Automated Method for Tracking Individual Red Blood Cells Within Capillaries to Compute Velocity and Oxygen Saturation

2005 ◽  
Vol 12 (6) ◽  
pp. 507-515 ◽  
Author(s):  
Shruti A. Japee ◽  
Roland N. Pittman ◽  
Christopher G. Ellis
Keyword(s):  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Automated Method ◽  
Compute Velocity

Measurement of hemoglobin oxygen saturation in capillaries

1987 ◽  
Vol 252 (5) ◽  
pp. H1031-H1040 ◽  
Author(s):  
M. L. Ellsworth ◽  
R. N. Pittman ◽  
C. G. Ellis
Keyword(s):  
Light Intensity ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Optical Density ◽  
Blood Cells ◽  
Striated Muscle ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch

We present a computer-aided videodensitometric method for the determination of oxygen saturation in red blood cells flowing through capillaries of the hamster cheek pouch retractor muscle. The optical density (OD) of red blood cells is determined at two wavelengths. At the first, 431 nm, there is a maximum difference between absorption by oxygen deoxyhemoglobin. At the second, 420 nm, absorption is equal for the two absorbing species (isosbestic wavelength). In capillaries of the retractor muscle a relationship between oxygen saturation (S) and the following OD ratio was obtained as S = -1.71 (OD431/OD420) + 2.20. The error (95% confidence interval) in oxygen saturation associated with a determination of the OD ratio is estimated to be +/- 4.8%. The computerization of the method employs a frame-by-frame analysis of the light intensity over a selected capillary segment. The light intensity waveform along the segment is digitized and the minimum (I) and maximum (I0) light intensities are used to compute an optical density (OD = log10 [I0/I]). These minimum and maximum intensities correspond to the presence and absence of a red blood cell, respectively. The method permits the off-line analysis of videotaped scenes and provides a means of assessing the extent of temporal and spatial heterogeneity of oxygen saturation in selected capillary networks. The method has been developed for use in capillaries in transilluminated striated muscle but should be generally applicable to the measurement of capillary oxygen saturation in other tissues.

scholarly journals Development of an Automated Enzymatic Method to Quantify Pyruvate Kinase in Red Blood Cells

2019 ◽  
Vol 5 (1) ◽  
pp. 54-61
Author(s):  
Jun Lu ◽  
David G Grenache
Keyword(s):  
Linear Regression ◽  
Red Blood Cells ◽  
Pyruvate Kinase ◽  
Blood Cells ◽  
Limit Of Detection ◽  
Linear Regression Analysis ◽  
Method Comparison ◽  
Reference Interval ◽  
Automated Method ◽  
K Factor

Abstract Background Pyruvate kinase (PK) deficiency is the most common cause of nonspherocytic hemolytic anemia owing to defective glycolysis. This study developed and validated an automated method to measure PK activity in red blood cells (RBCs). Methods PK catalyzes the reaction of phosphoenolpyruvate with ADP to form pyruvate and ATP. The pyruvate is reduced in the presence of lactate dehydrogenase and NADH to produce lactate and NAD+. The rate of absorbance decrease at 340 nm is proportional to PK activity. PK and hemoglobin (Hb) measurements were performed on a Roche cobas c501 analyzer. After establishing a k-factor, accuracy, linearity, imprecision, sensitivity, and stability were validated and the reference interval was verified. Results The k-factor was −9477. Accuracy was evaluated by method comparison (n = 56). Linear regression yielded y = 1.0x − 0.57, and R2 of 0.93. Linearity was determined by combining a high sample with hemolyzing solution in 6 different ratios. Linear regression analysis yielded y = 1.02x − 2.68, and R2 of 1.0. The assay was linear to 87 U/dL. Precision was evaluated by testing hemolysates in 3 replicates/day for 10 days. Within-run imprecision was 1.9% and 2.5% and total imprecision was 4.0% and 5.6% at 14.0 and 8.1 U/g Hb, respectively. The limit of blank was 0.0, and the limit of detection was 1.0 U/dL. Stability was determined in 4 sample types at 3 different temperatures; the changes were all <10% when compared with t0. The current PK reference interval of 4.6 to 11.2 U/g Hb was verified. Conclusions This automated assay for quantifying PK in RBCs has acceptable performance characteristics and is fit for intended use.

