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PubMed1992

[Estimation of genetic parameters by using analysis of variance within unit].

In the estimation of heritability, various non-genetic factors must be excluded from the variance of sire or dam. The methods of sib correlation within unit, suggested by professor Sheng Zhilian is commonly used in China. This paper will provide evidence to verify this method theoretically and discuss the application of the method to systematic classification. In addition, in this paper the author suggest some other methods to estimate heritability by using analysis of variance within unit when the blood relationship exists between sire and dam. These methods not only make the estimation procedure of hertability simple but also have the same function of analyzing variance with multiple factors.

Analysis of Variance↗

PubMed1989

Study on the behavior management of children at dental treatment. Various factors affecting the frequency of training.

Search was made using quantification method of the first and second type to search the factors affecting the frequency of training, and to estimate it. The following conclusions were led; 1. Factors giving large effect on the decision of the frequency of training were 'Frankl classification', 'ages at the initial examination' and 'if children have any experience of dental treatment or not'. 2. With the factors concerned with educational environments including mothers, 'number of brothers and sisters', 'mother's educational history' and 'if mothers works or not' showed high correlation. 3. Among the factors concerned with character analysis, 'emotional stability' 'if children can control themselves or not' gave much effect. 4. As the factors to estimate the frequency of training, the reliable factors include 'Frankl classification', 'ages at initial examination', and 'sexes'. 5. With the factors concerned with educational environments including mothers, 'mother's educational history', 'number of brothers and sisters' 'birth order' were highly reliable. 6. With the factors concerned with character analysis, 'emotional stability', 'if children fants are degenerative or productive' showed high reliability. 7. Multiple correlation coefficient for all the 27 factors was 0.823, which was found to be highly reliable for the estimation of the frequency of training.

Behavior Therapy↗

PubMed1989

[Study on the behavior management at dental treatment. Research of various factors affecting the frequency of training by multivariate analysis].

A Search was made using quantification methods of the first and second type to discover the factors affecting the frequency of training, and to estimate it. The following conclusions were obtained; 1. Factors having a large effect on the decision of the frequency of training were the Frankl classification, ages at the initial examination and if children have any experience of dental treatment or not. 2. With the factors concerned with educational environments encompasing mothers, number of brothers and sisters, the mother's educational history and wether the mothers work or not high correlation was shown. 3. Among the factors concerned with character analysis, emotional stability, if children can control themselves or not had considerable effect. 4. As for the factors for estimating the frequency of training, the reliable factors include Frankl classification, ages at initial examination, and sexes. 5. With the factors concerned with educational environment including mothers, the mothers' educational history, the number of brothers and sisters, birth order were highly reliable. 6. With the factors concerned with character analysis, emotional stability, if children are degenerative or productive showed high reliability. 7. Multiple correlation coefficient for all the 27 factors was 0.823, which was found to be highly reliable for the estimation of the frequency of training.

Behavior Therapy↗

PubMed1996

The ongoing challenge of retroperitoneal vascular injuries.

BACKGROUND: Retroperitoneal vascular injury remains one of the most frequent causes of death following abdominal trauma. A risk analysis of the association between potential outcome predictors and mortality following abdominal aorta and inferior vena cava injuries was performed. METHODS: Eighty-nine patients sustaining abdominal aortic or inferior vena cava injury were concurrently evaluated for a 10-year period and retrospectively reviewed. A multiple logistic regression model evaluated the following variables:presence of shock on admission, base deficit (< -10 or > or = -10), classification by the organ injury scale (OIS), blood transfusion, crystalloid infusion, total infusion volume, associated injuries, site of injury, and presence of retroperitoneal tamponade. RESULTS: Overall mortality for all injuries was 57%. Excluding all death on arrival (DOA) patients, the mortality rate decreased to 45.7%. Death following abdominal aortic injuries was significantly associated with free bleeding in the peritoneal cavity, acidosis, and an injury in the suprarenal location (OIS > 4). For inferior vena cava injuries and combined abdominal aortic and inferior vena cava injuries, death was associated with free bleeding, the suprarenal location (OIS = 4), and the presence of shock on admission as well. CONCLUSIONS: Despite advances in transport and resuscitation, mortality of aortic and vena cava injuries remains unchanged. Shock on admission, bleeding without retroperitoneal tamponade, acidosis, and the suprarenal location each play a significant role in mortality. Immediate identification associated with a rapid surgical approach are the only factors that may improve survival of such devastating injuries.

