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PubMed1983

Compensatory eye movement and gaze fixation upon passive head- and body rotation and active head rotation.

To detect differences in compensatory eye movement and gaze fixation, normal subjects and patients with bilateral loss of labyrinthine functions were subjected to passive head-and-body rotation and performed active head rotation. In normal subjects, there was no difference between passive and active rotation with respect to compensatory eye movement in the dark and spatial gaze fixation; on the other hand, the ability to gaze fixedly on a head-fixed target was better during passive than active rotation. In our patients, the findings obtained upon passive rotation resembled those already reported for active rotation, indicating that observing compensatory eye movements and gaze fixation during passive rotation is useful in the detection of disorders of the vestibulo-ocular reflex.

Adult↗
PubMed1987

Varus-valgus and rotational stability in rotationally unconstrained total knee arthroplasty.

This study was designed to test the ability of the ligaments to restore rotational stability to the knee after rotationally unconstrained anterior cruciate-sacrificing total knee arthroplasty (TKA). Rotational and varus-valgus stability both were returned to near-normal values, and the normal screw home pattern of coupled external rotation with extension was restored when the ligaments were correctly tensioned. When the ligaments were tensioned so that the knee was either too loose or too tight, both varus-valgus and rotational laxity were affected equally. Rotational constraint is not necessary in a TKA system to achieve normal rotational stability of the knee, as long as normal varus-valgus stability is restored.

Humans↗
PubMed1982

[A new approach for evaluation of the rotational deformity in scoliosis. Part I: The development of an apparatus measuring truncal cross-sections and quantitative rotational indices of scoliosis].

It is indispensable in the diagnosis and treatment of idiopathic scoliosis to estimate the axial rotation deformity as well as the lateral flexion deformity. Because of lack of methodology till now, appropriate quantitative estimation of the former deformity has not been available for the routine clinical use. The purpose of this investigation was to propose a new approach which makes it possible to evaluate the rotational deformity of scoliosis more precisely than ever. To realize an idea that a two-dimentional morphologic measurement through horizontal planes is reasonable for the recognition of the rotational deformity, a new experimental apparatus named Laser Torsograph was constructed for the purpose of measuring horizontal cross-sections of the human body surface. The fundamentals of the measuring system is an optical triangulation using a laser spot which is detected by a line sensor camera. While the laser spot is turned around the trunk horizontally for 360 degrees, input data of the positions of the laser spot on the trunk surface are compiled into a minicomputer and processed to be visualized as cross-sectional figures on a display and X-Y plotter. Each cross-sections thus measured are computerized for the quantitative assessment of the deformity and three parameters (theta, phi, psi) are obtained full-automatically. Theta represents the degree of the spatial rotation of the cross-section (the position change). Phi represents the degree of the distorsion of the cross-section itself (the shape change). Psi represents the difference of thickness between the right and left half of the cross-section. By measuring cross-sections at multi-levels of each spinous processes for a scoliotic patient, the rotational indices of scoliosis are determined as the maximum values of each parameters. As a result of application of Laser Torsography to 109 cases of idiopathic scoliosis, the usefulness of this method has been established. The rotational deformity was obvious on inspection of cross-sections and convincing informations about structural changes were offered which were helpful, for example, to define the curve patterns objectively. Our innovative approach will provide the routine clinical situations with the precise visualization and appropriate quantitative data on the axial rotational deformity in scoliosis.

Adolescent↗
PubMed1999

Vibration-Internal Rotation-Overall Rotation Interactions in CH(2)DOH and CHD(2)OH.

