Reversal of hemoglobin-induced vasoconstriction with sustained release of nitric oxide

Blood Haemoglobin Concentration Is Directly and Independently Related with Pulse Wave Velocity, a Measure of Large Artery Stiffness

High haemoglobin level has been associated with metabolic syndrome, elevated blood pressure (BP), and increased mortality risk. In this cross-sectional study, we investigated the association of blood haemoglobin with haemodynamics in 743 subjects, using whole-body impedance cardiography and pulse wave analysis. The participants were allocated to sex-stratified haemoglobin tertiles with mean values 135, 144, and 154 g/L, respectively. The mean age was similar in all tertiles, while body mass index was higher in the highest versus the lowest haemoglobin tertile. The highest haemoglobin tertile had the highest erythrocyte and leukocyte counts, plasma C-reactive protein, uric acid, renin activity, and aldosterone. The lipid profile was less favourable and insulin sensitivity lower in the highest versus the lowest haemoglobin tertile. Aortic BP, cardiac output, and systemic vascular resistance were similar in all tertiles, while the pulse wave velocity (PWV) was higher in the highest versus the lowest haemoglobin tertile. In linear regression analysis, age (Beta 0.478), mean aortic BP (Beta 0.178), uric acid (Beta 0.150), heart rate (Beta 0.148), and aldosterone-to-renin ratio (Beta 0.123) had the strongest associations with PWV (p < 0.001 for all). Additionally, haemoglobin concentration was an explanatory factory for PWV (Beta 0.070, p = 0.028). To conclude, blood haemoglobin concentration had a small direct and independent association with a measure of large artery stiffness.

Factors influencing new-onset hypertension in elderly patients with obstructive sleep apnea: A multicenter cohort study

Investigating the influencing factors of new-onset hypertension in the elderly with obstructive sleep apnea (OSA). 450 Chinese older patients with OSA who were non-hypertensive at baseline were enrolled. All patients had undergone polysomnography monitoring in the multicenter study. The primary endpoint was incident hypertension. Kaplan-Meier survival analysis was performed, and multivariate Cox proportional hazards models were generated to determine the factors influencing new-onset hypertension. A total of 176 (39.1%) patients developed hypertension. The hypertension group had older age, higher hemoglobin (Hb) level and apnea-hypopnea index (AHI) values than the non-hypertension group (all p < 0.05). During the median 33-month follow-up period, multivariate Cox analysis showed age (hazard ratio (HR) = 1.039, 95% confidence interval (95% CI): 1.016-1.062), AHI (HR = 1.015, 95% CI: 1.007-1.023) and Hb level (HR = 1.016, 95% CI: 1.008-1.025) were independent predictors of new-onset hypertension. However, continuous positive airway pressure (CPAP; HR = 0.508, 95% CI: 0.271-0.951) reduced the risk of developing hypertension. Notably, the subgroup analysis demonstrated that the plasma glucose level (HR = 1.168, 95% CI: 1.029-1.326) was a risk factor for male patients. Besides length of time with the pulse oxygen saturation less than 90% (Tsat90; HR = 1.005, 95% CI: 1.003-1.007), body mass index (BMI; HR = 1.170, 95% CI: 1.043-1.311), and dyslipidemia (HR = 2.335, 95% CI: 1.144-4.766) had statistically significant effects on the incidence of hypertension in certain subgroups. Although this study lacked analysis of items such as living habits and medication, it did show age, AHI, Hb and CPAP affected the development of hypertension in elderly OSA patients. These findings suggested that targeted interventions in specific populations may be more effective in preventing hypertension.

Correlation Between Hemoglobin Levels and Polycystic Ovary Syndrome Metabolic Disorder

Objective

The purpose of this study was to explore the relationship between hemoglobin levels and metabolic disorders in patients with PCOS.

Methods

A total of 573 patients were selected, based on the hemoglobin level; 342 patients with PCOS were divided into two groups as follows: Group A (normal Hb group, n = 269) and Group B (high Hb group, n = 73); 231 non-PCOS patients were divided into two groups as follows: Group C (normal Hb group, n = 199), and Group D (high Hb group, n = 32). The general information, glucose and lipid metabolism indicators, and uric acid levels of all patients were compiled for data analysis.

Results

(1) Hb, HGB concentration in mean red blood cells and RDW in PCOS patients were higher than those in non-PCOS patients, and MCV was lower than that in non-PCOS patients (P < 0.05); (2) Compared with Group A, patients in Group B had higher BMI, Hb, 2-hPG, FINS, 2-hINS, HOMA-IR, LDL-C, and uric acid levels while the QUICKI was lower; in Group C, the age, FSH, HDL-C, and LDL-C were higher, and AMH, BMI, T, TG, and uric acid level were lower (P<0.05); compared with Group D, AMH, BMI, FINS, HOMA-IR, TG, uric acid level increased, while age, FSH, and QUICKI decreased in Group B; and Hb and T decreased in Group C (P<0.05); (3) Pearson's correlation analysis indicated that Hb in PCOS patients was positively correlated with BMI, FPG, 2-hPG, FINS, 2-hINS, and HOMA-IR, and negatively correlated with the QUICKI (P<0.05); (4) Multi-factor logistic regression analysis suggested that the high Hb level in PCOS patients was an independent risk factor of IR (P<0.05).

Conclusion

Hb level in patients with PCOS was associated with BMI and glucose metabolism indicators; a high Hb level may be an independent risk factor for IR.

The associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents: a prospective cohort study

Uncontrolled pediatric hypertension may increase the risk of hypertension in adulthood. Several studies have reported an association between hematological parameters and blood pressure (BP) levels. However, epidemiologic evidence of this association in children and adolescents remains scarce. This study aims to explore the associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents. This longitudinal study was conducted with 1368 participants aged 6-8 years from baseline visit to follow-up visit. Compared with participants from the normal blood pressure (BP) group, participants from the elevated BP group had significantly higher baseline red blood cell (RBC) counts, hemoglobin (Hb) counts and hematocrit (Hct) levels (all P < 0.001). A multilevel linear mixed model was conducted to analyze the relationship between hematological parameters and BP levels. The results suggested that SBP, DBP and MAP increased significantly with a quartile increase of levels of hematological parameters (all P < 0.05). Furthermore, a multilevel mixed logistic regression model was used to analyze the risk of per interquartile range increase in hematological parameters on the incidence of prehypertension and hypertension. The risk of prehypertension and hypertension incidence increased by (1.34 (95%CIs: 1.20, 1.50)), (1.38 (95%CIs: 1.24,1.54)), (1.33 (95%CIs: 1.19,1.50)), (1.14 (95%CIs: 1.03,1.26)) fold with a one-quartile increase in levels of RBC, Hb, Hct and Fe, respectively (all P < 0.05). This longitudinal study showed that hematological parameters were positively associated with BP levels in healthy children and adolescents, which excluded the effect of antihypertensive drugs on BP levels that often appeared in adults.

