Patients' understanding of disease status and treatment plan at initial hematopoietic stem cell transplantation consultation.

Patients referred for hematopoietic stem cell transplantation (HSCT) often have knowledge deficits about their disease and overestimate their prognosis making it difficult initially to discuss potentially life-threatening transplant options. To determine patients' understanding of their disease and the adequacy of a 3-h consultation at our center, we developed a survey that measured perceived knowledge deficits of disease, prognosis, and emotional status before and after their initial consultation. Ninety nine consecutive eligible patients completed the survey. Although 76.7% claimed adequate information about their disease pre-HCST visit, 51.5 and 41.4% respectively lacked knowledge about their 1-year prognosis with and without any therapy. After the visit, 66.7% of the patients had obtained enough information to make an informed decision regarding HSCT versus 23.2% pre-visit, and a significant reduction in the need for further information was reported by 53.5% of patients (P<0.001). Patients were not overwhelmed or confused by the visit and there was a small but significant decrease in negative affect. Measures to increase patients understanding of their disease and its prognosis pre-HSCT consultation visit are warranted; however, a 3-h consultation visit provides the majority of patients with sufficient information to make an informed decision about the risk/benefit ratio of HSCT.

Dynamic analysis of human visuo-oculo-manual coordination control in target tracking tasks.

Human subjects tracked a visual target controlled either by a function generator (sine wave at different frequencies) or directly by the observer's arm. Gain and phase curves of the oculomotor response as a function of target frequency were determined. Data show that the upper frequency limit of smooth pursuit is higher when the target is driven by the observer's hand, confirming previous reports that smooth pursuit can reach higher velocities when tracking self-moved targets. Comparative analysis of ocular tracking with and without manual target control showed that subjects could be classified into two groups. One group exhibited an increase in gain at high frequency, but showed no significant phase changes. Conversely, the reverse was found in the other group: a significant decrease of phase lag at high frequency and no change in gain. These results demonstrate the existence, within the oculo-manual coordination control system, of at least two separate mechanisms (or strategies), tending either to synchronize the eye and arm motor activities (timing coordination) or to adjust their gain (spatial coordination).

Gaze control in humans: eye-head coordination during orienting movements to targets within and beyond the oculomotor range.

Gaze, the direction of the visual axis in space, is the sum of the eye position relative to the head (E) plus head position relative to space (H). In the old explanation, which we call the oculocentric motor strategy, of how a rapid orienting gaze shift is controlled, it is assumed that 1) a saccadic eye movement is programmed with an amplitude equal to the target's offset angle, 2) this eye movement is programmed without reference to whether a head movement is planned, 3) if the head turns simultaneously the saccade is reduced in size by an amount equal to the head's contribution, and 4) the saccade is attenuated by the vestibuloocular reflex (VOR) slow phase. Humans have an oculomotor range (OMR) of about +/- 55 degrees. The use of the oculocentric motor strategy to acquire targets lying beyond the OMR requires programming saccades that cannot be made physically. We have studied in normal human subjects rapid horizontal gaze shifts to visible and remembered targets situated within and beyond the OMR at offsets ranging from 30 to 160 degrees. Heads were attached to an apparatus that permitted short unexpected perturbations of the head trajectory. The acceleration and deceleration phases of the head perturbation could be timed to occur at different points in the eye movement. 4. Single-step rapid gaze shifts of all sizes up to at least 160 degrees (the limit studied) could be accomplished with the classic single-eye saccade and an accompanying saccadelike head movement. In gaze shifts less than approximately 45 degrees, when head motion was prevented totally by the brake, the eye attained the target. For larger target eccentricities the gaze shift was interrupted by the brake and the average eye saccade amplitude was approximately 45 degrees, well short of the OMR. Thus saccadic eye movement amplitude was neurally, not mechanically, limited. When the head's motion was not perturbed by the brake, the eye saccade amplitude was a function of head velocity: for a given target offset, the faster the head the smaller the saccade. For gaze shifts to targets beyond the OMR and when head velocity was low, the eye frequently attained the 45 degrees position limit and remained there, immobile, until gaze attained the target.(ABSTRACT TRUNCATED AT 400 WORDS)

Human gaze shifts in which head and eyes are not initially aligned.

