Blood Oxygen Transport Research Articles

Hydrogen sulphide toxicity and the importance of amphibious behaviour in a mangrove fish inhabiting sulphide-rich habitats.

We investigated amphibious behaviour, hydrogen sulphide (H2S) tolerance, and the mechanism of H2S toxicity in the amphibious mangrove rivulus (Kryptolebias marmoratus). We found that fish emersed (left water) in response to acutely elevated [H2S] (~ 130-200µmoll-1). The emersion response to H2S may be influenced by prior acclimation history due to acclimation-induced alterations in gill morphology and/or the density and size of neuroepithelial cells (NECs) on the gills and skin. Thus, we acclimated fish to water (control), H2S-rich water, or air and tested the hypotheses that acclimation history influences H2S sensitivity due to acclimation-induced changes in (i) gill surface area and/or (ii) NEC density and/or size. Air-acclimated fish emersed at significantly lower [H2S] relative to fish acclimated to control or H2S-rich water, but exhibited no change in gill surface area or in NEC density or size in the gills or skin. Despite possessing exceptional H2S tolerance, all fish lost equilibrium when unable to emerse from environments containing extremely elevated [H2S] (2272 ± 46µmoll-1). Consequently, we tested the hypothesis that impaired blood oxygen transport (i.e., sulphemoglobin formation) causes H2S toxicity in amphibious fishes. In vitro exposure of red blood cells to physiologically relevant [H2S] did not cause a substantial increase in sulphemoglobin formation. We found evidence, however, for an alternative hypothesis that H2S toxicity is caused by impaired oxidative phosphorylation (i.e., cytochrome c oxidase inhibition). Collectively, our results show that amphibious behaviour is critical for the survival of K. marmoratus in H2S-rich environments as fish experience impaired oxidative phosphorylation when unable to emerse.

Association of endothelial nitric oxide synthase gene G894T polymorphism with blood oxygen transport

BackgroundNitric oxide (NO) is involved in formation of oxygen transport function of blood and oxygen transport in tissues by means of interaction with haemoglobin. Endothelial nitric oxide synthase gene G894T polymorphism affects the expression and the activity of the NO synthase enzyme. The influence of this polymorphism on the formation of oxygen-dependent processes in the body has not been completely investigated. ObjectiveTo evaluate the associations between G894T polymorphism of the endothelial nitric oxide synthase gene and the condition of oxygen transport function of blood in healthy male volunteers. MethodsThe study subjects were healthy young males aged 18–24 years (n = 165). The blood was drawn from the cubital vein at rest after 12 h following the last food intake. G984T polymorphism and the blood oxygen indices pO2, CvO2, SO2, pH, р50stand (the temperature was 37°С, рН = 7.4, рСО2 = 40 mm Hg) and р50act (actual temperature, рН and рСО2), etc. were determined. ResultsIn persons with the TT-genotype, the oxygen content in venous blood was 48.7% (q = 0.019) lower compared to subjects with the GT-genotype and 49.4% (q = 0.019) lower compared to subjects with the GG-genotype. The saturation of blood in carriers of the TT-genotype was 32.4% (q = 0.021) and 35.9% (q = 0.019) lower as opposed to subjects with the GT-genotype and the GG-genotype, respectively. In blood of subjects with the TT-genotype, the oxygen tension was 26.1% (q = 0.019) lower as compared to subjects with the GT-genotype and 27.4% (q = 0.019) lower as opposed to the GG-genotype. In turn, volunteers having a common allele in their genotype (GG + GT) demonstrated oxygen tension to be 26.7% (q = 0.019) higher compared to subjects with the TT-genotype. The blood pH values of the subjects having the recessive genotype were 0.022 units lower compared to the GG (q = 0.044) and GT (q = 0.042) genotypes. In volunteers with the TT-genotype, the p50stand parameter was 5.8% (q = 0.027) lower compared to subjects with the GT-genotype and 6.8% (q = 0.019) lower compared to volunteers with the GG-genotype. In persons with two T-alleles in their genotype, p50act was 5.4% (q = 0.019) lower compared to subjects with the GT-genotype and 6.4% (q = 0.019) lower compared to persons with the GG-genotype. ConclusionThe T-allele of G894T polymorphism is associated with low values for oxygen content, oxygen tension, acidic pH shift and increased haemoglobin affinity for oxygen under standard and real conditions. The presence of a minor allele in G894T polymorphism of the NOS3 gene contributes to formation of oxygen transport function of blood.

