Home About us Contact
|
Home About us Contact | ||
|
|
||
History Information (history + information)
Kinds of History Information Selected AbstractsMultiple genetic tests for susceptibility to smoking do not outperform simple family historyADDICTION, Issue 1 2009Coral E. Gartner ABSTRACT Aims To evaluate the utility of using predictive genetic screening of the population for susceptibility to smoking. Methods The results of meta-analyses of genetic association studies of smoking behaviour were used to create simulated data sets using Monte Carlo methods. The ability of the genetic tests to screen for smoking was assessed using receiver operator characteristic curve analysis. The result was compared to prediction using simple family history information. To identify the circumstances in which predictive genetic testing would potentially justify screening we simulated tests using larger numbers of alleles (10, 15 and 20) that varied in prevalence from 10 to 50% and in strength of association [relative risks (RRs) of 1.2,2.1]. Results A test based on the RRs and prevalence of five susceptibility alleles derived from meta-analyses of genetic association studies of smoking performed similarly to chance and no better than the prediction based on simple family history. Increasing the number of alleles from five to 20 improved the predictive ability of genetic screening only modestly when using genes with the effect sizes reported to date. Conclusions This panel of genetic tests would be unsuitable for population screening. This situation is unlikely to be improved upon by screening based on more genetic tests. Given the similarity with associations found for other polygenic conditions, our results also suggest that using multiple genes to screen the general population for genetic susceptibility to polygenic disorders will be of limited utility. [source] Subject and informant characteristics influence the reliability and validity of family history information: an analysis based on the generalized estimating equations approachINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2000Reinhard Heun Abstract Family history information is a necessary surrogate for unavailable interview information in family studies. However, the reliability and validity of such information has rarely been assessed during the conduct of family studies. This paper presents a reanalysis of data on the reliability and validity of family history information for dementia and depression using the general estimation equations approach. All available relatives of patients and controls were interviewed and questioned about the psychiatric morbidity of other family members. Interinformant reliability of this family history information was evaluated as well as factors influencing this information. The validity of family history was investigated by comparing the informant derived diagnoses with interview-derived diagnoses. To account for possible lack of independence of family history provided by several family members on other family members, the generalized estimating equations (GEE) were used in statistical analysis. The interinformant reliability for depression (kappa = 0.13) was low. It was fair for dementia (kappa = 0.34). The informants more frequently agreed about the diagnosis of dementia when the subject was older. The sensitivity of family history was 35.2% for dementia and 31.8% for depression. The specificity of family history information was generally above 97%. The sensitivity of family history increased significantly with the severity of both disorders. The sensitivity of the family history for dementia was higher when the informant was a first-degree relative, when he was younger and when the index subject of the family suffered from dementia. The specificity of the family history was slightly reduced with higher age. The observed low sensitivity of family history information leads to underestimation of psychiatric disorders. The informants provide more useful information on more severe disorders. The sensitivity of family history was higher in families with an affected index subject than in control families, so familial aggregation of dementia might be overestimated in studies using the family history method. Copyright © 2000 Whurr Publishers Ltd. [source] The role of trout in stream food webs: integrating evidence from field surveys and experimentsJOURNAL OF ANIMAL ECOLOGY, Issue 2 2006KRISTIAN MEISSNER Summary 1We evaluated the effects of brown trout on boreal stream food webs using field surveys and enclosure/exclosure experiments. Experimental results were related to prey preference of uncaged trout in the same stream, as well as to a survey of macroinvertebrate densities in streams with vs. without trout. Finally, we assessed the generality of our findings by examining salmonid predation on three groups of macroinvertebrate prey (chironomid midges, epibenthic grazers, invertebrate predators) in a meta-analysis. 