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51.
The unique opportunity given by the "fiscal code", an alphanumeric identification with demographic information on any single person residing in Italy, introduced in 1976 by the Ministry of Finance, allowed a database of all potential Italian twins to be created. This database contains up to now name, surname, date and place of birth and home address of about 1,300,000 "possible twins". Even though we estimated an excess of 40% of pseudo-twins, this still is the world's largest twin population ever collected. The database of possible twins is currently used in population-based studies on multiple sclerosis, Alzheimer's disease, celiac disease, and type 1 diabetes. A system is currently being developed for linking the database with data from mortality and cancer registries. In 2001, the Italian Government, through the Ministry of Health, financed a broad national research program on twin studies, including the establishment of a national twin registry. Among all the possible twins, a sample of 500,000 individuals are going to be contacted and we expect to enrol around 120,000 real twin pairs in a formal Twin Registry. According to available financial resources, a sub sample of the enrolled population will be asked to donate DNA. A biological bank from twins will be then implemented, guaranteeing information on future etiological questions regarding genetic and modifiable factors for physical impairment and disability, cancers, cardiovascular diseases and other age related chronic illnesses.  相似文献   
52.
The contribution that oxidative damage to DNA and/or RNA makes to the aging process remains undefined. In this study, we used the hMTH1‐Tg mouse model to investigate how oxidative damage to nucleic acids affects aging. hMTH1‐Tg mice express high levels of the hMTH1 hydrolase that degrades 8‐oxodGTP and 8‐oxoGTP and excludes 8‐oxoguanine from both DNA and RNA. Compared to wild‐type animals, hMTH1‐overexpressing mice have significantly lower steady‐state levels of 8‐oxoguanine in both nuclear and mitochondrial DNA of several organs, including the brain. hMTH1 overexpression prevents the age‐dependent accumulation of DNA 8‐oxoguanine that occurs in wild‐type mice. These lower levels of oxidized guanines are associated with increased longevity and hMTH1‐Tg animals live significantly longer than their wild‐type littermates. Neither lipid oxidation nor overall antioxidant status is significantly affected by hMTH1 overexpression. At the cellular level, neurospheres derived from adult hMTH1‐Tg neural progenitor cells display increased proliferative capacity and primary fibroblasts from hMTH1‐Tg embryos do not undergo overt senescence in vitro. The significantly lower levels of oxidized DNA/RNA in transgenic animals are associated with behavioral changes. These mice show reduced anxiety and enhanced investigation of environmental and social cues. Longevity conferred by overexpression of a single nucleotide hydrolase in hMTH1‐Tg animals is an example of lifespan extension associated with healthy aging. It provides a link between aging and oxidative damage to nucleic acids.  相似文献   
53.
Mesoscale circulation generated by the Loop Current in the Northern Gulf of Mexico (NGOM) delivers growth-limiting nutrients to the microbial plankton of the euphotic zone. Consequences of physicochemically driven community shifts on higher order consumers and subsequent impacts on the biological carbon pump remain poorly understood. This study evaluates microbial plankton <10 μm abundance and community structure across both cyclonic and anti-cyclonic circulation features in the NGOM using flow cytometry (SYBR Green I and autofluorescence parameters). Non-parametric multivariate hierarchical cluster analyses indicated that significant spatial variability in community structure exists such that stations that clustered together were defined as having a specific ‘microbial signature’ (i.e. statistically homogeneous community structure profiles based on relative abundance of microbial groups). Salinity and a combination of sea surface height anomaly and sea surface temperature were determined by distance based linear modeling to be abiotic predictor variables significantly correlated to changes in microbial signatures. Correlations between increased microbial abundance and availability of nitrogen suggest nitrogen-limitation of microbial plankton in this open ocean area. Regions of combined coastal water entrainment and mesoscale convergence corresponded to increased heterotrophic prokaryote abundance relative to autotrophic plankton. The results provide an initial assessment of how mesoscale circulation potentially influences microbial plankton abundance and community structure in the NGOM.  相似文献   
54.
55.
The Golgi apparatus: an organelle with multiple complex functions   总被引:1,自引:0,他引:1  
Remarkable advances have been made during the last few decades in defining the organizational principles of the secretory pathway. The Golgi complex in particular has attracted special attention due to its central position in the pathway, as well as for its fascinating and complex structure. Analytical studies of this organelle have produced significant advances in our understanding of its function, although some aspects still seem to elude our comprehension. In more recent years a level of complexity surrounding this organelle has emerged with the discovery that the Golgi complex is involved in cellular processes other than the 'classical' trafficking and biosynthetic pathways. The resulting picture is that the Golgi complex can be considered as a cellular headquarters where cargo sorting/processing, basic metabolism, signalling and cell-fate decisional processes converge.  相似文献   
56.
An increasing amount of data has revealed the importance of inducible promoters in ciliate research and in ciliate-related industries. However, knowledge about these promoters and related genes is relatively sparse. Here we report a novel inducible promoter from a Tetrahymena cytoplasmic Hsp70 gene member, HSP70-2. The reported promoter was able to induce the endogenous gene up to ~9000-fold after a short heat shock treatment and this remarkable feature has been retained when a relatively short region of the promoter was introduced into a reporter construct followed by transformation. During the recovery period following a short heat shock, both the mRNA and protein levels of the reporter gene were maintained high up to two hours. A constant heat shock treatment to the transformed cells led to a stabilization of the reporter mRNA up to at least six hours and the reporter protein continued to accumulate up to around three hours. The promoter strength appears to be similar to that of the cadmium-induced metallothionein gene (MTT1) promoter. Therefore, the HSP70-2 promoter represents an attractive alternative for the over-expression of proteins in Tetrahymena, and the promoter-reporter gene construct used in this study is an ideal tool to help in understanding the regulation mechanisms of heat shock genes in ciliates.  相似文献   
57.
