Anterior Regions (anterior + regions)

Distribution by Scientific Domains


Selected Abstracts


Cloning a novel developmental regulating gene, Xotx5: Its potential role in anterior formation in Xenopus laevis

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2000
Hiroki Kuroda
The vertebrate Otx gene family is related to otd, a gene contributing to head development in Drosophila. In Xenopus, Xotx1, Xotx2, and Xotx4 have already been isolated and analyzed. Here the cloning, developmental expression and functions of the additional Otx Xenopus gene, Xotx5 are reported. This latter gene shows a greater degree of homology to Xotx2 than Xotx1 and Xotx4. Xotx5 was initially expressed in Spemann's organizer and later in the anterior region. Ectopic expression of Xotx5 had similar effects to other Xotx genes in impairing trunk and tail development, and especially similar effects to Xotx2 in causing secondary cement glands. Taken together, these findings suggest that Xotx5 stimulates the formation of the anterior regions and represses the formation of posterior structures similar to Xotx2. [source]


Angelman Syndrome: Difficulties in EEG Pattern Recognition and Possible Misinterpretations

EPILEPSIA, Issue 8 2003
Kette D. Valente
Summary: Purpose: This study aimed to evaluate the sensitivity of the EEG in Angelman syndrome (AS), to verify the age at onset of suggestive EEGs and to study EEG patterns, analyzing variations and comparing our findings with nomenclature previously used. Methods: Seventy EEG and 15 V-EEGs of 26 patients were analyzed. Suggestive EEG patterns of AS were classified in delta pattern (DP), theta pattern (TP), and posterior discharges (PDs). Generic terms were used to simplify the analysis. Results: Suggestive EEGs were observed in 25 (96.2%) patients. DP occurred in 22 patients with four variants,hypsarrhythmic-like: irregular, high-amplitude, generalized delta activity (DA) with multifocal epileptiform discharges (EDs); slow variant: regular, high-amplitude, generalized DA with rare EDs; ill-defined slow spike-and-wave: regular, high-amplitude, generalized DA with superimposed EDs characterizing a slow wave, with notched appearance; triphasic-like: rhythmic, moderate-amplitude DA over anterior regions with superimposed EDs. TP was observed in eight patients, as generalized or over the posterior regions. PDs were seen in 19 patients as runs of sharp waves or runs of high-amplitude slow waves with superimposed EDs. TP was the only age-related pattern (younger than 8 years) and observed only in patients with deletion. In 15 patients who had an EEG before the clinical diagnosis, 60% had a suggestive tracing. Conclusions: Although some EEG descriptions are not very detailed, and every author describes findings in a slightly different manner, obviously a common denominator must exist. In this context, EEG seems to be a very sensitive method for the diagnosis of AS, offering an opportunity to corroborate this etiologic diagnosis. Conversely, we do not believe that these patterns may be accounted as specific, except for the delta pattern, which seems to be extremely unusual in other syndromes. Other EEG patterns observed in AS, such as theta activity and PDs, occur in a wide variety of disorders. Nonetheless, their importance for the EEG diagnosis of AS is supported by the fact that they are associated with other features and may be helpful in a proper clinical setting. [source]


Functional magnetic resonance imaging response to increased verbal working memory demands among patients with multiple sclerosis

HUMAN BRAIN MAPPING, Issue 1 2006
Lawrence H. Sweet
Abstract Multiple sclerosis (MS) patients frequently experience impaired verbal working memory (VWM). Functional magnetic resonance imaging (fMRI) may help identify neural mechanisms underlying these deficits. Neuroimaging studies of healthy adults have characterized responses associated with increased VWM demands during the n-Back task, suggesting that this experimental paradigm could help identify neural correlates of VWM deficits among MS patients. Fifteen MS patients and 15 matched control participants completed the n-Back during whole-brain fMRI. Mean signal during adjacent 0-Back blocks was subtracted, on a voxel-wise basis, from mean signal observed during n-Back blocks. Resulting difference scores for 1-, 2-, and 3-Back were compared across groups and difficulty levels. Signal intensity was positively related to difficulty level in anterior regions, including premotor, supplementary motor, and dorsolateral prefrontal cortices. MS patients exhibited significantly greater intensity in these areas compared to controls during the 1-Back, while portions of the left superior frontal gyrus, cingulate, and parahippocampal gyri were relatively less intense at more difficult levels. MS group responses were slower during the 1-Back and tended to be slower during the 3-Back; however, accuracy did not differ at any level. Lesion load was positively related to only 1-Back activity and unrelated to any performance measure. Results suggest that compensatory activity occurs among MS patients matched on performance accuracy. Furthermore, compensatory activity occurs predominantly in regions associated with VWM, and this may decline relative to controls as task demands increase. These findings may help to explain why MS patient performance decreases as a function of effort on neuropsychological tests. Hum Brain Mapp, 2005. © 2005 Wiley-Liss, Inc. [source]


Neurocalcin-like immunoreactivity in embryonic stages of the gastropod molluscs Aplysia californica and Lymnaea stagnalis

