908 resultados para PMD Link Coefficient
Resumo:
Novel magnetic resonance imaging sequences have and still continue to play an increasing role in neuroimaging and neuroscience. Among these techniques, diffusion-weighted imaging (DWI) has revolutionized the diagnosis and management of diseases such as stroke, neoplastic disease and inflammation. However, the effects of aging on diffusion are yet to be determined. To establish reference values for future experimental mouse studies we tested the hypothesis that absolute apparent diffusion coefficients (ADC) of the normal brain change with age. A total of 41 healthy mice were examined by T2-weighted imaging and DWI. For each animal ADC frequency histograms (i) of the whole brain were calculated on a voxel-by-voxel basis and region-of-interest (ROI) measurements (ii) performed and related to the animals' age. The mean entire brain ADC of mice <3 months was 0.715(+/-0.016) x 10(-3) mm2/s, no significant difference to mice aged 4 to 5 months (0.736(+/-0.040) x 10(-3) mm2/s) or animals older than 9 months 0.736(+/-0.020) x 10(-3) mm2/s. Mean whole brain ADCs showed a trend towards lower values with aging but both methods (i + ii) did not reveal a significant correlation with age. ROI measurements in predefined areas: 0.723(+/-0.057) x 10(-3) mm2/s in the parietal lobe, 0.659(+/-0.037) x 10(-3) mm2/s in the striatum and 0.679(+/-0.056) x 10(-3) mm2/s in the temporal lobe. With advancing age, we observed minimal diffusion changes in the whole mouse brain as well as in three ROIs by determination of ADCs. According to our data ADCs remain nearly constant during the aging process of the brain with a small but statistically non-significant trend towards a decreased diffusion in older animals.
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Endometriosis may progress to invasive endometrioid adenocarcinoma, particularly in the ovary. Up to now, little is known of the molecular mechanisms possibly involved in the malignant transformation of endometriosis. Therefore, in this study, extragonadal endometriosis (n = 10), ovarian endometriosis without malignancy (n = 10), ovarian endometriosis with direct transition into endometrioid adenocarcinoma (n = 8), and normal endometrium (n = 12) were investigated for numerical chromosomal aberrations by fluorescence in situ hybridization using centromere enumeration probes. The proportions of cells with aneusomies were semiquantitatively assessed. Trisomies 1 and 7, and monosomies 9 and 17 were found in endometriosis, ovarian endometrioid adenocarcinoma, and normal endometrium. The proportions of aneusomic cells were significantly higher in ovarian endometrioid carcinoma compared with ovarian endometriosis (P < 0.001), and in ovarian endometriosis compared with extragonadal endometriosis and normal endometrium (P < 0.001). The data provide new evidence of a common lineage of endometriosis and ovarian endometrioid carcinoma. The higher frequency of chromosomal aberrations in endometrioid carcinoma than in endometriosis may reflect an expansion of aberrant cell clones already present in endometriosis during the progression to cancer. The higher frequency of chromosomal aberrations in ovarian endometriosis than in extragonadal endometriosis suggests a role of the ovarian stromal milieu in the induction of genetic changes, which may eventually lead to invasive cancer.
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Darier's disease is a rare, inherited autosomal dominant skin disorder caused by a mutation in the sarcoendoplasmatic reticulum calcium transporter (SERCA)-2-gene. In a number of pedigrees, Darier's disease closely relates with affective disorder. The most likely hypothesis for this is a susceptibility gene for affective disorder near the SERCA-2-gene. A 6.5-megabase region could be identified as a susceptibility locus. This region constitutes a susceptability locus also in affective disorder without Darier's disease. The underlying gene has not yet been identified.
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OBJECTIVES: Diffusion-weighted MRI is sensitive to molecular motion and has been applied to the diagnosis of stroke. Our intention was to investigate its usefulness in patients with brain tumor and, in particular, in the perilesional edema. METHODS: We performed MRI of the brain, including diffusion-weighted imaging and mapping of the apparent diffusion coefficient (ADC), in 16 patients with brain tumors (glioblastomas, low-grade gliomas and metastases). ADC values were determined by the use of regions of interest positioned in areas of high signal intensities as seen on T2-weighted images and ADC maps. Measurements were taken in the tumor itself, in the area of perilesional edema and in the healthy contralateral brain. RESULTS: ADC mapping showed higher values of peritumoral edema in patients with glioblastoma (1.75 x 10(-3)mm(2)/s) and metastatic lesions (1.61 x 10(-3)mm(2)/s) compared with those who had low-grade glioma (1.40 x10(-3)mm(2)/s). The higher ADC values in the peritumoral zone were associated with lower ADC values in the tumor itself. CONCLUSIONS: The higher ADC values in the more malignant tumors probably reflect vasogenic edema, thereby allowing their differentiation from other lesions.
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ABSTRACT: Recent progress in neuroscience revealed diverse regions of the CNS which moderate autonomic and affective responses. The ventro-medial prefrontal cortex (vmPFC) plays a key role in these regulations. There is evidence that vmPFC activity is associated with cardiovascular changes during a motor task that are mediated by parasympathetic activity. Moreover, vmPFC activity makes important contributions to regulations of affective and stressful situations.This review selectively summarizes literature in which vmPFC activation was studied in healthy subjects as well as in patients with affective disorders. The reviewed literature suggests that vmPFC activity plays a pivotal role in biopsychosocial processes of disease. Activity in the vmPFC might link affective disorders, stressful environmental conditions, and immune function.