The zeroth-order kinetic energy is developed for the vibrating-rotating-internally rotating CH(2)DOH and CHD(2)OH molecules using the general theory of Guan and Quade for the vibration-rotation-large amplitude internal motion interactions in molecules. A T transformation is applied to obtain the necessary (G(-1))(0) vibrational matrix elements in the kinetic energy for the R transformation that separates the internal rotation from the 3N-7 other vibrations. Then, a second T transformation is used to separate rotation from the 3N-7 other vibrations in zeroth order in the kinetic energy. The overall rotation and internal rotation remain coupled in zeroth order. All zeroth-order kinetic energy coefficients are calculated from the molecular structure and masses for the methyl alcohol molecules. The physical significance of the transformations is discussed in detail. This paper reports the results of the first segment of the three segments that are necessary in the calculation of the full solution to the problem. Copyright 1999 Academic Press.

Journal Article↗
PubMed1990

Rotational relaxation rate of 1,6-diphenyl-1,3,5-hexatriene in cytoplasmic membranes of Bacillus subtilis. A new model of heterogeneous rotations.

The temperature dependence of fluorescence anisotropy, lifetime and differential tangent of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its polar trimethylammonium derivative (TMA-DPH) were investigated in cytoplasmic membranes of Bacillus subtilis. The fluorescence parameters were compared in the two types of membranes prepared from bacteria cultivated at 20 and 40 degrees C. Steady-state anisotropy measurements showed that within a broad range of temperatures, membranes cultivated at 20 degrees C exhibit significantly lower values than those prepared from cells cultivated at 40 degrees C. The temperature dependence of lifetime and differential tangent measurements (differential polarized phase fluorimetry) were fully consistent with steady-state anisotropy data of both DPH and TMA-DPH. The low anisotropy values in the case of TMA-DPH could be explained by a shorter lifetime and higher temperature-induced decrease as compared with DPH. Surprisingly, the temperature dependence of rotational rate R calculated according to the model of hindered rotations (Lakowicz 1983) gave misleading results. When increasing the temperature from 5 to 25 degrees C, a marked drop of rotational relaxation rate was observed. The minimum R values were measured between 25 and 30 degrees C and further increase of temperature (up to 60 degrees C) was reflected as increase of the R values. Therefore, a new model of "heterogeneous rotations" was developed. This model assumes that even at low temperatures (approaching 0 degrees C) where the differential tangent reaches zero, a fraction of fast rotating molecules exists. The ratio between fast and slowly rotating molecules may be expressed by this model, the newly calculated rotational rates are fully consistent with anisotropy, lifetime and differential tangent measurements and represent the monotonically increasing function of temperature.

Bacillus subtilis↗
PubMed1985

Effects of a psychiatric rotation on psychiatric knowledge and attitudes towards psychiatry in rotating interns.

The attitudes of trainees toward Psychiatry affect their career choice and ability to properly identify and manage emotional disorders in their patients. These attitudes are determined by several factors which include preclinical and clinical training among others. We report here a study of the attitude of interns toward psychiatry using the 30 item attitude toward psychiatry (ATP-30) scale. The ATP-30 and a multiple choice questionnaire examination (MCQE) in psychiatry were completed by 96 interns at the beginning and end of their compulsory four week psychiatry rotation. The degree of satisfaction of the trainees was rated in four areas--orientation, teaching/learning experience, overall rating of rotation and relevance of rotation to career choice. There was no significant change in the mean ATP-30 scores (N = 55) during the four week rotation, but the MCQE scores (N = 74) improved significantly (P less than 0.0001). A repeated analysis of variance for the four satisfaction variables by change score in MCQE and change score in ATP-30 did not show any significant main effects or significant interactions between these change scores except with relevance of rotation. Reasons for the absence of changes in the ATP-30 scores during this rotation were explored. The implications of the improved knowledge during this rotation are also discussed. We also conclude that attitudinal change and knowledge are two independent factors which should be assessed independently in trainees.

Adult↗
PubMed1997

Femoral anteversion related to side differences in hip rotation. Passive rotation in 1,140 children aged 8-9 years.

