in intron 1 of the ZNF9 gene on chromosome 3q21.3. Because of the clinical heterogeneity, the diagnosis of DM2 should rely on DNA analysis alone. [source] Aberrant responses to acoustic stimuli in mice deficient for neural recognition molecule NB-2EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2003Hong Li Abstract NB-2, a member of the contactin subgroup in the immunoglobulin superfamily, is expressed specifically in the postnatal nervous system, reaching a maximum level at 3 weeks postnatal. NB-2 displays neurite outgrowth-promoting activity in vitro. To assess its function in the nervous system, we generated mutant mice in which a part of the NB-2 gene was ablated and replaced with the tau-LacZ gene. The general appearance of NB-2-deficient mice and their gross anatomical features were normal. The LacZ expression patterns in heterozygous mice revealed that NB-2 is preferentially expressed in the central auditory pathways. In the audiogenic seizure test, NB-2-deficient mice exhibited a lower incidence of wild running, but a higher mortality rate than the wild-type littermates. c-Fos immunohistochemistry demonstrated that neural excitability induced by the audiogenic seizure test in the NB-2-deficient mice was prominently attenuated in both the dorsal and external cortices of the inferior colliculus, where enhanced neural excitability was observed in the wild-type mice. In response to pure-tone stimulation after priming, NB-2-deficient mice exhibited a diffuse and low level of c-Fos expression in the central nucleus of the inferior colliculus, which was distinctly different from the band-like c-Fos expression corresponding to the tonotopic map in the wild-type littermates. Taken together, these results suggest that a lack of NB-2 causes impairment of the neuronal activity in the auditory system. [source] Identity styles and causality orientations: in search of the motivational underpinnings of the identity exploration processEUROPEAN JOURNAL OF PERSONALITY, Issue 5 2005Bart Soenens Abstract This study examines relationships between constructs based on two perspectives on the development of self-governance, namely Self-Determination Theory (SDT; Deci & Ryan, 2000) and Berzonsky's (1990) identity style model. Theoretically predictable relationships are found between the three causality orientations defined by SDT (autonomous, controlled, and impersonal) and the three identity styles proposed by Berzonsky (informational, normative, diffuse,avoidant) in a sample of Belgian late adolescents. An autonomous causality orientation is positively related to an informational identity style and negatively related to a diffuse,avoidant style. A controlled orientation is positively associated with a normative identity style, and an impersonal orientation is positively related to a diffuse,avoidant identity style. Participants' gender does not moderate these relationships. The findings suggest that the causality orientations late adolescents employ may play an important role in how actively and thoroughly they explore identity-relevant issues. Copyright © 2005 John Wiley & Sons, Ltd. [source] Diffusion of strongly sorbed solutes in soil: a dual-porosity model allowing for slow access to sorption sites and time-dependent sorption reactionsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2010M. Ptashnyk We use homogenization techniques to derive a dual (or double) porosity model of solute diffusion and reaction in soil, allowing for slow access to sorption sites within micro-aggregates and time-dependent sorption reactions. We give a means for determining the conditions in which micro-scale concentration gradients affect macro-scale gradients and fluxes. We present equations for a unit volume of soil represented as a series of uniformly-spaced, porous spherical particles, containing and surrounded by solution through which solutes diffuse. The methods we use can, in principle, be applied to more complex geometries. We compare the model's predictions with those of the equivalent single porosity model for commonly used boundary conditions. We show that failure to allow for slow access to reaction sites can lead to seriously erroneous results. Slow access has the effect of decreasing the sorption of solute into soil from a source or desorption from soil to a sink. As a result of slow access, the diffusion coefficients of strongly-sorbed solutes measured at the macro-scale will be time-dependent and will depend on the method of measurement. We also show that slow access is more often likely to limit macro-scale diffusion than rates of slow chemical reactions per se. In principle, the unimportance of slow reactions except at periods longer than several weeks of diffusion simplifies modelling because, if slow access is correctly allowed for, sorption can be described with equilibrium relations with an understanding of speciation and rapid sorption-desorption reactions. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||