Effect of Topical Anesthesia on Episcleral Venous Pressure in Normal Human Subjects

2015 ◽  
Vol 56 (5) ◽  
pp. 2968 ◽  
Author(s):  
Mehrdad Malihi ◽  
Jay W. McLaren ◽  
Arthur J. Sit
Keyword(s):  
Human Subjects ◽  
Venous Pressure ◽  
Topical Anesthesia ◽  
Episcleral Venous Pressure ◽  
Normal Human

Diastolic pressure determines autonomic responses to pressure perturbation in humans

1989 ◽  
Vol 66 (2) ◽  
pp. 800-807 ◽  
Author(s):  
J. S. Sanders ◽  
D. W. Ferguson
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Sympathetic Nerve Activity ◽  
Diastolic Pressure ◽  
Human Subjects ◽  
Muscle Sympathetic Nerve Activity ◽  
Venous Pressure ◽  
Central Venous ◽  
Nerve Activity ◽  
Normal Human

Arterial baroreceptors reflexly regulate sympathetic and heart rate responses to alteration of blood pressure. The primary mechanical determinant of arterial baroreceptor activity in humans remains unclear. We examined the influence of systolic, diastolic, pulse, and mean arterial pressures on efferent muscle sympathetic nerve activity (MSNA, microneurography) and heart rate responses during perturbation of arterial pressure in 10 normal human subjects [age 25 +/- 2 (SE) yr]. We directly measured arterial pressure, heart rate, and MSNA during intravenous vasodilator infusion (nitroprusside, 6 +/- 1 micrograms.kg-1.min-1, n = 6; or hydralazine, 16 +/- 2 mg, n = 4) while central venous pressure was held constant by simultaneous volume expansion. Changes in arterial pressures were compared with changes in heart rate and MSNA over 3-min periods of vasodilator infusion during which we observed increases in systolic and pulse pressures with simultaneous decreases in mean and diastolic pressures. During vasodilator infusion, there were increases in systolic (124.2 +/- 2.1 to 131.7 +/- 2.9 Torr, P less than 0.001) and pulse pressures (57.0 +/- 2.2 to 72.7 +/- 2.7 Torr, P less than 0.001) although mean arterial pressure fell (88.0 +/- 2.6 to 80.4 +/- 2.7 Torr, P less than 0.001) because of decreases in diastolic pressure (67.2 +/- 3.0 to 59.0 +/- 2.7 Torr, P less than 0.001). The changes in arterial pressures were accompanied by simultaneous increases in heart rate (66.4 +/- 3.0 to 92.6 +/- 4.8 beats/min, P less than 0.001) and MSNA (327 +/- 59 to 936 +/- 171 U, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Observations on a Relationship between Steroid Metabolism and the Concentration of Plasma Fibrinogen

1963 ◽  
Vol 10 (02) ◽  
pp. 400-405 ◽  
Author(s):  
B. A Amundson ◽  
L. O Pilgeram
Keyword(s):  
Blood Coagulation ◽  
Methyl Ether ◽  
Broad Spectrum ◽  
Human Subjects ◽  
Plasma Fibrinogen ◽  
Steroid Metabolism ◽  
Specific Site ◽  
Chain Reaction ◽  
Normal Human ◽  
A Chain

SummaryEnovid (5 mg norethynodrel and 0.075 mg ethynylestradiol-3-methyl ether) therapy in young normal human subjects causes an increase in plasma fibrinogen of 32.4% (P >C 0.001). Consideration of this effect together with other effects of Enovid on the activity of specific blood coagulatory factors suggests that the steroids are exerting their effect at a specific site of the blood coagulation and/or fibrinolytic system. The broad spectrum of changes which are induced by the steroids may be attributed to a combination of a chain reaction and feed-back control.

Relationship Between Mepacrine-Labelled Dense Body Number, Platelet Capacity to Accumulate 14C-5-HT and Platelet Density in the Bernard-Soulier and Hermansky-Pudlak Syndromes

1979 ◽  
Vol 42 (02) ◽  
pp. 694-704 ◽  
Author(s):  
F Rendu ◽  
A T Nurden ◽  
M Lebret ◽  
J P Caen
Keyword(s):  
Dense Body ◽  
Human Subjects ◽  
Human Platelets ◽  
Dense Bodies ◽  
Storage Organelle ◽  
Hereditary Disorders ◽  
Labelling Procedure ◽  
Normal Human ◽  
Hermansky Pudlak Syndrome ◽  
Bernard Soulier Syndrome

SummaryWe have used the mepacrine-labelling procedure to measure the dense body (serotonin storage organelle) content of the platelets of 2 hereditary disorders where abnormalities in dense body number were suspected. The platelets were incubated with mepacrine and examined by fluorescence microscopy. A mean number of 5.4 ± 0.8 (SD) dense bodies per platelet was calculated from the data obtained using platelets isolated from 40 normal human subjects. In contrast the platelets of 2 patients with the Bernard-Soulier syndrome contained an average of 14 and 17 labelled granules. This increase was associated with a much greater capacity of the platelets to accumulate 14C-5-HT. The opposite result was obtained using the platelets from 2 patients with the Hermansky-Pudlak syndrome which contained few granules labelled by mepacrine and took up less 14C-5-HT than normal human platelets. Centrifugation of the patients’ platelets on discontinuous sucrose gradients showed that the platelets of the 2 Bemard-Soulier patients were much denser than normal whereas a high proportion of low density platelets was observed in the Hermansky-Pudlak syndrome. These results further define the platelet abnormalities in the two syndromes and suggest that dense body number may be one of the factors governing platelet density.

