Browsing by Subject "Hemoglobins"
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Item Open Access Allylation of intraerythrocytic hemoglobin by raw garlic extracts.(J Med Food, 2010-08) Bonaventura, Joseph; Rodriguez, Eva N; Beyley, Veronica; Vega, Irving ERecent studies have shown that deoxygenated human red blood cells (RBCs) converted garlic-derived polysulfides into hydrogen sulfide, which in turn produced vasorelaxation in aortic ring preparations. The vasoactivity was proposed to occur via glucose- and thiol-dependent acellular reactions. In the present study, we investigated the interaction of garlic extracts with human deoxygenated RBCs and its effect on intracellular hemoglobin molecules. The results showed that garlic extract covalently modified intraerythrocytic deoxygenated hemoglobin. The modification identified consisted of an addition of 71 atomic mass units, suggesting allylation of the cysteine residues. Consistently, purified human deoxyhemoglobin reacted with chemically pure diallyl disulfide, showing the same modification as garlic extracts. Tandem mass spectrometry analysis demonstrated that garlic extract and diallyl disulfide modified hemoglobin's beta-chain at cysteine-93 (beta-93C) or cysteine-112 (beta-112C). These results indicate that garlic-derived organic disulfides as well as pure diallyl disulfide must permeate the RBC membrane and modified deoxyhemoglobin at beta-93C or beta-112C. Although the physiological role of the reported garlic extract-induced allyl modification on human hemoglobin warrants further study, the results indicate that constituents of natural products, such as those from garlic extract, modify intracellular proteins.Item Open Access Association of anemia and long-term survival in patients with pulmonary hypertension.(Int J Cardiol, 2011-08-04) Krasuski, Richard A; Hart, Stephen A; Smith, Brad; Wang, Andrew; Harrison, J Kevin; Bashore, Thomas MBACKGROUND: Anemia is a marker of worsened clinical outcome in patients with heart failure from left ventricular dysfunction. Pulmonary hypertension often results in right ventricular dysfunction. Accordingly we sought to examine the association of hemoglobin levels and long-term all-cause mortality in a cohort of patients with pulmonary hypertension. METHODS: Baseline demographic information, clinical characteristics and fasting blood work were obtained in a cohort of 145 patients with pulmonary hypertension referred for pulmonary vasodilator testing. Data was retrospectively analyzed with Cox-proportional hazards analysis. RESULTS: Baseline characteristics of the cohort included age (mean±SD) 55.8±14.6 years, 75% women, 50% with idiopathic pulmonary hypertension, mean pulmonary artery pressure 46.1±14.2 mm Hg and arterial O(2) saturation 91±6 %. The most commonly utilized pulmonary hypertension specific therapeutic agents in descending order of frequency were epoprostenol (27%), sildenafil (21%), bosentan (17%), and treprostinil (6%). Over a median follow-up of 2.1 years, there were 39 deaths (26.9%). Patients who died had significantly lower hemoglobin levels than those survived (12.2±2.3 vs. 13.7±2.0, p<0.001). After adjustment for known predictors of death and pulmonary hypertension etiology, anemic patients were 3.3 times more likely to die than non-anemic patients (95% CI [1.43-7.51], p=0.005). CONCLUSIONS: Hemoglobin levels closely parallel survival in pulmonary hypertension. Modification of anemia in this disorder could alter the clinical course and calls for further research in this area.Item Open Access Bipolar tissue sealant device decreases hemoglobin loss in multilevel spine surgery.(Transfusion, 2012-12) Hill, Steven E; Broomer, Bob; Stover, John; White, William; Richardson, WilliamBackground
Traditional techniques for obtaining hemostasis during orthopedic surgery, such as conventional electrocautery and sealants, have limited clinical effectiveness in reducing hemoglobin (Hb) loss and requirement for transfusion. The bipolar tissue sealant device studied in this trial combines radiofrequency energy with saline irrigation to hemostatically seal both cut bone and soft tissue, potentially aiding hemostasis.Study design and methods
Sixty patients undergoing multilevel posterior lumbar instrumentation and fusion were randomly assigned to unipolar cautery alone (control group) or unipolar cautery plus use of the bipolar tissue sealant device (treatment group). Hb loss from the surgical field was measured (rather than estimated) and compared between the two groups. The primary hypothesis was that the treatment group would lose significantly less Hb than the control group.Results