Approaches on the Major Predictors of Blood Transfusion in Cardiovascular Surgery: A Systematic Review

Introduction: Experimental Clinical studies have shown that loss of up to 77.0% of red cell mass can be tolerated as long as it kept the blood volume. However, the blood volume loss of about 34.0% is fatal. The initial attention in patients with bleeding should be given to maintaining blood volume and oxygen transport. Thus, transfusions of allogeneic blood products are associated with an increased risk of morbidity and mortality in cardiac surgery. Some transfusion risk scores have been proposed for cardiac surgery patients. Objective: To review and discuss literature blood transfusion (blood components gradient) in cardiovascular surgery versus polytrauma, gastrointestinal bleeding, and neoplastic diseases. Methods: The model followed for the review was PRISMA. We used the databases as Scielo, Lilacs, Google Scholar, PubMed articles and works of scientific and doctoral theses master. Results: According to the discussion in the literature, the acute bleeding of large volumes is challenging to emergency services. Accordingly, the need to support hemotherapeutics led to the development of protocols for more rational utilization of the monitored blood components. Conclusion: Hemotherapy services have adopted a very dynamic approach to the clinical condition presented by patients, the need for four or more red blood cell units.

Numerical analysis of cellular blood flow and oxygen transport in microcirculations

Numerical analysis of cellular blood flow and oxygen transport in microcirculations

The effects of aerobic exercise in ski beginners at altitudes of 1250-2000m on blood oxygen transport parameters

Problem: Lower altitude stay (1250m) and extensive recreational aerobic activity like skiing at lower to moderate altitude (1250-2000m) and its effect on oxygen transport parameters had not been thoroughly investigated. Methods: The experimental group (N=17) underwent an intervention, a typical 10-day ski-trip. They slept at 1250 m and performed 5-6 hours of aerobic activity (skiing) at 1250-2000m altitude. The control group (N=15) stayed at sea level and performed their regular activities. The ferritin levels, reticulocyte count, RBC parameters and erythropoietin before and 48 h after the trip were measured in both groups. Results: The reticulocyte count increased (44.5±16.6 to 67.9±19.18 G/L) and somewhat surprisingly erythropoietin decreased in experimental group (6.04±2.39 to 4.91±1.54 IU/L, ANOVA p=<0.001). Ferritin levels decreased and reticulocyte count increased in 88% of all experimental group subjects while in control group it changed in both directions. The initial erythrocyte concentration was foundto be a good predictor of reticulocyte increase changes, while ferritin reserveswasdid not. No significant changes after intervention were observed in other parameters. Discussion: In recreational population, sleeping at lower altitudes in combination with aerobic activity of longer daily duration like skiing, elicits changes in erythropoiesis.

FBXO11 Activates Erythroid Gene Transcription By Degrading Heterochromatin-Associated Protein BAHD1

