Visual and Other Factors Influencing Caloric Nystagmus in Normal Subjects

1957 ◽  
Vol 66 (1) ◽  
pp. 46-53 ◽  
Author(s):  
J. L. MAHONEY ◽  
W. L. HARLAN ◽  
R. G. BICKFORD
Keyword(s):  
Normal Subjects ◽  
Factors Influencing ◽  
Caloric Nystagmus

scholarly journals Adrenomedullin(1–52) measured in human plasma by radioimmunoassay: plasma concentration, adsorption, and storage

1998 ◽  
Vol 44 (3) ◽  
pp. 571-577 ◽  
Author(s):  
Lynley K Lewis ◽  
Mary W Smith ◽  
Timothy G Yandle ◽  
A Mark Richards ◽  
M Gary Nicholls
Keyword(s):  
Plasma Concentration ◽  
Detection Limit ◽  
Normal Subjects ◽  
Hplc Separation ◽  
Freeze Thaw ◽  
Factors Influencing ◽  
Calcitonin Gene ◽  
Vasoactive Hormones ◽  
Assay Precision ◽  
And Storage

Abstract We describe a specific and sensitive RIA for human adrenomedullin (AM)(1–52). The detection limit and the concentration required for 50% inhibition of binding were 0.1 and 1.2 fmol/tube, respectively. Cross-reactivities with AM(1–12), AM(13–52), calcitonin gene-related peptide, amylin, and other vasoactive hormones were negligible. AM immunoreactivity in normal subjects ranged from 2.7 to 10.1 pmol/L (n = 44). We investigated factors influencing the recovery and measurement of AM in the assay. Recovery of labeled AM (>80%) was markedly higher than that of unlabeled AM (56%). Immunoreactivity of exogenous AM added to plasma decreased up to 70% over four freeze–thaw cycles, whereas endogenous AM was stable. Alkali-treated casein (1 g/L) reduced adsorption of AM to surfaces and significantly increased assay precision compared with bovine serum albumin (P <0.0001). HPLC separation of extracted plasma verified the presence of AM(1–52). We suggest that considerable care is needed to ensure that accurate and reproducible results are obtained from studies quantifying this peptide.

scholarly journals Optimisation of the prescription for trans-tibial (TT) amputees

1997 ◽  
Vol 21 (3) ◽  
pp. 168-174 ◽  
Author(s):  
A. Cortés ◽  
E. Viosca ◽  
J. V. Hoyos ◽  
J. Prat ◽  
J. Sánchez-Lacuesta
Keyword(s):  
Quantitative Method ◽  
Clinical Information ◽  
Normal Subjects ◽  
Individual Variability ◽  
Classification Criteria ◽  
The Other ◽  
Human Gait ◽  
Factors Influencing ◽  
The Subject

The great diversity of prosthetic mechanisms available nowadays leads to the question of which type of artificial foot would be the most advisable for a particular person. To answer correctly, it is necessary to establish, in an objective way, the performance of each type of prosthetic mechanism. This knowledge is obtained by means of the study of the subject-prosthesis interaction, both in static and dynamic conditions. This paper, based on the analysis of 8 transtibial (TT) amputees, presents a quantitative method for the study of human gait which allows the determination of the influence of four different prosthetic ankle-foot mechanisms (SACH, Single-axis, Greissinger and Dynamic) on gait. To do this, 1341 gait trials at different cadences were analysed (383 with normal subjects and 958 with amputees, using the four prosthetic feet under study). From all the variables available for study only those which offered interpretable clinical information were chosen for analysis. A total of 18 variables (kinetic, kinematic and time-related) were selected. A covariance analysis (ANOVA) of these variables was made, which showed that the factors influencing TT amputee gait were, in order of importance, cadence and leg studied (sound or prosthetic), inter-individual variability and, finally, the prosthetic mechanism used. When looking at the performance during gait of the 4 prosthetic mechanisms studied it can be observed that there are similarities in the kinetic study between SACH and Dynamic feet on one hand and Single-axis and Greissinger feet on the other. These results seem to support the classification criteria of articulated and non-articulated prosthetic mechanisms.