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This report describes 4 patients presenting with multiple teeth affected by invasive cervical resorption (ICR). The cases came to our attention between 2006 and 2008; previously, no cases of multiple ICR (mICR) had been reported in Switzerland. Characteristics common to all 4 cases included progression of disease over time, similar clinical and radiographic appearance of lesions, and obscure etiology. The histologically assessed teeth showed a similar pattern of tooth destruction, with resorptive lesions being confined to the cervical region. Howship's lacunae and multinucleated, tartrate-resistant acid phosphatase-positive odontoclasts were detected. None of the teeth presented with internal resorption. The positive pulp sensitivity corresponded to the histologic findings, indicating that the pulp tissue resisted degradation even in advanced stages of resorptive lesions. Although mICR is rare in humans, a similar disease known as feline odontoclastic resorptive lesions (FORL) is common in domestic, captive, and wild cats. The etiology of FORL, like that of mICR, remains largely unknown. Because FORL has been associated with feline viruses, we asked our mICR patients whether they had had contact with cats, and interestingly, all patients reported having had direct (2 cases) or indirect (2 cases) contact. In addition, blood samples were taken from all patients for neutralization testing of feline herpes virus type 1 (FeHV-1). Indeed, the sera obtained were able to neutralize (2 cases) or partly inhibit (2 cases) replication of FeHV-1, indicating transmission of feline viruses to humans. Future studies on mICR (and FORL) should evaluate the possible role of a (feline) virus as an etiologic (co-)factor in this disease.
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OBJECTIVE: To determine the characteristics of asthma (A) and allergic rhinitis (AR) among asthma patients in primary care practice. RESEARCH DESIGN AND METHODS: Primary care physicians, pulmonologists, and allergologists were asked to recruit consecutive asthma patients with or without allergic rhinitis from their daily practice. Cross-sectional data on symptoms, severity, treatment and impact on quality of life of A and AR were recorded and examined using descriptive statistics. Patients with and without AR were then compared. RESULTS: 1244 asthma patients were included by 211 physicians. Asthma was controlled in 19%, partially controlled in 27% and not controlled in 54%. Asthma treatment was generally based on inhaled corticosteroids (ICS) with or without long acting beta 2 agonists (78%). A leukotriene receptor antagonist (LTRA) was used by 46% of the patients. Overall, 950 (76%) asthma patients had AR (A + AR) and 294 (24%) did not (A - AR). Compared to patients with A - AR, A + AR patients were generally younger (mean age +/- standard deviation: 42 +/- 16 vs. 50 +/- 19 years, p < 0.001) and fewer used ICS (75% vs. 88%, p < 0.001). LTRA usage was similar in both groups (46% vs. 48%). Asthma was uncontrolled in 53% of A + AR and 57% of A - AR patients. Allergic rhinitis was treated with a mean of 1.9 specific AR medications: antihistamines (77%), nasal steroids (66%) and/or vasoconstrictors (38%), and/or LTRA (42%). Rhinorrhoea, nasal obstruction, or nasal itching were the most frequently reported AR symptoms and the greatest reported degree of impairment was in daily activities/sports (55%). CONCLUSIONS: Allergic rhinitis was more common among younger asthma patients, increased the burden of symptoms and the need for additional medication but was associated with improved asthma control. However, most asthma patients remained suboptimally controlled regardl-ess of concomitant AR.
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PURPOSE: To determine how the ADC value of parotid glands is influenced by the choice of b-values. MATERIALS AND METHODS: In eight healthy volunteers, diffusion-weighted echo-planar imaging (DW-EPI) was performed on a 1.5 T system, with b-values (in seconds/mm2) of 0, 50, 100, 150, 200, 250, 300, 500, 750, and 1000. ADC values were calculated by two alternative methods (exponential vs. logarithmic fit) from five different sets of b-values: (A) all b-values; (B) b=0, 50, and 100; (C) b=0 and 750; (D) b=0, 500, and 1000; and (E) b=500, 750, and 1000. RESULTS: The mean ADC values for the different settings were (in 10(-3) mm2/second, exponential fit): (A) 0.732+/-0.019, (B) 2.074+/-0.084, (C) 0.947+/-0.020, (D) 0.890+/-0.023, and (E) 0.581+/-0.021. ADC values were significantly (P <0.001) different for all pairwise comparisons of settings (A-E) of b-values, except for A vs. D (P=0.172) and C vs. D (P=0.380). The ADC(B) was significantly higher than ADC(C) or ADC(D), which was significantly higher than ADC(E). ADC values from exponential vs. logarithmic fit (P=0.542), as well as left vs. right parotid gland (P=0.962), were indistinguishable. CONCLUSION: The ADC values calculated from low b-value settings were significantly higher than those calculated from high b-value settings. These results suggest that not only true diffusion but also perfusion and saliva flow may contribute to the ADC.