Effect of Temperature on Fixation Suppression Ability in Normal Subjects: The Need for Temperature-and Age-Dependent Normal Values

1989 ◽  
Vol 98 (5) ◽  
pp. 369-372 ◽  
Author(s):  
Gary P. Jacobson ◽  
Kenneth G. Henry
Keyword(s):  
Normal Values ◽  
Normal Subjects ◽  
Test Battery ◽  
Effect Of Temperature ◽  
Slow Phase ◽  
Caloric Testing ◽  
Upper Limits ◽  
Age Dependent ◽  
The Subject

The purpose of the present investigation was to determine whether temperature has an effect on the magnitude of fixation suppression (FS) in normal subjects. The subject population consisted of 23 patients ranging in age from 35 to 74 years (mean age of 58.13 years). Each subject received a conventional vestibulometric test battery that included bithermal caloric testing and the FS test. The warm caloric media elicited larger nystagmus slow-phase eye velocities than the cool caloric media. Following warm caloric irrigations, FS was significantly smaller than that following cool caloric irrigations. It also worsened as a function of subject age. The results suggest that separate normal upper limits for FS need to be determined for cool and warm caloric testing. They also suggest that FS ability may decrease with age.

Distribution of ventilation in normal subjects from 7 to 45 years of age

1965 ◽  
Vol 20 (1) ◽  
pp. 77-78 ◽  
Author(s):  
M. M. Orzalesi ◽  
M. C. Hart ◽  
C. D. Cook
Keyword(s):  
Normal Values ◽  
Normal Subjects ◽  
Gas Distribution ◽  
Lung Clearance ◽  
Nitrogen Washout ◽  
Lung Clearance Index ◽  
Age Dependent

Distribution of ventilation was investigated in 57 normal subjects of both sexes ranging in age from 7 to 45 years using the nitrogen washout method. Normal values for nitrogen clearance delay and the lung clearance index are presented for children and adults. No significant sex- or age-dependent difference was found in either of these parameters. The present data are compared with those in the literature. nitrogen washout; respiration in children and adults; distribution of inspired gas in children and adults; gas distribution Submitted on April 13, 1964

Does Posturography Differentiate Malingerers from Vertiginous Patients?

1995 ◽  
Vol 5 (2) ◽  
pp. 117-124
Author(s):  
Seija Uimonen ◽  
Kyösti Laitakari ◽  
Heikki Kiukaanniemi ◽  
Martti Sorri
Keyword(s):  
Normal Values ◽  
Normal Subjects ◽  
Vestibular Neuritis ◽  
Body Sway ◽  
Test Situation ◽  
Staff Members ◽  
Static Posturography ◽  
Test Conditions ◽  
The Subject ◽  
Analysis System

Voluntary, simulated vertigo and acute vertigo due to vestibular neuritis were examined by means of static posturography in 81 tests to evaluate the extent to which intentional malingering can be detected. Thirty healthy, normal subjects were first instructed to stand as still as possible on a static force platform and then to simulate dizziness. The true cases consisted of 21 patients with vestibular neuritis. The parameters analyzed included body sway velocity (BSV), body sway area of ellipse (BSE), and the Romberg quotient. Both the simulated and pathological posturographic BSV and BSE values differed from normal values under all test conditions, but they did not differ from each other, whereas the simulated values could be differentiated from the pathological ones with the Romberg quotient based on BSV. Five staff members of our audiological department were able to differentiate between the simulations and pathological cases quite well, with a median sensitivity of 0.77 and a specificity of 0.71 in a blinded test. A posturographic measurement, even performed once, can be useful to some extent for detecting simulation, but more investigation and development of the analysis system is required to obtain more specific results. For the present, the results obtained by trained observation of the subject in the test situation are at least as reliable as those obtained through the analysis of statistical measurements.