2In a preliminary experiment, invertebrate predators showed a strong negative response to trout, whereas chironomids benefited from trout presence. In the main experiment, trout impact increased with prey size. Trout had the strongest effect on invertebrate predators and cased caddis larvae, whereas Baetis mayfly and chironomid larvae were unaffected. Trout impact on the largest prey seemed mainly consumptive, because prey emigration rates were low and independent of fish presence. Despite strong effects on macroinvertebrates, trout did not induce a trophic cascade on periphyton. Uncaged trout showed a strong preference for the largest prey items (predatory invertebrates and aerial prey), whereas Baetis mayflies and chironomids were avoided by trout. 3Densities of invertebrate predators were significantly higher in troutless streams. Baetis mayflies also were less abundant in trout streams, whereas densities of chironomids were positively, although non-significantly, related to trout presence. Meta-analysis showed a strong negative impact of trout on invertebrate predators, a negative but variable impact on mobile grazers (mainly mayfly larvae) and a slightly positive impact on chironomid larvae. 4Being size-selective predators, salmonid fishes have a strong impact on the largest prey types available, and this effect spans several domains of scale. Discrepancies between our experimental findings and those from the field survey and meta-analysis show, however, that for most lotic prey, small-scale experiments do not reflect fish impact reliably at stream-wide scales. 5Our findings suggest that small-scale experiments will be useful only if the experimental results are evaluated carefully against natural history information about the experimental system and interacting species across a wide array of spatial scales. [source] Ossification sequence of the avian order anseriformes, with comparison to other precocial birdsJOURNAL OF MORPHOLOGY, Issue 9 2008Erin E. Maxwell Abstract Ossification sequences are poorly known for most amniotes, and yet they represent an important source of morphogenetic, phylogenetic, and life history information. Here, the author describes the ossification sequences of three ducks, the Common Eider Somateria mollissima dresseri, the Pekin Duck Anas platyrhynchos, and the Muscovy Duck Cairina moschata. Sequence differences exist both within and among these species, but are generally minor. The Common Eider has the most ossified skeleton prior to hatching, contrary to what is expected in a subarctic migrant species. This may be attributed to a tradeoff between growth rate and locomotory performance. Growth rate is higher in hatchlings with more cartilaginous skeletons, but this may compromise locomotion. No major ossification sequence differences were observed in the craniofacial skeleton when compared with Galliformes, which suggests that the influence of adult morphology on ossification sequence might be relatively minor in many taxa. Galliformes and Anseriformes, while both highly ossified at hatching, differ in the location of their late-stage ossification centers. In Anseriformes, these are most often located in the appendicular skeleton, whereas in Galliformes they are in the thoracic region and form the ventilatory apparatus. J. Morphol., 2008. © 2008 Wiley-Liss, Inc. [source] Family history information on essential tremor: Potential biases related to the source of the casesMOVEMENT DISORDERS, Issue 2 2001Elan D. Louis MD Abstract The proportion of essential tremor (ET) cases that can be attributed to genetic factors is unknown; estimates range from 17,100%. One possible reason for this variability is that clinic and community cases may differ with regard to family history of ET. This is because clinic patients are self-selected and represent as few as 0.5% of all ET cases. Our goal was to determine whether ET cases ascertained from a clinic differed from those ascertained from a community in terms of the family history information that they provided. Subjects (57 clinic, 64 community) underwent a family history interview. Clinic cases were 4.73 times more likely to report an affected relative than were community cases. We conclude that there was a substantial difference between our clinic and community ET cases in terms of the information they provided regarding their family history. Selection and reporting biases could have accounted for this difference. Because of these biases, the source of the cases must be taken into consideration when investigators are trying to synthesize the widely variable results of studies that have estimated the genetic contribution to ET. © 2001 Movement Disorder Society. [source] "Life history space": A multivariate analysis of life history variation in extant and extinct Malagasy lemursAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010Kierstin K. Catlett Abstract Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source] Gail Model Risk Factors: Impact of Adding an Extended Family History for Breast CancerTHE BREAST JOURNAL, Issue 3 2008Anna Crispo ScD Abstract:, An approach commonly used in estimating breast cancer risk is the Gail model. The objective of this study was to evaluate the feasibility and impact of adding extended family history as a new breast cancer risk factor into the