Haemodynamic effects of low-dose isoproterenol and aminophylline after coronary embolization in dogs

1973 ◽  
Vol 7 (1) ◽  
pp. 63-68 ◽  
Author(s):  
R. E. FALICOV ◽  
H. LIPP ◽  
L. RESNEKOV ◽  
S. KING
Keyword(s):  
Low Dose ◽  
Haemodynamic Effects ◽  
Coronary Embolization

Haemodynamic effects of vasopressin in man are related to posture

1986 ◽  
Vol 70 (2) ◽  
pp. 177-184 ◽  
Author(s):  
H. C. R. Simpson ◽  
J. E. Zubillaga ◽  
J. G. Collier ◽  
E. D. Bennett ◽  
V. T. Y. Ang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Low Dose ◽  
Forearm Blood Flow ◽  
Haemodynamic Effects ◽  
High Dose ◽  
Dose Infusion

1. Ten healthy volunteers received intravenous infusions of arginine vasopressin (AVP) at 0.1 m-unit min−1 kg−1 and 5% d-glucose on separate days. AVP caused a small fall in forearm blood flow and small rises in mean arterial pressure and systemic vascular resistance. Cardiac output was unaffected. 2. When subjects were tilted to 50° the fall in forearm blood flow was much greater, mean fall being 44.8% with AVP compared with 18.2% with d-glucose. Cardiac output also fell significantly more with AVP, and diastolic pressure, mean arterial pressure and systemic vascular resistance rose significantly more on tilting during AVP infusion than with d-glucose. 3. Six of the same volunteers were given sequential infusions of ‘low dose’ (0.0125 m-unit min−1 kg−1) and ‘high dose’ (0.3 m-unit min−1 kg−1) AVP on a third occasion. Tilting still produced a mean fall in forearm blood flow of 41.2% during low dose infusion, despite a mean plasma AVP level of only 1.9 pg/ml, which is well within the physiological range. When the AVP concentration was increased 24-fold to the high dose, forearm blood flow fell only a further 8.8%. The low dose infusion was also associated with a marked fall in cardiac output on tilting and a rise in systemic vascular resistance. 4. We conclude that AVP has profound haemodynamic effects in man at physiological concentrations. Although these effects are modest in the supine position, they become marked on tilting, suggesting a possible role for AVP in the postural control of blood pressure.

LOW-DOSE CAPTOPRIL IN CHRONIC HEART FAILURE: ACUTE HAEMODYNAMIC EFFECTS AND LONG-TERM TREATMENT

The Lancet ◽  
1980 ◽  
Vol 316 (8205) ◽  
pp. 1154-1157 ◽  
Author(s):  
D.N. Sharpe ◽  
R.J. Coxon ◽  
J.E. Douglas ◽  
B. Long
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Low Dose ◽  
Term Treatment ◽  
Haemodynamic Effects ◽  
Long Term Treatment

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

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