The control group experienced a mean Hb loss of 102.4 g while the treatment group showed a significantly lower mean Hb loss of 66.2 g (p = 0.0004). No significant difference was found between groups with respect to secondary endpoints including length of surgery, number of red blood cell units transfused, number of total blood component units transfused, transfusion avoidance, length of stay, or serious adverse events.Conclusion
Use of a bipolar tissue sealant device in addition to unipolar cautery significantly decreased Hb loss during multilevel, posterior lumbar spinal instrumentation and fusion when compared with unipolar cautery alone.Item Open Access Comparison of visually estimated blood loss with direct hemoglobin measurement in multilevel spine surgery.(Transfusion, 2013-11) Guinn, Nicole R; Broomer, Bob W; White, William; Richardson, William; Hill, Steven EBackground
Estimates of blood loss in the operating room are typically performed as a visual assessment by providers, despite multiple studies showing this to be inaccurate. Use of a less subjective measurement of blood loss such as direct measurement of the hemoglobin (Hb) mass lost from the surgical field may better quantify surgical bleeding. The objective of this investigation was to compare anesthesiologist estimates of intraoperative blood loss with measured Hb loss.Study design and methods
Sixty patients undergoing posterior spine surgery were enrolled in a prospective, randomized trial comparing intraoperative blood loss using unipolar cautery alone or with use of a bipolar tissue sealant device. Hb concentration and fluid volume were measured from all surgical sponges, suction canisters, and the cell salvage device. Using the volume and concentration of Hb from each solution allowed calculation of Hb mass, which was converted into volume of blood lost and compared with estimates of blood loss documented by the anesthesia team. A single-sample t test of no difference was used to compare estimated with measured blood loss.Results
Mean estimated blood loss exceeded measured blood loss by 246 mL (860 mL vs. 614 mL, p < 0.0001).Conclusion
Estimated blood loss exceeded measured blood loss by 40% on average. The likely etiology of this discrepancy relates to the inability to visually determine Hb concentration of sanguineous solutions in suction canisters and surgical sponges. Ramifications of excessive bleeding estimates include unnecessary transfusion and overadministration of intravenous fluids, both of which may have deleterious effects.Item Open Access Development of hemispheric specialization for lexical pitch-accent in Japanese infants.(J Cogn Neurosci, 2010-11) Sato, Yutaka; Sogabe, Yuko; Mazuka, ReikoInfants' speech perception abilities change through the first year of life, from broad sensitivity to a wide range of speech contrasts to becoming more finely attuned to their native language. What remains unclear, however, is how this perceptual change relates to brain responses to native language contrasts in terms of the functional specialization of the left and right hemispheres. Here, to elucidate the developmental changes in functional lateralization accompanying this perceptual change, we conducted two experiments on Japanese infants using Japanese lexical pitch-accent, which changes word meanings with the pitch pattern within words. In the first behavioral experiment, using visual habituation, we confirmed that infants at both 4 and 10 months have sensitivities to the lexical pitch-accent pattern change embedded in disyllabic words. In the second experiment, near-infrared spectroscopy was used to measure cortical hemodynamic responses in the left and right hemispheres to the same lexical pitch-accent pattern changes and their pure tone counterparts. We found that brain responses to the pitch change within words differed between 4- and 10-month-old infants in terms of functional lateralization: Left hemisphere dominance for the perception of the pitch change embedded in words was seen only in the 10-month-olds. These results suggest that the perceptual change in Japanese lexical pitch-accent may be related to a shift in functional lateralization from bilateral to left hemisphere dominance.Item Open Access Jehovah's Witnesses and cardiac surgery: a single institution's experience.