Biorheology - Volume 29, issue 5-6

Authors: Maire, Catherine | Bouchy, Michel | Donner, Mireille | André, Jean-Claude

Article Type: Research Article

Abstract: A study of the labelling of isolated resealed erythrocyte membranes by TMA-DPH has been carried out. A quantitative study shows that saturation appears to take place when increasing the relative quantity of probe bulk concentration to membrane concentration; this is readily interpreted by a simple incorporation model with a limited number of sites in the membrane. A qualitative study shows that an increase in the labelling leads to an evolution of the probe fluorescence properties; the existence of different types of sites is involved in the interpretation but the system is too complex to allow it to be represented by …a simple model. As a consequence of this study, care has to be taken in labelling biological material so as to avoid excessive probe incorporation. Show more

Keywords: Molecular probe, TMA-DPH, fluorescence anistrophy, erythrocyte membrane

DOI: 10.3233/BIR-1992-295-611

Citation: Biorheology, vol. 29, no. 5-6, pp. 507-519, 1992

Authors: Lee, Belinda | Litt, Mitchell | Buchsbaum, Gershon

Article Type: Research Article

Abstract: The rheological properties of the vitreous body of the eye are believed to be a function of composition and to differ among species, as well as to vary regionally within the vitreous. These properties are essential to the mechanical functioning of the eye. Although there are gross, qualitative data on vitreous rheology available in the literature, quantitative rheological measurements on human vitreous and on eyes of other species are sparse and incomplete. The aim of the research reported in this series of papers is to study the rheological behavior of human, bovine, and porcine vitreous, to measure the macromolecular and …electrolyte content of these samples, and to correlate and compare these values for the different species as a function of location in the vitreous. In this paper, the rheological model used to correlate viscoelasticity of the vitreous is presented, and a detailed description of the rheological instrumentation and methods of analysis used is given. Data on the rheological properties of human vitreous, as a function of location within the eye, are presented. The results show that in the human eye there are significant differences in a number of the viscoelastic parameters as a function of location within the vitreous body. Show more

Keywords: Vitreous body, viscoelasticity, creep, compliance, human eye

DOI: 10.3233/BIR-1992-295-612

Citation: Biorheology, vol. 29, no. 5-6, pp. 521-533, 1992

Authors: Casley-Smith, J.R.

Article Type: Research Article

Abstract: A mathematical model has been constructed to investigate the alterations, in amount and in importance, of the Factors controlling interstitial fluid volume in a number of steady-state oedemas. There are many so-called “Safety Factors” (at least 15), including a whole group concerned with regulating the amount of protein in the tissues (and thus tissue colloidal osmotic pressure). They are often in long hierarchies (of even up to 11 Factors), each influencing the next. Sometimes a Factor is recursive, i.e. , it influences itself (either positively or negatively) via a Hierarchy of other Factors. The effects of some Factors differ …in different Hierarchies, i.e. , an increase in the Factor will increase VI via some of the Hierarchies and decrease it via some other Hierarchies. Which effect is most important varies with the Hierarchies and conditions existing at the time. The Factors are best compared if expressed in the same units: ml/min/100g of tissue. This is possible via appropriate multiplication factors derived from the relevant equations. Show more

Keywords: Interstitial fluid volume—variations in, hierarchies of safety factors, steady-states, oedemas—low and high protein, proteolysis in the tissues, benzo-pyrones

DOI: 10.3233/BIR-1992-295-613

Citation: Biorheology, vol. 29, no. 5-6, pp. 535-548, 1992

Authors: Chang, Raymond R.K. | Chien, Norman T.Y. | Chen, Ching-Hsien | Jan, Kung-Ming | Schmid-Schönbein, Geert W. | Chien, Shu

Article Type: Research Article

Abstract: Recent animal studies have suggested that there exists an activated subpopulation of circulating granulocytes which plays an important part in microvascular sequestration and tissue injury during shock and ischemia. In this respect, spontaneous granulocyte activation in form of pseudopod formation, a manifestation of actin polymerization, is a high risk for microvascular entrapment. The present investigation was carried out to determine if there is a significant difference in pseudopod formation in vitro between granulocytes obtained from healthy volunteers without symptoms and patients with acute cardiovascular illnesses. Blood samples from 25 healthy volunteers, 12 patients with acute myocardial infarction (AMI) and …12 patients with acute cerebral infarction (ACI) to determine spontaneous pseudopod formation in granulocytes with a high resolution light microscope over a period of several hours. The results revealed that the mean percentage of cells with pseudopod formation in the control group was below 10% in the first 3 hours, and increased to about 50% at 12 hours. In AMI patients, the level of activation within the first hour was not significantly different from the controls, but it rose rapidly to 90% in 4 to 5 hours. Patients with cerebral infarction, however, showed no significant difference from the control group. When the granulocytes of healthy subjects were incubated in plasma of AMI, the cells were activated similar to AMI granulocytes in their own plasma. When AMI plasma was serially diluted with Ringer’s solution, the activation curve fell successively. These results indicate that AMI patients’ blood contains plasma factor(s) which can activate granulocytes at a more rapid rate than controls. Show more

Keywords: Leukocyte, activation, pseudopod formation, acute myocardial infarction, cerebral infarction

DOI: 10.3233/BIR-1992-295-614

Citation: Biorheology, vol. 29, no. 5-6, pp. 549-561, 1992

Authors: Liepsch, D. | Moravec, St. | Baumgart, R.

Article Type: Research Article

Abstract: Flow studies were done in an elastic true-to-scale silicone rubber model of an aortic arch to study further hemodynamic influences on atherosclerosis. The model was prepared from a cast of a young woman. A revised model technique was used. The model had a compliance similar to that of the human aortic arch. Velocity measurements were done. in the model with a two component laser-Doppler-anemometer in steady and pulsatile flow using a calcium chloride solution with a viscosity of η = 3.18 mPas and density of ρ = 1.28 kg/m3 at 20°C. The time average Reynolds numbers over …a whole cycle in the ascending aorta was Re = 1350. The Womersley parameter for pulsatile flow was a = 20. The pulse wave velocity in the ascending aorta was about c = 5.4 m/sec. The secondary flow behavior was discussed for steady and pulsatile flow. Reverse flows were found, especially along the inner radius of the aortic arch in the descending aorta in steady and pulsatile flow and also in small areas of the ascending aorta and at the branches of the aortic arch. The formation of atherosclerotic plaques at preferred local flow regions is discussed. Show more

Keywords: Laser-Doppler-anemometer, flow visualization, elastic true-to-scale model, human aortic arch

DOI: 10.3233/BIR-1992-295-615

Citation: Biorheology, vol. 29, no. 5-6, pp. 563-580, 1992

Authors: Seno, S. | Zhang, D. | Inoue, S.

Article Type: Short Communication

Keywords: Micropipette, fabrication, trimming, fracturing, RBC

DOI: 10.3233/BIR-1992-295-616

Citation: Biorheology, vol. 29, no. 5-6, pp. 581-587, 1992

Article Type: Other

DOI: 10.3233/BIR-1992-295-617

Citation: Biorheology, vol. 29, no. 5-6, pp. 589-590, 1992