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At least 19 recordsLinked to original sources
PubMed1992

Hemophilia A carrier detection by restriction fragment length polymorphism analysis and discriminant analysis based on ELISA of factor VIII and vWf.

We performed carrier determination on female subjects from 32 hemophilia A kindreds with a combination of restriction fragment length polymorphism analysis and discriminant analysis of factor VIII antigen and von Willebrand factor antigen analyzed by enzyme-linked immunosorbent assay. Subjects included 25 obligate carriers, 30 at-risk female subjects from 19 kindreds each with two or more male subjects, with hemophilia and 28 at-risk female subjects from 13 kindreds each with a single sporadic case. Deoxyribonucleic acid (DNA) analysis with factor VIII intragenic probes clarified the carrier status of 15 female subjects, and extragenic probes classified an additional 14. Discriminant analysis, which identified 24 of 25 (96%) obligate carriers with carrier probabilities greater than or equal to 0.71 and 37 of 39 (95.0%) normal female subjects with probabilities less than or equal to 0.30, was useful for clarifying the carrier status of the female subjects who were not helped by DNA analysis and those that were classified by extragenic probes alone. Twenty-nine female subjects could not be categorized by restriction fragment length polymorphism analysis because DNA was unavailable from the subject or from key family members, key female subjects were noninformative, or carriership could not be excluded by restriction fragment length polymorphism in kindreds with sporadic cases. We studied 28 of these female subjects by discriminant analysis; 15 had carrier probabilities of greater than or equal to 0.71, 12 less than or equal to 0.30, and 1 = 0.35. All carriers by extragenic probes had carrier probability values greater than or equal to 0.71, whereas all noncarriers had values less than or equal to 0.30. In some families, particularly those in which gonadal mosaicism was a possibility, extensive family studies together with DNA and discriminant analyses were required for clarifying the source of the mutation, and hence the carrier status of the at-risk female subjects. Thus DNA and discriminant analyses complement each other, and when combined with careful pedigree analysis, the power of carrier determination is increased in some families.

DNA↗
PubMed1978

Discriminant analysis.

Discriminant analysis (DA) is a pattern recognition technique that has been widely applied in medical studies. It allows multivariate observations ("patterns" or points in multidimensional space) to be allocated to previously defined groups (diagnostic categories). The relationships between DA and other multivariate statistical techniques of interest in medical studies will be briefly discussed. The main emphasis is on linear discriminant functions (LDF). The theoretic assumptions underlying DA using LDFs will be presented, and the effect of violations to these assumptions will be reviewed in detail. Alternative methods will be presented when violations cause serious problems. It has been shown that the familiar LDF is fairly robust to departures from the assumptions. The application of the LDF in less than ideal situations therefore often does not cause much harm (if the violations are not too grotesque). Another set of problems reviewed is how to estimate the misallocation probabilities when using discriminant functions. The selection of the "best" subset of variables out of the complete set will be discussed. Practical guide lines are given based on the theoretic studies reviewed. When possible, available computer programs for various problems of DA will be indicated. The review does not aim at covering all medical studies where DA has been applied, since emphasis is on the practical conclusions of the theory of DA.

Discriminant Analysis↗
PubMed1978

Discriminant analysis of bronchial asthma by linear discriminant function with parameters of flow-volumes: discriminant analysis of bronchial asthma in young male non-smokers.

With the parameters of a flow-volume and a volume-time curve, the discriminant analysis of bronchial asthma is described. The subjects were classified into three groups (healthy adults, mild asthmatic patients and moderates ones). The difference of the mean vectors of the parameters of the three groups was made clear by the selection methods of the discriminant analysis between any two of the groups both with 6 parameters (%FVC, FEV1.0%, peak flow rate (PF), flow rate at 50% of FVC (V50), flow rate at 25% of FVC (V25), and V50/V25) and with 8 (6 parameters mentioned above and V75, V10). Forced expiratory volume in 1 second percent (FEV1.0%) or V50 was selected at the first step with 6 parameters, and V75 was selected at the first step with 8 parameters. Probabilities of misclassification with 8 parameters were lower than those with 6 ones and the probability of misclassification at the discriminant analysis between healthy adults and mild asthmatic patients with 8 parameters was 15.75% at the final step.

