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41.
Vincenzo De Giorgi  MD    Daniela Massi  MD    Elisa Trez  MD    Camilla Salvini  MD    Elena Quercioli  MD    Paolo Carli  MD 《Dermatologic surgery》2003,29(9):965-967
In dermoscopy, the correct recognition of the single parameters is fundamental to achieve great diagnostic accuracy, but the scarce morphologic expression of a parameter may lead to diagnostic errors. We report the case of a 27-year-old white man presenting a pigmented lesion of the back, which was present since puberty. Clinical examination revealed on the back the presence of a flat, gray-blue lesion and at the periphery a small dark-brown papule. An assessment of the lesion by means of dermoscopy was performed. The purpose of this report was to analyze the Blue Hue in dermoscopy with its histopathologic correlates, starting with the discussion of a clinical case.  相似文献   
42.
OBJECTIVE: This study aims to evaluate the efficiency of top-down and bottom-up processes in the extrastriate cortex of cirrhotic patients without overt hepatic encephalopathy (HE). METHODS: Reaction times (RTs), accuracy and event-related potentials (ERPs) were recorded during the execution of a visual Simon task in 17 cirrhotic patients and 10 healthy controls. Amplitude and latency of the P1 and N1 (indexes of bottom-up processes) and of the N2pc (index of top-down processes) were measured. RESULTS: Patients were slower than controls, and patients with minimal HE (MHE) were slower than patients without MHE. The distribution analysis of RTs showed that the Simon effect decays with slower RTs in all the groups and that the shape of the distribution was different in MHE patients. No differences were found between cirrhotic patients and controls for P1 and N1 amplitude and latency. In contrast, N2pc latency was delayed in cirrhotic patients compared to controls independently of MHE. CONCLUSIONS: In the extrastriate cortex of cirrhotic patients without HE, top-down processes are altered whereas bottom-up processes are preserved. SIGNIFICANCE: The analysis of exogenous and endogenous visual components of ERPs provides a model to study the functional dissociation between top-down and bottom-up processes inside the extrastriate cortex.  相似文献   
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44.
The Helicobacter pylori cytotoxin is proteolytically cleaved at a flexible hydrophilic loop into two subunits. Deletion of the loop sequences had no effect on biological activity of the toxin in the HeLa cell vacuolation assay but favored the organization of the protein into hexameric rather than heptameric structures.  相似文献   
45.
BACKGROUND: Calcific aortic stenosis (AS), the most frequent heart valve disorder in developed countries, leads to the calcification and fibrous thickening of the valve. While several studies have addressed the process of valvular calcification, the molecular pathomechanisms of the extensive matrix remodeling remain unclear. Because inflammation is present in stenotic valves, we hypothesized that the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha) might influence cell proliferation and regulate the expression and activation of matrix metalloproteinases (MMPs)--enzymes that are thought to be involved in calcific AS. METHODS: Immunohistochemistry for leukocytes, TNFalpha, MMP-1, and the endogenous MMP inhibitor tissue inhibitor of metalloproteinase (TIMP)-1 was performed on human stenotic (n = 19) and control (n = 8) valves. Primary cultures of human aortic valve myofibroblasts were incubated with and without TNFalpha, and cell proliferation was assessed. The expression and activation of MMP-1 were detected by Western blotting and a specific MMP-1 activity assay. RESULTS: Control valves showed scattered macrophages and low expression of TNFalpha, MMP-1, and TIMP-1. In stenotic valves, leukocyte infiltration and a strong, colocalized expression of TNFalpha and MMP-1 were present, while TIMP-1 remained unchanged. Double-label immunofluorescence localized TNFalpha mainly to macrophages. In cultured human aortic valve myofibroblasts, TNFalpha stimulated proliferation and induced a time-dependent increase in MMP-1 expression and activation, while TIMP-1 remained unchanged. CONCLUSION: The results indicate that matrix remodeling in calcific AS involves the expression and activation of MMPs. Activated leukocytes, by the secretion of TNFalpha, may stimulate valvular myofibroblasts to proliferate and express MMPs, thus regulating actively the matrix remodeling in calcific AS.  相似文献   
46.
BACKGROUND: It has been argued that lay interviewers' use of fully-structured interviews could lead to a diagnostic pattern different to that by treating physicians. Clinical interviewers in community samples should probably identify cases that are closer to those seen in clinical settings. The greatest advantage of using clinical interviewers consists of the immediate assessment of a possible psychopathology, i.e. the evaluation of current disorders. METHODS: Two thousand three hundred and sixty-three citizens from the community of Sesto Fiorentino, Italy, were interviewed by their own general practitioners using the Mini International Neuropsychiatric Interview (MINI). Positive cases for any lifetime psychiatric disorder as well as a random sample of the negative cases were re-interviewed by psychiatrists or trained residents in psychiatry using the Florence Psychiatric Interview (FPI). RESULTS: The point prevalence for any current disorder was 8.7%; the two disorders with the highest prevalence were generalised anxiety disorder (2.9%) and major depressive episode (2.7%). The figures increase about 50% when the sub-threshold sequelae of previous disorders are considered. Current comorbidity was generally high. The one-year prevalence of any disorder was 10.6%. Ninety-two percent of the cases sought help, 82% were being treated at the moment of interview. Social impairment was considerable. CONCLUSIONS: The period prevalence rates for most of the disorders considered were generally comparable with the range defined by previous studies conducted in other Western countries, despite using different methodologies. Conversely, the use of health facilities, the treatment received and the social impairment were much higher than those reported by the other studies, suggesting a greater similarity with the clinical samples.  相似文献   
47.