Monocular and Binocular Testing to Improve the Diagnostic Value of Horizontal Optokinetic Nystagmus

1993 ◽  
Vol 2 (3) ◽  
pp. 44-47
Author(s):  
Cynthia G. Fowler ◽  
Carol A. Zizz ◽  
Robert H. I. Blanks
Keyword(s):  
Optokinetic Nystagmus ◽  
Chronic Phase ◽  
Normal Subjects ◽  
Diagnostic Value ◽  
Slow Phase ◽  
Surgical Removal ◽  
Nerve Section ◽  
Intermediate Period ◽  
Flat Screen ◽  
The Subject

This report describes the effects of unilateral peripheral vestibular lesions on the binocular and monocular optokinetic nystagmus (OKN). Six subjects who had undergone surgical removal of an acoustic neuroma were compared to 14 normal subjects. Stimuli consisted of 15° vertical stripes projected onto a flat screen 1 m from the subject. Stimulus velocities were 15, 30, 45, and 60°/sec. Before surgery, contralateral gain of the slow phase velocity was low, approximately 0.6, compared to 0.9 for ipsilateral gain at 60°/sec. In the acute postoperative period (<30 days), the gains of horizontal OKN were low and symmetrical for both stimulus directions. In the intermediate period (30–60 days postoperative), the OKN was asymmetrical (contralateral gain lower than ipsilateral gain), with the greatest discrepancy at 60°/sec. During the chronic phase (>2 months) the OKN was still asymmetrical in 3 of the 6 subjects. These data suggest that monocular and binocular optokinetic testing can be used to monitor the vestibular compensation of subjects following vestibular nerve section.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Age does not necessarily influence latency of event-related potentials

2014 ◽  
Vol 33 (10) ◽  
pp. 723-727
Author(s):  
M. Westermann ◽  
I. W. Husstedt ◽  
A. Okegwo ◽  
S. Evers
Keyword(s):  
Normal Values ◽  
Rank Correlation ◽  
Event Related Potentials ◽  
Intrinsic Property ◽  
Total Sample ◽  
Oddball Paradigm ◽  
Age Dependent ◽  
Related Potentials ◽  
The Mean ◽  
P3 Component

SummaryEvent-related potentials (ERP) are regarded as age dependent. However, it is not known whether this is an intrinsic property of ERP or an extrinsic factor. We designed a setting in which ERP were evoked using a modified oddball paradigm with highly differentiable and detectable target and non-target stimuli. A total of 98 probands were enrolled in this study. We evaluated the latency and amplitude of the P3 component of visually evoked ERP. The mean P3 latency was 294 ± 28 ms and was not related to age (r = –0.089; p = 0.382; Spearman-rank-correlation). The P3 amplitude was related to age in the total sample (r = –0.323; p = 0.001; Spearmanrank-correlation) but not in the probands under the age of 60 years. There were no significant differences regarding sex. Our findings suggest that ERP are not age dependent if highly differentiable and detectable stimuli are used. This should be considered when normal values of ERP are created for clinical use.

Computerized method for validating laboratory reference ranges for triiodothyronine and thyroxin immunoassays

1991 ◽  
Vol 37 (3) ◽  
pp. 438-442 ◽  
Author(s):  
Brian Luttrell ◽  
Sall Watters
Keyword(s):  
Reference Range ◽  
Normal Values ◽  
Reference Group ◽  
Normal Population ◽  
Normal Subjects ◽  
Reference Ranges ◽  
Large Samples ◽  
Laboratory Reference ◽  
Euthyroid Status ◽  
Computer Based

Abstract We used a computer-based method to help validate the reference ranges of assays for triiodothyronine (T3) and thyroxin (T4). A retrospective search of a database of laboratory results for the previous six months identified all patients with apparent euthyroid status, as defined by methods independent of the immunoassay under review. A computer-generated reference group (CGR Group) of 2001 records had a gaussian distribution of T4 values and a reference range (mean +/- 2 SD) of 56-161 nmol/L, compared with the supplier's suggested range for euthyroid subjects (58-148 nmol/L) and an in-house range of 60-144 nmol/L for a group of 97 normal subjects. A similar CGR Group of 1902 records gave a reference range for T3 of 0.7-2.1 nmol/L (manufacturer's range 0.8-2.8; normal subjects 0.8-2.2). An attempt to devise a reference range for thyrotropin failed when we found that its concentration in the population of patients with normal values for thyroid hormones was distributed differently from that in the normal population. The method is intended to be used in addition to conventionally derived ranges based on results for healthy subjects. It allows the laboratory to conveniently verify the reference ranges for T3 and T4 assays at regular intervals by using very large samples with appropriate age, sex, and weight distribution, drawn from the population of patients' samples submitted for analysis.

