Total Hemoglobin Concentration Research Articles

Influence of Cognitive Task Difficulty in Postural Control and Hemodynamic Response in the Prefrontal Cortex during Static Postural Standing

In daily life, we perform several tasks simultaneously, and it is essential to have adequate postural control to succeed. Furthermore, when performing two or more tasks concurrently, changes in postural oscillation are expected due to the competition for the attentional resources. The aim of this study was to evaluate and compare the center of pressure (CoP) behavior and the hemodynamic response of the prefrontal cortex during static postural standing while performing cognitive tasks of increasing levels of difficulty on a smartphone in young adults. Participants were 35 healthy young adults (mean age ± SD = 22.91 ± 3.84 years). Postural control was assessed by the CoP analysis (total excursion of the CoP (TOTEX CoP), displacements of the CoP in medial–lateral (CoP-ML) and anterior–posterior (CoP-AP) directions, mean total velocity displacement of CoP (MVELO CoP), mean displacement velocity of CoP in medial–lateral (MVELO CoP-ML) and anterior–posterior (MVELO CoP-AP) directions, and 95% confidence ellipse sway area (CEA)), the hemodynamic response by the oxyhemoglobin ([oxy-Hb]), deoxyhemoglobin ([deoxy-Hb]), and total hemoglobin ([total-Hb]) concentrations using a force plate and functional near-infrared spectroscopy (fNIR), respectively. The results showed that the difficult cognitive task while performing static postural standing caused an increase in all CoP variables in analysis (p < 0.05) and of [oxy-Hb] (p < 0.05), [deoxy-Hb] (p < 0.05) and [total-Hb] (p < 0.05) compared to the postural task. In conclusion, the increase in the cognitive demands negatively affected the performance of the postural task when performing them concurrently, compared to the postural task alone. The difficult cognitive task while performing the postural task presented a greater influence on postural sway and activation of the prefrontal cortex than the postural task and the easy cognitive task.

Blood volume and structural imaging as an early indicator for photodynamic response

This study aims to discuss blood volume (BV), total hemoglobin concentration quantification, and ultrasound signal variations for their correlation with photodynamic therapy-induced modifications in the tumor and possibly with tumor response. The images were interpreted in the frequency domain by applying a two-dimensional fast Fourier transform to the spatial domain images. The experimental results from animals treated with verteporfin showed a significant reduction in BV.

Hypoxia-mediated immunotoxicity in the blood clam Tegillarca granosa

In marine ecosystems, dissolved oxygen (DO) is essential for maintaining intracellular energy balance during aerobic metabolism. Bivalve mollusks are frequently exposed to hypoxia environments due to tides, temperature changes, and anthropogenic activities. The blood clam, Tegillarca granosa, mainly inhabits intertidal mudflats and is more susceptible to low oxygen events. In this study, we investigated the effect of hypoxia on immune responses in clams, and showed that hypoxia exposure reduced total hemocyte counts (THC), hemoglobin concentrations, and intracellular reactive oxygen species (ROS) levels. Also, phagocytic and cell activities of hemocyte were significantly inhibited. Furthermore, immune-related gene expression was also down-regulated. In conclusion, hypoxia greatly affected immune functions in blood clams, and our research provided the foundation for further mechanistic studies on hypoxia tolerance in clams.

Functional photoacoustic microscopy of hemodynamics: a review.

Functional blood imaging can reflect tissue metabolism and organ viability, which is important for life science and biomedical studies. However, conventional imaging modalities either cannot provide sufficient contrast or cannot support simultaneous multi-functional imaging for hemodynamics. Photoacoustic imaging, as a hybrid imaging modality, can provide sufficient optical contrast and high spatial resolution, making it a powerful tool for in vivo vascular imaging. By using the optical-acoustic confocal alignment, photoacoustic imaging can even provide subcellular insight, referred as optical-resolution photoacoustic microscopy (OR-PAM). Based on a multi-wavelength laser source and developed the calculation methods, OR-PAM can provide multi-functional hemodynamic microscopic imaging of the total hemoglobin concentration (CHb), oxygen saturation (sO2), blood flow (BF), partial oxygen pressure (pO2), oxygen extraction fraction, and metabolic rate of oxygen (MRO2). This concise review aims to systematically introduce the principles and methods to acquire various functional parameters for hemodynamics by photoacoustic microscopy in recent studies, with characteristics and advantages comparison, typical biomedical applications introduction, and future outlook discussion.