The artificial oxygen carrier erythrocruorin-characteristics and potential significance in medicine

The diminishing supply and increasing costs of donated blood have motivated research into novel hemoglobin-based oxygen carriers (HBOCs) that can serve as red blood cell (RBC) substitutes. HBOCs are versatile agents that can be used in the treatment of hemorrhagic shock. However, many of the RBC substitutes that are based on mammalian hemoglobins have presented key limitations such as instability and toxicity. In contrast, erythrocruorins (Ecs) are other types of HBOCs that may not suffer these disadvantages. Ecs are giant metalloproteins found in annelids, crustaceans, and some other invertebrates. Thus far, the Ecs of Lumbricus terrestris (LtEc) and Arenicola marina (AmEc) are the most thoroughly studied. Based on data from preclinical transfusion studies, it was found that these compounds not only efficiently transport oxygen and have anti-inflammatory properties, but also can be modified to further increase their effectiveness. This literature review focuses on the structure, properties, and application of Ecs, as well as their advantages over other HBOCs. Development of methods for both the stabilization and purification of erythrocruorin could confer to enhanced access to artificial blood resources.

Positive Association between Hemoglobin Concentration and Blood Pressure in Adults: A Cross-Sectional Study Based on Rafsanjan Cohort Study

Introduction

Identification of factors associated with blood pressure (BP), including hemoglobin, can be used in diagnosing, controlling, and predicting the prognosis of patients. This study aims to investigate the cross-sectional association between hemoglobin concentration and BP in people aged 35-70 years in a cohort study of Rafsanjan, Iran.

Method

This cross-sectional study was conducted on 9398 urban and rural population of Rafsanjan adult cohort study as a part of the prospective epidemiological research studies in Iran (PERSIAN). Demographic information, medical history, history of smoking and alcohol intake, systolic and diastolic BP, and hemoglobin concentration were collected. A logistic regression test was performed to evaluate the relationship between hemoglobin concentration and BP in 4 unadjusted and adjusted models based on demographic indicators, clinical and laboratory findings using SPSS.24 software and SAS software version 9.2.

Results

The mean age of the participants was 49.78 ± 9.53 years, and 53.2% (5002 people) were women. Adjusted models 3 and 4 showed a positive association between BP and hemoglobin. For each unit increase in hemoglobin, the odds ratio (OR) of BP in the adjusted model 3 was 1.062 (95% CI: 1.005-1.121), and in the adjusted model 4, it was 1.090 (95% CI: 1.031-1.153).

Conclusion

Based on the results, the positive trend of BP and hemoglobin levels may indicate the need to pay more attention to these people as higher-risk groups for hypertension.

Integrating Health Data-Driven Machine Learning Algorithms to Evaluate Risk Factors of Early Stage Hypertension at Different Levels of HDL and LDL Cholesterol

Purpose: Cardiovascular disease (CVD) is a major worldwide health burden. As the risk factors of CVD, hypertension, and hyperlipidemia are most mentioned. Early stage hypertension in the population with dyslipidemia is an important public health hazard. This study was the application of data-driven machine learning (ML), demonstrating complex relationships between risk factors and outcomes and promising predictive performance with vast amounts of medical data, aimed to investigate the association between dyslipidemia and the incidence of early stage hypertension in a large cohort with normal blood pressure at baseline. Methods: This study analyzed annual health screening data for 71,108 people from 2005 to 2017, including data for 27 risk-related indicators, sourced from the MJ Group, a major health screening center in Taiwan. We used five machine learning (ML) methods—stochastic gradient boosting (SGB), multivariate adaptive regression splines (MARS), least absolute shrinkage and selection operator regression (Lasso), ridge regression (Ridge), and gradient boosting with categorical features support (CatBoost)—to develop a multi-stage ML algorithm-based prediction scheme and then evaluate important risk factors at the early stage of hypertension, especially for groups with high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels within or out of the reference range. Results: Age, body mass index, waist circumference, waist-to-hip ratio, fasting plasma glucose, and C-reactive protein (CRP) were associated with hypertension. The hemoglobin level was also a positive contributor to blood pressure elevation and it appeared among the top three important risk factors in all LDL-C/HDL-C groups; therefore, these variables may be important in affecting blood pressure in the early stage of hypertension. A residual contribution to blood pressure elevation was found in groups with increased LDL-C. This suggests that LDL-C levels are associated with CPR levels, and that the LDL-C level may be an important factor for predicting the development of hypertension. Conclusion: The five prediction models provided similar classifications of risk factors. The results of this study show that an increase in LDL-C is more important than the start of a drop in HDL-C in health screening of sub-healthy adults. The findings of this study should be of value to health awareness raising about hypertension and further discussion and follow-up research.

Design, Synthesis, and Antisickling Investigation of a Nitric Oxide-Releasing Prodrug of 5HMF for the Treatment of Sickle Cell Disease

5-hydroxyfurfural (5HMF), an allosteric effector of hemoglobin (Hb) with an ability to increase Hb affinity for oxygen has been studied extensively for its antisickling effect in vitro and in vivo, and in humans for the treatment of sickle cell disease (SCD). One of the downstream pathophysiologies of SCD is nitric oxide (NO) deficiency, therefore increasing NO (bio)availability is known to mitigate the severity of SCD symptoms. We report the synthesis of an NO-releasing prodrug of 5HMF (5HMF-NO), which in vivo, is expected to be bio-transformed into 5HMF and NO, with concomitant therapeutic activities. In vitro studies showed that when incubated with whole blood, 5HMF-NO releases NO, as anticipated. When incubated with sickle blood, 5HMF-NO formed Schiff base adduct with Hb, increased Hb affinity for oxygen, and prevented hypoxia-induced erythrocyte sickling, which at 1 mM concentration were 16%, 10% and 27%, respectively, compared to 21%, 18% and 21% for 5HMF. Crystal structures of 5HMF-NO with Hb showed 5HMF-NO bound to unliganded (deoxygenated) Hb, while the hydrolyzed product, 5HMF bound to liganded (carbonmonoxy-ligated) Hb. Our findings from this proof-of-concept study suggest that the incorporation of NO donor group to 5HMF and analogous molecules could be a novel beneficial strategy to treat SCD and warrants further detailed in vivo studies.