(Transfusion, 2014-10) McCartney, Sharon; Guinn, Nicole; Roberson, Russell; Broomer, Bob; White, William; Hill, StevenBACKGROUND: Based on biblical doctrines, patients of the Jehovah's Witness faith refuse allogeneic blood transfusion. Cardiac surgery carries a high risk of blood transfusion, but has been performed in Jehovah's Witnesses for many years. The literature contains information on the outcomes of this cohort, but does not detail the perioperative care of these patients. This article describes a single institution's experience in perioperative care of Jehovah's Witnesses undergoing cardiac surgery. STUDY DESIGN AND METHODS: A chart review of adult Jehovah's Witness patients undergoing cardiac surgery at Duke University between January 2005 and June 2012 was completed. Institutional protocols regarding preoperative erythropoietin (EPO) therapy and intraoperative isovolemic hemodilution are detailed. Patient demographics and use of various blood conservation techniques are described. Hemoglobin (Hb) at various points throughout the perioperative management, hospital length of stay, and mortality are reviewed as indicators of outcome. RESULTS: Forty-five Jehovah's Witness patients underwent cardiac surgery at Duke University Medical Center. Preoperative EPO increased the mean Hb by 1.2 g/dL before surgery. Intraoperative normovolemic hemodilution was used in 37 patients with intraoperative mean nadir Hb of 10.3 g/dL. Antifibrinolytics and desmopressin were commonly used as coagulation adjuncts. Mean cardiopulmonary bypass time was 137 minutes, with mean nadir temperature of 30.5°C. The mean length of hospital stay was 6.2 days, with mean intensive care unit stay of 1.7 days. This cohort had zero 90-day mortality in the perioperative period. CONCLUSIONS: This case series demonstrates that bloodless cardiac surgery can be performed in select patients refusing allogeneic blood transfusion.Item Open Access Nitric oxide loading reduces sickle red cell adhesion and vaso-occlusion in vivo.(Blood advances, 2019-09) McMahon, Timothy J; Shan, Siqing; Riccio, Daniel A; Batchvarova, Milena; Zhu, Hongmei; Telen, Marilyn J; Zennadi, RahimaSickle red blood cells (SSRBCs) are adherent to the endothelium, activate leukocyte adhesion, and are deficient in bioactive nitric oxide (NO) adducts such as S-nitrosothiols (SNOs), with reduced ability to induce vasodilation in response to hypoxia. All these pathophysiologic characteristics promote vascular occlusion, the hallmark of sickle cell disease (SCD). Loading hypoxic SSRBCs in vitro with NO followed by reoxygenation significantly decreased epinephrine-activated SSRBC adhesion to the endothelium, the ability of activated SSRBCs to mediate leukocyte adhesion in vitro, and vessel obstruction in vivo. Because transfusion is frequently used in SCD, we also determined the effects of banked (SNO-depleted) red blood cells (RBCs) on vaso-occlusion in vivo. Fresh or 14-day-old normal RBCs (AARBCs) reduced epinephrine-activated SSRBC adhesion to the vascular endothelium and prevented vaso-occlusion. In contrast, AARBCs stored for 30 days failed to decrease activated SSRBC adhesivity or vaso-occlusion, unless these RBCs were loaded with NO. Furthermore, NO loading of SSRBCs increased S-nitrosohemoglobin and modulated epinephrine's effect by upregulating phosphorylation of membrane proteins, including pyruvate kinase, E3 ubiquitin ligase, and the cytoskeletal protein 4.1. Thus, abnormal SSRBC NO/SNO content both contributes to the vaso-occlusive pathophysiology of SCD, potentially by affecting at least protein phosphorylation, and is potentially amenable to correction by (S)NO repletion or by RBC transfusion.Item Open Access Noninvasive monitoring of tissue hemoglobin using UV-VIS diffuse reflectance spectroscopy: a pilot study.(Opt Express, 2009-12-21) Bender, Janelle E; Shang, Allan B; Moretti, Eugene W; Yu, Bing; Richards, Lisa M; Ramanujam, NirmalaWe conducted a pilot study on 10 patients undergoing general surgery to test the feasibility of diffuse reflectance spectroscopy in the visible wavelength range as a noninvasive monitoring tool for blood loss during surgery. Ratios of raw diffuse reflectance at wavelength pairs were tested as a first-pass for estimating hemoglobin concentration. Ratios can be calculated easily and rapidly with limited post-processing, and so this can be considered a near real-time monitoring device. We found the best hemoglobin correlations were when ratios at isosbestic points of oxy- and deoxyhemoglobin were used, specifically 529/500 nm. Baseline subtraction improved correlations, specifically at 520/509 nm. These results demonstrate proof-of-concept for the ability of this noninvasive device to monitor hemoglobin concentration changes due to surgical blood loss. The 529/500 nm ratio also appears to account for variations in probe pressure, as determined from measurements on two volunteers.Item Open Access Pharmacologically augmented S-nitrosylated hemoglobin improves recovery from murine subarachnoid hemorrhage.(Stroke, 2011-02) Sheng, H; Reynolds, JD; Auten, RL; Demchenko, IT; Piantadosi, CA; Stamler, JS; Warner, DSBackground and purpose