Mature red blood cells (RBC) contain approximately 95% cytosolic hemoglobin for the purpose of blood oxygen transport. This specialized state is achieved during erythropoiesis by regulated gene expression and protein degradation. During late-stage erythropoiesis, ubiquitin ligases eliminate unnecessary proteins and maintain quality control by degrading unstable proteins, including unpaired hemoglobin subunits. However, ubiquitin ligases are expressed at all stages of erythropoiesis and the functions of most are unknown. To study ubiquitin ligases involved in RBC formation, we performed a Cas9/single guide (sg) RNA screen for functional ubiquitin-proteasome components in HUDEP-2 cells, an immortalized human cell line that proliferates as immature erythroblasts and can be induced to undergo terminal maturation. We identified the E3 ubiquitin ligase FBXO11 as a top-ranked candidate. FBXO11 is a member of the F-box protein family that assembles into a SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase complex. Depletion of FBXO11 by 2 different sgRNAs in HUDEP-2 cells inhibited erythroid maturation, as evidenced by reduced hemoglobinization, failure to induce the maturation marker Band3 and persistence of immature cell morphology. In primary human CD34+ cells, suppression of FBXO11 expression by Cas9 + two independent sgRNAs inhibited erythroid maturation, as evidenced by reduced Band3 expression (5.3% vs. 15.6% for non-targeting sgRNA, P < 0.001; n=4). RNA-seq analysis of FBXO11-depleted HUDEP-2 cells revealed 951 decreased transcripts (enriched for erythroid genes) and 339 increased transcripts (enriched for genes expressed in activated T-cells) compared to control cells expressing non-targeting gRNA (P < 0.05). Thus, FBXO11 is required for erythroid maturation and facilitates erythroid gene expression.We sought to establish how FBXO11 modulates erythropoiesis and erythroid gene expression by identifying the relevant ubiquitination substrate(s). Combined quantitative proteome analysis with RNA-seq of FBXO11-depleted HUDEP-2 cells identified several proteins that are upregulated with no change in their corresponding mRNA. We tested whether reduction of these candidate substrates could alleviate the erythroid maturation block conferred by FBXO11 depletion. In FBXO11 gene-disrupted HUDEP-2 cells, suppression of the heterochromatin-associated protein BAHD1 partially rescued hemoglobinization and Band3 expression (4.2% for Cas9 + non-targeting sgRNA vs. 21.7% for Cas9 + BAHD1 sgRNAs, P < 0.01; n=3) . Conversely, stable overexpression of V5-epitope-tagged BAHD1 in WT HUDEP-2 cells reduced Band3 expression from 25.0% to 11.4% (P < 0.001; n=3) and inhibited hemoglobinization. Transcriptome analysis demonstrated a significant inverse correlation between genes deregulated by BAHD1-V5 overexpression and FBXO11 deficiency in HUDEP-2 cells, particularly for erythroid genes that are downregulated (P < 0.0001).BAHD1, named after its bromo-adjacent homology domain that interacts with H3K27me3, is part of a transcriptional repressor complex. We showed that BAHD1 and FBXO11 co-immunoprecipitated in cells and that BAHD1 amino (N)-terminal segments of 188 or 240 amino acids were robustly modified with ubiquitin by SCFFBXO11 complex. Chromatin immunoprecipitation-sequencing analysis of BAHD1-V5-expressing WT HUDEP-2 cells showed strong enrichment for BAHD1 occupancy on erythroid gene promoters that were downregulated by FBXO11-deficiency (P < 0.0001). We next investigated whether a specific set of histone marks distinguish FBXO11-regulated genes in normal erythroblasts. We found that most FBXO11-regulated genes in both HUDEP-2 and primary CD34+ derived erythroblasts harbor histone marks H3K4me3 and H3K27me3, indicating a “bivalent” epigenetic state that supports low level transcription in stem or progenitor cells. Together, these data indicate that FBXO11 activates expression of erythroid genes by ubiquitinating and degrading bivalent promoter-bound BAHD1 repressor complexes with likely resolution to a monovalent transcriptionally active state.Overall, our findings identify FBXO11 as a ubiquitin ligase that utilizes a novel mechanism to activate erythroid genes during RBC formation. This newly identified pathway may contribute to known activities of FBXO11 as a tumor suppressor and developmental regulator in non-erythroid tissues. DisclosuresNo relevant conflicts of interest to declare.

A model of oxygen transport in the rat renal medulla.

The renal medulla is prone to hypoxia. Medullary hypoxia is postulated to be a leading cause of acute kidney injury, so there is considerable interest in predicting the oxygen tension in the medulla. Therefore we have developed a computational model for blood and oxygen transport within a physiologically normal rat renal medulla, using a multilevel modeling approach. For the top-level model we use the theory of porous media and advection-dispersion transport through a realistic three-dimensional representation of the medulla's gross anatomy to describe blood flow and oxygen transport throughout the renal medulla. For the lower-level models, we employ two-dimensional reaction-diffusion models describing the distribution of oxygen through tissue surrounding the vasculature. Steady-state model predictions at the two levels are satisfied simultaneously, through iteration between the levels. The computational model was validated by simulating eight sets of experimental data regarding renal oxygenation in rats (using 4 sets of control groups and 4 sets of treatment groups, described in 4 independent publications). Predicted medullary tissue oxygen tension or microvascular oxygen tension for control groups and for treatment groups that underwent moderate perturbation in hemodynamic and renal functions is within ±2 SE values observed experimentally. Diffusive shunting between descending and ascending vasa recta is predicted to be only 3% of the oxygen delivered. The validation tests confirm that the computational model is robust and capable of capturing the behavior of renal medullary oxygenation in both normal and early-stage pathological states in the rat.