Relationship Between Hemoglobin and Blood Pressure Levels in the Context of Chronic Morbidity Among Older Adults Residing in a Developing Country: A Community-Level Comparative Cross-Sectional Study

Objectives: The objective of this study is to assess the association between hemoglobin (Hb) and blood pressure (BP) levels among community-dwelling older adults.

Materials and Methods: This comparative cross-sectional study was conducted in April 2021 in West Bengal, India. Individuals who are receiving treatment for hypertension, or had a history of blood transfusion, or had a history of intake of iron and vitamins were excluded from the study. A total of 81 and 106 individuals were recruited in “Group 1” (no self-reported comorbidity) and “Group 2” (self-reported comorbidity present), respectively.

Results: The mean (SD) age of the participants (n = 187) was 67.4 (7.4) years; 54% (n = 101) were males; and 45.4% (n = 85) were obese. We found a significant association of Hb level with systolic blood pressure (SBP) (r = 0.22, p = 0.04) and mean arterial pressure (MAP) (r = 0.22, p = 0.04) in “Group 1”. The quantum of increases in SBP, diastolic blood pressure (DBP), pulse pressure (PP), and MAP with one gram/dl change in Hb level were 3.24 (95% CI: -0.75 to 7.24) mmHg, 1.17 (95% CI: -0.84 to 3.20) mmHg, 2.06 (95% CI: -0.67 to 4.81) mmHg, and 1.87 (95% CI: -0.65 to 4.39) mmHg, respectively, in “Group 1” after adjustment for age, gender, and body mass index. The findings were inconsistent in “Group 2”, and the changes in Hb level were 0.5 (95% CI: -3.77 to 2.77) mmHg, 0.92 (95% CI: -0.72 to 2.75) mmHg, -1.42 (95% CI: -4.09 to 1.24) mmHg, and 0.45 (95% CI: -1.05 to 2.40) mmHg, respectively.

Conclusion: Hb level has a positive correlation with SBP and MAP only in those without comorbidities.

The Application of Nitric Oxide for Ocular Hypertension Treatment

Despite of various therapeutic methods for treating ocular hypertension and glaucoma, it still remains the leading cause of irreversible blindness. Intraocular pressure (IOP) lowering is the most effective way to slow disease progression and prevent blindness. Among the ocular hypotensive drugs currently in use, only a couple act on the conventional outflow system, which is the main pathway for aqueous humor outflow and the major lesion site resulting in ocular hypertension. Nitric oxide (NO) is a commendable new class of glaucoma drugs that acts on the conventional outflow pathway. An increasing number of nitric oxide donors have been developed for glaucoma and ocular hypertension treatment. Here, we will review how NO lowers IOP and the types of nitric oxide donors that have been developed. And a brief analysis of the advantages and challenges associated with the application will be made. The literature used in this review is based on Pubmed database search using ‘nitric oxide’ and ‘glaucoma’ as key words.

Effects of recreational sports and combined training on blood pressure and glycated hemoglobin in middle-aged and older adults: A systematic review with meta-analysis

BACKGROUND

Combined resistance and aerobic training (CT) is the most suitable form of exercise training to simultaneously improve strength and cardiometabolic profile in middle-aged and older adults. Recreational sports (RS) emerge as an alternative to CT to improve these outcomes. We performed a meta-analysis on the effects of RS and CT on systolic blood pressure (SBP), diastolic blood pressure (DBP) and glycated hemoglobin (HbA1c) in middle-aged and older adults and to compare these exercise interventions to a non-exercising control group (CON).

METHODS

Search was conducted using the databases at PubMed, COCHRANE and SciELO between July and August 2020. Studies that included men and women aged ≥45 years, healthy or with values for SBP ≥130 mmHg or DBP ≥80 mmHg or with type 2 diabetes and performed RS or CT versus CON.

RESULTS

From 6017 records, 27 studies were included (9 RS and 18 CT). The analysis included 1411 participants with 55 ± 8 years. RS and CT were associated with reductions in SBP (RS: -7.2 mmHg, P = 0.03; CT: -3.6 mmHg, P < 0.001) and DBP (RS: -3.6 mmHg, P = 0.02; CT: -3.1 mmHg, P < 0.001) versus CON. Only CT was associated with a reduction in HbA1c versus CON (-0.47%; P < 0.001).

CONCLUSIONS

RS and CT are effective exercise interventions to improve BP in middle-aged and older adults. CT seems to be an excellent strategy to reduce HbA1c, and future studies are necessary to confirm the effectiveness of RS to improve HbA1c.

Hemoglobin and hematocrit levels are positively associated with blood pressure in children and adolescents 10 to 18 years old

To investigate the associations between hemoglobin (Hb) concentration and hematocrit (Hct), and blood pressure (BP) in children and adolescents. The study population consisted of 7950 subjects total (4229 boys and 3721 girls) aged 10-18 years who participated in the Korea National Health and Nutrition Examination Surveys conducted between 2007 and 2017. The prevalence of hypertension was 19.19% (21.51% for boys and 16.5% for girls) among the study population, and the prevalence of obesity was 9.59% (10.5% for boys and 8.6% for girls). Hb count and Hct tended to increase with the degree of obesity and BP elevation. Systolic BP (SBP) and diastolic BP (DBP) positively correlated with Hb count and Hct in both sexes. Following multiple linear regression analysis, Hb count and Hct presented a positive association with SBP and DBP after adjusting for age, BMI SDS, alcohol consumption, smoking status, physical activity, rural residence, household income, diagnosis of T2DM, hypertension, and dyslipidemia. Hb count and Hct were positively associated with SBP and DBP in children and adolescents 10-18 years old.