We assessed whether the range of passive hip motion is reliable for predicting abnormal femoral anteversion. We measured the passive medial and lateral rotation in extension in both hips of 1,140 children between 8 and 9 years of age. The children were divided into 3 groups: group 1: difference between lateral and medial rotation less than 10 degrees; group 2: medial rotation more than 10 degrees greater than the lateral; group 3: lateral rotation more than 10 degrees greater than the medial. Group 1 comprised 90% of the children, whereas 8% belonged to group 2 and 2% to group 3. The angle of femoral neck anteversion was measured in 57 children from the first group, in 67 from the second and in 24 children from the third group, using biplane radiography. The mean anteversion angles in the 3 groups were 24 degrees, 36 degrees and 14 degrees, respectively. To predict an abnormally high anteversion angle (above mean +2SD), the difference between medial and lateral rotation must be 45 degrees or more, whereas an abnormally low anteversion angle (lower than mean -2SD) could be predicted when the lateral rotation was at least 50 degrees higher than the medial rotation.

Child↗
PubMed1987

Response characteristics of neurons in the cat vestibular nuclei during slow and constant velocity off-vertical axes rotations in the clockwise and counterclockwise rotations.

The responses to slow constant velocity rotations in the clockwise (CW) and counterclockwise (CCW) directions about an axis tilted 10 degrees from the earth's vertical were studied in static tilt-sensitive neurons in the vestibular nuclei of decerebrate cats. Each unit responded to any 360 degrees unidirectional rotation with a position-dependent discharge maximum. The location of the maximum, obtained by rotation in one direction, differed from that obtained by an oppositely directed rotation (phase difference). In about 80% of the units such phase difference (up to 160 degrees in second-order neurons) in response to oppositely directed rotations was unaffected by different amplitudes of head displacement (5-25 degrees). Units were thus classified into two groups depending on the location of the CW discharge maximum relative to the CCW counterpart. The direction of rotation had no influence on the response gains of these units.

Animals↗
PubMedDate not supplied

Sensitivity to full-field visual movement compatible with head rotation: variations among axes of rotation.

Movement detection thresholds for full-field visual motion about various axes were measured in three subjects using a two-alternative forced-choice staircase method. Thresholds for 1-s exposures to rotation about different rotation axes varied significantly over the range 0.139 +/- 0.05 deg/s to 0.463 +/- 0.166 deg/s. The highest thresholds were found in response to rotation about axes closely aligned to the line of sight. Variations among the thresholds for different axes could not be explained by different movement patterns in the fovea or variations in motion sensitivity with eccentricity. The variations can be well simulated by a three-channel model for coding the axis and velocity of full-field visual motion. A three-channel visual coding system would be well suited for extracting information about self-rotation from a complex pattern of retinal image motion containing components due to both rotation and translation. A three-channel visual motion system would also be readily compatible with vestibular information concerning self-rotation arising from the semicircular canals.

Adult↗
PubMed1988

The effects of gravitoinertial force level and head movements on post-rotational nystagmus and illusory after-rotation.

The effect of Coriolis, cross-coupled stimulation on the vestibuloocular reflex and the elicitation of motion sickness depends on background gravitoinertial force level (DiZio et al. 1986, 1987; Graybiel et al. 1977; Lackner and Graybiel 1984, 1986). We have explored whether this response dependency is related to the unusual patterns of sensorimotor activity present during exposure to non-terrestrial gravitoinertial force levels, to alterations in the encoding of head movements in different gravitoinertial force environments, or to some combination thereof. Blindfolded subjects were exposed to sudden stops after constant velocity, vertical z-axis rotation, sometimes with and sometimes without post-rotational head movements, in the 0 G, 1 G, and 1.8 G force phases of parabolic flight. After sudden stops without head movements, the time constant of decay of post-rotational nystagmus was significantly lower in 0 G than in 1 G and lower to a smaller extent in 1.8 G. Post-rotational head movements decreased the decay time constants in 1 G and in 1.8 G, but not in free fall. The same pattern emerged for the duration of illusory after-rotation. Systematic changes were not found in the peak slow phase velocity of nystagmus. These results suggest that tonic levels of otolithic and somatosensory activity in combination with canalicular, cervical, and motor activity regulate the velocity storage mechanism of the horizontal vestibuloocular reflex (Cohen et al. 1977; Raphan et al. 1979) and sensations of after-rotation. These same factors are likely to be important etiological elements in space motion sickness.