Adolescent↗

PubMed2006

Multiscale classification using nearest neighbor density estimates.

Density estimates based on k-nearest neighbors have useful applications in nonparametric discriminant analysis. In classification problems, optimal values of k are usually estimated by minimizing the cross-validated misclassification rates. However, these cross-validation techniques allow only one value of k for each population density estimate, while in a classification problem, the optimum value of k for a class may also depend on its competing population densities. Further, it is computationally difficult to minimize the cross-validated error rate when there are several competing populations. Moreover, in addition to depending on the entire training data set, a good choice of k should also depend on the specific observation to be classified. Therefore, instead of using a single value of k for each population density estimate, it is more useful in practice to consider the results for multiple values of k to arrive at the final decision. This paper presents one such approach along with a graphical device, which gives more information about classification results for various choices of k and the related statistical uncertainties present there. The utility of this proposed methodology has been illustrated using some benchmark data sets.

Algorithms↗

PubMed2000

Phylogeny of the treehoppers (Insecta: Hemiptera: Membracidae): evidence from two nuclear genes.

We present a molecular systematic investigation of relationships among family-group taxa of Membracidae, comprising nearly 3.5 kb of nucleotide sequence data from the nuclear genes elongation factor-1alpha (EF-1alpha: 958 bp) and 28S ribosomal DNA (28S rDNA: 2363 bp); data partitions are analyzed separately and in combination for 79 taxa. Analysis of the combined sequence data provided a better-resolved and more robust hypothesis of membracid phylogeny than did separate analyses of the individual genes. Results support the monophyly of the family Membracidae and indicate the presence of two major lineages (Centrotinae + Stegaspidinae + Centrodontinae and Darninae + Membracinae + Smiliinae). Within Membracidae, molecular data support the following assertions: (1) the previously unplaced genera Antillotolania and Deiroderes form a monophyletic group with Microcentrini; (2) Centrodontini and Nessorhinini are monophyletic clades that arise independently from within the Centrotinae; (3) Centrotinae is paraphyletic with respect to Centrodontinae; (4) the subfamily Membracinae is monophyletic and possibly allied with the darnine tribe Cymbomorphini; (5) the subfamily Darninae is paraphyletic; (6) the subfamily Smiliinae is paraphyletic, with molecular evidence indicating the exclusion of Micrutalini and perhaps Acutalini and Ceresini; and (7) Membracidae arose and diversified in the New World with multiple subsequent colonizations of the Old World. Our phylogenetic results suggest that morphology-based classifications of the Membracidae need to be reevaluated in light of emerging molecular evidence.

Animals↗

PubMed1998

BCL-6 gene mutations in posttransplantation lymphoproliferative disorders predict response to therapy and clinical outcome.

Posttransplantation lymphoproliferative disorders (PT-LPDs) represent a heterogeneous group of Epstein-Barr virus-associated lymphoid proliferations that arise in immunosuppressed transplant recipients. Some of these lesions regress after a reduction in immunosuppressive therapy, whereas some progress despite aggressive therapy. Morphological, immunophenotypic, and immunogenotypic criteria have not been useful in predicting clinical outcome. Although structural alterations in oncogenes and/or tumor suppressor genes identified in some PT-LPDs correlate with a poor clinical outcome, the presence of these alterations has not been a consistently useful predictor of lesion regression after reduction of immunosuppression. We examined 57 PT-LPD lesions obtained from 36 solid organ transplant recipients for the presence of mutations in the BCL-6 proto-oncogene using single-strand conformation polymorphism and sequence analysis, followed by correlation with histopathologic classification and clinical outcome, which was known in 33 patients. BCL-6 gene mutations were identified in 44% of the specimens and in 44% of the patients; none were identified in the cases classified as plasmacytic hyperplasia. However, mutations were present in 43% of the polymorphic lesions and 90% of the PT-LPDs diagnosed as non-Hodgkin's lymphoma or multiple myeloma. BCL-6 gene mutations predicted shorter survival and refractoriness to reduced immunosuppression and/or surgical excision. Our results suggest that the BCL-6 gene structure is a reliable indicator for the division of PT-LPDs into the biological categories of hyperplasia and malignant lymphoma, of which only the former can regress on immune reconstitution. The presence of BCL-6 gene mutations may be a useful clinical marker to determine whether reduction in immunosuppression should be attempted or more aggressive therapy should be instituted.