The levels of hemoglobin are positively associated with arterial stiffness in community-dwelling Chinese adults

BACKGROUND AND AIMS

Hemoglobin (Hb) concentrations are known to be related to cardiovascular diseases. This study investigated the association between Hb levels and arterial stiffness, as assessed by measurement of the brachial-ankle pulse wave velocity (baPWV).

METHODS AND RESULTS

3576 adults (2139 males and 1437 females) from the general Chinese population who had their physical check-ups in the health examination centers of Jiangmen Central Hospital were enrolled into the study. The anthropometrics and laboratory data as well as the baPWV and Hb levels were subsequently obtained. Age-adjusted partial correlation and multivariable stepwise linear regression analyses were used to evaluate the relationships between Hb and baPWV for men and women separately. In both sexes, Hb levels were positively associated with body mass index, total cholesterol, low-density lipoprotein cholesterol, triglycerides, glutamic-pyruvic transaminase, γ-glutamyltranspeptidase, uric acid and baPWV, but negatively correlated with the estimated glomerular filtration rate. Multivariable linear regression analysis showed that Hb was significantly and independently associated with arterial stiffness in men (β = 0.043, 95% CI 0.010-0.077, p < 0.05) and women (β = 0.035, 95% CI 0.001-0.069, P < 0.05), after adjustment for confounding factors.

CONCLUSION

The data indicate that high Hb concentration significantly correlate with increased baPWV in general Chinese population.

Sex-dependent correlates of arterial stiffness in Tanzanian adults

OBJECTIVE

Arterial stiffness is a known indicator for cardiovascular disease. However, the factors that lead to arterial stiffening have primarily been studied in participants from high-income countries. Here, we examine clinical and lifestyle metrics in relation to arterial stiffness in Tanzanian adults.

METHODS

We performed pulse wave velocity (PWV), the gold standard measure of arterial stiffness, on 808 Tanzanian adults (ages 18-65) enrolled in a longitudinal cohort studying trends in blood pressure.

RESULTS

As expected, PWV was strongly associated with age, blood pressure and sex. We controlled for these factors in our statistical analysis. Lifestyle metrics were compared across multiple PWV quantiles. We found that determinants of PWV varied by sex: in female participants, PWV was associated with common obesity metrics and menopause, while in male participants, PWV was associated with HIV status and duration of anti-retroviral therapy (ART). Further clinical and lifestyle factors such as marriage status and type of occupation were also significantly associated with PWV and moderated by sex.

CONCLUSION

Together, our data demonstrate the importance of studying sex-specific causal pathways for arterial stiffness and of including under-represented populations in these studies.

Understanding the Potential Role and Delivery Approaches of Nitric Oxide in Chronic Wound Healing Management

Nitric oxide (NO) is a promising pharmaceutical component that has vasodilator, anti-bacterial, and wound healing activities. Chronic ulcers are non-healing disorders that are generally associated with distortion of lower limbs. Among the severe consequence derivatives of these diseases are the problems of chronic wound progression. NO, which is categorized as the smallest gaseous neurotransmitter, has beneficial effects in different phases of chronic inflammation. The defensive mechanism of NO is found useful in several severe conditions, such as gestational healing, gastrointestinal healing, and diabetic healing. The current review presents an updated collection of literature about the role of NO in chronic ulcers due to the prevalence of diabetes, DPN, and diabetic foot ulcers, and because of the lack of available effective treatments to directly address the pathology contributing to these conditions, novel treatments are being sought. This review also collects information about deficiency of NO synthase in diabetic patients, leading to a lack of vascularization of the peripheral nerves, which causes diabetic neuropathy, and this could be treated with vasodilators such as nitric oxide. Apart from the pharmacological mechanism of NO, the article also reviewed and analyzed to elucidate the potential of transdermal delivery of NO for the treatment of chronic ulcers.

Red cell index: A novel biomarker for 3-month mortality in acute ischemic stroke patients treated with intravenous thrombolysis

BACKGROUND

The red cell index (RCI) was described as a biomarker for evaluating respiratory function in previous studies, but the relationship between RCI and stroke, remained a mystery. The present study aimed to probe the association between RCI at 24-hr and 3-month mortality and functional outcomes among acute ischemic stroke (AIS) patients treated with recombinant tissue plasminogen activator (r-tPA).

METHODS

A total of 217 AIS patients between January 2016 and January 2019 were recruited in this retrospective study. AIS patients were grouped in terms of RCI tertiles. Predictive factors were confirmed via multivariate logistic regression analysis. The receiver operating characteristic (ROC) was used to assess the ability of RCI in predicting mortality. In addition, the risk of 3-month all-cause mortality was evaluated by Cox proportional hazard model.

RESULTS

We grouped AIS patients into tertiles with the purpose of comparing clinical factors and RCI levels. Multivariate logistic regression analysis presented that RCI (odds ratio [OR] = 1.443, 95% confidence interval [CI] [1.167-1.786], p = 0.001) was an independent biomarker for 3-month all-cause mortality. The best cutoff value of RCI was 2.41 (area under the curve [AUC] = 0.639, 95% CI [0.501-0.778], p = .032), with a sensitivity of 40.9% and a specificity of 89.7%. Cox survival analysis demonstrated a positive significant correlation between RCI (hazard ratio [HR] = 1.332, 95% CI [1.148-1.545], p < .001) and mortality risk.

CONCLUSION

RCI, a potential predictor, was significantly associated with 3-month mortality in AIS patients with r-tPA.