Coriolis Force↗
PubMed1987

Periodic rotational crosses. III. Sire-breed rotations with overlapping generations among dams.

Sire-breed rotations are defined as the changing of sire breeds ignoring the sire-breed pedigree of dams from overlapping generations. The limiting theoretical proportion of maximum potential heterozygosity maintained at equilibrium when there is no culling of dams was found to be equal to that of a composite population with the same breed composition. Heterozygosity was simulated with a deterministic model that assumed 20% of reproducing females in each age group were culled each mating period. Maximum age of reproducing females was varied from 3 to 10 mating periods (years for cattle and sheep, half-years for swine). Consecutive use of each sire breed in a sire-breed sequence from two to four mating periods maintained more heterozygosity than predicted by the limiting theoretical formula, which did not take the culling of females into account. Compared with complete sire and dam rotations, sire-breed rotations with the same breed sequence resulted in reductions of .03 to .13 of potential heterosis. Among two-breed, periodic rotations, the difference ranged from .03 to .08. The smaller differences were generally associated with younger maximum reproducing females ages and the larger differences with older maximum ages. Heterozygosity difference times heterosis is a measure of the expected returns for the more intensive management often needed for complete rotations. Scaled breed difference ranges over which one periodic rotation of sire breeds exceeds another are shifted by overlapping generations among the females. Breed utilization is unchanged by overlapping generations, but relative differences in heterosis utilization are altered.

Animal Husbandry↗
PubMed2000

Observations of rotation within the F(o)F(1)-ATP synthase: deciding between rotation of the F(o)c subunit ring and artifact.

F(o)F(1)-ATP synthase mediates coupling of proton flow in F(o) and ATP synthesis/hydrolysis in F(1) through rotation of central rotor subunits. A ring structure of F(o)c subunits is widely believed to be a part of the rotor. Using an attached actin filament as a probe, we have observed the rotation of the F(o)c subunit ring in detergent-solubilized F(o)F(1)-ATP synthase purified from Escherichia coli. Similar studies have been performed and reported recently [Sambongi et al. (1999) Science 286, 1722-1724]. However, in our hands this rotation has been observed only for the preparations which show poor sensitivity to dicyclohexylcarbodiimde, an F(o) inhibitor. We have found that detergents which adequately disperse the enzyme for the rotation assay also tend to transform F(o)F(1)-ATP synthase into an F(o) inhibitor-insensitive state in which F(1) can hydrolyze ATP regardless of the state of the F(o). Our results raise the important issue of whether rotation of the F(o)c ring in isolated F(o)F(1)-ATP synthase can be demonstrated unequivocally with the approach adopted here and also used by Sambongi et al.

Actins↗
PubMed1999

A new method for estimating the axis of rotation and the center of rotation.

A new method is presented for estimating the parameters of two different models of a joint. The two models are: (1) A rotational joint with a fixed axis of rotation, also referred to as a hinge joint and (2) a ball and socket model, corresponding to a spherical joint. Given the motion of a set of markers, it is shown how the parameters can be estimated, utilizing the whole data set. The parameters are estimated from motion data by minimizing two objective functions. The method does not assume a rigid body motion, but only that each marker rotates around the same fixed axis of rotation or center of rotation. Simulation results indicate that in situations where the rigid body assumption is valid and when measurement noise is present, the proposed method is inferior to methods that utilize the rigid body assumption. However, when there are large skin movement artefacts, simulation results show the proposed method to be more robust.

Artifacts↗
PubMed1976

Mental rotation by the blind: does mental rotation depend on visual imagery?