Most studies of rapid orienting gaze shifts generated by combined eye and head movements have focused on an experimental condition in which gaze displacements are started with the subject's eyes in the normal straight-ahead position in the orbit. Such an experimental approach does not permit a clear identification of the input signal to the head motor system, because target offset angle is the same for both the eye and head. We have studied gaze shifts in human subjects which began with the visual axis straight ahead relative to the body (i.e., gaze or line of sight aligned with body sagittal plane) and with head offset from straight ahead at various angular positions. In our experimental conditions, the amplitude of head movement during a gaze shift was nearly equal to the angular distance between the target position and the starting head position (target-re-head), even though subjects were not specifically instructed to move their heads. This observation contrasts with other published reports in the literature showing considerable variability amongst subjects in the amplitude of head rotation within a given task and between tasks. The difference may be related to the initial conditions which required subjects to align the eye and head on specific starting targets, since others have shown that requiring head alignment enhances head displacement. The amplitude of the saccadic eye movement was not determined by either the target's position relative to the starting eye or head positions. The value that best described the eye movement amplitude was the eye position in the orbit at the end of the saccade.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional eye movement monitor for clinical and laboratory recordings.

A photo-electric device designed to monitor simultaneously vertical and horizontal eye movements within a 20 degrees range is presented with illustrating experimental data. Four small infrared detecting cells are mounted on a light spectacle-like frame together with a miniature true infrared (9000 A) emitting diode. This original design which eliminates separate source illumination artifacts is extremely light, preserves maximum vision field size, and has particularly straightforward operation. The instrument resolution is less than 1 minute of arc with a 1000 c/sec bandwidth and a 5% linearity over the maximum operating range.

Eye-head coordination in cats.

Gaze is the position of the visual axis in space and is the sum of the eye movement relative to the head plus head movement relative to space. In monkeys, a gaze shift is programmed with a single saccade that will, by itself, take the eye to a target, irrespective of whether the head moves. If the head turns simultaneously, the saccade is correctly reduced in size (to prevent gaze overshoot) by the vestibuloocular reflex (VOR). Cats have an oculomotor range (OMR) of only about +/- 25 degrees, but their field of view extends to about +/- 70 degrees. The use of the monkey's motor strategy to acquire targets lying beyond +/- 25 degrees requires the programming of saccades that cannot be physically made. We have studied, in cats, rapid horizontal gaze shifts to visual targets within and beyond the OMR. Heads were either totally unrestrained or attached to an apparatus that permitted short unexpected perturbations of the head trajectory. Qualitatively, similar rapid gaze shifts of all sizes up to at least 70 degrees could be accomplished with the classic single-eye saccade and a saccade-like head movement. For gaze shifts greater than 30 degrees, this classic pattern frequently was not observed, and gaze shifts were accomplished with a series of rapid eye movements whose time separation decreased, frequently until they blended into each other, as head velocity increased. Between discrete rapid eye movements, gaze continued in constant velocity ramps, controlled by signals added to the VOR-induced compensatory phase that followed a saccade. When the head was braked just prior to its onset in a 10 degrees gaze shift, the eye attained the target. This motor strategy is the same as that reported for monkeys. However, for larger target eccentricities (e.g., 50 degrees), the gaze shift was interrupted by the brake and the average saccade amplitude was 12-15 degrees, well short of the target and the OMR. Gaze shifts were completed by vestibularly driven eye movements when the head was released. Braking the head during either quick phases driven by passive head displacements or visually triggered saccades resulted in an acceleration of the eye, thereby implying interaction between the VOR and these rapid-eye-movement signals. Head movements possessed a characteristic but task-dependent relationship between maximum velocity and amplitude. Head movements terminated with the head on target. The eye saccade usually lagged the head displacement.(ABSTRACT TRUNCATED AT 400 WORDS)

Body temperatures in relation to heart rate for workers wearing impermeable clothing in a hot environment.