Cell Transformation, Neoplastic↗

PubMed2000

Loss of nucleus basalis neurons containing trkA immunoreactivity in individuals with mild cognitive impairment and early Alzheimer's disease.

Recent studies indicate that there is a marked reduction in trkA-containing nucleus basalis neurons in end-stage Alzheimer's disease (AD). We used unbiased stereological counting procedures to determine whether these changes extend to individuals with mild cognitive impairment (MCI) without dementia from a cohort of people enrolled in the Religious Orders Study. Thirty people (average age 84.7 years) came to autopsy. All individuals were cognitively tested within 12 months of death (average MMSE 24.2). Clinically, 9 had no cognitive impairment (NCI), 12 were categorized with MCI, and 9 had probable AD The average number of trkA-immunoreactive neurons in persons with NCI was 196, 632 +/- 12,093 (n = 9), for those with MCI it was 106,110 +/- 14,565, and for those with AD it was 86,978 +/- 12,141. Multiple comparisons showed that both those with MCI and those with AD had significant loss in the number of trkA-containing neurons compared to those with NCI (46% decrease for MCI, 56% for AD). An analysis of variance revealed that the total number of neurons containing trkA immunoreactivity was related to diagnostic classification (P < 0.001), with a significant reduction in AD and MCI compared to NCI but without a significant difference between MCI and AD. Cell density was similarly related to diagnostic classification (P < 0.001). There was a significant correlation with the Boston Naming Test and with a global score measure of cognitive function. The number of trkA-immunoreactive neurons was not correlated with MMSE, age at death, education, apolipoprotein E allele status, gender, or Braak score. These data indicate that alterations in the number of nucleus basalis neurons containing trkA immunoreactivity occurs early and are not accelerated from the transition from MCI to mild AD.

Aged↗

PubMed2002

Multilevel modelling of medical data.

This tutorial presents an overview of multilevel or hierarchical data modelling and its applications in medicine. A description of the basic model for nested data is given and it is shown how this can be extended to fit flexible models for repeated measures data and more complex structures involving cross-classifications and multiple membership patterns within the software package MLwiN. A variety of response types are covered and both frequentist and Bayesian estimation methods are described.

Algorithms↗

PubMed2002

Multiple genes and the monophyly of Ischnocera (Insecta: Phthiraptera).

Whereas most traditional classifications identify Ischnocera as a major suborder of lice in the order Phthiraptera, a recent molecular study based on one gene did not recover monophyly of Ischnocera. In this study we test the monophyly of Ischnocera using sequences of portions of three different genes: two nuclear (EF1 alpha and 18S) and one mitochondrial (COI). Analysis of EF1 alpha and COI sequences did not recover monophyly of Ischnocera, but these genes provided little support for ischnoceran paraphyly because homoplasy is high among the divergent taxa included in this study. Analysis of 18S sequences recovered ischnoceran monophyly with strong support. Sequences from these three gene regions showed significant conflict with the partition homogeneity test, but this heterogeneity probably arises from the dramatic differences in substitution rates. In support of this conclusion, Kishino-Hasegawa tests of the EF1 alpha and COI genes did not reject several trees containing ischnoceran monophyly. Combined analysis of all three gene regions supported monophyly of Ischnocera, although not as strongly as analysis of 18S by itself. In sum, although rapidly evolving genes can retain some phylogenetic signal for deep phylogenetic relationships, strong support for such relationships is likely to come from more slowly evolving genes.

Animals↗

PubMed1982

Phonological process development with MLU-referenced guidelines.

