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PubMed1987

Fibrinogen lysine residue A alpha 157 plays a crucial role in the fibrin-induced acceleration of plasminogen activation, catalyzed by tissue-type plasminogen activator.

In previous studies, we have shown that the stretch 148-197 of the fibrinogen A alpha chain plays a crucial role in the acceleration of the tissue-type plasminogen activator (t-PA)-catalyzed plasminogen activation. In this study we have synthesized parts of A alpha 148-197 and analogues thereof. We found that the peptides with sequences identical with A alpha 148-161 and A alpha 149-161 of human fibrinogen accelerate the plasminogen activation by t-PA, whereas the corresponding peptides in which lysine residues A alpha 157 had been replaced by valine or arginine had no accelerating capacity. Furthermore, succinylation of the lysine residue(s) in the synthesized peptides A alpha 148-161 and A alpha 149-161 leads to loss of accelerating action. These findings show that lysine residue A alpha 157 is crucial for the accelerating action of fibrin on the t-PA-catalyzed plasminogen activation.

Amino Acids↗

PubMed1988

[Fetal heart rate accelerations and fetal oxygen pressure sub partu].

By means of tcPO2 measurement, a total of 297 FHR accelerations from 55 oxygen cardiotocograms were analysed with regard to their association with changes in fetal oxygen pressure sub partu. It could be demonstrated that the transcutaneous oxygen pressure of 2.3 kPa (17.1 mmHg) with occasional accelerations was significantly (alpha less than 0.05) higher than that of 2.2 kPa (16.6 mmHg) with periodic accelerations. Oxygen pressure with occasional accelerations with "classical parameters" (amplitude greater than or equal to 15 bpm, duration greater than or equal to 15 sec) did not significantly differ from that with one or both parameters below these minimal values. Furthermore, our results suggest the production of periodic accelerations by pressorreceptor reflex due to intermittent disturbance in umbilico-placental perfusion.

Blood Gas Monitoring, Transcutaneous↗

PubMed1985

The role of surface charge on the accelerating action of heparin on the antithrombin III-inhibited activity of alpha-thrombin.

We have compared surface charge and the surface charge density on the polyanions heparin and potassium polyvinyl sulfate (KPVS), as well as on hydrolyzed heparin and KPVS, with their accelerating effect on the inhibitory action of antithrombin III on thrombin. Polyelectrolyte titration of thrombin with KPVS or heparin at pH 7.4 clearly indicates an electrostatic interaction. In contrast, at the same pH no electrostatic interaction is observed between polyanions and antithrombin III. KPVS accelerates the inhibitory action of antithrombin III to the same extent as heparin on the basis of charge equivalence. Heparin and KPVS with a mean distance between two charged centers of less than 0.75 and 0.95 nm, respectively, accelerate strongly whereas hydrolysates with lower charge densities are far less active. The following observations are indicated. Intramolecular neutralization of oppositely charged residues occurs within thrombin, antithrombin III, and partially hydrolyzed heparin. Heparin acts on the antithrombin III-thrombin reaction through cooperative electrostatic binding to thrombin and nonelectrostatic interaction with antithrombin III. This indicates a quasi-catalytic action of the polyelectrolyte. Hydrolysis of only a few N-sulfate residues within the heparin molecule decreases the linear surface charge density to such an extent that the accelerating action is drastically reduced. The loss of accelerating capacity agrees with the sudden loss of counterion condensation due to the decrease of the linear surface charge density beyond limits postulated by Manning in a theory of polyelectrolytes.

Antithrombin III↗

PubMed1979

The temporal relationship between infant heart rate acceleration and crying in an aversive situation.

The temporal relationship between heart rate (HR) acceleration and crying was examined in 16 8-16-month-old infants. Consistently, the HR acceleration began well before the onset of crying, suggesting that such acceleration is not merely a by-product of crying. The accelerations observed were above and beyond a return to baseline following orienting. The crying itself validates the association between these instances of HR acceleration and negative effect.

Affect↗

PubMed1970

Pre- and post-natal growth acceleration and increased sugar consumption in Canadian Eskimos.