Monocular Nystagmic Responses to Caloric Stimulation

1979 ◽  
Vol 88 (1) ◽  
pp. 79-85 ◽  
Author(s):  
James W. Wolfe
Keyword(s):  
Phase Velocity ◽  
Rhesus Monkeys ◽  
Cold Water ◽  
Normal Subjects ◽  
Closed Circuit ◽  
Slow Phase ◽  
Vestibular Nystagmus ◽  
Differential Activation ◽  
Slow Phase Velocity ◽  
Left And Right

Twenty-five normal subjects and 173 clinical patients received standard bithermal caloric testing. Vestibular nystagmus was evaluated for cumulative slow phase velocity from the summated horizontal eye recording and independent recording of the left and right eye. These data revealed that cold water stimulation produced more intense activation of the ipsilateral eye. Simultaneous closed-circuit video and D.C. electro-oculographic recordings from eight normal rhesus monkeys in response to cold water irrigations confirmed the fact that this stimulus leads to differential activation of the extraocular muscles. A possible explanation for this finding is discussed.

Mechanics of the rib cage and diaphragm during sleep

1977 ◽  
Vol 43 (4) ◽  
pp. 600-602 ◽  
Author(s):  
K. Tusiewicz ◽  
H. Moldofsky ◽  
A. C. Bryan ◽  
M. H. Bryan
Keyword(s):  
Tidal Volume ◽  
Supine Position ◽  
Marked Reduction ◽  
Normal Subjects ◽  
Upright Position ◽  
Rapid Eye Movement Sleep ◽  
Sleep State ◽  
Quiet Sleep ◽  
Rib Cage ◽  
The Subject

The pattern of motion of the rib cage and abdomen/diaphragm was studied in three normal subjects during sleep. Sleep state was monitored by electroencephalograph and electrocculograph. Intercostal electromyographs (EMG's) were recorded from the second interspace parasternally. Abdominothoracic motion was monitored with magnetometers and these signals calibrated by isovolume lines either immediately before going to sleep, or if there was movement, on awakening. Respiration was recorded using a jerkin plethysmograph. In the awake subject in the supine position, the rib cage contributed 44% to the tidal volume and had essentially the same contribution in quiet sleep. However, in active or rapid eye movement sleep the rib cage contribution fell to 19% of the tidal volume. This was accompanied by a marked reduction in the intercostal EMG. With the subject in the upright position the rib cage appears to be passively driven by the diaphragm. However, the present data suggest that active contraction of the intercostal muscles is required for normal rib cage expansion in the supine position.

scholarly journals A study of adsorption isotherms for the removal of herbicide Atlantis WG from aqueous solutions by using Bentonite clay

2015 ◽  
Vol 12 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Process ◽  
Equilibrium Concentration ◽  
Bentonite Clay ◽  
Langmuir Model ◽  
Effect Of Temperature ◽  
Isotherm Models ◽  
Sorption Data ◽  
Freundlich Model ◽  
The Subject

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.

Effect of temperature on arterial blood gas tensions and pH during exercise

1964 ◽  
Vol 19 (2) ◽  
pp. 243-245 ◽  
Author(s):  
Alf Holmgren ◽  
Malcolm B. McIlroy
Keyword(s):  
Metabolic Acidosis ◽  
Normal Subjects ◽  
Bicycle Ergometer ◽  
Effect Of Temperature ◽  
Membrane Diffusion ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Capillary Membrane ◽  
Severe Exercise ◽  
Alveolar Capillary

We measured arterial blood Po2, Pco2 and pH at rest and during a standard exercise test on a bicycle ergometer in ten normal subjects. In five we measured esophageal and five arterial blood temperature during the exercise and corrected the arterial blood values to the temperature at the time the samples were collected. We found an average rise in temperature of 1 C (range 0.2–1.6 C) during exercise lasting about 30 min at loads up to an average of 1,200 kg-m/min. At the highest load the average correction for PaOO2 was 5.6 mm Hg, for PaCOCO2 1.6 mm Hg and for pH 0.014 units. Our corrected values showed a fall in PaCOCO2 and pH and a rise in PaOO2 during severe exercise. These findings are compatible with the development of a metabolic acidosis during severe exercise and indicate that our subjects were not limited by diffusion across the alveolar-capillary membrane. metabolic acidosis; alveolar capillary membrane diffusion; hyperventilation; PaOO2 and PaCOCO2 in severe exercise Submitted on June 17, 1963

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