Hemoglobin and Erythropoietin After Commercial Saturation Diving.

Saturation divers are exposed to elevated partial pressure of oxygen (ppO2) in their hyperbaric work environment. Experimental studies indicate that oxygen transport is altered, and we have previously reported a drop in hematocrit and extensive downregulation of genes involved in blood oxygen transport capacity after decompression from professional saturation diving. Here we investigate the initial period of hematological adjustment back to normobaric air after professional saturation diving. Erythropoietin (EPO) and hemoglobin (Hb) were measured in blood from 13 divers at two time-points after saturation assignments lasting up to 4 weeks; first immediately after decompression and again 24 h later. Pre-dive levels defined baselines. The ppO2 varied from 40 kPa in the saturation chambers during storage, 50 to 80 kPa during bell excursions, and gradually reduced to 21 kPa during decompression to surface pressure. EPO was similar to baseline immediately after saturation diving (P = 0.4), and markedly increased within the next 24 h (99%, P < 0.0002). Hb levels remained slightly reduced at both time-points (4% immediately after; P = 0.02, 8% 24 h after; P < 0.001). The results imply that the hematological acclimatization back to normobaric air was ongoing, but not completed, during the first 24 h after professional saturation diving.

Correction of Metabolic Indicators of Erythrocytes and Myocardium Structure with Ozonized Red Blood-Cell Mass

The early posttransfusion period after acute blood loss using erythromass without ozone was characterized by decreased electrophoretic mobility of erythrocytes (EPME), ATP, 2,3-diphosphoglycerate (2,3- DPG) concentration, Na+-K+-ATPase activity, and increased concentration of malonic dialdehyde (MDA) and catalase activity in erythrocytes. Most parameters gradually were restored over 5 days, but a reduced concentration of 2,3-DPG was observed throughout the entire experiment with transfusion of erythromass without ozone. Transfusion of the ozonized erythrocyte mass 1 h after its administration caused an increase in 2,3- DPG concentration in erythrocytes circulating in the vascular bed. Twenty-four hours later, increased catalase activity, EPPE, and ATP concentration were registered, and, after 5 days, enhanced Na+-K+-ATPase activity was registered. Their values were maintained until the end of the experiment at a higher level than in animals that had undergone transfusion of the nonozonized erythromass. Ozonized erythrocyte mass improves the functional metabolic state of erythrocytes, promotes an earlier recovery of the oxygen transport in blood, and limits the damage to the microcirculatory bed of the myocardium and cardiomyocytes during blood loss.

Simulation of blood and oxygen distributions in a hepatic lobule with sinusoids obstructed by cancer cells

The liver is one of the common metastatic sites for many cancers. The obstruction of sinusoids by circulating tumor cells changes liver microenvironments and is thus considered a source of hepatic metastases. To date, few studies provide detailed information, either experimentally or theoretically, concerning the changes in blood and oxygen distributions induced by the obstruction of sinusoids. In this study, we utilized a 3D porous medium-vascular tree geometric structure to mimic the hepatic lobule and studied theoretical blood flow and oxygen transport in the lobule. The simulation was validated with data from the literature. Then, the distributions of blood and oxygen in the presence of the obstruction by cancer cells were simulated. The area and degree of the liver damage induced by the obstruction were analyzed by comparing the difference of liver microenvironments between physiological (non-blocked sinusoid) and pathological (fully or partially blocked sinusoid) conditions and the minimum cancer cell sizes causing liver damage for various obstruction positions were obtained. The work presented in this study can be used to predict the degree of liver damage induced by the local ischemia caused by the obstruction of sinusoids and to characterize the relationship between hepatic metastases and liver microenvironments.