A striking increase in birth weights and height measurements in children of Canadian Eskimos was observed in recent years.The growth acceleration seen to varying degrees in different Eskimo groups appears most closely to parallel the increase in the per capita annual sugar consumption which has more than quadrupled during the last decade in some trading areas of the Canadian Central and Eastern Arctic, while the per capita consumption of protein derived from animal sources shows a reverse relationship.Canadian Eskimos do, therefore, contrary to what is stated in earlier publications, conform to the general secular growth acceleration patterns observed in all populations coming under the influence of modern civilization. They do not, however, conform to the commonly held explanation for this acceleration, namely increased consumption of high-quality proteins, since their traditionally extremely high consumption of meat and fish decreased markedly during the same period.Our observations confirm the relation of growth acceleration and consumption of sugar first established by the Swiss pediatrician, Eugen Ziegler. A hypothesis first advanced by Ziegler is elaborated to link this growth acceleration, in particular the extraordinary increase in birth weight, to "pseudo-diabetic" oral glucose tolerance patterns described previously by the author in a large proportion of Eskimos.

Adolescent↗

PubMed1981

In vitro growth of murine T cells. VI. Accelerated skin graft rejection caused by adoptively transferred cells expanded in T cell growth factor.

The ability of adoptively transferred cytotoxic T cells expanded in T cell growth factor (TCGF) to induce accelerated graft rejection of B10.BR skin grafts from normal B6AF1 recipient mice was tested. In vitro sensitized cells expanded in regular TCGF were capable of accelerating graft rejection when adoptively transferred i.v. 1 day after grafting. Cells expanded in LF-TCGF (lectin-free) were more effective in accelerating graft rejection than cells expanded in lectin containing TCGF. Nonsensitized cells or cells sensitized to irrelevant B10.D2 antigenic determinants in vitro and subsequently expanded in LF-TCGF were unable to induce accelerated rejection of the B10.BR grafts. Expanded cytotoxic effector cells known to be immunologically active in vivo were also unable to accelerate graft rejection if irradiated with 2000 R before adoptive transfer. The ability of cells to lyse the appropriate targets in 4-hr 51Cr release assays correlated poorly with the effectiveness of these cells after in vivo injection. These studies are the first to demonstrate that cytotoxic cells expanded in TCGF are capable of mediating a cytotoxic function in vivo.

Animals↗

PubMed1980

Cardiovascular responses of man exposed to +Gz accelerations in a centrifuge.

Cardiovascular investigations were conducted in male volunteer subjects exposed to +Gz accelerations. Some of them did not have any previous experience of the centrifuge. Electrocardiogram, blood pressure, heart rate, stroke volume, and cardiac output were recorded. Accelerations ranging from +1.5 Gz to +6 Gz were applied during periods of from 30 s to 20 min. Acceleration was achieved in 10-90 s. Heart rate markedly increased as a function of acceleration intensity, reaching 160 beats/s. Decreases in cardiac output (30-40%) and stroke volume were also observed. Protection by an anti-G suit reduces tachycardia. Accelerations induce various electrocardiographic disorders lasting several minutes after the stress has been stopped. These are sometimes the first symptoms of functional cardiovascular failure. The centrifuge turns out to be an excellent screening tool. However, when used for testing various aircrew equipment, strict monitoring of the subjects is required.

Adult↗

PubMed1996

Role of Cu/Zn-superoxide dismutase in xenobiotic activation. I. Chemical reactions involved in the Cu/Zn-superoxide dismutase-accelerated oxidation of the benzene metabolite 1,4-hydroquinone.

