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91.
The azimuth (the least angle with the north-south direction) of the first cleavage furrow and anteroposterior axes of neurula was measured on projections of photographs of natural clutches. The azimuth distribution of the craniocaudal axis ofRana dalmatina neurulae in clutches from southern Italy and the first cleavage furrows ofR. arvalis embryos in clutches from central Russia proved identical. Both craniocaudal axes and first cleavage furrows were mostly oriented from west to east. The azimuth distribution of the craniocaudal axis ofR. arvalis neurulae in clutches subjected to repeated cold shock proved to be random. The causes and mechanisms of predominant orientation of the embryos in natural clutches of frogs are discussed. We propose that magnetic sensitivity is acquired by cytoskeleton elements, most likely microtubules, during reorganization in the course of normal development or due to experimental influences.  相似文献   
92.
To study in HBsAg chronic carriers the expression of liver hsa-miR-125a-5p and its correlation with liver HBV-DNA values and clinical presentation, 27 consecutive Caucasian, HBsAg/anti-HBe/HBV-DNA-positive patients who were naive to nucleos(t)ide analogues and interferon therapy and had no marker of HCV, HDV or HIV infection and no history of alcohol intake were enrolled. For each patient, liver HBV DNA and liver hsa-miR-125a-5p were quantified by real-time PCR in relation to β-globin DNA or RNU6B, respectively. Liver fibrosis and necroinflammation were graded by applying Ishak''s scoring system. Liver hsa-miR-125a-5p was detected in all patients enrolled and a correlation between its concentration and liver HBV DNA was demonstrated (p<0.0001). Higher liver hsa-miR-125a-5p concentrations were observed in patients with HBV-DNA plasma level >103 IU/ml (p<0.02), in those with HAI >6 (p = 0.02) and those with fibrosis score >2 (p<0.02) than in patients with lower scores. Higher HBV-DNA liver concentrations were found in patients with abnormal AST (p = 0.005) and ALT serum levels (p = 0.05), in those with serum HBV DNA higher than 10E3 IU/mL (p = 0.001) and those with fibrosis score >2 (p = 0.02) than in patients with a lower load. By multivariate logistic regression analysis, liver hsa-miR-125a-5p was identified as an independent predictor of disease progression: O.R. = 4.21, C.I. 95%  = 1.08–16.43, p<0.05, for HAI >6; O.R. = 3.12, C.I. 95%  = 1.17–8.27, p<0.05, for fibrosis score >2. In conclusion, in HBsAg/anti-HBe-positive patients, the liver hsa-miR-125a-5p level correlated with liver and plasma HBV-DNA values and was associated to a more severe disease progression.  相似文献   
93.
Based on sequence homology, several fungal Cys-rich secreted proteins have been grouped in the cerato-platanin (CP) family, which comprises at least 40 proteins involved mainly in eliciting defense-related responses. The core member of this family is cerato-platanin, a moderately hydrophobic protein with a double ψ–β barrel fold. CP and the recently identified orthologous cerato-populin (Pop1) are involved in host–fungus interaction, and can be considered non-catalytic fungal PAMPs. CP is more active in inducing defense when in an aggregated conformation than in its native form, but little is known about other CP-orthologous proteins. Here, we cloned, expressed, and purified recombinant Pop1, which was used to characterize the protein aggregates. Our results suggest that the unfolded, self-assembled Pop1 is more active in inducing defense, and that the unfolding process can be induced by interaction with hydrophobic inanimate surfaces such as Teflon, treated mica, and gold sheets. In vivo, we found that both CP and Pop1 interact with the hydrophobic cuticle of leaves. Therefore, we propose that the interaction of these proteins with host cuticle waxes could induce unfolding and consequently trigger their PAMP-like activity.  相似文献   
94.
Motivation: Biologists and chemists are facing problems of high computational complexity that require the use of several computers organized in clusters or in specialized grids. Examples of such problems can be found in molecular dynamics (MD), in silico screening, and genome analysis. Grid Computing and Cloud Computing are becoming prevalent mainly because of their competitive performance/cost ratio. Regrettably, the diffusion of Grid Computing is strongly limited because two main limitations: it is confined to scientists with strong Computer Science background and the analyses of the large amount of data produced can be cumbersome it. We have developed a package named GRIMD to provide an easy and flexible implementation of distributed computing for the Bioinformatics community. GRIMD is very easy to install and maintain, and it does not require any specific Computer Science skill. Moreover, permits preliminary analysis on the distributed machines to reduce the amount of data to transfer. GRIMD is very flexible because it shields the typical computational biologist from the need to write specific code for tasks such as molecular dynamics or docking calculations. Furthermore, it permits an efficient use of GPU cards whenever is possible. GRIMD calculations scale almost linearly and, therefore, permits to exploit efficiently each machine in the network. Here, we provide few examples of grid computing in computational biology (MD and docking) and bioinformatics (proteome analysis).