Broadband diffuse optical spectroscopy of two-layered scattering media containing oxyhemoglobin, deoxyhemoglobin, water, and lipids.

We investigated the relationship between chromophore concentrations in two-layered scattering media and the apparent chromophore concentrations measured with broadband optical spectroscopy in conjunction with commonly used homogeneous medium inverse models. We used diffusion theory togenerate optical data from a two-layered distribution of relevant tissue absorbers, namely, oxyhemoglobin, deoxyhemoglobin, water, and lipids, with a top-layer thickness in the range 1–15 mm. The generated data consisted of broadband continuous-wave (CW) diffuse reflectance in the wavelength range 650–1024 nm, and frequency-domain (FD) diffuse reflectance at 690 and 830 nm; two source-detector distances of 25 and 35 mm were used to simulate a dual-slope technique. The data were inverted using diffusion theory for a semi-infinite homogeneous medium to generate reduced scattering coefficients at 690 and 830 nm (from FD data) and effective absorption spectra in the range 650–1024 nm (from CW data). The absorption spectra were then converted into effective total concentration and oxygen saturation of hemoglobin, as well as water and lipid concentrations. For absolute values, it was found that the effective hemoglobin parameters are typically representative of the bottom layer, whereas water and lipid represent some average of the respective concentrations in the two layers. For concentration changes, lipid showed a significant cross-talk with other absorber concentrations, thus indicating that lipid dynamics obtained in these conditions may not be reliable. These systematic simulations of broadband spectroscopy of two-layered media provide guidance on how to interpret effective optical properties measured with similar instrumental setups under the assumption of medium homogeneity.

Semiparametric mixed-effects model for analysis of non-invasive longitudinal hemodynamic responses during bone graft healing.

When dealing with longitudinal data, linear mixed-effects models (LMMs) are often used by researchers. However, LMMs are not always the most adequate models, especially if we expect a nonlinear relationship between the outcome and a continuous covariate. To allow for more flexibility, we propose the use of a semiparametric mixed-effects model to evaluate the overall treatment effect on the hemodynamic responses during bone graft healing and build a prediction model for the healing process. The model relies on a closed-form expectation-maximization algorithm, where the unknown nonlinear function is estimated using a Lasso-type procedure. Using this model, we were able to estimate the effect of time for individual mice in each group in a nonparametric fashion and the effect of the treatment while accounting for correlation between observations due to the repeated measurements. The treatment effect was found to be statistically significant, with the autograft group having higher total hemoglobin concentration than the allograft group.

Total Hemoglobin Trajectories from Pregnancy to Postpartum in Rural Northeast Brazil: Differences between Adolescent and Adult Women.

This study examines total hemoglobin (THB) trajectories during pregnancy and postpartum and associated factors among adolescents and adults from a low-income community. This is an observational, longitudinal study, part of the Adolescence and Motherhood Research (AMOR) project, performed between 2017 and 2019 in the Trairi region of Rio Grande do Norte state, Brazil. The THB levels of 100 primigravida adolescents and adults were monitored up to 16 weeks of gestation, in the third trimester, and 4–6 weeks postpartum, along with socioeconomic characteristics, anthropometrics, and health-related variables. Mixed-effect linear models evaluated the trajectories of THB and the associated factors. THB levels decreased between first and second assessments and increased between the second and postpartum assessments. For the adolescent cohort, the rebound in THB concentration between the third trimester and postpartum was not enough to make up for the initial losses, as occurred in the adult cohort. For the adult group, higher THB levels were associated with pregnancy planning and good self-rated health. Race was marginally associated to THB levels, with black/brown women presenting higher concentrations in the adolescent and lower concentration in the adult group. Special attention to prenatal care among pregnant adolescents should consider their higher risk of anemia and its negative effects.

Epileptic seizure-related changes in electrocorticogram, cortical temperature, and cerebral hemodynamics obtained via an implantable multimodal multichannel probe during preoperative monitoring: illustrative case.

