580 research outputs found
Establishing the precise evolutionary history of a gene improves prediction of disease-causing missense mutations
PURPOSE: Predicting the phenotypic effects of mutations has become an important application in clinical genetic diagnostics. Computational tools evaluate the behavior of the variant over evolutionary time and assume that variations seen during the course of evolution are probably benign in humans. However, current tools do not take into account orthologous/paralogous relationships. Paralogs have dramatically different roles in Mendelian diseases. For example, whereas inactivating mutations in the NPC1 gene cause the neurodegenerative disorder Niemann-Pick C, inactivating mutations in its paralog NPC1L1 are not disease-causing and, moreover, are implicated in protection from coronary heart disease. METHODS: We identified major events in NPC1 evolution and revealed and compared orthologs and paralogs of the human NPC1 gene through phylogenetic and protein sequence analyses. We predicted whether an amino acid substitution affects protein function by reducing the organism’s fitness. RESULTS: Removing the paralogs and distant homologs improved the overall performance of categorizing disease-causing and benign amino acid substitutions. CONCLUSION: The results show that a thorough evolutionary analysis followed by identification of orthologs improves the accuracy in predicting disease-causing missense mutations. We anticipate that this approach will be used as a reference in the interpretation of variants in other genetic diseases as well. Genet Med 18 10, 1029–1036
Fuzzy Inference Systems for Invariant Pattern Recognition in MFL NDE
Defect related information present in NDE signals is frequently obscured by the presence of operational variables inherent in the system. A typical NDE system comprises of an energy source, a test specimen and a sensor array. Operational variables include uncontrollable changes in source signal strength and/or frequency, variations in the sensitivity of the sensor and alterations in the material properties of the test specimen. These operational variables can confuse subsequent signal interpretation schemes, such as those relying on artificial neural networks. Invariant pattern recognition methods are required to ensure accurate signal characterization in terms of the underlying defect geometry. This paper describes a generalized invariance transformation technique to compensate for operational variables in NDE systems. An application to magnetic flux leakage (MFL) inspection of gas transmission pipelines is presented. The technique is employed to compensate for variations in magnetization characteristics in the pipe wall
Biophysical and electrochemical studies of protein-nucleic acid interactions
This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail
Nanotechnology in Head and Neck Cancer: The Race Is On
Rapid advances in the ability to produce nanoparticles of uniform size, shape, and composition have started a revolution in the sciences. Nano-sized structures herald innovative technology with a wide range of potential therapeutic and diagnostic applications. More than 1000 nanostructures have been reported, many with potential medical applications, such as metallic-, dielectric-, magnetic-, liposomal-, and carbon-based structures. Of these, noble metallic nanoparticles are generating significant interest because of their multifunctional capacity for novel methods of laboratory-based diagnostics, in vivo clinical diagnostic imaging, and therapeutic treatments. This review focuses on recent advances in the applications of nanotechnology in head and neck cancer, with special emphasis on the particularly promising plasmonic gold nanotechnology
Neuropathologic Correlates of Hippocampal Atrophy in the Elderly: A Clinical, Pathologic, Postmortem MRI Study
The volume of the hippocampus measured with structural magnetic resonance imaging (MRI) is increasingly used as a biomarker for Alzheimer's disease (AD). However, the neuropathologic basis of structural MRI changes in the hippocampus in the elderly has not been directly assessed. Postmortem MRI of the aging human brain, combined with histopathology, could be an important tool to address this issue. Therefore, this study combined postmortem MRI and histopathology in 100 elderly subjects from the Rush Memory and Aging Project and the Religious Orders Study. First, to validate the information contained in postmortem MRI data, we tested the hypothesis that postmortem hippocampal volume is smaller in subjects with clinically diagnosed Alzheimer's disease compared to subjects with mild or no cognitive impairment, as observed in antemortem imaging studies. Subsequently, the relations of postmortem hippocampal volume to AD pathology, Lewy bodies, amyloid angiopathy, gross infarcts, microscopic infarcts, and hippocampal sclerosis were examined. It was demonstrated that hippocampal volume was smaller in persons with a clinical diagnosis of AD compared to those with no cognitive impairment (P = 2.6×10−7) or mild cognitive impairment (P = 9.6×10−7). Additionally, hippocampal volume was related to multiple cognitive abilities assessed proximate to death, with its strongest association with episodic memory. Among all pathologies investigated, the most significant factors related to lower hippocampal volume were shown to be AD pathology (P = 0.0018) and hippocampal sclerosis (P = 4.2×10−7). Shape analysis allowed for visualization of the hippocampal regions most associated with volume loss for each of these two pathologies. Overall, this investigation confirmed the relation of hippocampal volume measured postmortem to clinical diagnosis of AD and measures of cognition, and concluded that both AD pathology and hippocampal sclerosis affect hippocampal volume in old age, though the impacts of each pathology on the shape of the hippocampus may differ
Surfing the internet for health information: an italian survey on use and population choices
BACKGROUND:
Recent international sources have described how the rapid expansion of the Internet has precipitated an increase in its use by the general population to search for medical information. Most studies on e-health use investigated either through the prevalence of such use and the social and income patterns of users in selected populations, or the psychological consequences and satisfaction experienced by patients with particular diseases. Few studies have been carried out in Europe that have tried to identify the behavioral consequences of Internet use for health-related purposes in the general population.The aims of this study are to provide information about the prevalence of Internet use for health-related purposes in Italy according to demographic and socio-cultural features, to investigate the impact of the information found on health-related behaviors and choices and to analyze any differences based on health condition, self-rated health and relationships with health professionals and facilities.
