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At least 163 records · Page 9Linked to original sources
PubMed1989

[Multivariate statistical analysis in stabilometry in human upright standing (the first report)--age-related factor].

Posturography is not a clearly defined examination. Recently a number of parameters can be obtained in stabilometry by means of computers. To evaluate each parameter and to decide its normal range, subject's age must be considered. The age-related factors found in stabilometry were studied in terms of both multiple regression analysis and cluster analysis. The parameters used in this study were as follows: the area of an ellipse for rejection and of the figure displayed on an X-Y recorder, the maximum width on both the X axis (left and right direction) and the Y axis (anterior and posterior direction), the total length and the sum of excursion in each direction, the root mean square, the velocity, the acceleration, and the averaged frequency of body sway in both X and Y directions. One hundred normal subjects, aged from the second to sixth decade, including 10 males and 10 females in each decade, were tested. Each subject was asked to stand on a platform in Romberg's position for 60 seconds with both eyes open and closed. The significant parameters to predict age, which were determined by multiple regression analysis, were as follows (P less than 0.05): the averaged frequency in the Y direction with eyes closed, the maximum width in the X direction with eyes open, the area of the ellipse for rejection and of the figure with eyes closed, the maximum width in the Y direction and the area of the ellipse and the velocity in the X direction with eyes open. All test subjects were successfully classified into two groups by cluster analysis. One was the younger group aged less than 40 years and the other was the older group not younger than 40-year-old. However, the difference between with eyes open and with eyes closed was not significant (P less than 0.01) as regards the parameters of root mean square and averaged frequency in both sexes and at every decade. The difference between both sexes was supposed to be significant in the Y direction in the younger group and in the X direction in the older one.

Adult↗
PubMed1989

[Multivariate statistical analysis in stabilometry in human upright standing (second report)--pattern recognition of a stabilogram].

A pattern of a figure which is displayed by an X-Y recorder or by a polygraph in stabilometry may present several qualitative facts about the standing ability of a test-subject. The purpose of this study was to make a quantitative evaluation of the body stability in both normal and ataxic patients who were standing erect. The technique utilised was pattern-recognition, composed of principal component analysis and discriminant analysis. Stabilometrical examinations were carried out in 20 normal subjects, 39 with peripheral vestibular disturbance and 11 with disturbance of the central origin. Each examinee was ordered to keep an upright posture for 60 seconds both with the eyes open and with the eyes closed. The following parameters were used: the area of the ellipse for rejection by a statokinesigram, the maximum width and the total length of body excursion, the root mean square, the velocity, the acceleration and the average frequency in the horizontal plane. These were the same parameters that were used in the first report. Each component predicting a specific character in stabilometry was identified by this study of principal component analysis. The relationship between the components in order and its prediction were as follows: the first component predicted the size of the body movement, the second the force, the third the density, the fourth the difference between body movement with the eyes open and with the eyes closed and the fifth the direction of body sway. Furthermore, the principal components were successfully utilized to allow the classification of the test subjects into three groups: those who were normal, those with peripheral vestibular disturbance and those with disturbance of the central origin. Discriminant functions were also used to classify the above mentioned three groups and another five groups, namely: those who were normal, those with vestibular neuronitis, those with positional vertigo of the benign paroxysmal type, those with Ménière's disease and those with cerebellar ataxia. In classification of the three groups, the significant parameters used for discrimination were as follows (P less than 0.05): the root mean square with the eyes open, the distance and the maximum width of body excursion in the Y direction with the eyes open, the area of the ellipse for rejection both with the eyes open and with the eyes closed, the maximum width and the average frequency in the X direction with the eyes closed.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

Multivariate statistical analysis of electron micrographs of a mammalian transcription initiation complex.

We describe the appearance of the murine ribosomal protein (rp) L32 gene transcription initiation complex as determined by electron image analysis. Using a fractionated nuclear extract enriched for transcription factors necessary for rpL32 gene transcription in vitro and a DNA fragment containing the rpL32 gene promoter, the transcription initiation complex was prepared and viewed by standard transmission electron microscopy. Image analysis demonstrated that the complex was a multilobed structure.

