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Frequent Alteration (frequent + alteration)
Selected AbstractsLand cover change and land degradation in parts of the southwest coast of NigeriaAFRICAN JOURNAL OF ECOLOGY, Issue 2009Mayowa Fasona Abstract Frequent alteration in land cover often leads to decreased stability of ecosystems which can also increase the vulnerability of rural communities to externalities of environmental change. This study carried out in parts of the coast of southwestern Nigeria utilized topographic base maps and two-time Landsat TM imageries to assess the trend in land cover changes and ecosystems degradation for the three time periods 1965, 1986 and 2001. Remote sensing, geographic information systems and landscape pattern analysis were employed for data processing and analysis. The focus of the analysis was on land cover change, land degradation, and changes in landscape pattern resulting from interplay of natural and anthropogenic drivers. The results show increased trend in human-induced land cover change with concomitant severe negative impacts on ecosystems and livelihoods. About 98,000ha (30% of the area) was seriously degraded as at 2001. About 33,000ha (10%) was under permanent saline water inundation with about 21 communities already dislocated. Loss of fragile ecosystems including marshland (from 7.7% in 1965 to 1% in 2001) and mangrove (from 14.6% in 1965 to 3.1% in 2001) was intense, while over 300 ponds/small lakes which are important for the local fishing economy have disappeared. About eighteen communities were also dislocated by erosion in a section around the southeastern parts of the coastline. Landscape metrics generated, suggested increased ecosystems perturbation and landscape fragmentation. The paper also discussed the implications of these rapid changes for ecosystems stability, food security and sustainable rural livelihoods in the area. [source] Extrarenal rhabdoid tumors of soft tissue: Clinicopathological and molecular genetic review and distinction from other soft-tissue sarcomas with rhabdoid featuresPATHOLOGY INTERNATIONAL, Issue 6 2006Yoshinao Oda Malignant rhabdoid tumor (MRT) of the soft tissue is a rare and highly aggressive tumor that occurs in infancy or childhood. It predominantly involves a deep axial location such as the neck or paraspinal region. Microscopically, the tumor is composed of a diffuse proliferation of rounded or polygonal cells with eccentric nuclei, prominent nucleoli and glassy eosinophilic cytoplasm containing hyaline-like inclusion bodies, arranged in sheets and nests. These characteristic ,rhabdoid cells' are also present in certain soft-tissue sarcomas such as synovial sarcoma, extraskeletal myxoid chondrosarcoma and leiomyosarcoma. The existence of rhabdoid cells in these other sarcomas is correlated with a worse prognosis for the patients. Cytogenetic and molecular analyses have shown abnormalities in the long arm of chromosome 22 and alteration of the hSNF5/INI1 (SMARCB1) gene in renal, extrarenal and intracranial MRT. This gene alteration has been considered to be a specific molecular event in MRT, but a recent study has also demonstrated frequent alteration of this gene in proximal-type epithelioid sarcoma (ES). Both MRT of soft tissue and proximal-type ES show immunoreactivity for vimentin, cytokeratin and epithelial membrane antigen. The tumor cells of proximal-type ES are also occasionally positive for CD34 and ,-catenin, whereas MRT of soft tissue has no immunoreaction for these markers. Detailed clinicopathological and immunohistochemical evaluations are necessary to distinguish MRT of soft tissue from proximal-type ES, because these tumors demonstrated a similar morphology and the same gene alteration. [source] Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central ItalyPEDIATRIC DIABETES, Issue 1 2010Claudia Brufani Brufani C, Ciampalini P, Grossi A, Fiori R, Fintini D, Tozzi A, Cappa M, Barbetti F. Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central Italy. Childhood obesity is epidemic in developed countries and is accompanied by an increase in the prevalence of type 2 diabetes (T2DM). Aims: Establish prevalence of glucose metabolism alterations in a large sample of overweight/obese children and adolescents from Central Italy. Methods: The study group included 510 overweight/obese subjects (3,18 yr). Oral glucose tolerance test (OGTT) was performed with glucose and insulin determination. Homeostatic model assessment of insulin resistance (HOMA-IR) and insulin sensitivity index (ISI) were derived from fasting and OGTT measurements. Beta-cell function was estimated by insulinogenic index. Fat mass was measured by dual-energy x-ray absorptiometry. Results: Glucose metabolism alterations were detected in 12.4% of patients. Impaired glucose tolerance (IGT) was the most frequent alteration (11.2%), with a higher prevalence in adolescents than in children (14.8 vs. 4.1%, p < 0.001); silent T2DM was identified in two adolescents (0.4%). HOMA-IR and glucose-stimulated insulin levels were higher in patients with IGT than individuals with normal glucose tolerance (HOMA-IR = 4.4 ± 2.5 vs. 3.4 ± 2.3, p = 0.001). Fat mass percentage and insulinogenic index were not different between the two groups. In multivariate analysis, age, fasting glucose, and insulin resistance influenced independently plasma glucose at 120 min of OGTT. Individuals with combined impaired fasting glucose/IGT (IFG/IGT) and T2DM were older and had reduced plasma insulin values at OGTT when compared to patients with simple IGT. Conclusions: Glucose metabolism alterations are frequently found among children and adolescents with overweight/obesity from Central Italy. Age, fasting glucose, and insulin resistance are main predictors of IGT. We suggest the use of OGTT as a screening tool in obese European adolescents. [source] Recent advances in the molecular pathology of soft tissue sarcoma: Implications for diagnosis, patient prognosis, and molecular target therapy in the futureCANCER SCIENCE, Issue 2 2009Yoshinao Oda In the present paper, recent advances in the molecular pathology of soft tissue sarcomas (STS) and the implications for their prognostic value are reviewed, and the potential targets of molecular therapy are discussed. According to the molecular genetic aspect, STS are divided into two groups: chromosome translocation-associated sarcomas and sarcomas without specific translocation. In the former group, specific fusion transcripts, such as SS18,SSX, EWS,FLI1, and PAX3,FKHR, could be detected in synovial sarcoma, Ewing's sarcoma and primitive neuroectodermal tumor, and alveolar rhabdomyosarcoma, respectively. The direct or indirect interactions between these fusion transcripts and cell cycle regulators have been elucidated by several investigators. Therefore, these fusion transcripts are promising candidates as molecular targets. As evaluated in carcinomas, alterations of several tumor-suppressor genes and adhesion molecules and overexpression of growth factors and their receptors have been extensively assessed in STS. In mixed-type STS, epidermal growth factor receptor overexpression was associated with decreased overall survival, suggesting the beneficial role of epidermal growth factor receptor inhibitors in STS. In malignant rhabdoid tumor and epithelioid sarcoma, frequent alteration of the SMARCB1/INI1tumor-suppressor gene and the loss of its protein have been demonstrated, indicating that this molecule could be an effective target of these sarcomas. In sarcomas with epithelioid differentiation, such as synovial sarcoma and epithelioid sarcoma, overexpression of dysadherin, which downregulates E-cadherin expression, was a poor prognostic factor. In conclusion, further studies are necessary to search for effective and specific molecules for the inhibition of tumor growth in each type of STS, especially in sarcomas without specific translocation. (Cancer Sci 2009; 100: 200,208) [source] | ||||||||||