Adult↗
PubMed1975

Amino acid residues of serum and CSF protein in multiple sclerosis. Clinical application of statistical discriminant analysis.

Statistical discriminant analysis of the amino acid compostion of serum and cerebrospinal fluid (CSF) proteins provides an objective method for distinguishing between normal controls and patients with multiple sclerosis (MS). This method also results in a high degree of specificity in separating MS patients from those with other diseases of the nervous system. The CSF protein serine residue is highly correlated with the CSF IgG and holds promise for a more sensitive diagnostic test for MS than the currently used CSF IgG. Finally, the serum/CSF protein serine ratio seems to correlate best with clinically determined degree of activity for the disease, the most active cases having the lowest ratio. These results suggest that investigation of the amino acid composition of serum and CSF protein in multiple sclerosis and, possibly, in other diseases might lead to the development of clinically useful tests of diagnosis and degree of activity of MS.

Amino Acids↗
PubMed1978

Quantitative nuclear image analysis: differentiation between normal, hyperplastic, and malignant appearing uterine glands in a paraffin section. IV. The use of Markov chain texture features in discriminant analysis.

Discriminant analysis was applied to Markov chain texture features and elementary features calculated from data from microscope photometry of nuclei in a paraffin section. The results from measurements on the nuclei of morphologically normal, atypical hyperplastic and carcinomatous uterine glands were used in discriminant analysis. With this technique it is possible to classify up to 88.1% of the nuclei correctly in one of the three groups of uterine glands. The discriminating power of several smaller subsets indicated that with more than 28 features there is hardly any increase in discriminating power. Discriminant analysis with a selection from elementary and Markov chain features provides objective criteria of assistance in histopathological diagnosis.

Cell Nucleus↗
PubMed1977

[Repeated characterization, analysis of variance limitation and discrimination analysis classification of EEG-activity patterns in human sleep].

1. To describe quantitatively and to deliminate nine EEG sleep patterns, mean values and standard deviations of abundances of the frequencies 0.8 ... 1.8 c/sec, 2...3.5 c/sec, 4...13c/sec, 14 to 17 c/sec, 18 to 22 c/sec, and 23 to 40 c/sec as well as of the average amplitudes in selected frequency ranges were calaculated and the distributions represented. 2. All nine EEG activity patterns could be separated by means of univariate and multivariate analyses of variance on the basis of all 28 as well as the 17 indispensable variables. 3. In the course of a stepwise reduction of variables within the framework of a linear discriminant analysis an optimal set of 17 variables was determined for the separation of the patterns, comprising: the percent quantity of the frequencies 0.8 ... 3.5 c/sec, 7 ... 9 c/sec and 18 to 40 c/sec as well as the average amplitudes in the frequency ranges 0.8 to 3.5 c/sec and 7.5 to 40 c/sec. 4. By linear regression analyses it could be shown that the sleep scording system used, can be reflected on an interval scale with the aid of discriminant functions; this can be achieved on the basis of the optimal set of variables as well as of the five most indispensable variables. 5. Finally the degree of the objectivity of the scoring procedures was demonstrated. Advantages and disadvantages of sleep scoring systems were discussed and possibilities of the utilization of results suggested, also in respect to the further development of the automatic recognition of EEG activity patterns.

Analysis of Variance↗
PubMed1975

[Statistical evaluation of biochemical data by the method of discrimination analysis. Selection of the discriminant biochemical variables. Attempted biochemical discrimination of intrahepatic cholestasis, extrahepatic obstruction and liver cancer].

An original method of statistical treatment of biological data is proposed. It permits satisfactory biochemical classification of 322 patients divided up into 3 groups : intrahepatic cholestasis (235 patients), extrahepatic obstruction (44 patients) and carcinoma of the liver (43 patients). On the basis of 32 tests, it was possible to define discriminating areas permitting satisfactory diagnosis in 95 per cent of published cases. The reduction in the number of tests necessary for diagnosis was considered. The selection technic used was original to the extent that it dose not require, like most methods used today, the determination of better individual discriminators, but the establishment of a better discriminating subunit, obtained from the initial subunit composed of a group of variables. From the 32 parameters contained in the standard liver function tests, a search for a better discriminating subunit consisting of the best four tests, permitted the authors to select a group of 10 tests : bilirubin, alkaline phosphatase, 5-nucleotidase, Thymolturbidity, Cetavlon test, serum albumin, total LDH, TGP (ALAT), OCT, GLDH, of which the discriminating value remains very satisfactory.

Analysis of Variance↗
PubMed1978

Discriminant analysis and structure-activity relationships. 1. Naphthoquinones.

Discriminant analysis has been used to study the data for naphthoquinones as antitumor agents in three different animal tumor systems. In each case the most significant variables for classifying the compounds into two groups according to their antitumor activities were determined by a stepwise procedure. The usefulness of discriminant analysis in the design of drugs is discussed.

Animals↗
PubMed1977

Quantitative nuclear image analysis: differentiation between normal, hyperplastic, and malignant appearing uterine glands in a paraffin section. II. Computer assisted recognition by discriminant analysis.

Quantitative image analysis was applied to data from microscope photometry of nuclei in a paraffin section. The data were essentially the same as described in a previous publication (Baak and Diegenbach, 1977). The results from measurements on the nuclei of morphologically normal, atypical hyperplastic and carcinomatous uterine glands were used in discriminant analysis. With this method it is possible to discriminate between the three groups of nuclei. Depending on the (sub)set of the variables used, 60-70% of all nuclei are correctly classified in one of the three groups. Discrimination of one of the groups against the other two results in up to 81% correct classifications. Therefore, discriminant analysis offers a possibility of assisting diagnosis in an objective way.

Cell Nucleus↗
PubMed1992

Discriminant analysis when all variables are ordered.

Determination of the equation that relates an ordered dependent variable to ordered independent variables is sought. One solution, non-parametric discriminant analysis (NPD), involves obtaining the best monotonic step function by means of a computer search procedure. Although one can use alternative selection criteria in obtaining the equation, the illustrative examples use absolute distance. This paper compares the prediction procedures obtained from NPD with those from linear discriminant analysis, linear regression (with and without transformed variables), and logistic regression. We show that NPD is analogous to regression tree analysis with incorporation of ordered variables and monotonicity. We use various prediction functions to predict the example data, the data using the leave-one-out technique, and a verification set. Consistently, non-parametric discriminant analysis performs as good as or better than the tested alternatives.

Craniocerebral Trauma↗
PubMed1992

Factors involved in burn mortality: a multivariate statistical approach based on discriminant analysis.

This article suggests an alternative statistical model for studying the mortality of burned patients: discriminant analysis. This model was applied to our population of 532 patients among whom 71 died. It is not the first time that this model has been applied to assess burn mortality, although it is not frequently used for that application. We found four factors that are statistically significant: age, TBSA, inhalation injury and sex (female). Discriminant analysis allowed us to demonstrate an impressive correlation between death, age and TBSA; inhalation injury by itself and sex, the two other significant factors in our study, seem to have a minor influence on the final outcome of the burned patients and their predictive value is virtually nil. The advantages of this statistical model are compared with logistic regression, the commonly chosen statistical method.

Adult↗
PubMed1975

[The differential-diagnostic value of evoked potentials in depressive patients according to discriminant analysis findings].

The authors conducted a discriminant analysis of visual evoked potentials in depressive patients and in normals. The depressive syndrome was correctly diagnosed in 76--90% of the cases. The main role in the diagnosis of such cases belongs to interhemispheric correlational connections in the frontal brain areas. Between these connections there was an intercompensatory relationship. It was possible to demonstrate some traits of intrahemispheric connections in the left hemisphere of normals and in the right hemisphere of the depressed patients. Certain tendencies were marked in the distribution of patients according to the expressiveness of affective disorders.

Adult↗
PubMed1992

Classification of turkeys as low or high volume semen producers using discriminant analysis.

Medium White turkeys in Generation 10 of divergent selection for semen ejaculate volume (SEV) were classified into lines that produce either low or high volumes of semen using a multivariate statistical technique, discriminant analysis. The discriminant function was based on records of hen fertility, embryonic mortality in the early and late incubation periods, and the incidence of pipped eggs. A hit ratio, the proportion of birds correctly categorized as low or high, of .60 was obtained. The discriminant function was subsequently used to classify birds in Generation 12. A misclassification rate of .28 and .48 was obtained for birds in the low and high lines, respectively. It was concluded that the relatively low rates of misclassification indicate a potential method for identifying male and female turkeys as belonging to low or high SEV lines, based on fertility and incubation records.

Animals↗
PubMed1979

Genetics of classic von Willebrand's disease. II. Optimal assignment of the heterozygous genotype (diagnosis) by discriminant analysis.

In classic von Willebrand's disease (vWd), assignment of the heterozygous genotype for genetic studies and diagnosis for clinical purposes (which are not exactly the same) are formidable problems. We have pointed out in the first report in this series that almost 50% of the members of two large kindred who transmitted this disease, and were therefore heterozygous, were scored as normal by the usual tests of hemostasis. This report describes how this large proportion can be significantly reduced by application of discriminant analysis. Using linear discriminants in three variables--coagulation factor VIII (VIII:C), factor-VII-related antigen (VIIIR:Ag), and the ristocetin cofactor related to factor VIII (VIIIR:WF)--we were able to classify as heterozygous more than 80% of the transmitters in the two large kindred. It was of particular interest that the four parents of two related vWd homozygotes could be scored as heterozygous by discriminant analysis even though all their laboratory tests were within the normal ranges.

Adult↗
PubMed1975

A simulation study of the efficacy of stepwise discriminant analysis in the detection and comparison of event related potentials.

Cortical average evoked potentials were simulated by summing five damped sinusoids. The characteristics of these "evoked" responses could be manipulated by changing parameters of the sinusoids. The synthesized signals were mixed with noise processes whose power and band-width were manipulated. Thus data were generated to stimulate a variety of conditions which could conceivably occur in an experiment on evoked potentials. Stepwise discriminant analysis (BMD07M) has been applied to these simulated data in an attempt to determine the degree to which the program identifies, in a sensible manner, the differences we introduced into the synthesized evoked responses. The simulation results indicate that stepwise discriminant analysis can indeed be an efficacious tool in research on evoked potentials. The program does detect differences in evoked potentials. It can be used, with some reservations, to identify the components of an evoked potential which the experimental variables have affected. In a special set of simulations we have attempted to determine the degree to which stepwise discriminant analysis could serve to detect the presence or absence of an evoked potential. These simulations show that the score of an average evoked potential in the data. The implications of this finding to the use of evoked potentials in sensory sensitivity testing were evaluated in studies for the effect on them of stimulus intensity.

Electroencephalography↗
PubMed1976

[Use of discrimination analysis in perinatology].

From 50 normal births blood of mother and child was examined simultaneously at three different times, meant for determination of 13 biochemical parameters. Evaluation of the measured values was done by the multivariate method of discriminance analysis. Basing on the observed data problems of discriminance analysis are dealt with in an introductive way. The perinatal example is used to demonstrate how in the case of a complex problem connections may be better visible by this method, though detailed informations are lost.

Adenosine Triphosphate↗
PubMed1978

Discriminant analysis in the differential diagnosis of hypercalcaemia.

Linear discriminant analysis, a multivariate statistical procedure, applied to serum calcium, phosphate, alkaline phosphatase, bicarbonate, chloride, creatinine and tubular reabsorption of phosphate, proved to be effective in distinguishing patients with Primary Hyperparathyroidism from other hypercalcaemic patients in eithy-four retrospective cases. The application of the model to thirty-four prospective cases enabled us to separate correctly, hyperparathyroid patients from non-parathyroid hypercalcaemic patients.

Diagnosis, Differential↗