METHODS:
A multicenter survey was designed within six representative Italian cities. Data were collected through a validated questionnaire administered in hospital laboratories by physicians. Respondents were questioned about their generic condition, their use of the Internet and their health behaviors and choices related to Internet use. Data were analyzed using descriptive statistics and logistic regression to assess any differences by socio-demographic and health-related variables.
RESULTS:
The sample included 3018 individuals between the ages of 18 and 65 years. Approximately 65% of respondents reported using the Internet, and 57% of them reported using it to search for health-related information. The main reasons for search on the Internet were faster access and a greater amount of information. People using the Internet more for health-related purposes were younger, female and affected by chronic diseases.
CONCLUSIONS:
A large number of Internet users search for health information and subsequently modify their health behaviors and relationships with their medical providers. This may suggest a strong public health impact with consequences in all European countries, and it would be prudent to plan educational and prevention programs. However, it could be important to investigate the quality of health-related websites to protect and inform user
Electronic gaming machine characteristics: it's the little things that count
A range of gamblers, from low-frequency social gamblers through to problem gamblers in treatment, participated in focus groups discussing the characteristics of Electronic Gaming Machines (EGMs) that they found attractive. Analyses of the resulting transcripts resulted in two groups of EGM characteristics being identified as important, one group associated with winning and one with betting. Overall, free spin features were identified in all groups as the most attractive characteristic of EGMS. Beyond that it was smaller win-related characteristics, and low-denomination machines with multiple playable lines that were associated with increased duration and intensity of gambling behaviour. The important characteristics were consistent across different levels of gamblers, with the key behavioural difference being a self-reported ‘expertise’, and ‘strategic’ approach to gambling amongst higher-frequency gamblers and problem gamblers in treatment. The key characteristics all occur frequently and result in more wins and extended gambling sessions. The patterns identified resonated with established behavioural principles, and with models describing the development of problem gambling and addictions more generally
Experiences and attitudes of Dutch rheumatologists and oncologists with regard to their patients’ health-related Internet use
The objective of this study is to explore the experiences and attitudes of rheumatologists and oncologists with regard to their patients’ health-related Internet use. In addition, we explored how often physicians referred their patients to health-related Internet sites. We sent a questionnaire to all the rheumatologists and oncologists in the Netherlands. The questionnaire included questions concerning demographics, experiences with patients’ health-related Internet use, referral behavior, and attitudes to the consequences of patients’ health-related Internet use (for patients themselves, the physician-patient relationship and the health care). The response rate was 46% (N = 238). Of these respondents, 134 practiced as a rheumatologist and 104 as an oncologist. Almost all physicians encountered their patients raising information from the Internet during a consultation. They were not, however, confronted with their patients’ health-related Internet use on a daily basis. Physicians had a moderately positive attitude towards the consequences of patients’ health-related Internet use, the physician-patient relationship and the health care. Oncologists were significantly less positive than rheumatologists about the consequences of health-related Internet use. Most of the physicians had never (32%) or only sometimes (42%) referred a patient to a health-related Internet site. Most physicians (53%) found it difficult to stay up-to-date with reliable Internet sites for patients. Physicians are moderately positive about their patients’ health-related Internet use but only seldom refer them to relevant sites. Offering an up-to-date site with accredited websites for patients might help physicians refer their patients
Awareness and acceptability of human papillomavirus vaccine: an application of the instrumental variables bivariate probit model
<p>Abstract</p> <p>Background</p> <p>Although lower uptake rates of the human papillomavirus (HPV) vaccine among socioeconomically disadvantaged populations have been documented, less is known about the relationships between awareness and acceptability, and other factors affecting HPV vaccine uptake.</p> <p>The current study aimed to estimate the potential effectiveness of increased HPV vaccine awareness on the acceptability of HPV vaccination in a nationally representative sample of women, using a methodology that controlled for potential non-random selection.</p> <p>Methods</p> <p>This study used a population-based sample from the 2007 Health Information National Trends Survey, a cross-sectional study of the US population aged 18 years or older, and focused on the subsample of 742 women who have any female children under the age of 18 years in the household. An instrumental variables bivariate probit model was used to jointly estimate HPV vaccine awareness and acceptability.</p> <p>Results</p> <p>The proportion of HPV vaccine acceptability among the previously aware and non-aware groups was 58% and 47%, respectively. Results from the instrumental variables bivariate probit model showed that the estimated marginal effect of awareness on acceptability was 46 percentage points, an effect that was even greater than observed.</p> <p>Conclusions</p> <p>Among populations who are not currently aware of the HPV vaccine, the potential impact of raising awareness on acceptability of HPV vaccination is substantial. This finding provides additional support to strengthening public health programs that increase awareness and policy efforts that address barriers to HPV vaccination.</p
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