Congentially blind adventitiously blind, and blindfolded sighted adults made same-different judgments of pairs of tactile forms. Two forms were presented in the same orientation, or one form differed from the other by a clockwise rotation of 30 degrees, 60 degrees, 120 degrees, or 150 degrees. Like the reaction times for the sighted and the adventitiously blind, reaction times for the congenitally blind increased as a linear function of angular discrepancy between stimuli, suggesting that the congentially blind, like the sighted and adventitiously blind, mentally rotated one form into congruence with the other to make judging easier. Corroboration of the mental rotation inference came from subjects' introspective reports. Inasmuch as the congenitally blind presumably do not have the ability to visually represent form, the present results suggest that mental rotation does not depend upon visual imagery. Thus, with respect to current speculation as to whether visual imagery is a necessary component of mental rotation, the present findings suggest that it is not.

Adolescent↗
PubMed1992

Role of the capsulo-ligamentous structures in rotation and combined flexion-rotation of the lumbar spine.

We carried out experiments on whole cadaveric lumbar spines in order to determine the role that each of the capsulo-ligamentous structures play in axial rotation in the neutral position and in the flexed position. Eight specimens were first tested intact, then after division of all the apophyseal joint capsules between L1 and the sacrum. Another five specimens were also first tested intact, then after division of the supra- and interspinous ligaments and yellow ligament, and finally after cutting the posterior longitudinal ligament and posterior annulus at each level as well. The results show that there is considerable variation in the axial rotation of the lumbar vertebrae within the same spine and across different spines. The apophyseal joint capsules limit rotation both in neutral and flexed positions. In flexion, the amplitude of rotation in the lumbar spine is reduced. Of the capsulo-ligamentous structures, it is the posterior annulus and the posterior longitudinal ligament that seem to play the more important role in limiting axial rotation while the spine is flexed.

Adult↗
PubMed1997

In vivo rotational stability of the kinematic rotating hinge knee prosthesis.

The in vivo rotary laxity and torsional stiffness of the knee joint were measured in 20 patients with wide intraarticular resection of the distal femoral tumor followed by reconstruction with a custom Kinematic rotating hinge endoprosthesis. The contralateral normal knee served as natural control. Twenty patients underwent 29 measurements, including 9 at the first year, 10 at the second year (4 of these also measured at year 1), and 10 at the third year (3 of these also measured at years 1 and 2; 2 also measured at year 2). The mean followup for the 15 survivors was 134 months (range, 102-156 months). The total rotatory laxity of the hinged knee was significantly greater than that of the contralateral knee. The torsional stiffness in external rotation of the hinged knee was 30.4% less than that of the contralateral knee in the first postoperative year, whereas the torsional stiffness in internal rotation was similar to that of the contralateral knee. Torsional stiffness of the hinged knee in the second year was significantly less than that of the contralateral knee whereas it was within the normal range of stiffness in the third year. The total rotatory laxity and torsional stiffness of the hinged knee in the early postoperative years could not predict the risk of late loosening. In vitro rotational stability of the rotating hinge device with axial load bearing was 6.7 and 8.1 Newton-meters (N-m) at 0 degrees and 20 degrees knee flexion, respectively, under an axial tibial load of 945 Newtons.

Adolescent↗
PubMed1985

Rotational behaviour elicited by intracerebral injections of apomorphine and pergolide in 6-hydroxy-dopamine-lesioned rats. II: The striatum of the rat is heterogeneously organized for rotational behaviour.

The present study compares the role of the nucleus accumbens and the striatum, as well as various regions of the striatum, in the ability of intracerebral injections of the dopamine agonists apomorphine and pergolide to elicit rotational behaviour in 6-hydroxy-dopamine-lesioned rats. We found that apomorphine and pergolide elicit rotational behaviour when injected into the denervated striatum, but not when injected into the ipsilateral nucleus accumbens. The striatum seems heterogeneously organized as regards rotational behaviour since maximal-apomorphine rotation was elicited from the corpus of the striatum as compared to the effects produced by injections into the head and the tail of the striatum. This topographical distribution is similar to the distribution of dopamine-stimulated cyclic AMP. The pergolide response is more evenly distributed in the striatum. It is suggested that the difference in the topographical distribution of the ability of apomorphine and pergolide to elicit rotational behaviour reflects a regional distribution of dopamine receptors in the striatum of the rat.