BACKGROUNDElectrocorticography (EcoG) plays an essential role in the preoperative evaluation of epilepsy, despite its high invasiveness. Brain temperature and cerebral hemodynamics also reflect brain activity. This study examined whether a multimodal multichannel probe that simultaneously records EcoG, cortical temperature, and cerebral hemodynamics can contribute to improving the assessment of epileptic seizures. After preoperative monitoring was performed in a patient with epilepsy, three generalized seizures and two focal seizures were observed.OBSERVATIONSA short-term power increase in the alternating current spectrogram, high-amplitude slow waves in direct current potential, an increase in cortical temperature, an increase in oxyhemoglobin (HbO2) concentration and total hemoglobin (HbT) concentration, and a decrease in deoxyhemoglobin (HHb) concentration, followed by a decrease in HbO2 and HbT concentrations and an increase in HHb concentration, were observed in generalized seizures. However, no changes in these pathophysiological signals were observed in focal seizures.LESSONSSeizure-related changes regarding generalized seizures were consistent with the results of previous studies. The results of generalized and focal seizures indicate that epileptic brain activity propagated from the epileptic focus in the right frontal lobe to the measurement area near the motor cortex in generalized seizures but not in focal seizures.

Estimation of Cerebral Hemodynamics and Oxygenation During Various Intensities of Rowing Exercise: An NIRS Study.

PurposeThis study aimed to investigate changes in cerebral hemodynamics and oxygenation at moderate, heavy, maximal and supramaximal intensities of rowing exercise. It also examined whether these changes reflect alterations in sensation of effort and mood. We also aimed to examine the effects of peak pulmonary oxygen consumption (O2peak) on cerebral oxygenation.MethodsEleven rowers, consisting out of six athletes and five recreational rowers [two female; age, 27 ± 9 years; height, 171 ± 7 cm, body mass, 67 ± 9 kg; O2peak, 53.5 ± 6.5 mL min–1 kg–1] rowed a 13-min session separated by 10 and 3 min, at 70 (Ex70%) and 80% of O2peak (Ex80%), respectively, on a rowing ergometer, followed by three sessions of 1-min supramaximal exercise (ExSp). After a warm-up at 60% of O2peak (ExM), seven male rowers performed a 2,000 m all-out test (Ex2000). Cardiovascular and respiratory variables were measured. Cerebral oxygenation was investigated by near-infrared time-resolved spectroscopy (TRS) to measure cerebral hemoglobin oxygen saturation (ScO2) and total hemoglobin concentration ([HbT]) in the prefrontal cortex (PFC) quantitatively. We estimated the relative changes from rest in cerebral metabolic rate for oxygen (rCMRO2) using TRS at all intensities. During Ex70% and Ex80%, ratings of perceived exertion (RPE) were monitored, and alteration of the subject’s mood was evaluated using a questionnaire of Positive-and-Negative-Affect-Schedule after Ex70% and Ex80%.ResultsWhen exercise intensity changed from Ex70% to Ex80%, the sense of effort increased while ScO2 decreased. [HbT] remained unchanged. After Ex70% and Ex80%, a negative mood state was less prominent compared to rest and was accompanied by increases in both ScO2 and [HbT]. At termination of Ex2000, ScO2 decreased by 23% compared to rest. Changes in ScO2 correlated with O2peak only during Ex2000 (r = −0.86; p = 0.01). rCMRO2 did not decrease at any intensities.ConclusionOur results suggest that alterations in the sense of effort are associated with oxygenation in the PFC, while positive changes in mood status are associated with cerebral perfusion and oxygen metabolism estimated by TRS. At exhaustion, the cerebral metabolic rate for oxygen is maintained despite a decrease in ScO2.

Possible Protective Role of Aqueous Tomato Extract on Hemato-Biochemical Parameters against Sodium Arsenite Toxicity in Albino Rats

Due to rapid industrialization and technological development, humans are constantly exposed to heavy metals at minimum to maximum tolerable levels. Arsenic is ubiquitously distributed and most concerned element now-a-days, inorganic arsenicals mainly enter into the body via the route of lungs and gastrointestinal tract and 55-95% of it gets absorbed. Sodium arsenite poisoning leads to disturbance in hematological and biochemical processes. In the present study, toxic effects of sodium arsenite on the hematological parameters, serum transaminases and possible modulatory role of aqueous tomato extract were studied. Female rats were allocated into four different groups: 1. Control (given normal diet), 2. Sodium arsenite treated (10mg/kg B.W.), 3. Combination of sodium arsenite (10 mg/kg B.W.) and aqueous tomato extract (50 mg/kg B.W.) treated rats 4. Only aqueous tomato extract treated (50mg/kg B.W.) rats. It was observed that arsenic significantly decreased the total erythrocytes count (RBC), hemoglobin concentration (Hb), hematocrit value (HCT) and platelets (PLT), whereas significantly elevated the total leucocytes count (TLC) and activities of serum transaminases such as ALT and AST. Supplementation of aqueous tomato extract to arsenic treated rats showed decrease in values of WBC, ALT and AST which almost matched to values of control rats. So, from this study it can be concluded that antioxidants and vitamins present in the aqueous tomato extract showed protective role against arsenic toxicity in albino rats.

