Optical mammography: bilateral breast symmetry in hemoglobin saturation maps

Whereas it is widely believed that animals native to high altitude show lower O2 partial pressures at 50% hemoglobin saturation (P50) than do related animals native to low altitude, that “fact” has not been well documented. Consequently, P50 at pH 7.4, PCO2(7.4), the CO2 Bohr effect, and the buffer slope (delta log PCO2/delta pH) were determined via the mixing technique in Peromyscus maniculatus native to a range of altitudes but acclimated to 340 or 3,800 m. PCO2(7.4) and buffer slope were substantially lower at high altitude. The change in P50(7.4) between acclimation altitudes was minimal (0.8% increase at 3,800 m), because of counterbalancing changes in PCO2, 2,3-diphospho-D-glycerate concentration, and perhaps other factors. At both acclimation altitudes there was a highly significant negative correlation between P50(7.4) and native altitude. Since pH in vivo probably increases slightly at high altitude, the data on P50 corrected to pH 7.4 are probably underestimates of the difference in in vivo P50 at low vs. high altitude. Hence these results corroborate theoretical predictions that low P50 is advantageous under severe hypoxic stress.

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A nomogram relating pO2, pH, temperature, and hemoglobin saturation in the dog.

Journal of Applied Physiology ◽

10.1152/jappl.1966.21.1.195 ◽

1966 ◽

Vol 21 (1) ◽

pp. 195-201 ◽

Cited By ~ 152

Author(s):

R G Rossing ◽

S M Cain

Keyword(s):

Hemoglobin Saturation

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Vasomotion induces regular major oscillations in jejunal mucosal tissue oxygenation

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1994.266.6.g978 ◽

1994 ◽

Vol 266 (6) ◽

pp. G978-G986 ◽

Cited By ~ 3

Author(s):

W. Hasibeder ◽

R. Germann ◽

H. Sparr ◽

M. Haisjackl ◽

B. Friesenecker ◽

...

Keyword(s):

Tissue Oxygenation ◽

Jejunal Mucosa ◽

Blood Gas ◽

Acid Base ◽

Oxygen Extraction Ratio ◽

Physiological Basis ◽

Midline Laparotomy ◽

Jejunal Segment ◽

Hemoglobin Saturation ◽

The Mean

The mucosa of the small intestine has some unique microcirculatory features that may result in significant tissue oxygenation changes even under physiological conditions. To prove this hypothesis we investigated mucosal and serosal oxygenation in an autoperfused, innervated jejunal segment in pigs. Eight animals (30-40 kg) were anesthetized, paralyzed, and normoventilated. A small segment of the jejunal mucosa and serosa was exposed by a midline laparotomy and an antimesenteric incision. Mucosal and serosal oxygen tensions were measured using Clark-type surface oxygen electrodes. Mucosal hemoglobin saturation and concentration were determined by tissue reflectance spectrophotometry. Systemic hemodynamics, mesenteric-venous acid base, and blood gas variables, as well as systemic acid-base and blood gas variables and jejunal electromyogenic potentials, were recorded. Measurements were performed after a rest period at 0, 30, 60, and 90 min. All animals remained hemodynamically stable. At time 0 the jejunal oxygen extraction ratio was 0.33 +/- 0.05, the mean serosal PO2 was 60.25 +/- 7.69, the mean mucosal PO2 was 25.47 +/- 4.41 mmHg, and the mean mucosal hemoglobin saturation was 46.36 +/- 6.22%. Mean values did not change with time. In contrast to serosal PO2, mucosal PO2, mucosal hemoglobin oxygen saturation, and hemoglobin concentration showed rhythmic oscillations with a frequency of 3.4-5 cycles/min that were unrelated to systemic hemodynamic parameters, respiratory frequency, and intestinal peristalsis. From this we concluded that the jejunal mucosa demonstrates significant, regular changes in oxygenation parameters that are locally mediated. We speculate that the physiological basis for this phenomenon is the countercurrent arrangement of microvessels in conjunction with vasomotion.(ABSTRACT TRUNCATED AT 250 WORDS)

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Hematological and Genetic Predictors of Daytime Hemoglobin Saturation in Tanzanian Children with and without Sickle Cell Anemia

ISRN Hematology ◽

10.1155/2013/472909 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Sharon E. Cox ◽

Julie Makani ◽

Charles R. Newton ◽

Andrew M. Prentice ◽

Fenella J. Kirkham

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Clinical Chemistry ◽

Pearson Correlation ◽

Transferrin Saturation ◽

Full Blood Count ◽

Hemoglobin F ◽

Hemoglobin Saturation ◽

Highly Correlated ◽

Glucose 6 Phosphate Dehydrogenase

Low hemoglobin oxygen saturation (SpO2) is common in Sickle Cell Anemia (SCA) and associated with complications including stroke, although determinants remain unknown. We investigated potential hematological, genetic, and nutritional predictors of daytime SpO2 in Tanzanian children with SCA and compared them with non-SCA controls. Steady-state resting pulse oximetry, full blood count, transferrin saturation, and clinical chemistry were measured. Median daytime SpO2 was 97% (IQ range 94–99%) in SCA (N = 458), lower () than non-SCA (median 99%, IQ range 98–100%; N = 394). Within SCA, associations with SpO2 were observed for hematological variables, transferrin saturation, body-mass-index z-score, hemoglobin F (HbF%), genotypes, and hemolytic markers; mean cell hemoglobin (MCH) explained most variability (, Adj ). In non-SCA only age correlated with SpO2. -thalassemia 3.7 deletion highly correlated with decreased MCH (Pearson correlation coefficient 0.60, ). In multivariable models, lower SpO2 correlated with higher MCH (-coefficient 0.32, ) or with decreased copies of -thalassemia 3.7 deletion (-coefficient 1.1, ), and independently in both models with lower HbF% (-coefficient 0.15, ) and Glucose-6-Phosphate Dehydrogenase genotype (-coefficient 1.12, ). This study provides evidence to support the hypothesis that effects on red cell rheology are important in determining SpO2 in children with SCA. Potential mechanisms and implications are discussed.

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