266,521 research outputs found
Point-of-care versus central testing of hemoglobin during large volume blood transfusion.
BACKGROUND: Point-of-care (POC) hemoglobin testing has the potential to revolutionize massive transfusion strategies. No prior studies have compared POC and central laboratory testing of hemoglobin in patients undergoing massive transfusions.
METHODS: We retrospectively compared the results of our point-of-care hemoglobin test (EPOC®) to our core laboratory complete blood count (CBC) hemoglobin test (Sysmex XE-5000™) in patients undergoing massive transfusion protocols (MTP) for hemorrhage. One hundred seventy paired samples from 90 patients for whom MTP was activated were collected at a single, tertiary care hospital between 10/2011 and 10/2017. Patients had both an EPOC® and CBC hemoglobin performed within 30 min of each other during the MTP. We assessed the accuracy of EPOC® hemoglobin testing using two variables: interchangeability and clinically significant differences from the CBC. The Clinical Laboratory Improvement Amendments (CLIA) proficiency testing criteria defined interchangeability for measurements. Clinically significant differences between the tests were defined by an expert panel. We examined whether these relationships changed as a function of the hemoglobin measured by the EPOC® and specific patient characteristics.
RESULTS: Fifty one percent (86 of 170) of paired samples\u27 hemoglobin results had an absolute difference of ≤7 and 73% (124 of 170) fell within ±1 g/dL of each other. The mean difference between EPOC® and CBC hemoglobin had a bias of - 0.268 g/dL (p = 0.002). When the EPOC® hemoglobin was \u3c 7 g/dL, 30% of the hemoglobin values were within ±7, and 57% were within ±1 g/dL. When the measured EPOC® hemoglobin was ≥7 g/dL, 55% of the EPOC® and CBC hemoglobin values were within ±7, and 76% were within ±1 g/dL. EPOC® and CBC hemoglobin values that were within ±1 g/dL varied by patient population: 77% for cardiac surgery, 58% for general surgery, and 72% for non-surgical patients.
CONCLUSIONS: The EPOC® device had minor negative bias, was not interchangeable with the CBC hemoglobin, and was less reliable when the EPOC® value was \u3c 7 g/dL. Clinicians must consider speed versus accuracy, and should check a CBC within 30 min as confirmation when the EPOC® hemoglobin is \u3c 7 g/dL until further prospective trials are performed in this population
Hemoglobin Subunit-Subunit Affinity-Determinant of Hemoglobin Formation
Hemoglobin A₂ is often elevated in β-thalassemia and decreased in α-thalassemia. This might be due to hemoglobin subunit-subunit affinity variation. It has been inferred from the study of abnormal hemoglobins that the a subunits have higher affinity for β subunits than for δ subunits. However, only in one study has the affinity of α, β, and δ subunits for each other been measured. In this work we have attempted to measure the hemoglobin subunit-subunit affinity with somewhat different approach, i.e., hybridization of hemoglobin A and A₂. It is shown that hybridization and recombination of equal amounts of hemoglobins A and A₂ lead always to the formation of more hemoglobin A than A₂. Incubation of pure α, β, and δ subunits forms more hemoglobin A than A₂ as the availability of a subunits declines. It is concluded that hemoglobin a subunits have approximately four-fold higher affinity for β subunits than for the δ subunits under these experimental conditions. This subunit-subunit affinity difference, which has been attributed to the variation in molecular electrostatic charges, explains the variation of hemoglobin A₂ levels in thalassemia syndromes
Oxidation of Native and Modified Hemoglobin and Myoglobin by Sodium Nitrate. Effect of Inositol Hexaphosphate
Native and modified hemoglobin, myoglobin and a and phemoglobin subunits were oxidized by sodium nitrite at pH 6. The experiments were carried out under oxy and deoxy conditions with and without inositol hexaphosphate (IHP). It is shown (a) that under oxy condition low concentration of IHP inhibits the oxidation of native hemoglobin only. However, high concentration of IHP inhibits the oxidation of both myoglobin and modified hemoglobin (digested or 0-93-SH groups blocked). This inhibition is partially counteracted by high oxygen pressure, (b) Under deoxy condition the oxidation rates of all hemeproteins studied are significantly faster than that of native hemoglobin. IHP inhibits the oxidation of all except the myoglobin and hemoglobin subunits. It is concluded that although the IHP inhibitory effect on hemoglobin oxidation by nitrite can be explained by the shift of the R↔T conformational equilibrium towards T conformation, some other structural changes such as alteration in molecular surface charges must occur to account for the effect of IHP on the oxidation of hemeproteins devoid of heme-heme interaction
Suppression of erythropoiesis by actinomycin D. 3. The effect of actinomycin D on the hemoglobin level of bone marrow erythrocytes and erythroblasts
For the purpose of revealing whether or not hemoglobin synthesis is inhibited by the AMD, the author estimated the hemoglobin level of AMD treated anilmals by microspectrophotometer, and found that the hemoglobin
levels of all the developmental stages of erythroid cells were not inhibited by the AMD. The data indicated that about one half of mRNA for hemoglobin is synthesized in the early stage of specialization with the supplementary synthesis at the later stages and all these mRNA is stable
and insensitive to AMD.</p
Improving Resulted Hemoglobin A1c Rates: A Feasibility Study for Point-of-Care Hemoglobin A1c Testing at an Urban Family Medicine Office
Study Aims: Our practice’s goal is to increase the number of up to date hemoglobin A1c for diabetic patients seen at JFMA in order to help improve glycemic control The aim of this study is to see if point of care (POC) hemoglobin A1C is a feasible way to increase the number of up to date hemoglobin A1C. We looked at various factors including timing, training, and flow.https://jdc.jefferson.edu/patientsafetyposters/1037/thumbnail.jp
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Identification of a Hemolysis Threshold That Increases Plasma and Serum Zinc Concentration.