INVERTEBRATE BIOLOGY, Issue 3 2001
Amanda J.G. Dickinson
Neurocalcin is a calcium-binding protein that has been localized in neural and non-neural tissues of vertebrates, the arthropod Drosophila melanogaster, and in juveniles and adults of the mollusc Aplysia californica. We examine the distribution of neurocalcin in pre-hatching stages of the molluscs A. californica and Lymnaea stagnalis to elucidate where this calcium-binding protein functions in early development, as well as to localize novel neuronal populations in early stages of ontogeny. Aplysia neurocalcin (ApNc)-like immunoreactivity was localized in shell-secreting cells in embryonic stages of both A. californica and L. stagnalis. In A. californica, central and anterior regions of the embryo were diffusely labeled, as were a few identifiable neurons in veliger stages, On the other hand, in L. stagnalis, ApNc-like immunoreactivity was clearly detected in cells and fibers in the same locations as neuronal elements that have been previously identified very early in development and throughout the embryonic period using techniques to localize specific transmitters and peptides. Furthermore, additional neurons are also identified with anti- ApNc in this species. Establishing the distribution of neurocalcin-like proteins in embryonic stages of these two molluscs provides the first step to understanding the role of such proteins during development. [source]


Architecture of the nervous system in mystacocarida (Arthropoda, crustacea),An immunohistochemical study and 3D reconstruction

JOURNAL OF MORPHOLOGY, Issue 2 2010
Georg Brenneis
Abstract Mystacocarida is a species-poor group of minute crustaceans with unclear phylogenetic affinities. Previous studies have highlighted the putative "primitiveness" of several mystacocarid features, including the architecture of the nervous system. Recent studies on arthropod neuroarchitecture have provided a wealth of characters valuable for phylogenetic reconstructions. To permit and facilitate comparison with these data, we used immunohistochemical labeling (against acetylated ,-tubulin, serotonin and FMRFamide) on the mystacocarid Derocheilocaris remanei, analyzing it with confocal laser-scanning microscopy and 3D reconstruction. The mystacocarid brain is fairly elongated, exhibiting a complicated stereotypic arrangement of neurite bundles. However, none of the applied markers provided evidence of structured neuropils such as a central body or olfactory glomeruli. A completely fused subesophageal ganglion is not present, all segmental soma clusters of the respective neuromeres still being delimitable. The distinct mandibular commissure comprises neurite bundles from more anterior regions, leading us to propose that it may have fused with an ancestral posterior tritocerebral commissure. The postcephalic ventral nervous system displays a typical ladder-like structure with separated ganglia which bears some resemblance to larval stages in other crustaceans. Ganglia and commissures are also present in the first three limbless "abdominal" segments, which casts doubt on the notion of a clear-cut distinction between thorax and abdomen. An unpaired longitudinal median neurite bundle is present and discussed as a potential tetraconate autapomorphy. Additionally, a paired latero-longitudinal neurite bundle extends along the trunk. It is connected to the intersegmental nerves and most likely fulfils neurohemal functions. We report the complete absence of serotonin-ir neurons in the ventral nervous system, which is a unique condition in arthropods and herein interpreted as a derived character. J. Morphol., 2010. © 2009 Wiley-Liss, Inc. [source]


Langerhans cell histiocytosis: oral/periodontal involvement in adult patients

ORAL DISEASES, Issue 8 2009
S Annibali
Objective:, Langerhans cell histiocytosis (LCH) is a clonal proliferative multisystem disease. Although bone and mucosae have been classified as non-risk organs, their involvement may increase the risk of disease progression. Oral and periodontal lesions are burdened with a significant impairment of quality of life for associated signs, symptoms and loss of function. Most of information regards paediatric disease; the disease in adults has received limited attention. Subjects and Methods:, A total of 31 adult patients affected by immuno-histopathology confirmed LCH have been prospectively examined; attention was paid to the occurrence and characterization of oral lesions. Results:, Twelve patients developed oral lesions. Posterior regions of jawbones were always affected; the involvement of anterior regions was not constant. Unifocal oral involvement was significantly associated with multisystemic disease while multifocal lesions were associated with unisystemic disease. Oral disease presented with soft tissue ulcers (50% of cases), gingival bleeding (66.7%), pain (83.4%), periodontal damage (50%), tooth mobility (16.7%), non-healing extraction socket (8.3%); 41.6% of patients complained of negative outcomes on quality of life. Oral lesions were easily handled with local measures. Conclusions:, Posterior regions require attention; single oral lesions may be part of multisystemic disease; oral and periodontal lesions may be early signs of disease reactivation. [source]


Impact of a novel, extended approach of perineal radical prostatectomy on surgical margins in localized prostate cancer

BJU INTERNATIONAL, Issue 1 2010
Shogo Inoue
Study Type , Therapy (case series) Level of Evidence 4 OBJECTIVE To validate the rationale of extended perineal radical prostatectomy (ePRP) for treating localized prostate cancer. PATIENTS AND METHODS Between December 2000 and May 2007, 196 patients with localized prostate cancer underwent PRP, among which 91 and 105 patients were treated with conventional PRP (cPRP) and ePRP, respectively. The apex, middle, base, and anterior regions of the prostate were separately analysed, and the focus of analysis was on the distribution, size, Gleason score, and positive surgical margins (PSMs) of prostate cancer foci. RESULTS The operation time was significantly shorter in ePRP compared with cPRP (161 min vs 188 min; P= 0.001), while there was no significant difference in estimated blood loss between cPRP and ePRP (550 mL vs 500 mL). At the apex and base, there was no significant difference in the PSM rate between cPRP and ePRP. In the middle, there was a lower incidence of PSMs in ePRP (2.4%) than in cPRP (10.9%; P= 0.009). On the anterior side, PSMs were more frequent in cPRP (21.6%) than in ePRP (7.1%; P= 0.029). Logistic regression analysis adjusted by PSA level showed that PSM rate was the most significantly affected by the surgical approach. CONCLUSION We think that ePRP provides an effective treatment strategy for localized prostate cancer in light of excellent cancer control and minimum potential of surgical invasiveness. [source]