Sixty subjects between the ages of 21 and 48 months were placed into groups based on mean length of utterance (MLU) and chronological age (CA) to test Stampe's hypothesis about the development of phonological processes. The subjects were given the Phonological Process Analysis (Weiner, 1979), and a proportion score for each of sixteen phonological processes was derived for each subject. The use of the various phonological processes across MLU groups and age groups was analyzed by multiple regression correlation, three-way ANOVA, and Tukey's HSD tests. MLU was found to be the best classification for the subjects for describing the phonological processes. The results and discussions present MLU-referenced guidelines regarding the emergence, duration, elimination, and universality of the sixteen phonological processes.

Age Factors↗

PubMed2002

Is anxiety a more common disorder than depression in rheumatoid arthritis?

OBJECTIVE: As most of the previous studies were done to study depressive disorders and/or symptoms in patients with rheumatoid arthritis, this study was performed to investigate whether anxiety disorder is as common as depressive disorder in these patients and to look for the socio-demographic as well as the clinical characteristics of the patients developing these disorders. METHODS: A detailed physical assessment of 80 patients with rheumatoid arthritis was performed. Also psychiatric assessment was done using Research Diagnostic Criteria for the International Classification of Diseases-10 (ICD-10). In addition, patients answered a Health Assessment Questionnaire (HAQ) to assess their functional capacity. RESULTS: Depression was diagnosed in 66.2% of the total sample while anxiety was diagnosed in 70%. Functional disability, social stress and morning stiffness were the factors highly associated with depression. Using multiple regression analysis, anxiety was highly associated with depression as well as Ritchie articular index. CONCLUSION: Psychiatric illness is a relatively common disorder in patients with RA, with a frequency higher than that of other general medical conditions. Anxiety is a more common disorder than depression. The first step in correct management is recognition of anxiety and depression so that appropriate treatment can be tried. Particular attention has to be paid to social stress and lack of social support.

Adult↗

PubMed1997

Cumulative and compensatory effects of competence and incompetence on depressive symptoms in children.

The authors tested 5 hypotheses from a competency-based model of child depression using classification and regression tree analysis. The authors obtained measures of 5 domains of competency (i.e., academic competence, social acceptance, sports competence, physical attractiveness, and behavioral conduct) and depressive symptoms that were derived from parent, teacher, peer, and self-reports on 1,063 3rd- and 6th-grade children. Results suggested that (a) multiple domains of competence related to depressive symptoms, (b) significant others' positive evaluations in multiple domains have a cumulative inverse relation to depressive symptoms, (c) negative evaluations in multiple domains have a cumulative but positive relation to depressive symptoms, (d) positive evaluations in one domain somewhat compensate for negative evaluations in another domain, and (e) negative evaluations in one domain offset positive evaluations in another domain.

Child↗

PubMed2005

Multirater agreement of arthroscopic grading of knee articular cartilage.

BACKGROUND: Acute and chronic cartilage injury of the knee has an important impact on prognosis. The validity of the classification of such injuries is critical for prospective multicenter studies. The agreement among multiple surgeons at different institutions for articular cartilage lesions has not been established. HYPOTHESIS: Arthroscopic classification of articular cartilage lesions is reliable and reproducible and can be used for multicenter studies involving multiple surgeons. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 1. METHODS: A total of 6 surgeons from 5 centers reviewed 31 videos of articular cartilage lesions. With grade 2 and grade 3 combined for the analysis, observed agreement ranged from 81% to 94%, and kappa ranged from 0.34 to 0.87. An additional 22 videos comprising grade 2 and grade 3 lesions were analyzed, and the observed agreement was 80%, with an overall kappa of 0.47. CONCLUSION: Arthroscopic grading of articular cartilage lesions is reproducible among surgeons at different centers. CLINICAL RELEVANCE: Articular cartilage lesions can be reliably classified among surgeons at different sites. Such reliability is important for multicenter clinical research studies involving arthroscopic knee surgery.

Arthroscopy↗

PubMed2005

Frontotemporal dementia, semantic dementia, and Alzheimer's disease: the contribution of standard neuropsychological tests to differential diagnosis.