Cells, Cultured↗
PubMed1991

Atherosclerotic lesion of the circle of Willis: its study applying an atherometric system using multivariate statistical techniques.

In 2043 autopsies divided into the high (HAG) and low (LAG) atherosclerosis group a set of variables of a new atherometric system (AS) was used to characterize the atherosclerotic lesion (AL) in the circle of Willis arteries: fatty streaks (X), fibrous plaques (Y), severe plaques (Z), index of stenosis (P) and index of benignity (B). Principal component analysis identified a first component of severity (Y, P and Z) and a second component of benignity (X and B). Fibrous plaques play the main role in the severity of AL in the circle of Willis. The new AS proved its usefulness in characterizing the state of AL, whereas discriminant analysis and AS distinguished between the HAG and the LAG. The classification was correct in 74.5% and 76.5% when using three (X, Y, Z) and five (X, Y, Z, P, B) variables, respectively.

Arteriosclerosis↗
PubMed1988

[Complex medico-genetic study of the populations of western Siberia. IV. A multivariate statistical analysis of the interrelation of quantitative and polymorphic monogenic traits].

Multidimensional statistical analysis for a set of morpho- and physiological traits (anthropological, hemodynamic and biochemical) was done by the principal components method with interpretation of the latter. Special features of phenotype relationships were established for some traits of pathogenetic values for human chronic pathology. Heterogeneity of distributions of genotype frequencies for polymorphic traits and chromosome Q segments in histogramms of principal components was shown. The distributions are considered to be of nonrandom patterns and reflect common population genetics processes affecting both classes of traits under study.

Anthropometry↗
PubMed1988

[Multivariate statistical analysis of the postoperative recurrence factors in uterine cervical carcinoma].

In 211 patients with postoperative cervical carcinoma, we studied the relationship between the recurrence and various factors, and the interrelation among the factors. 1) Lymph node metastasis, clinical stage, number of complaints, adenocarcinoma and adenosquamous carcinoma, and number of pregnancies were associated with recurrence. Signs of myelic injury and large cell non-keratinizing carcinoma were associated with less recurrence. Maintenance chemotherapy markedly improved the prognosis. 2) Lymph node metastasis was frequently associated with an advanced stage, adenocarcinoma or increased erythrocyte sedimentation. Increased sedimentation was rarely associated with greater numbers of pregnancy or keratinizing carcinoma. Signs of myelic injury were rare in cases of advanced stage or large cell carcinoma and frequent in cases of long periods of illness. 3) Intrapelvic recurrence was related to early recurrence and maintenance chemotherapy, and extrapelvic recurrence to increased sedimentation, late recurrence, adenocarcinoma and no chemotherapy. 4) Early recurrence was associated with shorter periods of illness, lymph node metastasis and no chemotherapy, but late recurrence was associated with longer periods of illness, no lymph node metastasis, maintenance chemotherapy and adenocarcinoma. 5) The prognosis and the required periods of maintenance chemotherapy could be determined by Z = 4.3817.X1 + 1.2366.X2-0.0916.X3 + 2.3257.X4-1.9606.X5 + 1.6477.X6-0.1967.X7- 7.3047, with rates of inaccuracy of 13.9% for cases of no recurrence and 15.1% for recurrent cases.

Analysis of Variance↗
PubMed1987

[Classification of the peripubertal stage of ontogeny in girls: a multivariate statistical solution].

Using the cluster analysis of objects in the space of physique factors the objective classification of peripubertal stage of ontogenesis in girls has been constructed. The factors were obtained by factor analysis of 26 anthropometric traits from a joint sample of girls aged 7 to 17 years. Four age groups (7-9, 10-11, 12-13, 14-17 years) distinguished by the factors and by the informative criteria of physique in total have been picked out. The diagnostic ability of the linear discriminant functions constructed by the stepwise discriminant analysis averages 80.0%. This level is in the limits determined in resolving problems of classification by using the anthropometric traits.

Adolescent↗