Gail model. The data of the present study include cases with breast cancer and hospitalized controls recruited in the National Cancer Institute of Naples (southern Italy) between 1997 and 2000. We compared the first-degree relative (FDR) risk factor (standard Gail model) with the second-degree relative (SDR) information; and the FDR risk factor (standard Gail model) with the combination of FDR and SDR. We computed the c-statistic by comparing the risks found in our population to those in Gail-US population. The concordance for the model with FDR was 0.55 (95% CI 0.53,0.58), the model with SDR shows a modest but significant discriminatory accuracy (0.56, 95% CI 0.53,0.59), and the combination of FDR+SDR gave the concordance statistic of 0.57 (95% CI 0.54,0.60), indicating a good comparison between the two models. The results of our study show that extended family history information could be useful to improve the discriminatory power of the Gail model risk factors. [source] The accuracy of medical history information in referral lettersAUSTRALIAN DENTAL JOURNAL, Issue 2 2010AF DeAngelis Abstract Background: Accurate medical history information is essential for good patient care and should be notified in the letter of referral. The aim of this study was to investigate the subjective opinion that the medical information in a large number of referrals is either inaccurate or non-existent. Methods: Medical histories from 54 patients with positive medical history findings upon taking the medical history at the initial consultation appointment were compared to the medical information supplied in the referral letter. Results: Overall, medical information was only 58.8% complete with dental referrals being 55.2% complete and medical referrals 62.4%. The majority of referral letters (70.4%) missed at least one relevant finding and only 29.6% of referrals were 100% complete. Conclusions: The results of this study suggest that the standard of referral letters needs to be improved as the received referrals were generally incomplete and contained inaccurate information. This highlights the need for each and every practitioner to take their own detailed medical history and not rely on the information supplied in the referral. [source] Analysing the history of the derelomine flower weevil,Carludovica association (Coleoptera: Curculionidae; Cyclanthaceae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2004NICO M. FRANZ The evolutionary history of the interaction among species of derelomine flower weevils (Coleoptera: Curculionidae: Derelomini) and the Panama-hat palm Carludovica (Cyclanthaceae) is analysed with emphasis on the congruence of (1) topologies and (2) character state transformations in each of the Neotropical clades. For this purpose cladistic analyses are complemented with host plant records, natural history information and selected morphological studies of the associated taxa. The interaction is specialized, involving pollination, oviposition into the inflorescences and the predation of seeds (particularly within Systenotelus). As results from a range of standard coevolutionary methods of analysis indicate, however, events of colonization, extinction and independent (non-reciprocal) speciation have been abundant throughout the history of the association. At the same time it is possible to specify the homology and succession of characters among species of derelomines and Carludovica and interpret them as reciprocal adaptations to attack and protect the seeds, respectively. It is argued that , in light of the limited evolutionary stability of many insect,plant interactions , the question of coevolution is most effectively addressed by combining information from the character- and topology-based approaches. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81, 483,517. [source] A Frailty-Model-Based Approach to Estimating the Age-Dependent Penetrance Function of Candidate Genes Using Population-Based Case-Control Study Designs: An Application to Data on the BRCA1 GeneBIOMETRICS, Issue 4 2009Lu Chen Summary The population-based case,control study design is perhaps one of, if not the most, commonly used designs for investigating the genetic and environmental contributions to disease risk in epidemiological studies. Ages at onset and disease status of family members are routinely and systematically collected from the participants in this design. Considering age at onset in relatives as an outcome, this article is focused on using the family history information to obtain the hazard function, i.e., age-dependent penetrance function, of candidate genes from case,control studies. A frailty-model-based approach is proposed to accommodate the shared risk among family members that is not accounted for by observed risk factors. This approach is further extended to accommodate missing genotypes in family members and a two-phase case,control sampling design. Simulation results show that the proposed method performs well in realistic settings. Finally, a population-based two-phase case,control breast cancer study of the BRCA1 gene is used to illustrate the method. [source] | |||||||||||||