Biorheology - Volume 16, issue 1-2

Article Type: Correction

DOI: 10.3233/BIR-1979-161-220

Citation: Biorheology, vol. 16, no. 1-2, pp. i-i, 1979

Authors: Copley, Alfred L.

Article Type: Editorial

DOI: 10.3233/BIR-1979-161-201

Citation: Biorheology, vol. 16, no. 1-2, pp. 1-2, 1979

Authors: Fukada, Eiichi

Article Type: Editorial

DOI: 10.3233/BIR-1979-161-202

Citation: Biorheology, vol. 16, no. 1-2, pp. 3-4, 1979

Article Type: Editorial

DOI: 10.3233/BIR-1979-161-203

Citation: Biorheology, vol. 16, no. 1-2, pp. 5-5, 1979

Authors: Snyder, Robert S. | Seaman, Geoffrey V.F.

Article Type: Research Article

Abstract: Microgravity, one of the unique features of space, offers the elimination of some major terrestrial difficulties which arise in the separation of cells and larger particles and also to some extent during measurements of their physicochemical properties. The gravitational effects which compromise separation processes and also some biorheological measurements are summarized. Past space results especially in the biological area are discussed and the experimental facilities and environment likely to be available on the Space Shuttle are documented.

DOI: 10.3233/BIR-1979-161-204

Citation: Biorheology, vol. 16, no. 1-2, pp. 7-11, 1979

Authors: Kimzey, Stephen L.

Article Type: Research Article

Abstract: The most significant effect of the space flight environment relative to the blood and blood-forming tissues in man has been a consistent reduction in the circulating red blood cell mass during the flight interval. This finding was first reported during the Gemini IV, V and VII missions, and has since been a consistent observation in the Apollo, Skylab and Apollo-Soyuz flights. Similar results have been reported by Russian scientists following their Salyut missions. It was initially proposed that the high concentration (near 100%) of oxygen in the spacecraft atmosphere was the cause of the red cell mass loss. This …hypothesis was strengthened by similar observations in a chamber study utilizing a 100 percent oxygen atmosphere at a total pressure of 5 psia (identical to that of Gemini and the later portion of the Apollo flights). Studies also revealed subtle alterations in red cell membrane integrity (decreased osmotic fragility, suppression of active potassium transport, increased plasma tocopheral, decreased membrane lipid content) consistent with the concept of a mild oxygen toxicity resulting in intravascular hemolysis. Data from the Skylab flights are not consistent with the concept of an oxygen-induced intravascular hemolysis. It would appear that some other factor characteristic of the space flight environment (weightlessness?) causes a suppression of red cell production that is not immediately relieved with a return to a normal 1-g environment, except, on longer flights, such as the 84-day Skylab 4 mission, when the red cell mass appears to begin to recover before re-entry. The variations in the magnitude of the loss in individual crewmen and the complicated postflight recovery kinetics suggest a complex relationship between the red cell mass loss and the duration of the exposure to weightlessness. This “anemia of space flight” was frequently accompanied by a reduction in plasma volume, apparently occurring early in the mission and sustained throughout the flight. Other, more subtle, effects have been observed with respect to the function and structure of red blood cells (significant changes in the distribution of red cell shapes during flight and a transient alteration in red cell specific gravity profiles postflight). The major emphasis of this review will be to address questions relative to the regulation of blood volume during space flight and the causes of its apparent failure. Show more

DOI: 10.3233/BIR-1979-161-205

Citation: Biorheology, vol. 16, no. 1-2, pp. 13-21, 1979

Authors: Saville, D.A.

Article Type: Research Article

Abstract: Selected examples of the behavior of single phase systems are used to illustrate the sorts of phenomena that persist in a micro-gravity environment. Although the strength of buoyancy driven flows is diminished, velocities of the order of several millimeters per second may persist. With buoyancy diminished, surface tension driven flows may be pre-eminent. In suspensions, particle swarms can also move at appreciable rates even though the sedimentation rate for an isolated particle is vanishingly small. Furthermore particle migration across streamlines due to inertia or particle deformation can have large cumulative effects.