Blood pressure, T cells, and mortality in people with HIV in Tanzania during the first 2 years of antiretroviral therapy

Cardiovascular disease is now a leading cause of mortality in people with HIV (PWH). High blood pressure is the major driver of cardiovascular disease. Despite this, little is known about blood pressure in PWH during the early years of antiretroviral therapy (ART). In this prospective cohort study in Tanzania, the authors conducted unobserved blood pressure measurements at enrollment, 3, 6, 12, 18, and 24 months in 500 PWH initiating ART and 504 HIV-uninfected adults. The authors excluded measurements taken on antihypertensive medications. Although PWH had a significantly lower blood pressure before ART initiation, they had a significantly greater increase in blood pressure during the first 2 years of ART compared to HIV-uninfected controls. Blood pressure correlates in PWH differed from HIV-uninfected controls. In PWH, lower baseline CD4⁺ T-cell counts were associated with lower blood pressure, and greater increases in CD4⁺ T-cell counts on ART were associated with greater increases in blood pressure, both on average and within individuals. In addition, PWH with a systolic blood pressure (SBP) <90 mm Hg at the time of ART initiation had ~30% mortality in the following 3 months due to occult infections. These patients require careful investigation for occult infections, and those with tuberculosis may benefit from corticosteroids.

The Impact of Beta Blockers on Survival in Heart Transplant Recipients: Insights from the Zabrze HTx Registry

Introduction

The data assessing the impact of beta blocker (BB) medication on survival in patients after heart transplantation (HTx) are scarce and unequivocal; therefore, we investigated this population.

Methods

We retrospectively analyzed the HTx Zabrze Registry of 380 consecutive patients who survived the 30-day postoperative period.

Results

The percentage of patients from the entire cohort taking BBs was as follows: atenolol 24 (17%), bisoprolol 67 (49%), carvedilol 11 (8%), metoprolol 28 (20%), and nebivolol 8 (6%). The patients receiving BBs were older (56.94 ± 14.68 years vs. 52.70 ± 15.35 years, p=0.008) and experienced an onset of HTx earlier in years (11.65 ± 7.04 vs. 7.24 ± 5.78 p ≤ 0.001). They also had higher hematocrit (0.40 ± 0.05 vs. 0.39 ± 0.05, p=0.022) and red blood cells (4.63 (10⁶/μl) ± 0.71 vs. 4.45 (10⁶/μl) ± 0.68, p=0.015). Survival according to BB medication did not differ among the groups (p=0.655) (log-rank test). Univariate Cox proportional hazard regression analysis revealed that the following parameters were associated with unfavorable diagnosis: serum concentration of albumin (g/l) HR: 0.87, 95% CI (0.81–0.94), p=0.0004; fibrinogen (mg/dl) HR: 1.006, 95% CI (1.002–1.008), p=0.0017; and C-reactive protein (mg/l) HR: 1.014, 95% CI (1.004–1.023), p=0.0044.

Conclusions

The use of BBs in our cohort of patients after HTx was not associated with survival benefits.

Metabolism of vascular smooth muscle cells in vascular diseases

Vascular smooth muscle cells (VSMCs) are the fundamental component of the medial layer of arteries and are essential for arterial physiology and pathology. It is becoming increasingly clear that VSMCs can alter their metabolism to fulfill the bioenergetic and biosynthetic requirements. During vascular injury, VSMCs switch from a quiescent "contractile" phenotype to a highly migratory and proliferative "synthetic" phenotype. Recent studies have found that the phenotype switching of VSMCs is driven by a metabolic switch. Metabolic pathways, including aerobic glycolysis, fatty acid oxidation, and amino acid metabolism, have distinct, indispensable roles in normal and dysfunctional vasculature. VSMCs metabolism is also related to the metabolism of endothelial cells. In the present review, we present a brief overview of VSMCs metabolism and how it regulates the progression of several vascular diseases, including atherosclerosis, systemic hypertension, diabetes, pulmonary hypertension, vascular calcification, and aneurysms, and the effect of the risk factors for vascular disease (aging, cigarette smoking, and excessive alcohol drinking) on VSMC metabolism to clarify the role of VSMCs metabolism in the key pathological process.

Spatial and temporal patterns of nitric oxide diffusion and degradation drive emergent cerebrovascular dynamics

Nitric oxide (NO) is a gaseous signaling molecule that plays an important role in neurovascular coupling. NO produced by neurons diffuses into the smooth muscle surrounding cerebral arterioles, driving vasodilation. However, the rate of NO degradation in hemoglobin is orders of magnitude higher than in brain tissue, though how this might impact NO signaling dynamics is not completely understood. We used simulations to investigate how the spatial and temporal patterns of NO generation and degradation impacted dilation of a penetrating arteriole in cortex. We found that the spatial location of NO production and the size of the vessel both played an important role in determining its responsiveness to NO. The much higher rate of NO degradation and scavenging of NO in the blood relative to the tissue drove emergent vascular dynamics. Large vasodilation events could be followed by post-stimulus constrictions driven by the increased degradation of NO by the blood, and vasomotion-like 0.1-0.3 Hz oscillations could also be generated. We found that these dynamics could be enhanced by elevation of free hemoglobin in the plasma, which occurs in diseases such as malaria and sickle cell anemia, or following blood transfusions. Finally, we show that changes in blood flow during hypoxia or hyperoxia could be explained by altered NO degradation in the parenchyma. Our simulations suggest that many common vascular dynamics may be emergent phenomena generated by NO degradation by the blood or parenchyma.

Apohemoglobin-haptoglobin complex attenuates the pathobiology of circulating acellular hemoglobin and heme

Haptoglobin (Hp) is the plasma protein that binds and clears cell-free hemoglobin (Hb), whereas apohemoglobin (apoHb, i.e., Hb devoid of heme) can bind heme. Therefore, the apoHb-Hp protein complex should facilitate holoHb-apoHb αβ-dimer exchange and apoHb-heme intercalation. Thus, we hypothesized that apoHb-Hp could facilitate both Hb and heme clearance, which, if not alleviated, could have severe microcirculatory consequences. In this study, we characterized apoHb-Hp and Hb/heme ligand interactions and assessed their in vivo consequences. Hb exchange and heme binding with the apoHb-Hp complex was studied with transfer assays using size-exclusion high-performance liquid chromatography coupled with UV-visible spectrophotometry. Exchange/transfer experiments were conducted in guinea pigs dosed with Hb or heme-albumin followed by a challenge with equimolar amounts of apoHb-Hp. Finally, systemic and microcirculatory parameters were studied in hamsters instrumented with a dorsal window chamber via intravital microscopy. In vitro and in vivo Hb exchange and heme transfer experiments demonstrated proof-of-concept Hb/heme ligand transfer to apoHb-Hp. Dosing with the apoHb-Hp complex reversed Hb- and heme-induced systemic hypertension and microvascular vasoconstriction, reduced microvascular blood flow, and diminished functional capillary density. Therefore, this study highlights the apoHb-Hp complex as a novel therapeutic strategy to attenuate the adverse systemic and microvascular responses to intravascular Hb and heme exposure.NEW & NOTEWORTHY This study highlights the apoHb-Hp complex as a novel therapeutic strategy to attenuate the adverse systemic and microvascular responses to intravascular Hb and heme exposure. In vitro and in vivo Hb exchange and heme transfer experiments demonstrated proof-of-concept Hb/heme ligand transfer to apoHb-Hp. The apoHb-Hp complex reverses Hb- and heme-induced systemic hypertension and microvascular vasoconstriction, preserves microvascular blood flow, and functional capillary density. In summary, the unique properties of the apoHb-Hp complex prevent adverse systemic and microvascular responses to Hb and heme-albumin exposure and introduce a novel therapeutic approach to facilitate simultaneous removal of extracellular Hb and heme.