Three-dimensional Multistructural Quantitative Photoacoustic and US Imaging of Human Feet in Vivo.

Background Monitoring the microcirculation in human feet is crucial in assessing peripheral vascular diseases, such as diabetic foot. However, conventional imaging modalities are more focused on diagnosis in major arteries, and there are limited methods to provide microvascular information in early stages of the disease. Purpose To investigate a three-dimensional (3D) noncontrast bimodal photoacoustic (PA)/US imaging system that visualizes the human foot morphologically and also reliably quantifies podiatric vascular parameters noninvasively. Materials and Methods A clinically relevant PA/US imaging system was combined with a foot scanner to obtain 3D PA and US images of the human foot in vivo. Healthy participants were recruited from September 2020 to June 2021. The collected 3D PA and US images were postprocessed to present structural information about the foot. The quantitative reliability was evaluated in five repeated scans of 10 healthy feet by calculating the intraclass correlation coefficient and minimal detectable change, and the detectability of microvascular changes was tested by imaging 10 healthy feet intentionally occluded with use of a pressure cuff (160 mm Hg). Statistically significant difference is indicated with P values. Results Ten feet from six healthy male volunteers (mean age ± standard deviation, 27 years ± 3) were included. The foot images clearly visualized the structure of the vasculature, bones, and skin and provided such functional information as the total hemoglobin concentration (HbT), hemoglobin oxygen saturation (SO2), vessel density, and vessel depth. Functional information from five independent measurements of 10 healthy feet was moderately reliable (intraclass correlation coefficient, 0.51-0.74). Significant improvements in HbT (P = .006) and vessel density (P = .046) as well as the retention of SO2 were observed, which accurately described the microvascular change due to venous occlusion. Conclusion Three-dimensional photoacoustic and US imaging was able to visualize morphologic and physiologic features of the human foot, including the peripheral microvasculature, in healthy volunteers. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Mezrich in this issue.

Impact of blood donor characteristics on quality of packed red blood cell concentrates.

Impact of blood donor characteristics on quality of packed red blood cell concentrates. To determine the impact of donor factors on the quality of packed red blood cell concentrates. The analytical cross sectional study was conducted on 505 whole blood donors after approval by the Institutional Ethics Committee and written informed consent from blood donors. Two mL EDTA sample was collected for pre-donation haemoglobin estimation and all relevant donor details were recorded. Whole blood was collected in 350mL double blood bags. PRBCs were prepared as per the departmental SOP. Volume of each PRBC was recorded and sample from each bag was taken for estimation of total haemoglobin content and haematocrit. Of 505 blood donors, 459 (90.9%) were males and 324 donors (64.2%) were less than 30 years of age. The majority of the donors were repeat donors (61%, n=308 repeat donors), vegetarians (52.9%, n=267 vegetarians) and non-smokers (92.7%, n=468). Mean haemoglobin was found to be significantly higher in males (14.9 vs. 13.3; P≤0.001), donors more than 30 years of age (15 vs. 14.7; P=0.042), repeat donors (14.9 vs. 14.7), non-vegetarians (15.1 vs. 14.6; P≤0.001) and smokers (15.3 vs. 14.8g/dL; P=0.020). PRBC units prepared from male blood donors, repeat donors and non vegetarians had significantly higher mean volume and mean total haemoglobin content. Strong positive correlation was observed between haemoglobin of the blood donor and total haemoglobin content of the PRBC and volume of blood collected. Donor characteristics do have effect on total haemoglobin content of packed red blood cells.