Thermal reactions and heart rate were measured for men wearing impermeable clothing in a hot environment. Even at rest, the Ts increase was remarkable. At the 30th minute, Ts reached 37.2 +/- .4 degrees (+/- SD). Experimental walking (wearing impermeable clothes) occasioned significant (p less than .001) rises in thermal reactions and HR in comparison to control walking; Tr, Tb, Ts at the 30th minute were 38.4, 38.4, 38.1 degree C respectively, and HR was 162 beats/min. No plateau for these responses was reached during 30 minutes of experimental walking. Tr continued to rise after the subjects stopped exercising. The regression equation of Tr on HR in experimental walking differed from that of control walking. If Tr is used as an index for work safety, a lower Tr is needed under such severe conditions.

Plasma catecholamines at rest and exercise in subjects with high- and low-trait anxiety.

The purpose of this study was to compare the plasma catecholamine concentration at rest and in response to exercise in subjects with low and high trait anxiety (TA). Six subjects with low TA and six subjects with high TA were selected among 149 males college students on the basis of their results on three TA tests (STAI, IPAT, 16 PF). Plasma norepinephrine (NE) and epinephrine (E) concentrations (pg/ml) were measured at rest in supine position and during mild and moderate exercises of 5 min duration (about 40% and 60% of the individual VO2max) on bicycle ergometer. Plasma E concentrations at rest and exercise were not significantly different in subjects with low (33 +/- 6, 82 +/- 11, and 197 +/- 49) or high TA (41 +/- 7, 62 +/- 13, and 229 +/- 52). Plasma NE concentration was not significantly different at rest and in response to mild exercise in low (235 +/- 52; 666 +/- 64) and high-TA subjects (223 +/- 36; 610 +/- 88) but was significantly higher in high-TA than in low-TA subjects in response to moderate exercise (2510 +/- 618 vs. 1243 +/- 234). These results show 1) that plasma NE and E concentrations at rest and in response to light exercise are similar in low- and high-TA subjects, and 2) that subjects with high TA have a greater plasma NE response to the psychologic stress and/or to the homeostatic challenge of moderate exercise.

Reproducibility of plasma catecholamine concentrations at rest and during exercise in man.

The purpose of this study was to test the reproducibility of plasma norepinephrine (NE) and epinephrine (E) concentrations, at rest and during exercise, in man. Twelve young men were evaluated on two occasions (one week apart) at rest in supine and sitting positions and during dynamic exercise on bicycle ergometer: 5 min at a low intensity workload (heart rate = 131-133 bt min-1) and 5 and 20 min at a higher intensity (174-175 bt min-1). Mean plasma NE and E concentrations were not significantly different (p less than 0.05) on the two occasions in any of the experimental situations. However large within-subject variations were present, and the "standard errors of a single measurement" corrected for the variability of the catecholamine assay, ranged from 14 to 50% for NE and 14 to 37% for E. These results indicate that the mean plasma NE and E concentrations observed in a group of subjects are reproducible from one week to the other, but that individual plasma NE and E concentrations are not. This lack of reliability of a single determination of plasma catecholamine concentrations might be due to cyclic variations of plasma NE and E concentrations over time.

Brain-stem afferents upon retinal projecting isthmo-optic and ectopic neurons of the pigeon centrifugal visual system demonstrated by retrograde transneuronal transport of rhodamine beta-isothiocyanate.