[Peripheral blood albumin level in significantly correlated with the severity of atherosclerosis in hypertensive patients]

OBJECTIVE

To investigate the relationship between peripheral blood albumin (Hb) level and the severity of arteriosclerosis in hypertensive patients.

METHODS

This retrospective analysis was conducted among 419 randomly selected patients with hypertension. The pulse wave velocity (ba-PWV) of the bilateral limbs was measured using an arteriosclerosis tester. According to the ba-PWV value (the higher value of the two sides), the hypertensive patients were divided into 4 groups, namely normal arterial group [S0 group, ba-PWV < 1400 cm/s; 49 cases (11.7%)], mild arteriosclerosis group [S1 group, ba-PWV of 1400-1800 cm/s; 190 cases (45.3%)], moderate arteriosclerosis group [S2 group, ba-PWV of 1800-2000 cm/s); 69 cases (16.5%)], and severe arteriosclerosis group [S3 group, ba-PWV > 2 000 cm/s; 111 cases (26.5 %)]. The clinical data of the patients were collected and multivariate logistic regression was used to analyze the risk factors of arteriosclerosis.

RESULTS

The patients' age, obesity, albumin, alanine aminotransferase (ALT), total bile acid, adenosine deaminase, urea nitrogen, serum creatinine, cystatin C, low-density lipoprotein, red blood cells, hemoglobin (Hb), fibrinogen, and FT3 all differed significantly between S0 group and the 3 arteriosclerosis groups (P < 0.05). Multivariate logistic regression analysis revealed that in hypertensive patients, age was an independent risk factor for severe arteriosclerosis (OR=1.094, 95% CI: 1.052-1.137, P < 0.05) and moderate arteriosclerosis (OR= 1.081, 95% CI: 1.039-1.125, P < 0.05); Hb was an independent risk factor for new-onset severe arteriosclerosis (OR= 1.025, 95% CI: 1.003-1.045, P < 0.05) and moderate arteriosclerosis (OR=1.035, 95% CI: 1.008-1.056, P < 0.05), and an increase of Hb levels by 1 standard deviation was associated with a doubled risk in hypertensive patients.

CONCLUSIONS

Peripheral Hb level is significantly correlated with the severity of arteriosclerosis and may serve as a new predictor for arteriosclerosis in hypertensive patients.

Association of Hemoglobin and Blood Pressure in a Chinese Community-Dwelling Population

This study investigated the relationship between hemoglobin (Hb) level and blood pressure in a Chinese community-dwelling population with normal glucose metabolism. Hb, fasting plasma glucose, glycated Hb A1c, hepatic and renal function, lipid, electrolytes, and anthropometric parameters were measured. Hb level was found to be positively correlated with systolic (SBP; r = 0.075, p < 0.001) and diastolic (DBP; r = 0.272, p < 0.001) blood pressure in the cohort. The relationship was not affected by age, BMI, serum creatinine (Cr), and low-density lipoprotein (LDL) in both males and females. Multivariate stepwise regression showed that age (β = 0.556, p < 0.001), BMI (β = 1.107, < 0.001), Hb (β = 0.082, p < 0.001), Cr (β = -0.032, p < 0.001), and LDL (β = 1.023, p < 0.001) were independent factors for SBP, and Hb (β = 0.168, p < 0.001), BMI (β = 0.519, p = 0.001), and LDL (β = 0.331, p < 0.001) for DBP. Hb level is positively associated with both SBP and DBP in a Chinese community-dwelling population with normal glucose metabolism.

Lymphocyte To High-Density Lipoprotein Ratio As A New Indicator Of Inflammation And Metabolic Syndrome

PURPOSE

Metabolic syndrome (MetS), which is a global public health problem, is a state of chronic low-grade inflammation. This study looked at the changes in hematological parameters and the predictive value of the lymphocyte to high-density lipoprotein cholesterol (HDL-C) ratio (LHR) as a new index in subjects with and without MetS in coastal cities in southern China.

PATIENTS AND METHODS

In this cross-sectional study, there were 852 participants (n = 598 with MetS and n = 254 without MetS). MetS was defined in accordance with the National Cholesterol Education Program, Adult Treatment Panel III (NCEP-ATP III) criteria.

RESULTS

MetS was positively correlated with white blood cell count, total lymphocyte count, neutrophil count, red blood cell count, hematocrit, hemoglobin, and high-sensitivity C-reactive protein levels (p<0.05). In addition, there was a positive correlation between LHR and the number of metabolic risk factors for MetS. In a logistic regression analysis, LHR (odds ratio: 4.117; 95% CI: 2.766-6.309; p<0.001) was an independent predictor of MetS. When a receiver operating characteristic (ROC) curve analysis was used to assess the value of LHR for predicting MetS, the area under the curve yielded a cut-off value of 1.657, with a sensitivity of 65% and a specificity of 64% (p<0.0001).

CONCLUSION

In summary, MetS can involve changes in blood parameters, and LHR may be a useful marker of inflammation to assess the presence and severity of MetS.