S-nitrosylated hemoglobin (S-nitrosohemoglobin) has been implicated in the delivery of O(2) to tissues through the regulation of microvascular blood flow. This study tested the hypothesis that enhancement of S-nitrosylated hemoglobin by ethyl nitrite inhalation improves outcome after experimental subarachnoid hemorrhage (SAH).Methods
A preliminary dosing study identified 20 ppm ethyl nitrite as a concentration that produced a 4-fold increase in S-nitrosylated hemoglobin concentration with no increase in methemoglobin. Mice were subjected to endovascular perforation of the right anterior cerebral artery and were treated with 20 ppm ethyl nitrite in air, or air alone for 72 hours, after which neurologic function, cerebral vessel diameter, brain water content, cortical tissue Po(2), and parenchymal red blood cell flow velocity were measured.Results
At 72 hours after hemorrhage, air- and ethyl nitrite-exposed mice had similarly sized blood clots. Ethyl nitrite improved neurologic score and rotarod performance; abated SAH-induced constrictions in the ipsilateral anterior, middle cerebral, and internal carotid arteries; and prevented an increase in ipsilateral brain water content. Ethyl nitrite inhalation increased red blood cell flow velocity and cortical tissue Po(2) in the ipsilateral cortex with no effect on systemic blood pressure.Conclusions
Targeted S-nitrosylation of hemoglobin improved outcome parameters, including vessel diameter, tissue blood flow, cortical tissue Po(2), and neurologic function in a murine SAH model. Augmenting endogenous Po(2)-dependent delivery of NO bioactivity to selectively dilate the compromised cerebral vasculature has significant clinical potential in the treatment of SAH.Item Open Access Rapid ratiometric determination of hemoglobin concentration using UV-VIS diffuse reflectance at isosbestic wavelengths.(Opt Express, 2010-08-30) Phelps, Janelle E; Vishwanath, Karthik; Chang, Vivide TC; Ramanujam, NirmalaWe developed a ratiometric method capable of estimating total hemoglobin concentration from optically measured diffuse reflectance spectra. The three isosbestic wavelength ratio pairs that best correlated to total hemoglobin concentration independent of saturation and scattering were 545/390, 452/390, and 529/390 nm. These wavelength pairs were selected using forward Monte Carlo simulations which were used to extract hemoglobin concentration from experimental phantom measurements. Linear regression coefficients from the simulated data were directly applied to the phantom data, by calibrating for instrument throughput using a single phantom. Phantoms with variable scattering and hemoglobin saturation were tested with two different instruments, and the average percent errors between the expected and ratiometrically-extracted hemoglobin concentration were as low as 6.3%. A correlation of r = 0.88 between hemoglobin concentration extracted using the 529/390 nm isosbestic ratio and a scalable inverse Monte Carlo model was achieved for in vivo dysplastic cervical measurements (hemoglobin concentrations have been shown to be diagnostic for the detection of cervical pre-cancer by our group). These results indicate that use of such a simple ratiometric method has the potential to be used in clinical applications where tissue hemoglobin concentrations need to be rapidly quantified in vivo.Item Open Access Red blood cell phenotype fidelity following glycerol cryopreservation optimized for research purposes.(PloS one, 2018-01) Rogers, Stephen C; Dosier, Laura B; McMahon, Timothy J; Zhu, Hongmei; Timm, David; Zhang, Hengtao; Herbert, Joseph; Atallah, Jacqueline; Palmer, Gregory M; Cook, Asa; Ernst, Melanie; Prakash, Jaya; Terng, Mark; Towfighi, Parhom; Doctor, Reid; Said, Ahmed; Joens, Matthew S; Fitzpatrick, James AJ; Hanna, Gabi; Lin, Xue; Reisz, Julie A; Nemkov, Travis; D'Alessandro, Angelo; Doctor, AllanIntact red blood cells (RBCs) are required for phenotypic analyses. In order to allow separation (time and location) between subject encounter and sample analysis, we developed a research-specific RBC cryopreservation protocol and assessed its impact on data fidelity for key biochemical and physiological assays. RBCs drawn from healthy volunteers were aliquotted for immediate analysis or following glycerol-based cryopreservation, thawing, and deglycerolization. RBC phenotype was assessed by (1) scanning electron microscopy (SEM) imaging and standard morphometric RBC