Comparison of buffer and red blood cell perfusion of guinea pig heart oxygenation

2003 ◽  
Vol 285 (5) ◽  
pp. H1819-H1825 ◽  
Author(s):  
Kenneth A. Schenkman ◽  
Daniel A. Beard ◽  
Wayne A. Ciesielski ◽  
Eric O. Feigl
Keyword(s):  
Oxygen Consumption ◽  
Guinea Pig ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Ventricular Function ◽  
Oxygen Tension ◽  
Blood Cells ◽  
Low Oxygen ◽  
Guinea Pig Heart ◽  
Perfused Hearts

Myocardial mean myoglobin oxygen saturation was determined spectroscopically from isolated guinea pig hearts perfused with red blood cells during increasing hypoxia. These experiments were undertaken to compare intracellular myoglobin oxygen saturation in isolated hearts perfused with a modest concentration of red blood cells (5% hematocrit) with intracellular myoglobin saturation previously reported from traditional buffer-perfused hearts. Studies were performed at 37°C with hearts paced at 240 beats/min and a constant perfusion pressure of 80 cmH2O. It was found that during perfusion with a hematocrit of 5%, baseline mean myoglobin saturation was 93% compared with 72% during buffer perfusion. Mean myoglobin saturation, ventricular function, and oxygen consumption remained fairly constant for arterial perfusate oxygen tensions above 100 mmHg and then decreased precipitously below 100 mmHg. In contrast, mean myoglobin saturation, ventricular function, and oxygen consumption began to decrease even at high oxygen tension with buffer perfusion. The present results demonstrate that perfusion with 5% red blood cells in the perfusate increases the baseline mean myoglobin saturation and better preserves cardiac function at low oxygen tension relative to buffer perfusion. These results suggest that caution should be used in extrapolating intracellular oxygen dynamics from buffer-perfused to blood-perfused hearts.

Determination of red blood cell oxygenation in vivo by dual video densitometric image analysis

1990 ◽  
Vol 258 (4) ◽  
pp. H1216-H1223 ◽  
Author(s):  
C. G. Ellis ◽  
M. L. Ellsworth ◽  
R. N. Pittman
Keyword(s):  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Striated Muscle ◽  
Wave Length ◽  
Retractor Muscle ◽  
Light Intensities ◽  
Microscopic Field

We have developed a new video microspectrophotometric system for the in vivo determination of oxygen saturation in red blood cells in striated muscle capillaries. This method allows one to quantify changes in the oxygenation of small groups of red blood cells as they traverse the capillary. Simultaneous images of a single microscopic field are recorded using two silicon-intensified target cameras and high-resolution video recorders. One image is recorded at an oxygen-dependent wave-length (431 nm) and the other at an isosbestic wavelength (420 nm). Light intensities from 10 adjacent pixels aligned along the axis of the capillary from identical 10-s segments of the video-tapes are digitized once per frame. Both sets of data are redisplayed simultaneously as two-dimensional images (10 pixels high x 300 frames wide) using a graphics system. These images show alternating bright and dark bands corresponding to plasma gaps and red blood cells. Light intensities in the presence and absence of red blood cells are determined by positioning a window over the appropriate region of the graphics image. Optical densities of single red blood cells at the two wavelengths, OD431 and OD420, are computed as is their ratio (OD431/OD420), which is linearly related to oxygen saturation. In vivo calibration studies in capillaries of the hamster retractor muscle indicate that the error in measuring oxygen saturation with this technique is approximately 2.7% saturation for a group of 10 cells.

Sulphaemoglobin formation in fish: a comparison between the haemoglobin of the sulphide-sensitive rainbow trout (Oncorhynchus Mykiss) and of the sulphide-tolerant common carp (Cyprinus Carpio)

2000 ◽  
Vol 203 (6) ◽  
pp. 1047-1058 ◽  
Author(s):  
S. Volkel ◽  
M. Berenbrink
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Common Carp ◽  
Cyprinus Carpio ◽  
Blood Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio

A method for the quantitative determination of sulphaemoglobin (SHb) in a mixture of haemoglobin derivatives by spectral deconvolution is described. SHb formation was studied in haemolysates and in red blood cells of the sulphide-sensitive rainbow trout (Oncorhynchus mykiss) and of the sulphide-tolerant common carp (Cyprinus carpio). Addition of sulphide caused the formation of SHb in haemolysates of both animals. However, haemoglobin from common carp was much less sensitive to sulphide than was trout haemoglobin. The maximal obtainable SHb fraction was approximately 30 % in trout and 10 % in carp haemolysates. In both animals, the SHb fraction increased with increasing Hb and sulphide concentrations up to 100 micromol l(−)(1) and 1 mmol l(−)(1), respectively, and was favoured by a low pH. An increase of temperature between 5 and 25 degrees C strongly increased SHb formation in trout haemolysate. In contrast, temperature changes had almost no effect on SHb production in carp. Within trout red blood cells, approximately 7 % of total haemoglobin was converted to SHb during 60 min of incubation (with 2.5 mmol l(−)(1) sulphide), inducing a 20 % loss of haemoglobin oxygen-saturation. In carp red blood cells incubated under identical conditions, SHb formation was minimal and haemoglobin oxygen-saturation was not affected.

Arterioles supply oxygen to capillaries by diffusion as well as by convection

1990 ◽  
Vol 258 (4) ◽  
pp. H1240-H1243 ◽  
Author(s):  
M. L. Ellsworth ◽  
R. N. Pittman
Keyword(s):  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Oxygen Transport ◽  
Blood Cells ◽  
Oxygen Exchange ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch ◽  
Local Oxygen

In the early part of this century, August Krogh proposed a model of oxygen transport in capillaries that assumes that all oxygen is delivered to the capillaries by convection from small terminal arterioles and lost from these capillaries by diffusion. This model and its consequences have been used extensively to interpret whole organ oxygen transport data in terms of diffusion between capillaries and tissues and to relate changes in microvascular hemodynamics to alterations in oxygen transport. We evaluated the appropriateness of such extrapolation by measuring oxygen saturation at discrete locations along the lengths of individual capillaries in the hamster cheek pouch retractor muscle. Our results indicate that the amount of oxygen lost from individual capillaries can be markedly affected by the presence of larger microvessels that frequently cross the capillary path. These larger vessels act either as a diffusive supply of oxygen for the red blood cells within the capillary or as an additional sink for the oxygen depending on the direction of the oxygen tension gradient. This transfer of oxygen between larger microvessels and capillaries attenuates the importance of capillary hemodynamics in oxygen exchange. Therefore, conclusions about local oxygen exchange that utilize only hemodynamic data from whole organ or microvascular experiments and the Krogh model will generally be invalid and should be viewed with caution.

Mechanisms of acute hemoconcentration in bullfrogs in response to hypoxemia

1993 ◽  
Vol 264 (4) ◽  
pp. R687-R695 ◽  
Author(s):  
A. W. Pinder ◽  
A. W. Smits
Keyword(s):  
Blood Cell ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Arterial Oxygen Saturation ◽  
Cell Swelling ◽  
Arterial Oxygen ◽  
Mean Corpuscular Hemoglobin

Three general mechanisms have been proposed to explain rapid increases in red blood cell concentration in vertebrates in response to hypoxia: spleen emptying, red blood cell swelling, and decreases in plasma volume. We have experimentally tested these potential mechanisms for the hemoconcentration of red blood cells associated with hypoxemia in cold (10 degrees C), submerged bullfrogs. The mean increase of hematocrit was approximately 1.4-fold (the increase was highly variable between individual frogs) when arterial oxygen saturation was reduced from 80% to 8% by lowering ambient O2 partial pressure (PO2). The largest response was seen when arterial oxygen saturation was below 33% (a saturation that is not unusual in submerged amphibians). There was no difference between hematocrit increases during hypoxemia in spleen-ligated compared with sham-operated frogs submerged in hyperoxic, normoxic, and hypoxic water, suggesting that spleen emptying is not the primary mechanism. Increased hematocrit was not due to red blood cell swelling: mean corpuscular hemoglobin concentration increased slightly as hematocrit increased, indicating that red blood cells shrank slightly rather than swelling. Plasma volume, measured in a separate group of animals by dilution of 51Cr-labeled autologous red blood cells, decreased almost 50% during hypoxemia, closely correlated with a mean increase of 1.76-fold of hematocrit. We thus conclude that the hematocrit increase seen during hypoxemia in bullfrogs is caused by a loss of plasma volume. This has important implications for cardiovascular function, since blood viscosity, oxygen carrying capacity, and cardiac output are all affected by changes in plasma volume.

Sign in / Sign up

Export Citation Format

Share Document