Cu/Zn-superoxide dismutase (Cu/Zn-SOD) has been shown to modulate the autoxidation of a variety of phenoic compounds, including 1,4-hydroquinone (HQ), a benzene-derived metabolite. The acceleration of autoxidation of HQ by Cu/Zn-SOD results in the production of 1,4-benzoquinone (BQ). It has been proposed that the chemical mechanism involved in the Cu/Zn-SOD-catalyzed autoxidation of HQ may be occur through either its conventional activity as a superoxide:superoxide oxidoreductase or as a semiquinone:superoxide oxidoreductase. However, Cu/Zn-SOD-accelerated oxidation of HQ has not been resolved experimentally. In this study, with ESR spectroscopy we investigated further the chemical reactions involved in the SOD-accelerated oxidation of HQ. In phosphate-buffered saline (PSB), HQ underwent a slow autoxidation to BQ, which was accelerated by Cu/Zn-SOD, Mn-SOD, or Fe-SOD with similar efficiency. In contrast, among free metals, only Cu(II) strongly mediated the oxidation of HQ to BQ. Mn(II) exhibited a slight capacity to oxidize HQ, whereas neither FE(II) nor FE(III) was capable of modulating the autoxidation of HG. The presence of either form of SOD also dramatically enhanced the formation of semiquinone anion radicals SQ-. from HQ. The SOD-accelerated oxidation of HQ was also accompanied by the generation of H202. In PBS containing bovine serum albumin (BSA) (PBS/BSA), HQ did not undergo autoxidation to SQ-., and as such the presence of SOD was unable to induce the formation of either SQ-. or BQ or the consumption of O2. The addition of 10 microM BQ to HQ (100 or 1000 microM) in PBS/BSA resulted in the formation of SQ-. and initiated a slow rate of oxidation of HQ to BQ. In this case, the presence of Cu/Zn-SOD strongly accelerated the oxidation of HQ to SQ-. and BQ and the utilization of O2. Furthermore, the enhancement by Cu/Zn-SOD of the generation of SQ-. or BQ from HQ in PBS/BSA was extensively inhibited under anaerobic conditions. The enhancement of SQ-. generation from HQ by all three forms of SOD does not support the possibility that Cu/Zn-SOD can oxidize SQ-. to BQ. Taken together, this study demonstrates that unlike free copper, Cu/Zn-SOD does not directly interact with HQ to cause its oxidation to BQ. Rather, the autoxidation of HQ to SQ-. is a prerequisite for the enhancing capacity of Cu/Zn-SOD, and the dismutation of superoxide anion radicals generated from the SQ-. in the presence of O2 appears to be the underlying mechanism responsible for the enhancement by Cu/Zn-SOD of the oxidation of HQ.

Anaerobiosis↗

PubMed1996

Is atherosclerosis accelerated by CAPD?

Cardiovascular complications in renal replacement therapy remain prevalent today. The question, "Is atherosclerosis accelerated in peritoneal dialysis (PD) patients," has not been resolved. Many cross-sectional studies have revealed that there are more atherogenic lipid profiles in continuous ambulatory peritoneal dialysis (CAPD) than in other dialytic modalities. However, it is not certain that CAPD per se may contribute to lipid abnormalities in continuing PD for a long time. Therefore, we tried to assess whether CAPD itself may change lipid profiles in the long-term period on CAPD. We measured conventional lipid profiles in 16 stable CAPD patients in whom total cholesterol (T.chol.) levels remained under 240 mg/dL at the time of starting observation. Diabetic end-stage renal disease (DMESRD) patients were excluded from this study. Blood sampling was performed under strict conditions indicating overnight fasting with 10 hours dwell of 2 L of 1.5% Dianeal. Plasma levels of T.chol., triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and atherogenic lipoprotein (apo B/A-I) did not show significant changes by serial measurements from the sixth month to the thirtieth month following the commencement of CAPD as their initial dialysis treatment. Recently it is reported that high plasma levels of Lp(a) lipoprotein are an independent risk factor in cardiovascular events in renal replacement therapy because Lp(a) has a close relation to intravascular thrombosis and acceleration of atherosclerosis. We found that the incident of vascular accidents was five episodes among 33 patients with higher (> 31 mg/dL) Lp(a) levels, while there was only one episode in 45 patients with lower (< 30 mg/dL) Lp(a) levels (p < 0.05, odds ratio: 7.9). However, severity of aortic calcification and incidence of positive treadmill test showed no difference in these two groups. No significant correlation was observed between duration on CAPD and plasma Lp(a) levels. From the fact mentioned above, we speculate that CAPD does not essentially affect lipid profiles if determined under the strict condition of blood sampling. In order to evaluate the atherosclerosis noninvasively, we have measured aortic pulse wave velocity (AoPWV) in 33 stable CAPD patients excluding those with DMESRD by two years' interval. Fifteen cases (46%) increased in AoPWV, however, lipid profiles did not differ from those of nonadvanced patients. Calcification of arteries is further evidence of acceleration in atherosclerotic change. Therefore, we have graded severity of abdominal aortic calcification into three categories: grade I denoted nil calcification, grade II denoted patchy calcification, and grade III denoted calcification along the entire abdominal wall, having a lead-pipe shape by lateral view of plain abdominal x-ray film. There were significant differences in the duration of CAPD (grade I: 41 months, grade II: 60 months, grade III: 68 months). AoPWV showed least in the grade I group, faster in grade II, and fastest in grade III, while lipid profiles did not show significant differences in three categories. From the analysis of serial changes of lipid profiles, AoPWV and aortic calcification, CAPD may present some risk of accelerating atherosclerosis, at least in some patients on long-term treatment. Risk factors contributing to acceleration of atherosclerosis is result not from lipid abnormalities, but from other factors which remained to be seen, for example, abnormalities in calcium metabolism.