Effect of targeted individualized nutrition support on patients with severe diseases during hospitalization

To evaluate effect of targeted individualized nutrition support on therapeutic effect and safety of patients with severe diseases during hospitalization. All patients were divided into control group and the observation group according to the time of admission. All enrolled patients received symptomatic treatment and intensive care. The control group received only basic nutrition support. There was no significant difference in NRS2002 score between the two groups at admission. Before intervention, there were no significant differences of total serum protein, serum albumin, hemoglobin content, liver and kidney functions and immune indexes between both groups. After intervention, the total serum protein, serum albumin and hemoglobin content of observation group was significantly higher than those of control group. The incidence of adverse events and complications of observation group was significantly lower than control group during hospitalization. The targeted individualized nutrition support could improve nutritional status of patients with severe surgical diseases during hospitalization.

In Vitro Validation of a New Tissue Oximeter Using Visible Light.

There is a clinical need to measure local tissue oxygen saturation (StO2), oxy-, deoxy- and total haemoglobin concentration ([O2Hb], [HHb], [tHb]) in human tissue. The aim was to validate an oximeter called OxyVLS applying visible light spectroscopy (VLS) to determine these parameters without needing to assume a reduced scattering coefficient (μ's). This problem is solved by appropriate calibrations. Compared to near-infrared spectroscopy (NIRS), OxyVLS determines the oxygenation in a much smaller more superficial volume of tissue, which is useful in many clinical cases. OxyVLS was validated in liquid phantoms with known StO2, [tHb], and μ's and compared to frequency domain NIRS as a reliable reference. OxyVLS showed a high accuracy for all the mentioned parameters and was even able to measure μ's. Thus, OxyVLS was successfully tested in vitro.

Plasmacytoma Variant Translocation-1 as Prognostic Markers in Pediatric Acute Lymphoblastic Leukemia

Introduction and Aim: Acute lymphoblastic leukemia (ALL) is the commonest form of childhood leukemia. Molecular studies can provide diagnostic and prognostic information with direct impact on the patient. Recent micro RNAs (miRNAs) studies showed that aberrant expression can be used as signatures of ALL with different subtypes and predict drug resistance. The present work aimed to evaluate the expression of Plasmacytoma Variant Translocation-1 (PVT1) in Childhood ALL patients.
 Methodology: The study included 55 children from 2 months to 15 years old; 45 patients with ALL before receiving any treatment, and 10 control children. Long non-coding RNA PVT1 expression in plasma cells was detected by reverse transcription quantitative polymerase chain reaction.
 Results: Lnc_PVT1 expression is upregulated by twelve-folds in ALL patients. At optimum cut-off value of 22.0, the biomarker has a sensitivity of 72% and 82% specificity to discriminate ALL patients from controls. Correlating the mean values of miR_1204gene fold expression with different subgroups concerning prognostic criteria, there was no statistical differences between age groups, gender, ALL phenotypes, cytogenetic abnormality, total leukocytes count, hemoglobin concentrations and platelet count. In contrast, statistical significance was detected with bone marrow blasts percentage, clinical response, and minimal residual disease.
 Conclusion: A higher expression of lnc-PVT1 was observed in ALL patients, and it had a diagnostic and prognostic potential. In addition, miR-1204 was down-regulated in pediatric ALL and associated with higher risk.

Toxicity assessment of beta-cyfluthrin with impact on haematology of fish, Channa punctatus

Âeta-cyfluthrin, a synthetic pyrethroid pesticide, is commonly used in agriculture for pest control and as household insecticide. It is relatively safe to mammals and birds but highly toxic to non-target aquatic organisms including fish. The 96- hour LC50 was determined using standard toxicity assessment tests. Alterations in haematological parameters were recorded after exposure to two sublethal concentrations of beta-cyfluthrin for a period of 15 and 30 days.The results showed a significant decrease in total erythrocyte count, haemoglobin concentration, haematocrit percentage and increase in total leucocyte count in exposed groups.The results of present study indicate a significant toxicological impact of beta-cyfluthrinon in Channa punctatus with marked alterations in haematological parameters.

Machine Learning Distinguishes Familiar from Unfamiliar Pairs of Subjects Performing an Eye Contact Task: A Systemic Physiology Augmented Functional Near-Infrared Spectroscopy Hyperscanning Study.