CERAD-NAB (Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery) data were compared between 51 patients with frontotemporal dementia, 13 with semantic dementia, and 69 with Alzheimer's disease. There were statistically significant differences between the 3 groups. Compared with patients with Alzheimer's disease, patients with frontotemporal dementia were more impaired on Animal Fluency but not on any other CERAD-NAB subtest. Patients with semantic dementia performed worse in Animal Fluency and Boston Naming Test compared with frontotemporal dementia and Alzheimer's disease. Multiple logistic regression analysis revealed that in the differentiation between frontotemporal dementia and Alzheimer's disease, the combination of Animal Fluency and Boston Naming Test correctly classified 90.5% of patients. In segregating semantic dementia and Alzheimer's disease, the combination of Boston Naming Test and Mini Mental State Examination resulted in a correct classification of 96.3%. These findings demonstrate that the Mini Mental State Examination and the language subtests of the CERAD-NAB are valuable clinical instruments for the differential diagnosis between early frontotemporal dementia, semantic dementia, and Alzheimer's disease.

Aged↗

PubMedDate not supplied

Association between glycaemic control and quality of life in diabetes mellitus.

BACKGROUND: Relationship between quality of life (QOL) and haemoglobin A1c (HbA1c) amongst diabetics in the community setting is unclear. AIMS: Assess the association between QOL and change in HbA1c in diabetic patients over one year. SETTINGS AND DESIGN: Cohort study of patients from four community clinics in California, USA. METHODS: Diabetic patients identified from databases using International Classification of Disease (ICD-9) codes were asked to complete Short Form 36 (SF-36), which measures health-related QOL, and invited to attend monthly diabetes workshops. From December 2000 to December 2001, data were collected on multiple parameters, including HbA1c. SF-36 surveys were re-collected at project termination. STATISTICAL ANALYSIS: Regression analysis was used to correlate change in HbA1c with change in QOL physical component summary (PCS) and mental component summary (MCS) scores, while considering potential confounders. RESULTS: Of 1679 eligible patients, 380 completed SF-36 at project initiation. 243 of those completed SF-36 at project termination. Pre and post HbA1c data were available for 170 of the 243 who completed SF-36 at both times. Average MCS increased by 8.46% and PCS decreased by 2.24%. After adjustment, a 5% decrease in HbA1c values was associated with a 1% increase in MCS. No association between changes in HbA1c and PCS was observed. CONCLUSIONS: Association between better HbA1c and improved mental, but not physical, QOL may reflect physical inconvenience of increased regimen complexity and mental empowerment from proactive disease management. Larger cohort studies with longer follow-up are needed to further elucidate the relationship between glycemic control and QOL.

Cohort Studies↗

PubMed1991

[Image diagnosis of polypoid lesions of the gallbladder].

Between 1980 and 1990, 120 cases of polypoid lesions of the gallbladder (GBPL), confirmed surgically and pathologically, were evaluated comprehensively with each kind of image examinations. 110 cases of B-US data were dealt with multiple stepwise regression analysis, and three carcinoma risk factors (size & location of the lesion, age of the patient) were found. The results of Mahalanobis' discriminant analysis showed that the conformity rates of retrospective test (80 cases) and prospective test (30 cases) were 94% and 90%, respectively. In addition, we put forward our own clinical classification of GBPL according to the surgical and pathological data and the need of clinical practice.

Adenocarcinoma↗

PubMed2005

A global view of pleiotropy and phenotypically derived gene function in yeast.

Pleiotropy, the ability of a single mutant gene to cause multiple mutant phenotypes, is a relatively common but poorly understood phenomenon in biology. Perhaps the greatest challenge in the analysis of pleiotropic genes is determining whether phenotypes associated with a mutation result from the loss of a single function or of multiple functions encoded by the same gene. Here we estimate the degree of pleiotropy in yeast by measuring the phenotypes of 4710 mutants under 21 environmental conditions, finding that it is significantly higher than predicted by chance. We use a biclustering algorithm to group pleiotropic genes by common phenotype profiles. Comparisons of these clusters to biological process classifications, synthetic lethal interactions, and protein complex data support the hypothesis that this method can be used to genetically define cellular functions. Applying these functional classifications to pleiotropic genes, we are able to dissect phenotypes into groups associated with specific gene functions.

Algorithms↗