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排序方式: 共有245条查询结果,搜索用时 15 毫秒
241.
Dynamic high-spatial-resolution MR imaging of suspicious breast lesions: diagnostic criteria and interobserver variability 总被引:8,自引:0,他引:8
Kinkel K Helbich TH Esserman LJ Barclay J Schwerin EH Sickles EA Hylton NM 《AJR. American journal of roentgenology》2000,175(1):35-43
OBJECTIVE: Our study was undertaken to develop diagnostic rules and to assess the reproducibility of dynamic and morphologic parameters for the characterization of suspicious breast lesions using dynamic high-spatial-resolution MR imaging. MATERIALS AND METHODS: Fifty-seven patients with suspicious mammographic or palpable findings underwent preoperative contrast-enhanced MR imaging of the breast using a three-time-point method of acquisition. Each lesion was prospectively analyzed by two independent radiologists for morphologic and visual dynamic enhancement characteristics. A classification and regression tree was used to examine the optimal order, cutoff points, and combination of imaging parameters to build a diagnostic rule separating benign from malignant lesions using histopathology findings as the standard of reference. Kappa statistics were used to determine observer variability. RESULTS: Among 23 benign and 34 malignant lesions (12 invasive, three ductal carcinoma in situ, and 19 mixed cancer), margin morphology (p = 0.001) and enhancement pattern (p = 0.001) were the most significant MR imaging findings for lesion characterization. Focal mass lesions were classified as malignant when spiculated margins or both the washout enhancement pattern and "nonsmooth" margins were present. Interobserver agreement was almost perfect for washout pattern and substantial for margin assessment. In the limited population tested retrospectively, the diagnostic rule yielded a sensitivity and positive predictive value of 97% each and a specificity and negative predictive value of 96% each. CONCLUSION: The washout enhancement pattern combined with lesion margin assessment on dynamic contrast-enhanced high-resolution MR imaging of the breast allows reproducible lesion characterization and may be a highly specific diagnostic tool. 相似文献
242.
Morgane Besson Yann Pelloux Ruth Dilleen David EH Theobald Alan Lyon Aude Belin-Rauscent Trevor W Robbins Jeffrey W Dalley Barry J Everitt David Belin 《Neuropsychopharmacology》2013,38(10):1963-1973
Impulsivity shares high comorbidity with substance abuse in humans, and high impulsivity (HI) in rats has been identified as a predictive factor for cocaine addiction-like behavior. Despite the evidence that high impulsivity is associated with altered function of corticostriatal networks, the specific neural substrates underlying the increased vulnerability of impulsive individuals to develop cocaine addiction remain unknown. We therefore investigated specific neural correlates of HI within the corticostriatal circuitry and determined how they interact with a protracted history of cocaine self-administration. We used in situ hybridization to map brain expression of two major genes implicated in impulsivity, encoding the dopamine D2 receptor (DA D2R) and the 5-HT2c receptor (5-HT2cR), and an immediate early gene associated with neuronal plasticity, zif268, in groups of rats selected for HI and low impulsivity (LI) on a 5-choice serial reaction time task (5-CSRTT) immediately after 5-CSRTT training, and following 10 or 50 days of cocaine self-administration. HI rats exhibited decreased DA D2R mRNA in the mesolimbic pathway, and increased 5-HT2cR mRNA in the orbitofrontal cortex compared with LI rats. HI rats also showed decreased zif268 mRNA in the ventral and dorsomedial striatum. Cocaine exposure decreased striatal D2R mRNA in both HI and LI rats, decreased 5-HT2cR mRNA differentially in striatal and prefrontal areas between HI and LI rats, and selectively decreased zif268 mRNA in the orbitofrontal and infralimbic cortices of HI animals. These findings implicate novel markers underlying the vulnerability of impulsive rats to cocaine addiction that localize to the OFC, infralimbic cortex, and striatum. 相似文献
243.
Background
Myocarditis is an uncommon disease that presents with a wide range of symptoms in children and adults. It is histologically characterized by varying degrees of myocardialnecrosis, edema and cellular infiltration myocardial inflammation is a nonspecificresponse to many triggers such as bacterial infection, cardio toxic agents, ormechanical injury.Objective
This study was carried out to investigate the experimental Streptococcus faecalis induction of myocarditis and its effect on some blood parameters, inflammatory markers and histopathological changes in male albino rats.Methods
Rats were infected by intraperitoneal injection of 10 8 CFU/ml of Streptococcus faecalis and sacrificed after one, two and seven days post infection. Biochemical analyses of blood were carried out to investigate the serum biomarkers of inflammation, liver function tests, cardiac enzymes & kidney function tests.Results
All biochemical analyses showed statistically significant increase in the measured parameters due to bacterial infections except for blood urea which appear to be normal. A significant positive correlation was observed between lactate dehydrogenase enzyme (LDH) with creatinine (r =0.778, P<0.01). In the 7 days group, there were significant positive correlations between aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (r=0.675, P<0.05), erythrocyte sedimentation rate (ESR) with Urea (r=0.659, P<0.05) and alkaline phosphatase (ALP) with C-reactive protein (CRP) (r=0.765, p<0.01).Conclusion
Many of these biomarkers will provide important new insights into pathophysiology and aid in the diagnosis and management of cardiovascular patients. 相似文献244.
Autoimmunity as an aetiological factor in vitiligo 总被引:2,自引:0,他引:2
N Rezaei†‡ NG Gavalas‡ AP Weetman‡ EH Kemp‡ 《Journal of the European Academy of Dermatology and Venereology》2007,21(7):865-876
Vitiligo is a common dermatological disorder characterized by the presence on the skin of depigmented macules resulting from the destruction of cutaneous melanocytes. Autoimmunity is an important hypothesis with regard to vitiligo aetiology and the evidence for autoimmune responses being involved in the pathogenesis of this disorder will be discussed in the present review. All immune system compartments, including innate and adaptive immunity have been implicated in vitiligo development. Particularly relevant are autoantibodies and autoreactive T cells in vitiligo patients that have cytotoxic effects upon pigment cells. Furthermore, predisposition to vitiligo appears to be associated with certain alleles of the major histocompatibility complex class II antigens as well as with other autoimmune-susceptibility genes. Moreover, the association of vitiligo with autoimmune disorders, the animal models of the disease, and the positive response to immunosuppressive therapeutic agents emphasize the role of autoimmunity in the development of this disorder. 相似文献
245.