DOI: 10.3233/BIR-1979-161-206

Citation: Biorheology, vol. 16, no. 1-2, pp. 23-27, 1979

Authors: Dintenfass, L.

Article Type: Research Article

Abstract: This paper outlines NASA experiment No. MPS77F113, proposed for Space Shuttle No. 3. The objectives of this investigation are: (a) to study aggregation of human red blood cells in order to define the maximum size and morphology of aggregates under near-zero gravity; (b) to define effects of various agents (such as fibrinogen, cholesterol, paraproteins, snake-venom derivatives, etc.) on the size of red cell aggregates and kinetics of their formation; (c) to study blood viscosity under high and low shear rates; and (d) to consider these tests with a view to possible use as, or elaboration of existing, diagnostic tests. The …space environment offers the advantage of weightlessness which allows formation of cell aggregates undisturbed by sedimentation. The background to these studies is given, and the development of the automatic parallel-plate slit-capillary viscometer is described. Aggregation of red cells is recorded by a photocamera equipped with bellows or with a microscope. Pressure drop and temperature are also recorded in the memory of a microprocessor. About six blood samples are used with a single set of plates. Blood samples from healthy donors and from patients suffering from hypertension, diabetes, myocardial infarction and some types of cancer are used. Effect of ABO blood group of the donor will be studied. Show more

DOI: 10.3233/BIR-1979-161-207

Citation: Biorheology, vol. 16, no. 1-2, pp. 29-36, 1979

Authors: Copley, Alfred L.

Article Type: Research Article

Abstract: Hemorheology, viz., rheology of blood and vessel wall, is considered to be affected in a near zero gravity environment. As body water, constituting a predominant component of the body mass of living subjects, is mainly distributed among intracellular, interstitial and plasma compartments, gravity appears to be important in the regulation of their volumes. Exposure of human and other vertebrate subjects to a near zero gravity environment may bring about a number of hemorheological changes, affecting the blood and the vessel structures with which blood or its components come into direct contact. Since no hemorheological studies have been made in such …an environment, experiments, employing a newly designed light-weight rheogoniometer (LWR), are proposed to be performed on ground and in the Spacelab Module. The modified Weissenberg Rheogoniometer is recommended for comparative testing the efficacy and precision of the LWR and accessories. The following studies, based on research in my laboratory, are proposed: 1. Viscosity and elasticity measurements of human blood (HB); 2. cinephotomicrographic recordings of HB in steady and oscillatory shears; 3. rheological studies of viscosity and elasticity of surface layers of purified fibrinogen and other proteins; 4. measurements of viscoelasticity and rigidity of fibrin gels. The findings to be secured promise to shed new light on recent findings in astronauts exposed to protracted stay in a near zero gravity environment. The information gained may also identify the role which gravity plays in situations on earth which thus far could not be fully appreciated. Our proposed studies may lead to corrective prophylactic measures to enable people to live and work during protracted stay in a near zero gravity environment. Show more

DOI: 10.3233/BIR-1979-161-208

Citation: Biorheology, vol. 16, no. 1-2, pp. 37-49, 1979

Authors: Adams, A.L. | Vroman, L.

Article Type: Research Article

Abstract: Effects of gravity in presence and absence of red blood cells, on adhesion of platelets to polyvinylchloride (pvc) slides, and of granulocytes to gamma globulin preabsorbed onto pvc, were studied by placing whole heparinized human blood or its red cell poor supernatant between 2 slides, and allowing this sandwich to reside in 1 position followed by the inverted one for various periods. Counts of adhering elements indicated that a) settling red cells drastically interfered with platelet and granulocyte adhesion to the surfaces facing up, but enhanced their adherence to surfaces facing down; b) in absence of red cells, granulocytes adhered …in great numbers to the globulin surfaces and platelets to the “blank” surfaces facing up during the first 5 min of the experiment, and few adhered to the surfaces that had faced down; c) upon inversion, granulocytes would still refuse to adhere to the surfaces that had initially faced down, while platelet adhesion increased during the subsequent 30 min; the nonadhering granulocytes would still be able to adhere if transferred to a new globulin-coated pvc surface facing up, and unused supernatant would still deposit granulocytes onto the used globulin-coated pvc surfaces if facing up. Experiments to be performed at near 0 gravity are suggested. Show more