Adult↗

PubMed1977

Acceleration patterns of the fetal heart rate before and during labour.

In infants in whom accelerations of the fetal heart rate were present during the first stage of labour, the incidence of low Apgar scores was significantly less than in those in whom accelerations were not present. Absence of acceleration patterns during the contraction stress test (CST) was associated with a lower birth weight. In patients in whom acceleration patterns were observed during a positive CST, fetal distress occurred in the minority of subsequent labours. When accelerations as well as late decelerations are observed during a CST, the possibility of a false positive test should be excluded.

Apgar Score↗

PubMed1997

Evidence of accelerated gastric emptying in longstanding diabetic patients after ingestion of a semisolid meal.

UNLABELLED: This study investigated the prevalence of accelerated gastric emptying in 40 consecutive nonselected patients with longstanding insulin-dependent diabetes mellitus (range 11-54 yr; mean 27 yr). METHODS: The gastric emptying of a semisolid meal labeled with 99mTc was continuously recorded with a dual-head gamma camera for 90 min in patients who were supine. RESULTS: Eleven patients demonstrated delayed gastric emptying, but three male diabetics showed accelerated gastric emptying with retention values that were different from controls already after 10 min of recording (89% +/- 3% versus 96% +/- 4%; p < 0.02). During the 90-min segment, accelerated gastric emptying reduced initial gastric contents to 11% +/- 8% (p < 0.001) as compared to 50% +/- 10% in control subjects and 78% +/- 6% (p < 0.001) in patients with delayed gastric emptyings. Accelerated gastric emptying was characterized by an almost equal initial meal distribution in proximal and distal compartments of stomach, both emptying approximately 90% of their contents within 90 min. Normal and delayed gastric emptying was characterized by a 60%-40% initial ratio of meal distribution between gastric compartments. During normal emptying, both compartments reduced contents with approximately 50%, but delayed gastric emptying was caused by only a 15% reduction of proximal contents accompanied by a 34% reduction in distal contents. CONCLUSION: Recording in the supine position to abolish gravitational influences demonstrated accelerated gastric emptying of a firm semisolid meal with a prevalence of 8%. However, delayed gastric emptying was shown as the predominant gastric manifestation of longstanding insulin-dependent diabetes mellitus with a prevalence of 28%.

Case-Control Studies↗

PubMed1996

[Impulsive angular acceleration evoked middle and long latency potentials in guinea pigs].

Middle and long latency evoked potentials have been successfully recorded in guinea pigs with impulsive angular acceleration delivered by a specially developed motor. The middle latency responses elicited by impulsive angular acceleration had peaks at about 9 ms, 15 ms and 24 ms with a mean peak to peak amplitude of about 28muV and the long latency responses after the delivering of impulsive angular acceleration in guinea pigs composed of a triphasic wave with a mean peak to peak amplitude of about 50 muV occurring during 32 ms to 130 ms with respect to the start of head stimuli. A series of experiments lead to the conclusion that the middle latency responses to impulsive angular acceleration are middle latency vestibular evoked potentials. The long latency response elicited by impulsive angular acceleration is not a specific response of auditory or vestibular pathway.

Animals↗

PubMed1998

Some scale estimators and lack-of-fit tests for the censored two-sample accelerated life model.

Some new scale estimators for the censored two-sample accelerated life model are introduced. They are zeros of some integrated weighted difference between the two cumulative hazard estimators. These estimators are asymptotically normal. The weight is chosen to result in estimators whose asymptotic variances do not involve the destiny functions and can be easily estimated. This provides a fast and simple means of statistical inference in the censored two-sample accelerated life model. Through investigating the asymptotic relative efficiency at some important censoring submodels and the finite example behaviors in various numerical studies, we obtain some estimators with very competitive performance. From the new class of scale estimators, some lack-of-fit tests for the accelerated life model are also derived. These tests are related to Gill-Schumacher type tests and require little extra computing time once the estimator is obtained. The estimators and tests are illustrated in two applications. For a vaginal cancer data set for rats, the effect of pretreatment regime was found to be well described by the two-sample accelerated life model. For a data set on progression of ovarian cancer, it was found that the effect of grade of disease could not be described either by the two-sample proportional hazards model or the two-sample accelerated life model.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2000

Multidimensional MR mapping of multiple components of velocity and acceleration by fourier phase encoding with a small number of encoding steps.