Animals↗
PubMed1994

Glycosaminoglycans of human rotator cuff tendons: changes with age and in chronic rotator cuff tendinitis.

OBJECTIVES: To analyse the glycosaminoglycans of the adult human rotator cuff tendon matrix, to characterise changes in the glycosaminoglycan composition with age and in chronic rotator cuff tendinitis. METHODS: Rotator cuff (supraspinatus) tendons (n = 84) and common biceps tendons (n = 26) were obtained from cadavers with no history of tendon pathology (age range 11-95 years). Biopsies of rotator cuff tendons (supraspinatus and subscapularis tendons, n = 53) were obtained during open shoulder surgery to repair shoulder lesions (age range 38-80 years). Glycosaminoglycans were extracted by papain digestion and analysed by cellulose acetate electrophoresis, the carbazole assay for uronic acid and the dimethylmethylene blue dye-binding assay for sulphated glycosaminoglycans. Some digests were analysed for keratan sulphate by 5D4 monoclonal antibody ELISA. Soluble proteoglycans were extracted in 4M guanidine hydrochloride and analysed by 4-15% SDS PAGE. RESULTS: The mean (SD) sulphated glycosaminoglycan (GAG) content of the normal cadaver supraspinatus tendon was 12.3 (4.3) micrograms/mg dry weight, between three and ten times greater than in the common biceps tendon [1.2 (0.6) micrograms/mg dry weight]. The major GAG was chondroitin sulphate [6.9 (2.6) micrograms/mg dry weight], with a smaller proportion of dermatan sulphate [2.5 (1.2) micrograms/mg dry weight]. In contrast, the common biceps tendon contained predominantly dermatan sulphate [0.8 (0.2) microgram/mg dry weight] with less chondroitin sulphate [0.2 (0.2) microgram/mg dry weight]. There was no difference in the concentration of hyaluronan in these tendons [9.3 (2.8) micrograms/mg dry weight and 10.8 (4.3) micrograms/mg dry weight respectively] and there was no significant change of hyaluronan with age. Keratan sulphate was a small but significant component of the supraspinatus tendon [0.43 (0.33) microgram/mg dry weight, n = 25], whereas there was little or none in the common biceps tendon [0.04 (0.05) microgram/mg dry weight, n = 8] and there was no significant change across the age range. In the supraspinatus tendon, there was a significant decrease in total glycosaminoglycan, chondroitin sulphate and dermatan sulphate with age (p < 0.001), whether expressed relative to the tendon dry weight or total collagen content, and no change in the relative proportion of the different GAG types. There was, however, a large degree of variation within the samples. Supraspinatus tendons from patients with chronic tendinitis had a significantly increased concentration of hyaluronan [30.4 (10.1) micrograms/mg dry weight, p < 0.001], chondroitin sulphate [8.4 (1.8) micrograms/mg dry weight, p < 0.05] and dermatan sulphate [3.8 (1.1) micrograms/mg dry weight, p < 0.001] compared with normal cadaver supraspinatus tendons, although the keratan sulphate content was not significantly different [0.18 (0.05) microgram/mg dry weight]. CONCLUSIONS: The normal supraspinatus tendon has the proteoglycan/glycosaminoglycan of tendon fibrocartilage, which it is suggested is an adaptation to mechanical forces (tension, compression and shear) which act on the rotator cuff tendons in the shoulder, although other factors such as reduced vascularity, low oxygen tension and the influence of local growth factors may also be important. This functional adaptation may have important consequences for the structural strength of the supraspinatus tendon and to influence the ability of the tendon to repair after injury. The glycosaminoglycan composition of tendon specimens from patients with chronic tendinitis is consistent with acute inflammation and new matrix proteoglycan synthesis, even in relatively old tendon specimens and after at least one injection of corticosteroid.

Adolescent↗