Brain-stem afferents to the n. isthmo-opticus (NIO) and ectopic neurons (EN) of the centrifugal visual system (CVS) were determined in the pigeon using the retrograde transneuronal transport of the fluorescent dye Rhodamine beta-isothiocyanate (RITC) after its intraocular injection. In other experiments, either RITC was injected into various periocular tissues (controls) or the retrograde tracer Fluoro-gold (FG) was injected stereotaxically in the NIO. Following intraocular injections, the RITC retrograde labeling of cell bodies was observed contralaterally in the NIO and EN and transneuronally in layers 9/10 of the optic tectum, area ventralis-Tsai, zona peri-NIII, mesencephalic and pontine reticular formation (PRF), n. linearis caudalis-raphe, and bilaterally within a region referred to as zona peri-n.NVI (Zp-n.NVI) immediately underlying the abducens nerve nucleus. None of the above structures were labeled after RITC periocular injections. The FG labeling revealed that the tectal efferent neurons were mainly medium-sized, multipolar cells whose dendrites extended superficially to retino-recipient tectal layers 6 and 5. Quantitative measurements of the distribution of layers 9/10 RITC-labeled neurons indicated the highest densities to be localized within the ventral tectum corresponding to the representation of the dorsal retina and inferior visual field. We suggest that visual and nonvisual brain-stem afferents upon NIO and EN may play a role in the proposed mechanism of the avian CVS in attention, ground-feeding behavior, and modulation of retinal sensitivity.

Body dimensions of Québecois children.

The present study examined the impact of sociocultural factors upon the body dimensions of primary school children (age 6-12 years) living within a uniquely francophone region of Québec. Data was collected prospectively on 546 students, drawn in approximately equal numbers from the two sexes and from urban and rural environments. Habitual activity was modified by allocating a half of the sample to an experimental programme that incorporated an additional five hours of required endurance activity per week into the primary school curriculum. Body dimensions at any given age were less in rural than in urban Québec, probably because of continuing socio-economic constraints. However, an increase of habitual physical activity did not modify body size. Stature was comparable with Demirjian 's Montr eal sample of francophone children, but was less than for anglophone children. Our within-sample variance suggests that socio-economic factors could explain only a part of the discrepancy. Relative to Toronto students, other dimensions such as height were affected less than standing height.

The "unisex phantom," sexual dimorphism, and proportional growth assessment.

The "unisex phantom" tactic of Ross and associates attempts to examine proportional growth, expressing body measurements relative to a phantom created from arbitrary mean dimensions and the observed coefficients of variation for an arbitrary sample of adult men and women. Fundamental assumptions of the model are (1) that data treated in unisex fashion have the normal distribution required of Z-type statistics throughout the period of growth, and (2) that it is reasonable to consider anthropometric measurements in all populations (regardless of ultimate size) as growing toward the common height chosen for the phantom. The validity and possible usefulness of this approach has been tested using anthropometric data collected on 546 francophone primary school children from the Trois Rivières district who had been measured repeatedly from 6 to 12 years of age. Over this age range, the mixing of data for girls and boys does not create a bimodal distribution, and has only a marginal effect upon skewing and kurtosis; however, the requirement of a normal distribution is not satisfied by quite a number of common anthropometric measurements even at this age. Moreover, application of the unisex phantom procedure to the Trois Rivières sample does little to clarify anticipated sex-related differences in regional growth, and it is argued that univariate standardization against a power function of an arbitrary adult height may not provide the best method of examining the multivariate problem of growth. Comparison of results with data from Saskatoon, previously treated by unisex phantom methodology, reveals puzzling inconsistencies; it is suggested that interlaboratory differences of methodology rather than ethnic differences are responsible for apparent discrepancies in growth patterns. It is urged that interlaboratory validation of techniques and landmarks should precede the ascription of apparent differences in body build to constitutional factors.

Prolactinemia in exercising male athletes.

8 male collegial athletes were submitted at random to three (55, 70 and 85% of VO2 max) ergocycle exercises of 20-min duration. Venous blood samples were obtained before, during and after ergocycling sessions by antecubital catheterization. Serum prolactin was measured by RIA using specific antiserum. The exercise treatments induced a blood prolactin response proportional to the intensity of the work loads.