Eye contact is an important aspect of human communication and social interactions. Changes in brain and systemic physiological activity associated with interactions between humans can be measured with systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) hyperscanning, enabling inter-brain and inter-body synchronisation to be determined. In a previous study, we found that pairs of subjects that are socially connected show higher brain and body synchrony. To enable a deeper understanding, our aim was to build and automatically detect the best set of features to distinguish between two different groups (familiar and unfamiliar pairs). We defined several features based on the Spearman correlation and wavelet transform coherence (WTC) of biosignals measured on 23 pairs of subjects (13 familiar and 10 unfamiliar pairs) during eye contact for 10 min. Additional custom features that identify the maximum brain-to-body coupling instants between pairs were generated. After testing on combinations of different feature extraction methods, four subsets of features with the strongest discrimination power were taken into account to train a decision tree (DT) machine learning (ML) algorithm. We have obtained 95.65% classification accuracy using a leave-one-out cross-validation. The coupling features which represent the two maximum mean values resulting from the sum of 7 time-dependent WTC signals (oxyhaemoglobin concentration of the right prefrontal region, total haemoglobin concentration of the left and right prefrontal region, heart rate, electrodermal activity on the left and right wrist, and skin temperature on the right wrist) played an essential role in the classification accuracy. Training the DT-ML algorithm with combined brain and systemic physiology data provided higher accuracy than training it only with brain or systemic data alone. The results demonstrate the power of the SPA-fNIRS hyperscanning approach and the potential in applying ML to investigate the strength of social bonds in a wide range of social interaction contexts.

Development and Design of Flexible Sensors Used in Pressure-Monitoring Sports Pants for Human Knee Joints

Flexible pressure sensors are being used widely in sports and human-health monitoring. The knee joint is one of the organs with the highest injury rate while running. By optimizing the structural design of sports pants, the lower limbs can be compressed appropriately to protect the knee joint and improve exercise efficiency. The point of innovation lies in the removable flexible pressure sensors implanted in these leggings developed to monitor the three-dimensional force on the knee in real time. Combined with data analysis, this can provide information to wearers while exercising and to the middle-aged and elderly to prevent knee-strain problems. The experimental results showed that the pressure values of the left and right knee joints measured using the flexible pressure sensors on the leggings in real time and those obtained using the AMI3037-5s Airbag pressure tester were accompanied by F-values and t-test statistical probability values greater than 0.05. This indicates that there was no significant difference between the two values, reflecting the credibility of the flexible pressure-monitoring data. The oxygen saturation and total hemoglobin content of a subjects’ legs after exercising were higher than those before exercising, indicating that the leggings performed well in terms of fatigue relief. The subjects’ body surface temperature, when exercising, changed steadily and dropped gradually in the later stage, indicating that the leggings perform well with respect to thermal and moisture comfort. Flexible sensing technology has promising application prospects in wearable smart clothing in future, particularly in the sports and health fields.

Preclinical Development of EDIT301, an Autologous Cell Therapy Comprising AsCas12a-RNP Modified Mobilized Peripheral Blood-CD34 + Cells for the Potential Treatment of Transfusion Dependent Beta Thalassemia