Insights into cerebral haemodynamics and oxygenation utilising in vivo mural cell imaging and mathematical modelling

The neurovascular mechanisms underpinning the local regulation of cerebral blood flow (CBF) and oxygen transport remain elusive. In this study we have combined novel in vivo imaging of cortical microvascular and mural cell architecture with mathematical modelling of blood flow and oxygen transport, to provide new insights into CBF regulation that would be inaccessible in a conventional experimental context. Our study indicates that vasoconstriction of smooth muscle actin-covered vessels, rather than pericyte-covered capillaries, induces stable reductions in downstream intravascular capillary and tissue oxygenation. We also propose that seemingly paradoxical observations in the literature around reduced blood velocity in response to arteriolar constrictions might be caused by a propagation of constrictions to upstream penetrating arterioles. We provide support for pericytes acting as signalling conduits for upstream smooth muscle activation, and erythrocyte deformation as a complementary regulatory mechanism. Finally, we caution against the use of blood velocity as a proxy measurement for flow. Our combined imaging-modelling platform complements conventional experimentation allowing cerebrovascular physiology to be probed in unprecedented detail.

ОСОБЕННОСТИ КИСЛОРОДТРАНСПОРТНОЙ ФУНКЦИИ КРОВИ И ПРООКСИДАНТНО-АНТИОКСИДАНТНОГО БАЛАНСА В ЗАВИСИМОСТИ ОТ ХАРАКТЕРА ТУБЕРКУЛЕЗНОГО ПРОЦЕССА

Background. In conditions of tuberculosis inflammation decompensation occurs in the system of lipid peroxidation- antioxidant protection, an important role in which belongs to the mechanisms of oxygen transport by blood. Purpose of the study. To study the features of blood oxygen transport and prooxidant-antioxidant state, depending on the character of the tuberculosis process. Material and methods. A total of 120 patients with various types of the tuberculosis process in the lungs were examined. In the first 10 days, after admission of the patient to the hospital, 10 ml of blood was taken from the ulnar vein under the restored outflow. Evaluation of blood oxygen transport was performed within an hour after venous blood sampling. The rest of the blood was separated by centrifugation into plasma and erythrocyte mass, which were stored at -80° C with the subsequent measurement of prooxidant-antioxidant status within one month.Results. The blood oxygen transport and prooxidant-antioxidant balance were analyzed for different types of the tuberculosis process. The most significant increase in p50 was observed in the advanced tuberculosis process (by 13.06% (p <0.05), in the presence of destruction in the lung tissue (by 13.06% (p <0.05).), in the presence of bacterial excretion (by 10.07% (p <0.05).) and in the multiple drug resistance of mycobacterium tuberculosis (by 9.89% (p <0.05). This was ccompanied by more pronounced activation of lipid peroxidation processes and a decreased antioxidant reserve. Conclusions. Changes in the blood oxygen transport as well as the activity of free radical oxidation in pulmonary tuberculosis depend on the extent of the tuberculosis process, the presence of destruction in the lung tissue, bacterial release and the presence of multiple drug resistance. The revealed features justify the administration of antioxidant therapy and drugs promoting tissue oxygenation.

A coupled analysis of movement of red blood cells and oxygen transport in the microcirculation

A coupled analysis of movement of red blood cells and oxygen transport in the microcirculation

Effect of Magnetic Field on Blood Oxygen Transport Function during a Hydrogen Sulfide Donor Introduction

Gas transmitters (hydrogen sulfide, H2S, nitric oxide, NO) belong to gaseous signaling compounds, which are important for transduction of physiological signals. However, contribution of hydrogen sulfide to effects of magnetic field (MF) on oxygen transport function is still poorly understood. So, the effect of magnetic field on oxygen transport function of the blood upon the administration of a hydrogen sulfide donor was evaluated in the work. The tail artery of outbred white male rats was exposed to MF, and the drugs affecting hydrogen sulfide formation, namely, sodium hydrosulfide (NaHS); L-arginine; NG -nitro-L-arginine methyl ester (L-NAME), a nonselective inhibitor of NO synthase; and DL-propargylglycine (PAG), an irreversible inhibitor of cystathionine-γ-lyase were injected intraperitoneally for 10 days. Oxygen transport function of the blood, the contents of hydrogen sulfide and nitrate/nitrite anions (NO2− /NO3−) were determined in the blood plasma. It has been shown that an exposure of rats to MF and administration of either NaHS or amino acid L-arginine leads to a decrease in the affinity of hemoglobin for oxygen and is accompanied by an increase in the content of gas transmitters (NO and H2S) in the blood. With the introduction of L-NAME and PAG, the effect of MF on the affinity of hemoglobin for oxygen is not manifested. Thus, MF realizes its effect through the hydrogen sulfide and nitric oxide.