Background: Plasma or serum zinc concentration (PZC or SZC) is the primary measure of zinc status, but accurate sampling requires controlling for hemolysis to prevent leakage of zinc from erythrocytes. It is not established how much hemolysis can occur without changing PZC/SZC concentrations.Objective: This study determines a guideline for the level of hemolysis that can significantly elevate PZC/SZC.Methods: The effect of hemolysis on PZC/SZC was estimated by using standard hematologic variables and mineral content. The calculated hemolysis threshold was then compared with results from an in vitro study and a population survey. Hemolysis was assessed by hemoglobin and iron concentrations, direct spectrophotometry, and visual assessment of the plasma or serum. Zinc and iron concentrations were determined by inductively coupled plasma spectrometry.Results: A 5% increase in PZC/SZC was calculated to result from the lysis of 1.15% of the erythrocytes in whole blood, corresponding to ∼1 g hemoglobin/L added into the plasma or serum. Similarly, the addition of simulated hemolysate to control plasma in vitro caused a 5% increase in PZC when hemoglobin concentrations reached 1.18 ± 0.10 g/L. In addition, serum samples from a population nutritional survey were scored for hemolysis and analyzed for changes in SZC; samples with hemolysis in the range of 1-2.5 g hemoglobin/L showed an estimated increase in SZC of 6% compared with nonhemolyzed samples. Each approach indicated that a 5% increase in PZC/SZC occurs at ∼1 g hemoglobin/L in plasma or serum. This concentration of hemoglobin can be readily identified directly by chemical hemoglobin assays or indirectly by direct spectrophotometry or matching to a color scale.Conclusions: A threshold of 1 g hemoglobin/L is recommended for PZC/SZC measurements to avoid increases in zinc caused by hemolysis. The use of this threshold may improve zinc assessment for monitoring zinc status and nutritional interventions
A Novel Real-Time Non-invasive Hemoglobin Level Detection Using Video Images from Smartphone Camera
Hemoglobin level detection is necessary for evaluating health condition in the human. In the laboratory setting, it is detected by shining light through a small volume of blood and using a colorimetric electronic particle counting algorithm. This invasive process requires time, blood specimens, laboratory equipment, and facilities. There are also many studies on non-invasive hemoglobin level detection. Existing solutions are expensive and require buying additional devices. In this paper, we present a smartphone-based non-invasive hemoglobin detection method. It uses the video images collected from the fingertip of a person. We hypothesized that there is a significant relation between the fingertip mini-video images and the hemoglobin level by laboratory gold standard. We also discussed other non-invasive methods and compared with our model. Finally, we described our findings and discussed future works
Evidence for multiple structural genes for the γ chain of human fetal hemoglobin
A sequence with a specific residue at each position was proposed for the γ chain of human fetal hemoglobin by Schroeder et al. (1) after a study in which hemoglobin from a number of individual infants was used. We have now examined in part the fetal hemoglobin components of 17 additional infants and have observed that position 136 of the γ chain may be occupied not only by a glycyl residue, as previously reported, but also by an alanyl residue
Incorporation in vitro of labeled amino acids into proteins of rabbit reticuloytes
Continuing our work on the incorporation of labeled amino acids into proteins (1), we have begun a study of the incorporation in vitro of C14-labeled glycine, L-histidine, L-leucine, and L-lysine into the proteins of rabbit reticulocytes. In preliminary experiments the incorporation into the hemoglobin isolated from the reticulocytes was determined. But, after it was found that plasma contains factors accelerating amino acid incorporation, it was decided to proceed as rapidly as possible toward the identification of these factors; we have, therefore, measured incorporation into the total proteins of the reticulocytes, since isolation of the hemoglobin was time-consuming. The results obtained with hemoglobin and with the total proteins are essentially the same, indicating that the other proteins of the reticulocytes incorporate amino acids at approximately the same rate as hemoglobin
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