Availability

GRIMD is available for free for noncommercial research at www.yadamp.unisa.it/grimd

Supplementary information

www.yadamp.unisa.it/grimd/howto.aspx  相似文献   
95.
Colorectal cancer (CRC) is the second leading cause of death of malignant tumors worldwide. Recent studies point to a role for the adiponectin-receptor axis in colorectal carcinogenesis, and in particular to the oncosuppressive properties of the T-cadherin receptor. In addition, the loss of T-cadherin expression in tumor tissues has been linked to cancer progression and attributed to aberrant methylation of its promoter. Recognizing the pivotal role of microRNAs in CRC, this study explores their possible contribution to the downregulation of T-cadherin. A systematic bioinformatics analysis, restricted by microRNA expression data in the colon or in cultured colorectal cell lines, predicted twelve top-ranking target miRNA sites within the 3ʹ UTR of T-cadherin. Experimental validation analyses based on luciferase reporter constructs and miRNA mimic or miRNA inhibitor transfections toward colorectal adenocarcinoma cell lines indicated that miR-377-3p was able to directly bind to the T-cadherin sequence, and thus downregulating its expression. Given the oncogenic activity of miR-377 and the oncosuppressive activity of T-cadherin in CRC, the regulatory circuit highlighted in this study may add new insights into molecular mechanisms driving colorectal carcinogenesis, and perspectively it could be exploited to identify novel biomarkers and therapeutic targets.  相似文献   
96.
97.

Background

Childhood asthma prevalence is widely measured by parental proxy report of physician-diagnosed asthma in questionnaires. Our objective was to validate this measure in a North American population.

Methods

The 2884 study participants were a subsample of 5619 school children aged 5 to 9 years from 231 schools participating in the Toronto Child Health Evaluation Questionnaire study in 2006. We compared agreement between "questionnaire diagnosis" and a previously validated "health claims data diagnosis". Sensitivity, specificity and kappa were calculated for the questionnaire diagnosis using the health claims diagnosis as the reference standard.

Results

Prevalence of asthma was 15.7% by questionnaire and 21.4% by health claims data. Questionnaire diagnosis was insensitive (59.0%) but specific (95.9%) for asthma. When children with asthma-related symptoms were excluded, the sensitivity increased (83.6%), and specificity remained high (93.6%).

Conclusions

Our results show that parental report of asthma by questionnaire has low sensitivity but high specificity as an asthma prevalence measure. In addition, children with "asthma-related symptoms" may represent a large fraction of under-diagnosed asthma and they should be excluded from the inception cohort for risk factor studies.  相似文献   
98.
99.

Background

The “cerato-platanin family” consists of fungal-secreted proteins that are involved in various stages of the host–fungus interaction and act as phytotoxins, elicitors of defense responses and allergens. Cerato-platanin (CP) is a moderately hydrophobic protein secreted and localized in the cell wall of Ceratocystis platani, the causal agent of a severe disease of Platanus. These properties make CP like the hydrophobins: these are self-assembling proteins that form a surface coating which is involved in the formation of aerial hyphae and in adherence to surfaces.

Methods

CP aggregation was monitored by ThT, circular dichroism, and AFM. The eliciting activity of CP aggregates was assayed on leaves and cells.

Results

The CP self-assembles forming amyloid-like aggregates via a nucleated growth mechanism which is joined up with a cleavage of the N-terminus. The ovoidal shape and the lack of a clear transition toward an all-β structure distinguish these aggregates from typical amyloid fibrils. Moreover, CP aggregates interact with hydrophobic surfaces and enhance the hypersensitive response of Platanus.

Conclusion and general significance

CP forms “ordered aggregates” for which the soluble prefibrillar structures are the end point of the aggregation process, and do not evolve to insoluble fibrils. An involvement in host–microbe interaction is also suggested.  相似文献   
100.
The evaluation of a series of piperazinyl carbamates and ureas, designed on the basis of previously reported TRPV1 antagonists and FAAH inhibitors, led to the identification of some ‘dual-action’ compounds targeting both FAAH and TRPV1 or TRPA1 receptors.  相似文献   
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