Knudson's two-hit hypothesis postulates that genetic alterations in both alleles are required for the inactivation of tumor-suppressor genes. Genetic alterations include small or large deletions and mutations. Over the past years, it has become clear that epigenetic alterations such as DNA methylation are additional mechanisms for gene silencing. Restriction Landmark Genomic Scanning (RLGS) is a two-dimensional gel electrophoresis that assesses the methylation status of thousands of CpG islands. RLGS has been applied successfully to scan cancer genomes for aberrant DNA methylation patterns. So far, the majority of this work was done using NotI as the restriction landmark site. Here, we describe the development of RLGS using AscI as the restriction landmark site for genome-wide scans of cancer genomes. The availability of AscI as a restriction landmark for RLGS allows for scanning almost twice as many CpG islands in the human genome compared with using NotI only. We describe the development of an AscI-EcoRV boundary library that supports the cloning of novel methylated genes. Feasibility of this system is shown in three tumor types, medulloblastomas, lung cancers, and head and neck cancers. We report the cloning of 178 AscI RLGS fragments via two methods by use of this library.  相似文献   
48.
Electrocardiographic imaging (ECGI) is a developing imaging modality for cardiac electrophysiology and arrhythmias. It reconstructs epicardial potentials, electrograms, and isochrones from electrocardiographic body-surface potentials noninvasively. Current ECGI methodology employs Tikhonov regularization, which imposes constraints on the reconstructed potentials or their derivatives. This approach can sometimes reduce spatial resolution by smoothing the solution. Accuracy depends on a priori knowledge of solution characteristics and determination of an optimal regularization parameter. These properties led us to implement an independent, iterative approach for ECGI—the generalized minimal residual (GMRes) method—which does not apply constraints. GMRes was applied to experimental data during activation/repolarization of normal and infarcted hearts. GMRes reconstructions were compared to Tikhonov reconstructions and to measured gold standards in isolated hearts. Overall, the accuracy of GMRes solutions was similar to Tikhonov regularization. However, in certain cases GMRes recovered localized potential features (e.g., multiple potential minima), which were lost in the Tikhonov solution. Simultaneous use of these two complementary methods in clinical ECGI will ensure reliability and maximal extraction of diagnostic information in the absence of a priori information about a patient's condition.© 2003 Biomedical Engineering Society. PAC2003: 8719Hh, 8757Gg  相似文献   
49.
Classical citrullinemia (CTLN1), a rare autosomal recessive disorder, is caused by mutations of the argininosuccinate synthetase (ASS) gene, localized on chromosome 9q34.1. ASS functions as a rate-limiting enzyme in the urea cycle. Previously, we identified 32 mutations in the ASS gene of CTLN1 patients mainly in Japan and the United States, and to date 34 different mutations have been described in 50 families worldwide. In the present study, we report ASS mutations detected in 35 additional CTLN1 families from 11 countries. By analyzing the entire coding sequence and the intron-exon boundaries of the ASS gene using RT-PCR and/or genomic DNA-PCR, we have identified 16 novel mutations (two different 1-bp deletions, a 67-bp insertion, and 13 missense) and have detected 12 known mutations. Altogether, 50 different mutations (seven deletion, three splice site, one duplication, two nonsense, and 37 missense) in 85 CTLN1 families were identified. On the basis of primary sequence comparisons with the crystal structure of E. coli ASS protein, it may be concluded that any of the 37 missense mutations found at 30 different positions led to structural and functional impairments of the human ASS protein. It has been found that three mutations are particularly frequent: IVS6-2A>G in 23 families (Japan: 20 and Korea: three), G390R in 18 families (Turkey: six, U.S.: five, Spain: three, Israel: one, Austria: one, Canada: one, and Bolivia: one), and R304W in 10 families (Japan: nine and Turkey: one). Most mutations of the ASS gene are "private" and are distributed throughout the gene, except for exons 5 and 12-14. It seems that the clinical course of the patients with truncated mutations or the G390R mutation is early-onset/severe. The phenotype of the patients with certain missense mutations (G362V or W179R) is more late-onset/mild. Eight patients with R86H, A118T, R265H, or K310R mutations were adult/late-onset and four of them showed severe symptoms during pregnancy or postpartum. However, it is still difficult to prove the genotype-phenotype correlation, because many patients were compound heterozygotes (with two different mutations), lived in different environments at the time of diagnosis, and/or had several treatment regimes or various knowledge of the disease.  相似文献   
50.
Clericuzio-type poikiloderma with neutropenia is a well-defined nosological entity, but despite a remarkable number of clinical reports, no long term follow-up data has been presented to date regarding patients with this rare condition.Here we describe the results of clinical follow-up of three siblings, one male (Patient 1) and two females (Patients 2 and 3), subsequent to their first clinical and then molecular diagnosis of Clericuzio-type poikiloderma with neutropenia syndrome due to mutation of USB1gene. Patient 1 always expressed the most severe phenotype, while patients 2 and 3 showed an intermediate and mild phenotype, respectively, as observed since their first clinical evaluation. None of the patients developed skin cancer and/or myelodysplastic disorders considering the peripheral haematological findings. Lens opacity, never reported before, was found in two of the three patients.The long term follow-up observations confirm the stability over time of the pronounced intra-familial heterogeneity of clinical manifestations observed prior to and upon molecular diagnosis. We conclude that prolonged follow-up is an adjunct tool to monitor intra-familial variability of PN clinical spectrum which may favour surveillance of more serious complications of the disease among siblings, when a patient-specific clinical expressivity is present.  相似文献   
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