DOI: 10.3233/BIR-1979-161-209

Citation: Biorheology, vol. 16, no. 1-2, pp. 51-55, 1979

Authors: King, Malcolm

Article Type: Research Article

Abstract: The relationship between the mechanical properties of tracheal mucus and its rate of transport on the mucus-depleted frog palate was investigated. Mucus samples were obtained from dogs subject to a variety of physiological interventions - barbiturate anesthesia, tranquilization, cholinergic stimulation, and dehydration. For each sample, the elastic modulus, G′, and the dynamic viscosity, η ′, were determined over the frequency range of 1 to 100 rad/sec by means of the magnetic rheometer technique, and the relative frog palate transport rate, Tr, was determined by previously described methods. For 102 control or near-control tracheal mucus samples, correlations were found relating the …relative transport rate to either the elastic modulus or the viscosity, and, in addition, to the loss tangent, tan δ . At constant tan δ , Tr vs. log G′ or log η ′ (determined at 1 rad/sec) gave partial correlation coefficients of −0.59; at constant G′, the partial correlation coefficient for Tr vs. tan δ was −0.45. Cholinergic stimulation and barbiturate anesthesia both induced rapid, gross changes in the tracheal mucus. With these acute interventions, the dependence of mucociliary transport on mucus mechanical properties was qualitatively similar to that seen in the chronic studies. The statistical variability was smaller, however, because the variation due to frog palate mucus was eliminated. Show more

DOI: 10.3233/BIR-1979-161-210

Citation: Biorheology, vol. 16, no. 1-2, pp. 57-68, 1979

Authors: Dintenfass, L.

Article Type: Research Article

Abstract: Our studies in theoretical, experimental and clinical haemorheology moved through a number of stages, but each of these stages contributed to a better insight into the microrheology of blood. While the first two stages dealt with instrumentation and comprehension of blood viscosity factors (i.e., concepts of the internal viscosity of the red cell, of the “inversion phenomenon” in the microcapillary flow, of spectra of coagulation times, viscosity and morphology of artificial thrombi), in the third stage these viscosity factors were correlated with protein levels or ratios, cholesterol, parathyroid hormone, SGOT, etc., and ABO blood groups. In the fourth stage a …correlation was sought between viscosity and clinical syndromes, physical fitness, ECG abnormality, etc. In recent studies the submaximal exercise work was found to be significantly related to the blood viscosity factors. Experimental work presented herewith shows a significant correlation between diastolic and/or systolic blood pressure and blood viscosity or blood viscosity factors. Of particular importance appears to be rigidity of red cells, and its role in blood pressure and viscosity homeostasis is considered. There is evidence for autoregulation of blood viscosity which might be involving a hypothetical “viscoreceptor” mechanism. Elevation of any of the blood viscosity factors is a ‘risk factor’ and a warning sign, the latter most important in the silent disorders. Show more

DOI: 10.3233/BIR-1979-161-211

Citation: Biorheology, vol. 16, no. 1-2, pp. 69-84, 1979

Authors: Cox, Robert H.

Article Type: Research Article

Abstract: Changes in passive arterial wall mechanical properties have been correlated with connective tissue composition during growth and development. These results indicate that passive arterial wall mechanics are determined in part by a) the total connective tissue content (collagen and elastin); b) the ratio of collagen to elastin; and c) the “concentration” of connective tissue in extracellular space. Studies of the mechanics and composition of arteries from different anatomical sites indicate that the low and high strain mechanics of these vessels correlates well with their elastin and collagen content, respectively. Differences in mechanics at moderate values of strain can be explained …on the basis of differences in the details of the recruitment of collagen fibers to support wall load with increasing strain in different arteries. Differences in the mechanics of carotid arteries from different species at high and low strain suggest that values of elastin and collagen elastic moduli may vary with amino acid composition, for example. Studies of stiffness during arterial smooth muscle activation (series elasticity, SE) in arteries from different anatomical locations revealed no correlation between values of SE and connective tissue composition. However, the results of these studies indicate that arteries with the stiffest SE had the most effective contractile apparatus producing relatively larger constriction responses for a given active stress response compared to other muscles. Smaller arteries from the same vascular bed exhibit similar characteristics with no differences in SE. The more effective contractile apparatus in this case is probably the result of a relatively larger wall thickness in the case of smaller arteries. Treatment of arteries with collagenase produces reductions in active stress development which parallel collagen removal. This suggests a role of collagen in the intercellular coupling of cellular force development. Thus, passive wall elements play a variety of roles in the arterial wall by contributing to both active and passive properties. Show more