ADRENERGIC CONTROL MECHANISM FOR ACTH SECRETION IN MAN

1973 ◽  
Vol 74 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Yoshikatsu Nakai ◽  
Hiroo Imura ◽  
Teruya Yoshimi ◽  
Shigeru Matsukura
Keyword(s):  
Intravenous Infusion ◽  
Human Subjects ◽  
Blocking Agent ◽  
Inhibitory Effect ◽  
Plasma Acth ◽  
Acth Secretion ◽  
Glucose Levels ◽  
Alpha Receptors ◽  
Normal Human ◽  
Adrenergic Blocking

ABSTRACT In order to determine if an adrenergic mechanism is involved in the secretion of corticotrophin (ACTH), the effect of adrenergic-blocking or -stimulating agent on plasma ACTH, cortisol and glucose levels was studied in normal human subjects. The intravenous infusion of methoxamine, an alpha adrenergic-stimulating agent, caused a rise in plasma ACTH and cortisol. This increase in plasma ACTH and cortisol was significantly inhibited by the simultaneous administration of phentolamine, an alpha adrenergic-blocking agent, in combination with methoxamine. The intravenous infusion of propranolol, a beta adrenergic-blocking agent, caused no significant change in plasma ACTH and cortisol, although it enhanced the plasma ACTH response to insulin-induced hypoglycaemia. On the other hand, alpha adrenergicblockade by intravenous infusion of phentolamine significantly suppressed the plasma ACTH response to insulin-induced hypoglycaemia. These studies suggest a stimulatory effect of alpha receptors and a possible inhibitory effect of beta receptors on ACTH secretion in man.

Specialized systems for the processing of mnemonic information within the primate frontal cortex

1996 ◽  
Vol 351 (1346) ◽  
pp. 1455-1462 ◽  
Keyword(s):  
Frontal Cortex ◽  
Specific Activity ◽  
Human Subjects ◽  
Long Term Memory ◽  
Executive Processing ◽  
Severe Impairment ◽  
Normal Human ◽  
Short And Long Term ◽  
Cortical Association Areas

The lateral frontal cortex is involved in various aspects of executive processing within short- and long-term memory. It is argued that the different parts of the lateral frontal cortex make distinct contributions to memory that differ in terms of the level of executive processing that is carried out in interaction with posterior cortical systems. According to this hypothesis, the mid-dorsolateral frontal cortex (areas 46 and 9) is a specialized system for the monitoring and manipulation of information within working memory, whereas the mid-ventrolateral frontal cortex (areas 47/12 and 45) is involved in the active retrieval of information from the posterior cortical association areas. Data are presented which support this two-level hypothesis that posits two distinct levels of interaction of the lateral frontal cortex with posterior cortical association areas. Functional activation studies with normal human subjects have demonstrated specific activity within the mid-dorsolateral region of the frontal cortex during the performance of tasks requiring monitoring of self-generated and externally generated sequences of responses. In the monkey, lesions restricted to this region of the frontal cortex yield a severe impairment in performance of the above tasks, this impairment appearing against a background of normal performance on several basic mnemonic tasks. By contrast, a more severe impairment follows damage to the mid-ventrolateral frontal region and functional activation studies have demonstrated specific changes in activity in this region in relation to the active retrieval of information from memory.

Effect of Age on Oxygen-Binding in Normal Human Subjects

1976 ◽  
Vol 51 (2) ◽  
pp. 185-188
Author(s):  
P. M. Tweeddale ◽  
R. J. E. Leggett ◽  
D. C. Flenley
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Tension ◽  
Inorganic Phosphate ◽  
Human Subjects ◽  
Oxygen Binding ◽  
Corpuscular Haemoglobin ◽  
Positive Correlation ◽  
Normal Human ◽  
Mean Corpuscular Haemoglobin ◽  
Effect Of Age

1. Oxygen-binding, plasma and intra-erythrocytic pH, and haemoglobin, 2,3-diphosphoglycerate and inorganic phosphate concentrations were measured in sixty-two healthy non-smokers aged between 18 and 89 years. 2. P50 (oxygen tension at 50% oxygen saturation) expressed at plasma pH 7·40 and Pco2 5·33 kPa showed a positive correlation with age. 3. This correlation of P50 with age was closer when P50 was expressed at a constant intra-erythrocytic pH 7·20. On average P50 at intra-erythrocytic pH 7·20 increased from 3·59 kPa at 20 years to 3·96 kPa at 90 years of age. 4. 2,3-Diphosphoglycerate, inorganic phosphate, haemoglobin and mean corpuscular haemoglobin concentrations did not correlate with P50 or with age.

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