Hemoglobin level and three-month clinical outcomes among ischemic stroke patients with elevated systolic blood pressure

BACKGROUND

Previous studies have reported that extreme low and high hemoglobin levels are positively associated with the risk of ischemic stroke. However, there are few reports on the relationship between hemoglobin at acute phase and clinical outcomes after ischemic stroke and the results of their association to date are inconsistent. We aimed to investigate the association between them in a large prospective cohort of ischemic stroke patients.

METHODS

Baseline hemoglobin levels were measured in 3881 patients with acute ischemic stroke. The primary outcome was defined as composite outcome of major disability and death (modified Rankin Scale score ≥ 3) at 3 months after stroke onset. Secondary outcomes were separately those of major disability and death.

RESULTS

Compared with the lowest quartile of hemoglobin, the multivariate adjusted odds ratios (95% confidence intervals) associated with the highest quartile were 1.38 (1.03-1.86), 1.49 (1.11-1.99), 0.79 (0.41-1.52) for primary outcome, major disability and death, respectively. Multiple-adjusted spline regression model showed linear associations of hemoglobin levels with primary outcome (P for linearity =0.037) and major disability (P for linearity =0.004). Subgroup analyses further confirmed the positive association between high hemoglobin and poor prognosis of ischemic stroke.

CONCLUSIONS

Elevated hemoglobin levels in the acute phase were associated with poor prognosis at 3 months after ischemic stroke. Further prospective studies from other samples of ischemic stroke patients are needed to validate our findings.

Exploring the relationship of peripheral total bilirubin, red blood cell, and hemoglobin with blood pressure during childhood and adolescence

OBJECTIVE

Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents.

METHODS

A total of 3776 students (aged from 6 to 16 years old) were examined using cluster sampling. Pre-high blood pressure and high blood pressure were respectively defined as the point of 90th and 95th percentiles based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Both systolic and diastolic blood pressure were standardized into z-scores.

RESULTS

Peripheral total bilirubin, red blood cell and hemoglobin levels were significantly correlated with age, and also varied with gender. Peripheral total bilirubin was negatively correlated with systolic blood pressure in 6- and 9-year-old boys, whilst positively correlated with diastolic blood pressure in the 12-year-old boys and 13- to 15-year-old girls (p<0.05). Higher levels of red blood cell and hemoglobin were observed in pre-high blood pressure and high blood pressure students when compared with their normotensive peers (p<0.01). The increases in red blood cell and hemoglobin were significantly associated with high blood pressure after adjusting for confounding factors. The ORs (95% CI) of each of the increases were 2.44 (1.52-3.92) and 1.04 (1.03-1.06), respectively. No statistical association between total bilirubin and high blood pressure was observed (p>0.05).

CONCLUSION

Total bilirubin could be weakly correlated with both systolic and diastolic blood pressure, as correlations varied with age and gender in children and adolescents; in turn, the increased levels of red blood cell and hemoglobin are proposed to be positively associated with the prevalence of high blood pressure.

A comparative cross-sectional study of some hematological parameters of hypertensive and normotensive individuals at the university of Gondar hospital, Northwest Ethiopia

Background

Hypertension is a major health problem worldwide. It can lead to cardiovascular disease and also leads to functional disturbances including hematological parameters. The abnormalities of haematological parameters may enhance an end-organ damage. Therefore, the aim of this study was to assess some hematological parameters of hypertensive individuals in comparison with normotensive individuals at University of Gondar hospital, northwest Ethiopia.

Methods

A cross sectional comparative study was conducted from October to November 2015 on a total of 126 hypertensive and 126 normotensive individuals at University of Gondar Hospital. All participants after taking informed consent were interviewed for detailed history and 3 ml of blood was collected for hematological test analysis. Independent t-test and the Mann Whitney u-test were used to find out significant difference and Pearson’s and Spearman’s correlation were used for correlation test. P values less than 0.05 was considered the level of significance.

Result

From a total of 252 study subjects, about 67.5% were females. The mean age of study subjects was 50.3 ± 11 years for hypertensive individuals and 49.8 ± 11.6 years for normotensive individuals with range of 18–65 years. In the present study, the median (IQR) value of WBC, RBC, Hgb, HCT, MCV and the mean value of MCHC, RDW, MPV and PDW were significantly higher in hypertensive group compared to apparently healthy normotensive groups. Additionally, WBC, RBC, Hgb, HCT and PLT showed statistically significant positive correlations with blood pressure indices. Platelet count and MCH did not show statistically significant difference between the two groups.

Conclusion

Hypertension has impact on hematological parameters. In this study, the mean and median values of haematological parameters in hypertensive individuals were significantly different compared to apparently healthy normotensive individuals. Hence, hematological parameters can be used to monitor the prognosis of the disease and manage hypertensive related complications, and it is important to assess hematological parameters for hypertensive individuals which may help to prevent complications associated hematological disorders.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12878-017-0093-9) contains supplementary material, which is available to authorized users.

Association of hematocrit with blood pressure and hypertension

BACKGROUND

Hypertension (HTN) is a risk factor for stroke, renal failure, and cardiovascular disease. The association between biochemical and hematological parameters with high blood pressure may provide a more precise approach to risk prediction conferred by HTN in these patients.

OBJECTIVE

The aim of current study was to explore whether biochemical and hematological parameters are associated with HTN in a cohort study with a 7-year follow-up.

MATERIALS AND METHODS

A total of 9808 individuals were enrolled and recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study, and biochemical and hematological factors were measured in all subjects. Univariate and multivariate logistic regression analysis were performed to determine the association of biochemical and hematological parameters with HTN.

RESULTS

Several biochemical parameters including fasting plasma glucose (FBG), serum high-sensitivity C-reactive protein (hs-CRP), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and uric acid were increased in hypertensive participants. In contrast, serum high-density lipoprotein cholesterol (HDL-C) was lower in hypertensive individuals. Furthermore, we demonstrated that hematological parameters including white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) were higher in the hypertensive group compared to the control group. But mean corpuscular volume (MCV), and red cell distribution width (RDW), were decreased in the hypertensive group. Furthermore, our results strongly suggested that among these parameters, hematocrit was the independent risk factor for hypertension in the population.

CONCLUSION

We demonstrated the association of altered biochemical and hematological factors with hypertension supporting the value of emerging markers for early prediction of high blood pressure in prone individuals.