Previous studies have shown that the multi-step approach of velocity or acceleration encoding is highly efficient in terms of the signal-to-noise ratio per unit time. This work describes a multidimensional extension of this method for simultaneously measuring multiple components of velocity and acceleration with a few encoding steps. N flow dimensions were encoded with an ND-matrix, obtained by combining the various flow-encoding gradients. The small matrix obtained with as few as two encoding steps can be extended by zero-filling in all N dimensions and using ND-Fourier transformation to obtain the maximum of the resulting peak in the ND-matrix, which gives simultaneously all the components of velocity and/or acceleration. The processing time was shortened by using a method of phase computation that gives the same precision as Fourier transformation, but is much faster. A rotating disk was used to show that the velocity-to-noise ratio increases with the number of dimensions acquired, demonstrating the efficiency of multidimensional flow measurements. The feasibility of the method is illustrated by 3D maps of the myocardium velocity, and 2D measurement of velocity and acceleration in the ascending aorta-both obtained by multidimensional phase encoding in volunteers.

Acceleration↗

PubMed2002

Clinical course of thrombocytopenia in patients treated with imatinib mesylate for accelerated phase chronic myelogenous leukemia.

We studied 28 patients with accelerated phase chronic myelogenous leukemia (CML) who were enrolled on the Novartis expanded access study 114. Diagnosis of accelerated phase CML was based on karyotypic evolution (n = 9) and hematologic criteria (n = 18). All patients were begun on 600 mg/day of imatinib mesylate. Dose reductions to 400 mg/day and then 300 mg/day were prescribed for an absolute neutrophil count (ANC) of <0.5/microl or a platelet count of <20,000/microl. Twenty-seven of the 28 patients continued treatment for a median of 34 weeks. Eleven patients developed thrombocytopenia following an average of 8.4 +/- 1.4 weeks of therapy. The onset of thrombocytopenia was associated with disease progression in one patient and a decline in bone marrow megakaryocytes in the other 10. Nine patients recovered to a platelet count of >20,000/microl after an average of 19.7 +/- 1.8 weeks. Patients who developed thrombocytopenia had a longer duration of disease (9.39 vs. 4.35 years; P < 0.01) and were more likely to be diagnosed with accelerated phase CML by hematologic criteria. Hematologic responses in patients with and without thrombocytopenia were comparable; however, 31.3% of patients without thrombocytopenia had a complete cytogenetic response compared to none of those with thrombocytopenia. Grade III-IV thrombocytopenia is common in accelerated phase CML and may be a marker for the inability to achieve cytogenetic response using single agent imatinib mesylate.

Antineoplastic Agents↗

PubMed1994

Abducens nerve responses of the frog during horizontal linear acceleration: data and model.

Abducens nerve responses of frogs were evoked by sinusoidal oscillations on a horizontal linear sled. The depth of modulation of these responses and their phases depended on the orientation of the head with respect to the direction of linear acceleration. Longitudinal acceleration evoked abducens responses that consisted of two discharge maxima per stimulus cycle. At consecutively more oblique head orientations, one of these two discharge maxima increased and the other decreased. Transverse accelerations evoked abducens responses that consisted of only one discharge maximum per stimulus cycle. Removal of the labyrinthine organs on one side abolished these responses in the contralateral abducens nerve but did not affect the responses in the ipsilateral abducens nerve. The latter result indicates that the responses in each abducens nerve originate from hair cells on the contralateral utricle. The experimentally determined modulation and phase values and their dependence on the orientation angle of the acceleration vector were used to characterize a functional cluster of hair cells located medially with respect to the striola in a fan-like sector on the utricle ('lateral rectus fan'). Parameters of this fan were used to develop a model that satisfactorily simulates the recorded abducens responses. This model predicts a majority of afferents with excitatory and a few afferents with inhibitory contributions to the abducens nerve responses. The phasic response components of about 90% of these afferents are larger than their tonic response components.

Abducens Nerve↗

PubMed1996

The human vertical vestibulo-ocular reflex during combined linear and angular acceleration with near-target fixation.