Influence of the blood gas transport system on brain millivolt scale direct current potentials in patients with vascular encephalopathy

Introduction . Millivolt Scale direct current potentials (DCP) registered from human scalp differ from other types of estimated electrical activity by closer association with cerebral energetic processes. Intense energy metabolism in the brain increases the difference between acidic products concentrations on both sides of the blood brain barrier which is reflected by higher DCP. Oxygen consumption of is one of the most important components of cerebral energy metabolism. Delivery of oxygen to neuron depends on the characteristics of blood oxygen transport system and cerebral blood flow. Objective . To test the hypothesis that brain DCP depends of the blood oxygen transport system characteristics and cerebral blood flow. Materials and methods. Erythrocytes number, erythrocyte sedimentation rate, hemoglobin and fibrinogen levels in blood were examined i n 135 patients with vascular encephalopathy (VE) Blood flow velocity in major head arteries was estimated using Doppler ultrasound. Associations between blood characteristics and blood flow velocity and the brain DCP, recorded in frontal, central, occipital areas along the midline and in both temporal areas, were determined. Results. Associations between brain DCP and the blood oxygen transport system characteristics as well as the cerebral blood flow velocity were discovered in patients with VE. Averaged values of DCP in all examined areas were significantly different in groups with high and low hemoglobin levels (Fisher coefficient (F) = 5.5; p = 0.02) and corpuscular hemoglobin levels (F = 7.0; p <0.01). The blood flow velocity in the internal carotid artery correlated with DCP in central areas of the head (r = 0.37; p = 0.003). The values of averaged DCP (over all areas) negatively correlated with blood sedimentation rate (r = -0.31; p= 0.002) and fibrinogen levels (r = -0.37; p <0.001). Conclusions . Evidences of the association between DCP and the brain oxygen transport system were obtained. Higher level of hemoglobin and a higher rate of cerebral blood flow promote more intensive rates of brain oxygen consumption. Discovered correlations between the blood oxygen transport system characteristics, cerebral blood flow and brain DCP confirm the potential benefit of using the millivolt range slow brain electrical activity measurement to characterize cerebral energy metabolism in clinical and experimental setting.

New advances in fetal cardiovascular magnetic resonance imaging for quantifying the distribution of blood flow and oxygen transport: Potential applications in fetal cardiovascular disease diagnosis and therapy.

Until recently, our modern understanding of fetal circulatory physiology has been largely based on invasive measurements made in fetal sheep. However, new MRI technology developed by our group has provided equivalent information about the distribution of blood flow and oxygen transport noninvasively. The initial findings largely confirm prior estimates about the human fetal circulation extrapolated from fetal sheep data and human ultrasound data. Here we describe the hemodynamics of the normal late gestation human fetal circulation by MRI and speculate about what the advent of this technology might mean in terms of the management of fetuses affected by placental insufficiency and congenital heart disease.

Baseline and stress-induced blood properties of male and female Darwin’s small ground finch (Geospiza fuliginosa) of the Galapagos Islands

Birds are renowned for exhibiting marked sex-specific differences in activity levels and reproductive investment during the breeding season, potentially impacting circulating blood parameters associated with stress and energetics. Males of many passerines often do not incubate, but they experience direct exposure to intruder threat and exhibit aggressive behaviour during the nesting phase in order to defend territories against competing males and predators. Nesting females often have long bouts of inactivity during incubation, but they must remain vigilant of the risks posed by predators and conspecific intruders approaching the nest. Here, we use 33 free-living male (n = 16) and female (n = 17) Darwin's small ground finches (Geospiza fuliginosa) on Floreana Island (Galapagos Archipelago) to better understand how sex-specific roles during the reproductive period impact baseline and stress-induced levels of plasma corticosterone (CORT), blood glucose and haematocrit. Specifically, we hypothesise that males are characterised by higher baseline values given their direct and relatively frequent exposure to intruder threat, but that a standardised stress event (capture and holding) overrides any sex-specific differences. In contrast with expectations, baseline levels of all blood parameters were similar between sexes (13.4 ± 1.9 ng ml−1 for CORT, 13.7 ± 0.4 mmol l−1 for glucose, 58.3 ± 0.8% for haematocrit). Interestingly, females with higher body condition had lower baseline haematocrit. All blood parameters changed with time since capture (range 1.2–41.3 min) in both sexes, whereby CORT increased linearly, haematocrit decreased linearly, and glucose increased to a peak at ∼20 min post-capture and declined to baseline levels thereafter. Our results do not support the hypothesis that sex-specific roles during the reproductive period translate to differences in blood parameters associated with stress and energetics, but we found some evidence that blood oxygen transport capacity may decline as finches increase in body condition.