Sustained Nitric Oxide-Releasing Nanoparticles Interfere with Methicillin-Resistant Staphylococcus aureus Adhesion and Biofilm Formation in a Rat Central Venous Catheter Model

Staphylococcus aureus is frequently isolated in the setting of infections of indwelling medical devices, which are mediated by the microbe's ability to form biofilms on a variety of surfaces. Biofilm-embedded bacteria are more resistant to antimicrobial agents than their planktonic counterparts and often cause chronic infections and sepsis, particularly in patients with prolonged hospitalizations. In this study, we demonstrate that sustained nitric oxide-releasing nanoparticles (NO-np) interfere with S. aureus adhesion and prevent biofilm formation on a rat central venous catheter (CVC) model of infection. Confocal and scanning electron microscopy showed that NO-np-treated staphylococcal biofilms displayed considerably reduced thicknesses and bacterial numbers compared to those of control biofilms in vitro and in vivo, respectively. Although both phenotypes, planktonic and biofilm-associated staphylococci, of multiple clinical strains were susceptible to NO-np, bacteria within biofilms were more resistant to killing than their planktonic counterparts. Furthermore, chitosan, a biopolymer found in the exoskeleton of crustaceans and structurally integrated into the nanoparticles, seems to add considerable antimicrobial activity to the technology. Our findings suggest promising development and translational potential of NO-np for use as a prophylactic or therapeutic against bacterial biofilms on CVCs and other medical devices.

Cross-sectional and longitudinal association between hemoglobin concentration and hypertension: A population-based cohort study

We investigated the cross-sectional and longitudinal associations between hemoglobin concentration and hypertension in a Korean population.Between 2006 and 2013, we examined 4899 participants with mean age of 56.6 years (range 35-88 years) from a rural community. We excluded 298 participants with a history of myocardial infarction or stroke and 264 participants with very low hemoglobin levels (men: <13.3 g/dL; women: <11.6 g/dL). Finally, we performed a cross-sectional analysis on 1629 men and 2708 women. Longitudinal associations were evaluated in 654 men and 1099 women, after excluding 2584 people with hypertension at baseline and those who did not participate in follow-up examinations. Hypertension was defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or use of antihypertensive treatment.The mean hemoglobin level was significantly higher in people with hypertension than in those without hypertension (P = 0.002 for men, P = 0.006 for women). On cross-sectional analysis, the odds ratio (95% confidence interval) for hypertension per 1 standard deviation increase in hemoglobin concentration (1.2 g/dL) was 1.11 (1.05-1.18) before adjustment and 1.20 (1.09-1.32) after adjusting for age, sex, body mass index, kidney markers, lifestyle factors, and comorbidities. On longitudinal analysis, the relative risk (95% confidence interval) for incident hypertension per 1 standard deviation increase in hemoglobin concentration was 1.09 (0.96-1.23) before adjustment and 0.91 (0.78-1.08) after adjusting for age, sex, body mass index, lifestyle factors, baseline blood pressure, baseline comorbidities, and baseline kidney markers.This study suggests that hemoglobin per se does not cause hypertension development.

Biodegradable Nanoparticles for Delivery of Therapeutics in CNS Infection

Despite the significant advances in neurological medicine, it remains difficult to treat ailments directly involving the brain. The blood brain barrier (BBB) is a tightly regulated, selectively permeable barrier that restricts access from the blood into the brain extracellular fluid (BEF). Many conditions such as tumors or infections in the brain are difficult to treat due to the fact that drugs and other therapeutic agents are unable to easily pass through this relatively impermeable barrier. Human Immunodeficiency Virus (HIV) presents a particular problem as it is able to remain dormant in the brain for years protected from antiretroviral drugs by the BBB. The development of nanoscale carriers over the past few decades has made possible the delivery of therapies with the potential to overcome membrane barriers and provide specific, targeted delivery. This review seeks to provide a comprehensive overview of the various aspects of nanoparticle formulation and their applications in improving the delivery efficiency of drugs, specifically antiretroviral therapeutics to the brain to treat HIV.

Suppressor of cytokine signaling 2 modulates the immune response profile and development of experimental cerebral malaria

Plasmodium falciparum infection results in severe malaria in humans, affecting various organs, including the liver, spleen and brain, and resulting in high morbidity and mortality. The Plasmodium berghei ANKA (PbA) infection in mice closely recapitulates many aspects of human cerebral malaria (CM); thus, this model has been used to investigate the pathogenesis of CM. Suppressor of cytokine signaling 2 (SOCS2), an intracellular protein induced by cytokines and hormones, modulates the immune response, neural development, neurogenesis and neurotrophic pathways. However, the role of SOCS2 during CM remains unknown. SOCS2 knockout (SOCS2(-/-)) mice infected with PbA show an initial resistance to infection with reduced parasitemia and production of TNF, TGF-β, IL-12 and IL-17 in the brain. Interestingly, in the late phase of infection, SOCS2(-/-) mice display increased parasitemia and reduced Treg cell infiltration, associated with enhanced levels of Th1 and Th17 cells and related cytokines IL-17, IL-6, and TGF-β in the brain. A significant reduction in protective neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF), was also observed. Moreover, the molecular alterations in the brain of infected SOCS2(-/-) mice were associated with anxiety-related behaviors and cognition impairment. Mechanistically, these results revealed enhanced nitric oxide (NO) production in PbA-infected SOCS2(-/-) mice, and the inhibition of NO synthesis through l-NAME led to a marked decrease in survival, the disruption of parasitemia control and more pronounced anxiety-like behavior. Treatment with l-NAME also shifted the levels of Th1, Th7 and Treg cells in the brains of infected SOCS2(-/-) mice to the background levels observed in infected WT, with remarkable exception of increased CD8(+)IFN(+) T cells and inflammatory monocytes. These results indicate that SOCS2 plays a dual role during PbA infection, being detrimental in the control of the parasite replication but crucial in the regulation of the immune response and production of neurotrophic factors. Here, we provided strong evidence of a critical relationship between SOCS2 and NO in the orchestration of the immune response and development of CM during PbA infection.

Sustained Nitric Oxide-Releasing Nanoparticles Induce Cell Death in Candida albicans Yeast and Hyphal Cells, