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PubMed1988

Discriminant analysis of dermatoglyphic measurements in fragile X males and females.

Two hundred and eight fragile X subjects (92 males and 116 females) and matched Australian (60 males and 32 females) and British (122 males and 118 females) normal samples were used to calculate 4 discriminant functions, based on dermatoglyphic measurements. The most efficient discriminating variables between fragile X and normal males, selected by means of the Wilk's stepwise method, included: ridge counts on fingers 1-3, the hallucal (f) count on soles, the atd angle, and pattern intensities in palmar areas 2, 4 and 5 as well as on fingers 4 and 5. In females, the ridge breadth, the hallucal (e) count, the atd angle and pattern intensities in palmar areas 3-5 as well as on fingers 1, 3 and 5 comprised the final discriminant. The misclassification rate based on distributions of individual discriminant scores in each pair of samples, and on prior probabilities, was lowest (16.8%) in fragile X males compared with the Australian normal subjects. In both female comparisons, this rate approached 44%. A bias to misclassification rates resulting from various analytical procedures and some properties of the data are discussed. We conclude that the discriminant function based on dermatoglyphic measured variables alone is not good enough for assessing carrier probabilities for fragile X, especially in females. However, we have been able to select the best discriminators which may be used, together with other measured body characteristics, to obtain a more powerful discriminant function. Moreover, a consideration of discriminant scores based on dermatoglyphic traits only may help in estimating carrier probabilities.(ABSTRACT TRUNCATED AT 250 WORDS)

Dermatoglyphics↗
PubMed1988

Discriminant analysis of clinical outpatients and public school children by TEMAS: a thematic apperception test for Hispanics and blacks.

This study investigated the utility of the minority version of the Tell Me a Story (TEMAS) test, a thematic apperception technique for minorities and nonminorities, by discriminating public school and clinical Hispanic and Black children. The test is composed of 23 stimuli, depicting minority characters interacting in urban settings, and is scored for nine personality functions (e.g., aggression and anxiety). The subjects were 100 outpatients at psychiatric centers and 373 public school students, all from low socioeconomic (SES), inner city families. All subjects were tested individually by examiners of the same ethnicity. Results indicated that TEMAS profiles significantly, p less than .001, discriminated the two groups and explained 21% of the variance independent of ethnicity, age, and SES. Classification accuracy, based on the discriminant function, was 89%. The TEMAS profiles interacted with ethnicity; better discrimination was evident for Hispanics than Blacks. Results are discussed in terms of the need to develop and validate culturally sensitive personality tests for ethnic minorities.

Adolescent↗
PubMed1989

Assessment of ultrasonic computed tomography in symptomatic breast patients by discriminant analysis.

From 95 subjects imaged with both speed of sound and attenuation ultrasonic computed tomography (UCT), quantitative analyses are presented on 40 cases where unequivocal correlating clinical diagnoses are available. Using four attenuation and speed of sound parameters from different regions of interest in the breast, a linear discriminator detects cancer with approximately 90% sensitivity and specificity. Increased confidence in the predictive power of this small study is given by a modern test of predictive power (jackknifing) and by the fact that diagnostic discrimination remains as high as 85% when only two parameters are employed--attenuation and speed of sound in the lesion minus those values in the remaining central mammary tissues. Speed of sound images appear particularly useful in older, fatty breasts where pulse echo ultrasound is particularly lacking. While UCT in the form studied here is not likely to receive wide clinical acceptance in the near future, a combined UCT/pulse echo system might find wide clinical utility if it can be sufficiently convenient and inexpensive.

Adenofibroma↗
PubMedDate not supplied

[Multidimensional discriminative analysis for predicting the outcome of Graves' disease (author's transl)].

Attempts to identify at an early stage of Graves' disease patients who will respond favorably to the various treatments available have been largely unsuccessful. However, all such studies have been based on the measurement of a single discriminant at a time, and in an attempt to improve predictive accuracy we have made use of multidimensional techniques which analyse several factors simultaneously. The overall accuracy in predicting the outcome in drug-treated patients, before treatment was started, was 79% ; in RAI treated patients 88 %. There remains a residuum of patients whose fluctuations in disease activity are such as to defy all prediction of outcome.