The purpose of this study was to examine the effect of fixation target distance on the human vestibuloocular reflex (VOR) during eccentric rotation in pitch. Such rotation induces both angular and linear acceleration. Eight normal subjects viewed earth-fixed targets that were either remote or near to the eyes during whole-body rotation about an earth-horizontal axis that was either oculocentric or 15 cm posterior (eccentric) to the eyes. Eye and head movements were recorded using magnetic search coils. Using a servomotor-driven chair, passive whole-body rotations were delivered as trains of single-frequency sinusoids at frequencies from 0.8 to 2.0 Hz and as pseudorandom impulses of acceleration. In the light, the visually enhanced VOR (VVOR) was recorded while subjects were asked to fixate targets at one of several distances. In darkness, subjects were asked to remember targets that had been viewed immediately prior to the rotation. In order to eliminate slip of the retinal image of a near target when the axis of rotation of the head is posterior to the eyes, the ideal gain (compensatory eye velocity divided by head velocity) of the VVOR and VOR must exceed 1.0. Both the VOR and VVOR were found to have significantly enhanced gains during sinusoidal and pseudorandom impulses of rotation (P < 0.05). Enhancement of VVOR gain was greatest at low frequencies of head rotation and decreased with increasing frequency. However, enhanced VOR gain only slightly exceeded 1.0, and VVOR gain enhancement was significantly lower than the expected ideal values for the stimulus conditions employed (P < 0.05). During oculocentric rotations with near targets, both the VOR and VVOR tended to exhibit small phase leads that increased with rotational frequency. In contrast, during eccentric rotations with near targets, there were small phase lags that increased with frequency. Visual tracking contributes during ocular compensatory responses to sustained head rotation, although the latency of visual tracking reflexes exceeds 100 ms. In order to study initial vestibular responses prior to modification by visual tracking, we presented impulses of head acceleration in pseudorandom sequence of initial positions and directions, and evaluated the ocular response in the epoch from 25 to 80 ms after movement onset. As with sinusoidal rotations, pseudorandom eccentric head rotation in the presence of a near, earth-fixed target was associated with enhancement of VVOR and VOR gains in the interval from 25 to 80 ms from movement onset. Despite the inability of visual tracking to contribute to these responses, VVOR gain significantly exceeded VOR gain for pseudorandom accelerations. This gain enhancement indicates that target distance and linear motion of the head are considered by the human ocular motor system in adjustment of performance of the early VOR, prior to a contribution by visual following reflexes. Vergence was appropriate to target distance during all VVOR rotations, but varied during VOR rotations with remembered targets. For the 3-m target distance, vergence during the VOR was stable over each entire trial but slightly exceeded the ideal value. For the 0.1-m near target, instantaneous vergence during the VOR typically declined gradually in a manner not corresponding to the time course of instantaneous VOR gain change; mean vergence over entire trials ranged from 60 to 90% of ideal, corresponding to target distances for which ideal gain would be much higher than actually observed. These findings suggest a dissociation between vergence and VOR gain during eccentric rotation with near targets in the frequency range from 0.8 to 2.0 Hz.

Acceleration↗

PubMed1986

M.I.T./Canadian vestibular experiments on the Spacelab-1 mission: 6. Vestibular reactions to lateral acceleration following ten days of weightlessness.

Tests of otolith function were performed pre-flight and post-flight on the science crew of the first Spacelab Mission with a rail-mounted linear acceleration sled. Four tests were performed using horizontal lateral (y-axis) acceleration: perception of linear motion, a closed loop nulling task, dynamic ocular torsion, and lateral eye deviations. The motion perception test measured the time to detect the onset and direction of near threshold accelerations. Post-flight measures of threshold and velocity constant obtained during the days immediately following the mission showed no consistent pattern of change among the four crewmen compared to their pre-flight baseline other than an increased variability of response. In the closed loop nulling task, crewmen controlled the motion of the sled and attempted to null a computer-generated random disturbance motion. When performed in the light, no difference in ability was noted between pre-flight and post-flight. In the dark, however, two of the four crewmen exhibited somewhat enhanced performance post-flight. Dynamic ocular torsion was measured in response to sinusoidal lateral acceleration which produces a gravitionertial stimulus equivalent to lateral head tilt without rotational movement of the head. Results available for two crewmen suggest a decreased amplitude of sinusoidal ocular torsion when measured on the day of landing (R+0) and an increasing amplitude when measured during the week following the mission.

Acceleration↗