DOI: 10.3233/BIR-1979-161-212

Citation: Biorheology, vol. 16, no. 1-2, pp. 85-94, 1979

Authors: Houbouyan, L. | Gaillard, S. | Goguel, A. | Stoltz, J.F.

Article Type: Research Article

DOI: 10.3233/BIR-1979-161-213

Citation: Biorheology, vol. 16, no. 1-2, pp. 95-100, 1979

Authors: Sabbah, Hani N. | Stein, Paul D.

Article Type: Research Article

Abstract: The purpose of this study is to determine if the normal semilunar valve leaflets contribute to turbulence in the region of the semilunar valves. Measurements of turbulence distal to a porcine aortic valve were made using an in vitro model of the cardiovascular system in which fluctuating velocities indicative of turbulence were measured with a hot film probe. The distribution of turbulence across the simulated aortic root was shown to relate to the location of the free margin of the aortic valve during systole. This indicates that turbulence resulted from the formation of eddies at the free margins of the …semilunar cusps which acted as projections in the stream of flow. Therefore, it is insufficient to rely upon the peak Reynolds number when attempting to determine when turbulence would occur in the region of the aortic or pulmonary valves. These observations are pertinent to understanding the genesis of cardiac murmurs that originate in the region of semilunar valves. Show more

DOI: 10.3233/BIR-1979-161-214

Citation: Biorheology, vol. 16, no. 1-2, pp. 101-108, 1979

Authors: Chaturani, P. | Upadhya, V.S.

Article Type: Research Article

Abstract: The present problem deals with a two-fluid model for blood flow through small diameter tubes. The two-fluid model consists of a core (suspension of red cells) and a peripheral red cell free plasma layer. The core has been considered as a couple stress fluid and the plasma layer as a Newtonian fluid. Using appropriate boundary conditions, analytic expressions for velocity profile, flow rate, percentage marginal flow rate and effective viscosity have been obtained. It is found that the velocity profiles obtained from this model are in better agreement with the experimental results of Bugliarello and Sevilla than the velocity profiles …given by other models. A critical study of other models and their comparison with the present model have been presented. It is observed that, for some reason, in these models, only one aspect of the flow, i.e., either velocity profiles or viscosity, has been studied, whereas for blood flow, both are equally important. It is shown that many of the existing two-fluid models are included in the present model as its special cases. It is of interest to note that the effective viscosity computed from the present model increases with tube radius; thus this model exhibits ‘Fahraeus-Lindquist Effect’ (FLE). Perhaps, the most important feature of this model is: it gives an analytic formula to determine the core viscosity experimentally, which so far, at least to authors’ knowledge, has not been determined. Finally, some biological implications of this theoretical investigation have been indicated. Show more

DOI: 10.3233/BIR-1979-161-215

Citation: Biorheology, vol. 16, no. 1-2, pp. 109-118, 1979

Authors: Singh, Megha | Coulter Jr., N.A.

Article Type: Short Communication

DOI: 10.3233/BIR-1979-161-216

Citation: Biorheology, vol. 16, no. 1-2, pp. 119-120, 1979

Authors: Chaturani, P. | Upadhya, V.S.

Article Type: Short Communication

DOI: 10.3233/BIR-1979-161-217

Citation: Biorheology, vol. 16, no. 1-2, pp. 121-122, 1979

Article Type: Abstract

DOI: 10.3233/BIR-1979-161-218

Citation: Biorheology, vol. 16, no. 1-2, pp. 123-132, 1979

Article Type: Announcement

DOI: 10.3233/BIR-1979-161-219

Citation: Biorheology, vol. 16, no. 1-2, pp. 133-133, 1979