Antithyroid Agents↗
PubMed1985

Age differences on alcoholic MMPI scales: a discriminant analysis approach.

Ninety-one male alcoholic inpatients were administered the MMPI after detoxification. Subjects were divided into four age groups. One-way analysis of variance was calculated on the 13 clinical scales and 15 experimental scales (A, R, ES, MT, LB, CA, DY, DO, RE, PR, ST, CN, AT, SO-R, AMAC). In addition, two discriminant analyses were calculated to evaluate whether the inclusion of the 15 experimental scales would increase the percent of correctly classified alcoholics according to age. Results indicated that the Psychopathic Deviant and Paranoia scales declined with increasing age. The Low Back Pain scale indicated a decline from the 50-65 group to the 20-29 group, while the Responsibility scale increased with age. Results from the two discriminant analyses suggested that inclusion of the 15 experimental scales improved the percentage of correctly classified alcoholics.

Adult↗
PubMed1984

Predicting male and female contraceptive behavior: a discriminant analysis of groups high, moderate, and low in contraceptive effectiveness.

An exploratory, multivariate study was carried out to assess (a) whether three contraceptive-effectiveness groups (high, moderate, and low) could be differentiated on the basis of variables that have been theoretically and empirically associated with contraceptive behavior and (b) whether an identified set of discriminating variables could accurately classify sexually active college students into these groups. Three hundred sixty-five sexually active, never-married college students (211 males and 154 females) completed instruments measuring variables related to contraception. Four separate discriminant analyses were performed, one for each sex for both their initial sexual encounter and their current sexual interactions. Discrimination and classification of the three contraceptive groups for both males' and females' initial sexual experience was not very successful. Moderate discrimination was achieved for the female current sexual activity subsample and good discrimination and classification was made for the currently sexually active male subsample. The results are discussed in terms of the implications of the findings for understanding contraceptive behavior of males and females, problems with the dependent variable of contraceptive use, and the mounting evidence that emotional orientation to sexuality influences contraceptive behavior.

Adult↗
PubMed1999

Drug discrimination analysis of partial agonists at the benzodiazepine site. I. Differential effects of U-78875 across training conditions in baboons and rats.

The benzodiazepine receptor ligand U-78875 [3-(5-cyclopro pyl-1,2, 4-oxadiazol-3-yl)-5-(1-methylethyl)imidazol(1, 5-a)quinoxalin-4(5H)-o-ne] was studied in rats trained to discriminate i.p. 1.0 mg/kg lorazepam, 1.0 mg/kg diazepam, or 10 mg/kg pentobarbital, and baboons trained to discriminate oral 1.8 mg/kg lorazepam or 10 mg/kg pentobarbital. U-78875 doses were 0.01 to 10 mg/kg i.p. in rats and 0.32 to 56 mg/kg orally in baboons. U-78875 occasioned drug-appropriate responding in pentobarbital-trained (ED50 = 1.8 mg/kg) and diazepam-trained (ED50 = 0.056 mg/kg) rats, but it occurred in only one pentobarbital-trained baboon and not in the majority of lorazepam-trained baboons or rats. In baboons that generalized to U-78875, discriminative effects were antagonized by flumazenil. The interaction of U-78875 with pentobarbital, diazepam, and lorazepam revealed further differences in its behavioral effects. U-78875 potentiated the effects of pentobarbital, even in baboons that did not generalize to U-78875, but U-78875 had little effect in combination with diazepam. In lorazepam-trained animals that did not generalize to it, U-78875 antagonized lorazepam's effects, but U-78875 neither antagonized nor potentiated lorazepam in animals that did generalize to U-78875. Thus, although U-78875 generally functioned as a benzodiazepine agonist in pentobarbital- and diazepam-trained animals, its unique effects in lorazepam-trained animals appear to reflect its in vitro profile as a partial agonist.

Acoustic Stimulation↗
PubMed1988

A simplified test to detect PKU heterozygotes by discriminant analysis in mentally retarded children and their mothers.