The importance of genetics and epigenetic changes in the pathogenesis of non alcoholic fatty liver disease (NAFLD) has been increasingly recognized. Adiponectin has a central role in regulating glucose and lipid metabolism and controlling inflammation in insulin-sensitive tissues and low adiponectin levels have been linked to NAFLD. APPL1 and APPL2 are adaptor proteins that interact with the intracellular region of adiponectin receptors and mediate adiponectin signaling and its effects on metabolism. The aim of our study was the evaluation of a potential association between variants at APPL1 and APPL2 loci and NAFLD occurrence. The impact on liver damage and hepatic steatosis severity has been also evaluated. To this aim allele frequency and genotype distribution of APPL1- rs3806622 and -rs4640525 and APPL2-rs 11112412 variants were evaluated in 223 subjects with clinical diagnosis of NAFLD and compared with 231 healthy subjects. The impact of APPL1 and APPL2 SNPs on liver damage and hepatic steatosis severity has been also evaluated. The minor-allele combination APPL1-C/APPL2-A was associated with an increased risk of NAFLD (OR = 2.50 95% CI 1.45–4.32; p<0.001) even after adjustment for age, sex, body mass index, insulin resistance (HOMA-IR), triglycerides and adiponectin levels. This allele combination carrier had higher plasma alanine aminotransferase levels (Diff = 15.08 [7.60–22.57] p = 0.001) and an increased frequency of severe steatosis compared to the reference allele combination (OR = 3.88; 95% CI 1.582–9.531; p<0.001). In conclusion, C-APPL1/A-APPL2 allele combination is associated with NAFLD occurrence, with a more severe hepatic steatosis grade and with a reduced adiponectin cytoprotective effect on liver.  相似文献   
58.
BACKGROUND: Patients with chronic renal failure (CRF) often have dyspeptic symptoms and may develop peptic disease or digestive disorders leading to severe gastrointestinal complications. The primary aim of this study was to evaluate the prevalence of peptic lesions and Helicobacter pylori infection, and the severity of dyspeptic symptoms, in dyspeptic patients with and without CRF. Our secondary aim was to investigate whether uremic status may affect the diagnostic efficiency of the [13]C-urea breath test ([13]C-UBT). PATIENTS AND METHODS: We consecutively enrolled in the study 50 dyspeptic patients with chronic kidney failure (mean age 52 +/- 5 years), of whom 11 were on hemodialysis treatment (HD), and 93 subjects (mean age 54 +/- 7 years) with chronic dyspepsia and normal renal function (NRF). All patients completed an oriented and validated questionnaire scoring the severity of nine dyspeptic symptoms (i.e. epigastric pain, epigastric burning, postprandial fullness, early satiety, bloating, belching, nausea and vomiting) and underwent upper endoscopy with multiple bioptic sampling for rapid urease test and histological examination, [13]C-UBT and HpSA test. RESULTS: The prevalences of peptic lesions and H. pylori infection and mean symptom score were 74%, 52% and 3.5 +/- 3, respectively, in dyspeptic patients with CRF and 18%, 36% and 8 +/- 5, respectively, in dyspeptic patients with NRF. The diagnostic accuracy of [13]C-UBT with respect to histological diagnosis was 94% and 97% for dyspeptic patients with and without renal failure, respectively. CONCLUSIONS: 1, A high frequency of peptic lesions and low symptom scores were observed in uremic patients in spite of H. pylori infection; 2, uremic status did not affect the diagnostic accuracy of [13]C-UBT.  相似文献   
59.
Antibody staining was observed in the electron microscope by means of untagged antibody and osmium fixation. The antibody was visualized as a change in morphology due to its deposition on the antigenic structures. Glycerinated chicken breast muscle was stained with antimyosin, anti-H-meromyosin, and antiactin. The staining patterns obtained by electron microscopy were consistent with those previously demonstrated by fluorescence microscopy. A second method was used for confirmation of antibody staining. This consisted of extraction of unstained portions of the sarcomere with 0.6 M potassium iodide, 10-4 M adenosine triphosphate solution. Stained regions of the sarcomere remained intact because of insolubility of the combined antigen and antibody.  相似文献   
60.
Lamin A, a main constituent of the nuclear lamina, is involved in mechanosignaling and cell migration through dynamic interactions with the LINC complex, formed by the nuclear envelope proteins SUN1, SUN2 and the nesprins. Here, we investigated lamin A role in Ewing Sarcoma (EWS), an aggressive bone tumor affecting children and young adults. In patients affected by EWS, we found a significant inverse correlation between LMNA gene expression and tumor aggressiveness. Accordingly, in experimental in vitro models, low lamin A expression correlated with enhanced cell migration and invasiveness and, in vivo, with an increased metastatic load. At the molecular level, this condition was linked to altered expression and anchorage of nuclear envelope proteins and increased nuclear retention of YAP/TAZ, a mechanosignaling effector. Conversely, overexpression of lamin A rescued LINC complex organization, thus reducing YAP/TAZ nuclear recruitment and preventing cell invasiveness. These effects were also obtained through modulation of lamin A maturation by a statin-based pharmacological treatment that further elicited a more differentiated phenotype in EWS cells. These results demonstrate that drugs inducing nuclear envelope remodeling could be exploited to improve therapeutic strategies for EWS.Subject terms: Nuclear organization, Cancer  相似文献   
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