Factors influencing the concentration of expired nitrogen after a breath of oxygen

1965 ◽  
Vol 20 (1) ◽  
pp. 103-109 ◽  
Author(s):  
R. J. Mills ◽  
P. Harris
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Time Constants ◽  
Alveolar Air ◽  
Initial Volume ◽  
Single Breath ◽  
Factors Influencing ◽  
Inspired Oxygen

In normal subjects, the change in the concentration of nitrogen in expired alveolar air after a single breath of oxygen has been found to be affected by the presence of a pause at the end of inspiration, by varying rates of expiration, and by variations in the initial volume of air in the lungs. The effects of these different respiratory maneuvers are analyzed in terms of the over-all dilution of the inspired oxygen, of the unequal and asynchronous movements of the chest wall, and of the presence of a distribution of ventilatory time constants. The evidence suggests that there is a greater uniformity of ventilatory time constants at a middle lung volume than at a high or low lung volume. distribution of ventilation Submitted on January 27, 1964

Caloric-Eye Tracking Pattern Test: I. Visual Suppression and the Possibility of Simplified Differential Diagnosis between Peripheral and Central Vertigo

1976 ◽  
Vol 85 (2) ◽  
pp. 261-267 ◽  
Author(s):  
E. Sakata ◽  
Y. Umeda
Keyword(s):  
Differential Diagnosis ◽  
Eye Tracking ◽  
Normal Subjects ◽  
Vestibular Nystagmus ◽  
View Point ◽  
Vestibular Disorder ◽  
Stationary Target ◽  
Visual Suppression ◽  
Suppression Mechanism ◽  
Caloric Nystagmus

During the examination of patients who complain of vertigo or who have equilibrium disorders, it is often difficult to determine the etiology of the disorders, that is, to determine whether it is dependent on a peripheral or central vestibular disorder. To attempt to guess the etiology in these cases, we devised a new method: the caloric eye-tracking pattern test. In normal subjects and in patients with peripheral disorders, as is well known, caloric nystagmus has little influence on the eye-tracking pattern. In contrast, in patients with central vestibular disorders, caloric nystagmus evoked abnormalities on the eye-tracking pattern, either superimposed or saccades, in spite of the fact that the eye-tracking pattern before the caloric stimulation is normal. These findings result from the visual suppression mechanism to the vestibular nystagmus. We can say that the visual suppression to the vestibular nystagmus is evoked more strongly by pursuing a moving visual stimulus than by gazing at a stationary target. These results are interesting, not only from the physiological view point, but also from the clinical view point. There is a possibility of the differential diagnosis between peripheral and central vertigo.

Factors Influencing the Urinary Excretion of Free Catecholamines in Man

1973 ◽  
Vol 44 (3) ◽  
pp. 253-265 ◽  
Author(s):  
Mary M. Townshend ◽  
A. J. Smith
Keyword(s):  
Physical Activity ◽  
Myocardial Infarction ◽  
Renal Function ◽  
Urinary Excretion ◽  
Diurnal Variation ◽  
Normal Subjects ◽  
Urinary Catecholamine ◽  
Catecholamine Excretion ◽  
Factors Influencing ◽  
Noradrenaline And Adrenaline

1. The 24 h urinary excretion of noradrenaline and adrenaline is significantly lower in recumbent than ambulant normal subjects. 2. A diurnal variation exists in catecholamine excretion, the lowest values occurring during sleep. 3. Diurnal variation in sodium excretion parallels that in noradrenaline and adrenaline loss but the cycles can be separated by acute alterations in sleep/awake pattern. 4. Diurnal variation is lost during exercise, after myocardial infarction and was absent pre-operatively in a patient with a phaeochromocytoma. 5. Acute alterations in renal blood flow, diuresis, natriuresis and urinary acidification do not alter catecholamine excretion significantly. 6. Urinary catecholamine excretion is related to physical activity and wakefulness; the normal diurnal variation is easily overriden by sustained sympatho-adrenal activity. Alterations in renal function in exercise or after myocardial infarction do not account for the observed increases in catecholamine excretion.

Factors Influencing the Production of Wheezes during Expiratory Maneuvers in Normal Subjects

Respiration ◽  
1988 ◽  
Vol 54 (1) ◽  
pp. 50-60 ◽  
Author(s):  
Y. Ploysongsang ◽  
R.P. Baughman ◽  
R.G. Loudon ◽  
M.C. Rashkin
Keyword(s):  
Normal Subjects ◽  
Factors Influencing
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