We have developed classification coefficients and an equation to detect heterozygotes for phenylketonuria. The combination of several variables (Phe, Phe/Tyr, Phe2/Tyr) gave a safe diagnosis in more than 96% of cases. We then computerized a random selection of our population, which was divided into two groups: the first was "selected" to compute discriminant functions, while the second, excluded from computation, was used to check the fitness of our method. Despite the reduction of sample size, 95.2% of unknown subjects were correctly classified. Finally, we used our equation to detect heterozygotes for phenylketonuria in a population of 26 children, affected by non-specific mental retardation, and their mothers. We found a high proportion of carriers for phenylketonuria, defined as subjects having a percent probability of correct classification higher than 90. By this method, heterozygosity was detected in two child-mother couples, four individual children and five mothers.

Adult↗
PubMed1991

Aggression in African-American boys: a discriminant analysis.

The main purposes of this study were to determine whether familial variables found to be related to the development of aggressive behavior in Caucasian boys may also be related to similar aggressive patterns in inner-city African-American boys and to assess the relative importance of these variables for classifying the subject population into aggressive and nonaggressive groups. Discriminant analyses were performed using 83 African-American boys, with a mean age of 13.9 years, who were classified as institutionalized aggressive, noninstitutionalized aggressive, and noninstitutionalized nonaggressive subjects. Although the same father and mother variables were used in the analyses, the father variables were not related to group membership. Furthermore, the results showed that both groups of aggressive boys reported more aggression within as well as outside their family home settings than their nonaggressive counterparts. Socioeconomic-related factors such as employment status of parent(s), size of family, and number of parents in the household were not useful predictors of aggressive and nonaggressive group membership.

Adolescent↗
PubMed2003

Two-color image analysis discriminates between mineralized and unmineralized bone nodules in vitro.

Functional assays of progenitor cell capacity for colony formation in vitro typically depend on the investigator's expertise with quantification. The ability to enumerate and analyze colony types with standardized criteria with no bias would be a useful tool for research and drug development. We report the development of a two-color automated analysis system for colony-forming unit-osteoblasts that is capable of reporting progenitor frequency and bone nodule number size, and type (mineralized or unmineralized). Our image analysis system was validated using the rat calvaria cell model to measure in vitro bone nodule development. With computer-aided image analysis, data on nodules can be rapidly generated with a minimum of user bias and fatigue. This novel tool will distinguish mineralized and unmineralized bone nodules, facilitates quantification, enable large-scale experimental design, allow for long-term data storage and tracking, and lead to the identification of new parameters that impact bone development.

Animals↗
PubMed1988

Categorical discriminant analysis of 3'-splice site signals of mRNA precursors in higher eukaryote genes.

With regard to the signals that direct excision of introns from mRNA precursors in higher eukaryote genes, a consensus sequence, (sequence; see text); has been proposed for the 3'-splice site, but actual 3'-splice site sequences differ from it to a greater or lesser degree. In the present paper, nucleotide sequences were transformed into categorical data, and quantification analysis (class II), as proposed by Hayashi, was applied to the system. Categorical weights given to variables related to position and the species of nucleotide were estimated so that the two classes of 3'-splice site sequences and sequences other than 3'-splice site might be discriminated most distinctly. The 3'-splice site signals were then characterized in terms of these categorical weight values. We also calculated partial correlation coefficient values, which explain the relative importance of each position in the 3'-splice site signal sequence.

Base Sequence↗
PubMed1985

Modified nucleosides in asbestos workers at high risk of malignant disease: results of a preliminary study applying discriminant analysis.

Patients with asbestos related malignant mesothelioma excrete high levels of modified nucleosides in their urine. The purpose of the present report was to explore further the usefulness of measuring these breakdown products of transfer RNA (tRNA) in male asbestos insulation workers who are at high neoplastic risk but without clinical signs of malignancy. Modified nucleoside levels (psi, m'A, m'I, m2G, and ac4C) were used as discriminator variables in a computer generated discriminant function in which 96% of the controls and 95% of the insulation workers were correctly classified. It was also found, using a similar multiple regression model, that 10 of 13 were correctly classified as having normal chest radiographs and 27 of 30 asbestos exposed subjects as exhibiting alterations in either the parenchyma, pleura, or both. The results suggest that measuring modified nucleosides levels in the urine of asbestos exposed workers, and perhaps others exposed to carcinogenic agents, has the potential for identifying, through multivariate statistical techniques, individuals who are at high neoplastic risk.