3D computational models of placental blood flow and oxygen transport

Studies of pregnancies in most strains of mice are optimized by attentive observation of external features of the estrous cycle to ensure pairing with a male during the female’s brief interval of receptivity to mating. Also important are recognition of the copulation plug, indicative of mating, and observation of the external appearance of the pregnant female that becomes distinctive from midgestation. Monitoring of external appearance can identify young females who became pregnant following undetected mating. This permits early decisions for appropriate usage of such animals. Premating obesity will complicate visual assessment of pregnancy and necessitate palpation of fetuses in the female’s abdomen to confirm that she is at mid- to late pregnancy. Palpation should not be undertaken before suspected gestation day 12 of pregnancy since it may cause implantation site damage. External features as well as postmortem dissections of the gravid mouse and its uterus are illustrated to show changes that progress over pregnancy.

Vitamen D Assessment In Iron Dificiency Anemic Pregnant Women and Their Newborn Compared to Controls

: Vitamin D is a prohormone nutrient, which is involved in skeletal and extra-skeletal functions. Iron is another essential nutrient that is necessary for the production of red blood cells and oxygen transport. This element plays important roles in enzymatic systems including those required for Vitamin D activation. Iron deficiency anemia (IDA) is one of the most common diseases among pregnant women worldwide. Vitamin D deficiency (VDD) during pregnancy might be associated with some adverse effects on fetal growth. This study was designed to assess the possible relationship between IDA in pregnant mothers, their corresponding newborns and vitamin D deficiency (VDD). Research Design and Methods: Maternal and fetal serum25-hydroxy vitamin D levels were evaluated using radioimmunoassay (RIA) technique, in 25 pregnancies with IDA compared to 15 age-matched uncomplicated term gestations. Birth weight and clinical status of the neonates were assessed. Results: The present study revealed that 25-hydroxy vitamin D level was statistically decrease in IDA pregnant group in comparison to the control group (p

Hypoxia tolerance and responses to hypoxic stress during heart and skeletal muscle inflammation in Atlantic salmon (Salmo salar).

Heart and skeletal muscle inflammation (HSMI) is associated with Piscine orthoreovirus (PRV) infection and is an important disease in Atlantic salmon (Salmo salar) aquaculture. Since PRV infects erythrocytes and farmed salmon frequently experience environmental hypoxia, the current study examined mutual effects of PRV infection and hypoxia on pathogenesis and fish performance. Furthermore, effects of HSMI on hypoxia tolerance, cardiorespiratory performance and blood oxygen transport were studied. A cohabitation trial including PRV-infected post-smolts exposed to periodic hypoxic stress (4 h of 40% O2; PRV-H) at 4, 7 and 10 weeks post-infection (WPI) and infected fish reared under normoxic conditions (PRV) was conducted. Periodic hypoxic stress did not influence infection levels or histopathological changes in the heart. Individual incipient lethal oxygen saturation (ILOS) was examined using a standardized hypoxia challenge test (HCT). At 7 WPI, i.e. peak level of infection, both PRV and PRV-H groups exhibited reduced hypoxia tolerance compared to non-infected fish. Three weeks later (10 WPI), during peak levels of pathological changes, reduced hypoxia tolerance was still observed for the PRV group while PRV-H performed equal to non-infected fish, implying a positive effect of the repeated exposure to hypoxic stress. This was in line with maximum heart rate (fHmax) measurements, showing equal performance of PRV-H and non-infected groups, but lower fHmax above 19°C as well as lower temperature optimum (Topt) for aerobic scope for PRV, suggesting reduced cardiac performance and thermal tolerance. In contrast, the PRV-H group had reduced hemoglobin-oxygen affinity compared to non-infected fish. In conclusion, Atlantic salmon suffering from HSMI have reduced hypoxia tolerance and cardiac performance, which can be improved by preconditioning fish to transient hypoxic stress episodes.