Beta thalassemia is one of the most common recessive hematological disorders in the world with more than 200 mutations identified to date. These mutations reduce or completely abrogate beta globin expression. As beta globin pairs with alpha globin to form adult hemoglobin (HbA, α2β2), reduced or absent beta globin results in excessive alpha globin chains, which form toxic aggregates. These aggregates cause maturation blockade and premature death of erythroid precursors, and hemolysis of red blood cells (RBC), leading to varying degrees of anemia. Patients with the most severe form of beta thalassemia, namely beta thalassemia major, are transfusion-dependent, i.e., requiring life-long RBC transfusions accompanied by the burden of iron chelation therapy.EDIT-301 is an experimental autologous cell therapy in which CD34 + cells are genetically modified to promote gamma globin expression. EDIT-301 is currently in clinical development for sickle cell disease, and IND enabling stage for transfusion-dependent beta thalassemia (TDT). Gamma globin decreases the alpha to beta globin chain imbalance in beta thalassemia by pairing with the over-abundant alpha globin chains to form fetal hemoglobin (HbF, α2γ2). Gamma globin induction, and consequently HbF induction, for EDIT-301 is achieved through AsCas12a ribonucleoprotein (RNP)-mediated editing of the distal CCAAT box region of the HBG1 and HBG2 promoters, where naturally occurring hereditary persistence of fetal hemoglobin (HFPH) mutations exist. We chose this target over BCL11A based on previous preclinical data demonstrating that BCL11A editing reduces erythroid output in NBSGW mice. An engineered AsCas12a RNP edits the HBG1 and HBG2 promoter distal CCAAT box with high efficiency and specificity. We have previously shown that on-target editing of >80% was achieved in mobilized peripheral blood (mPB) CD34 + cells from normal donors with no detectable off-target editing both at research scale and at clinical manufacturing scale. Edited normal donor CD34 + cells led to long-term, polyclonal, multilineage engraftment without lineage skewing in immunocompromised mice and sustained robust HbF production in their erythroid progeny.To test whether EDIT-301 may be an efficacious therapy for TDT, mPB CD34 + cells from individuals with TDT were electroporated with the engineered AsCas12a RNP targeting the HBG1 and HBG2 promoters. AsCas12a RNP edited mPB CD34 + cells from individuals with TDT as efficiently as CD34 + cells from normal donors. Importantly, EDIT-301 has the potential to address the underlying pathophysiology of TDT, i.e., the maturation blockade and premature death of erythroid precursors. Erythroid differentiation of edited beta thalassemia CD34 + cells showed significant improvement in erythroid maturation and health. Specifically, ~70% edited erythroblasts reached late erythroblast stage compared to ~53% unedited erythroblasts; ~56% edited erythroid cells underwent terminal maturation and enucleated compared to ~28% of unedited erythroid cells; and non-viable erythroblasts decreased from ~33% to ~22% after editing. The improved erythropoiesis was accompanied by significantly increased total hemoglobin content per cell. These data strongly support that editing of the HBG1 and HBG2 promoter CCAAT box using engineered AsCas12a RNP can reverse the dyserythropoiesis associated with beta thalassemia and increase the hemoglobin production.In summary, we have provided strong preclinical data supporting the development of EDIT-301 for the treatment of TDT. Edited mPB CD34 + cells retained their ability to engraft without lineage skewing, resulted in robust HbF induction long-term, improved erythropoiesis, and increased hemoglobin content in TDT erythroid cells. These data support that a single administration of EDIT-301 may have the potential to safely and effectively reverse dyserythropoiesis and ameliorate anemia in individuals with TDT long-term. Clinical studies to demonstrate the safety and efficacy of EDIT-301 in the treatment of TDT are currently being planned. DisclosuresSousa: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Janoudi: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. deDreuzy: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Shearman: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Zhang: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Chang: Editas Medicine: Current Employment, Current equity holder in publicly-traded company.

Cerebral and muscle near-infrared spectroscopy during lower-limb muscle activity - volitional and neuromuscular electrical stimulation.

Chronic venous insufficiency (CVI) can lead to blood clotting in the deep veins of the legs, a disease known as deep vein thrombosis. An estimated 40 percent of people in the United States have venous insufficiency that may be ameliorated with neuromuscular electrical stimulation (NMES). Near-infrared spectroscopy (NIRS) is a non-invasive optical imaging method for monitoring hemodynamics. NIRS, being an optical technique has no stimulation artefact, can be combined with NMES for theranostics application. In this study, we combined muscle NIRS (mNIRS) with electromyogram (EMG) of the calf muscles to detect blood volume changes (based on total hemoglobin concentration) in the muscle during volitional tiptoe movements at different frequencies. Also, blood volume changes were measured during NMES (using the geko™ device) at different device settings. In the mNIRS+NMES study, we also measured the cerebral hemodynamics using functional NIRS (fNIRS). The mNIRS was conducted using a frequency domain (FD) method (called FDNIRS) that used a multi-distance method to isolate muscle hemodynamics. FDNIRS-EMG study in ten healthy humans found a statistically significant (p<0.05) effect of the tiptoe frequencies on the EMG magnitude (and power) that increased with tiptoe frequency. Also, the muscle blood volume (standing/rest) decreased (p<0.01) with increasing tiptoe frequency and increasing NMES intensity that was statistically significantly (p<0.05) different between males and females. Moreover, increasing NMES intensity led to a statistically significant (p<0.01) increase in the cerebral blood volume - measured with fNIRS. Therefore, combined mNIRS and fNIRS with NMES can provide a theranostics application for brain+muscle in CVI.