Adult↗
PubMed1975

Discriminant analysis of antibiotic susceptibility as a means of bacterial identification.

This study shows that antibiotic susceptibility data can be used effectively in the presumptive identification of bacteria. Using 12 antibiotics and determining the zone sizes for each, 82% of the isolates considered were correctly identified without any other information. If the inability to distinguish between Escherichia coli and Shigella is disregarded, the percentage of correct identification is 92%. The method involves determining a set of discriminant functions and defining each taxon by a unique function. An unknown isolate is identified by evaluating each discriminant function and assigning the isolate to the taxon whose discriminant function has the largest value. A total of 468 isolates were examined. After eliminating the multiply resistant isolates, the remaining 369 isolates were used to determine the discriminant functions for the eight taxa considered.

Anti-Bacterial Agents↗
PubMed1989

Speech dysfunction of obstructive sleep apnea. A discriminant analysis of its descriptors.

We have previously demonstrated a relationship between abnormal speech and obstructive sleep apnea in a small subject sample. The present study was designed to replicate the previous one with a much larger population, analyze the perceptual characteristics of the speech quality, and determine the degree to which each of three descriptors of speech abnormality contributed to the perception of speech abnormality. Ten graduate students in speech pathology listened in two 1.5 hour sessions to 252 random speech samples presented on a master tape. There were 81 subjects comprised of 27 sleep apnea patients, 27 matched chronic obstructive pulmonary disease control patients, and 27 matched normal control subjects. Rating the speech along an equally-appearing interval scale from 1 to 7, the judges heard abnormal resonance, articulation or phonation in 74 percent of the sleep apnea subjects, 53 percent of the COPD subjects, and 7 percent of the normal subjects (significant difference by chi 2 test at the .01 level of confidence). Discriminant function equations based on these speech descriptors correctly identified 96.3 percent of the normal subjects and 63.0 percent of the sleep apnea subjects. Analysis of abnormal speech resonance, articulation and phonation may identify obstructive sleep apnea or may provide insight into its pathology.

Adult↗
PubMedDate not supplied

Depression among the head-injured and non-head-injured: a discriminant analysis.

Neuropsychologists often use traditional psychological tests to assess depression following a head injury; but the assumption that depression with a head injury resembles that in an uninjured person is suspect. The current study attempts to examine the cognitive manifestations of depression with and without a coexisting head-injury. Advanced statistical methods are used to assess whether or not the two depressions 'look alike' with respect to the neuropsychological sequelae of the disorders. A total of 1182 people were entered into one of two discriminant function analyses (DFA) for depression. Each person was a member of one of the following groups: (a) depressed, (b) non-depressed, (c) head-injured, or (d) head-injured and depressed. Two functions were performed for depression, one on the population of head-injured people and one on the population of uninjured people. Cross-validations were performed for each population and across populations in order to assess the utility of each population's function for the opposite group. This comparison allows the researcher to indirectly compare depression in the two populations. Both functions were successfully applied to either population when MMPI variables were included in the analyses. However, when only cognitive variables were included the function performed on the non-head-injured population did not correctly classify head-injured people as depressed or non-depressed. One explanation for this is that the range of cognitive scores in head-injured people is so great that it allows for a less accurate but more generalizable function. Suggestions for future research are discussed.

Adult↗
PubMed1980

[Use of discriminant analysis to study the personality traits of patients with the cerebral form of hypertension].

Results of experimental psychological examinations of 81 patients with the cerebral form of hypertensive disease are presented. The examinations were carried out using the method of personal subjective scaling. The informative value of 41 personal characteristics suitable for differentiation of the patients with reference to the disease gravity and the age at which they developed the disease was determined. On the basis of 10 personal characteristics found to be the most informative, linear discriminant functions were constructed which provided the following accuracy of the differentiation with reference to the disease gravity: correct answers -- 61%, vague -- 25%, erroneous -- 14%; with reference to the age of the disease development: correct answers -- 78%, vague -- 8%, erroneous -- 14%.

Adult↗