Erythrocyte sedimentation rate of healthy subjects--chronological aspects

Thanks to an elaborated mathematical approach, based on statistics and signal processing, the chronological changes of the Erythrocyte Sedimentation Rate (ESR) of young healthy subjects, considered from a collective point of view, have been discriminated into genuine and well-defined rhythms.

These rhythms are tied up either to natural (year, season) or 'social' (month, week, holidays) cycles, or to some other causes, still unknown and possibly intrinsic (such is probably the case of a 26.5-day strongly marked period).

The solar induced time variation strictly obeys a frequency modulation law, the relative amplitude of which is 10 per cent. Two axes of symmetry are found, centred on 8 August and 8 February. The rhythm is roughly in accordance with seasons. The modulation frequency is maximum at summer time.

Oscillations of the ESR are observed during the week and the month. Fridays and the last fortnight of each month appear to be low ESR time.     

Erythrocyte sedimentation rate. I. Volume fraction dependence in saline solution

We have measured volume fraction dependence of the sedimentation curve of swine erythrocytes in a physiological saline solution at 10 degrees C, 20 degrees C, 30 degrees C and 40 degrees C. The sedimentation curves were found to consist of initial constant velocity region and final plateau region at the lower temperatures of 10 degrees C and 20 degrees C, while modified S-shaped curves were observed at the higher temperatures of 30 degrees C and 40 degrees C. The volume fraction dependence of the initial slope v of the sedimentation curve was fitted well to the following exponential type equation at all the temperatures: v = vs,exp (1 - H)exp[-(BH + CH2)] where vs,exp is the velocity in infinite dilution corresponding to the Stokes velocity and H is the volume fraction of erythrocytes. The volume fraction dependence of the relative velocity v/vs,exp was in close agreement with a semi-empirical equation derived for slurrys in the field of chemical engineering at the lower temperatures, while a small deviation between the observed and calculated curves was found at the higher temperatures. The volume fraction dependence of v at 20 degrees C was also analyzed on a theory recently developed by Oka. The explicit functional form of the medium up-flow factor phi (H) and the deformability factor f in the theory were determined using the experimental data.     

Erythrocyte sedimentation rate II. Effects of tilt angle in saline solution

We have measured the sedimentation curves of swine erythrocytes in a physiological saline solution in inclined glass tubes. The curves are well fitted to the exponential type equation l = a[1 - exp(-bt)] for the tilt angle theta in the range of theta less than 80 degrees and hematocrits from 10 to 50%, where l and t are the medium length along the tube and the elapsed time from the sample injection, respectively. The coefficient a increases with theta and b is proportional to sin theta. The erythrocyte sedimentation rate ESR(theta) = (d l/dt)t----0 determined from the above empirical equation increases with the increase in sin theta roughly linearly. The experimental results are discussed with reference to the Ponder-Nakamura-Kuroda theory and some recent theories.     

Erythrocyte sedimentation rate III tube diameter dependence in saline solution

Erythrocyte sedimentation rate was measured in a physiological saline solution as a function of both the tube diameter d and the initial suspension length iota 0. All the sedimentation curves in the vertical tubes were found to overlap over the range 1 mm less than d less than 7 mm and 100 mm less than iota 0 less than 330 mm, within the precision of 8 %. The sedimentation curves in the tilted tubes fit well to an exponential equation of iota = a [1 - exp (-bt)], where iota and t are the medium length along the tube and the elapsed time from sample injection respectively: At fixed tilt angle theta and iota 0, a was roughly constant and b was roughly proportional to l/d, while at fixed theta and d, a was linearly proportional to iota 0 and b was constant. The initial slope ESR (theta) = (d iota/dt) t----0 = ab was represented by a unique straight line as a function of iota 0/d for each fixed tilt angle. The experimental results were compared with some recent theories.     

Erythrocyte sedimentation rate in diluted suspensions and their electrophoretic mobility in a vertical electrical field

The sedimentation rates (SR) of human red blood cells (RBC) were measured in diluted suspensions using the thin plate chamber. If the suspension medium was phosphate buffer saline or 0,18 M NaCl the SR-dependence on the distance to the chambers wall corresponded to SR distribution of small particles without interaction. The more NaCl content was decreased down to 0.145 M, the more temperature-dependent variations of SR were noted, while SR distribution became distinct with the predicted one for the non-interacting particles. The use of SR distribution is discussed for testing the RBC interaction in diluted suspensions caused by sedimentation. The electrophoretic measurements carried out under vertical oriented electrical field showed the rate of RBC movement to be the linear function of the field gradient and to be not influenced under the SR modifying conditions.     

Erythrocyte sedimentation realizable in terms of population dynamics

A phenomenological theory is formulated in analogy to the theory of population dynamics to account for the observed erythrocyte sedimentation-time and velocity-time curves. The least square fitting of experimental data to the derived equations is quite satisfactory. Several parameters in the proposed equations can be used to characterize these two curves of erythrocyte sedimentation: the biotic potential or intrinsic rate of decrease of the lacuna population, r; the total distance settled by the interface between plasma and red cell column, K.delta h; the maximal settling velocity of the interface, Vmax; the time when Vmax occurs, tmv; and the final position of the interface, Hf.     

Normal erythrocyte sedimentation rate in the elderly.

Two hundred subjects aged 60-89 were selected for a study aimed at defining a reference range for the erythrocyte sedimentation rate in the elderly. The study extended a previous survey in subjects aged 20-65. The results confirmed that the sedimentation rate increases with age and that women have higher values than men but suggested that over half of elderly patients with disease would have rates within the previously defined "normal" range. It is therefore suggested that an erythrocyte sedimentation rate exceeding 19 mm in the first hour in elderly men and 22 mm in the first hour in elderly women warrants investigation.     

The differentiated erythrocyte sedimentation rate

Summary The author has studied Erythrocyte Sedimentation Rates in the open air and in a copper container. All blood samples were obtained, every time, from the same subject. The results of the experiments, which lasted from May to September 1957, show a significant effect of the copper shield. The present article is the continuation of the studies published by the author in the Int. Journ. of Biocl. and Biomet. vol I, part IV, section C 1, 1957.     

The rate factor in DNA sedimentation studies

Zimm theory was used to study the effect of the rate of centrifugation on the coefficient and the profile of sedimentation of a polydispersed single-stranded DNA. There was a good agreement between the calculated and experimental DNA sedimentograms in alkaline lysates of irradiated rat bone marrow cells. This approach permited to take the rate factor into consideration on the basis of the parameters necessary for the work of the rotor and the gradient. Simple formulae were obtained connecting the molecular mass of DNA with the rate and the time necessary for its centrifugation. Possible consequences of not taking the rate factor into account in centrifuging the polymer DNA molecules are discussed.