indices, (2) osmotic fragility, (3) deformability, (4) endothelial adhesion, (5) oxygen (O2) affinity, (6) ability to regulate hypoxic vasodilation, (7) nitric oxide (NO) content, (8) metabolomic phenotyping (at steady state, tracing with [1,2,3-13C3]glucose ± oxidative challenge with superoxide thermal source; SOTS-1), as well as in vivo quantification (following human to mouse RBC xenotransfusion) of (9) blood oxygenation content mapping and flow dynamics (velocity and adhesion). Our revised glycerolization protocol (40% v/v final) resulted in >98.5% RBC recovery following freezing (-80°C) and thawing (37°C), with no difference compared to the standard reported method (40% w/v final). Full deglycerolization (>99.9% glycerol removal) of 40% v/v final samples resulted in total cumulative lysis of ~8%, compared to ~12-15% with the standard method. The post cryopreservation/deglycerolization RBC phenotype was indistinguishable from that for fresh RBCs with regard to physical RBC parameters (morphology, volume, and density), osmotic fragility, deformability, endothelial adhesivity, O2 affinity, vasoregulation, metabolomics, and flow dynamics. These results indicate that RBC cryopreservation/deglycerolization in 40% v/v glycerol final does not significantly impact RBC phenotype (compared to fresh cells).Item Open Access Snap-shot multispectral imaging of vascular dynamics in a mouse window-chamber model.(Opt Lett, 2015-07-15) Hendargo, Hansford C; Zhao, Yulin; Allenby, Taylor; Palmer, Gregory MUnderstanding tumor vascular dynamics through parameters such as blood flow and oxygenation can yield insight into tumor biology and therapeutic response. Hyperspectral microscopy enables optical detection of hemoglobin saturation or blood velocity by either acquiring multiple images that are spectrally distinct or by rapid acquisition at a single wavelength over time. However, the serial acquisition of spectral images over time prevents the ability to monitor rapid changes in vascular dynamics and cannot monitor concurrent changes in oxygenation and flow rate. Here, we introduce snap shot-multispectral imaging (SS-MSI) for use in imaging the microvasculature in mouse dorsal-window chambers. By spatially multiplexing spectral information into a single-image capture, simultaneous acquisition of dynamic hemoglobin saturation and blood flow over time is achieved down to the capillary level and provides an improved optical tool for monitoring rapid in vivo vascular dynamics.Item Open Access Thermal responsive microgels as recyclable carriers to immobilize active proteins with enhanced nonaqueous biocatalytic performance.(Chemical communications (Cambridge, England), 2013-12) Wu, Qing; Su, Teng; Mao, Yanjie; Wang, QigangWe describe the preparation of a thermoresponsive microgel, which can non-covalently immobilize active proteins with enhanced biocatalytic performance in organic solvents and easy reusability due to the porous microstructure and temperature responsive property.Item Open Access Unexplained anemia of aging: Etiology, health consequences, and diagnostic criteria.(Journal of the American Geriatrics Society, 2022-03) Guralnik, Jack; Ershler, William; Artz, Andrew; Lazo-Langner, Alejandro; Walston, Jeremy; Pahor, Marco; Ferrucci, Luigi; Evans, William JBackground
Up to 15% of people aged 60 and over are anemic, and the prevalence of anemia increases with age. In older men and women, anemia is associated with increases in the risk of death and all-cause hospitalization, poor functional capacity, quality of life, and depression.Methods and results
We reviewed the literature describing anemia in aging populations, focusing on the specific diagnostic criteria of anemia and potential causes in older men and women. Even after extensive etiologic workup that involves careful medical history, physical examination, laboratory measurements, and additional studies such as bone marrow biopsy, anemia of aging is unexplained in up to 40% of older patients with anemia. As a result, treatment options remain limited.Conclusions
The prevalence of unexplained anemia of aging (UAA; also called unexplained anemia of the elderly, UAE), its deleterious impacts on health, physical function, and quality of life, and the lack of effective treatment or therapy guidelines represent a compelling unmet clinical need. In this review and consensus document, we discuss the scope of the problem, possible causes of UAA, diagnostic criteria, and potential treatment options. Because even mild anemia is strongly linked to poor clinical outcomes, it should receive clinical attention rather than simply being considered a normal part of aging.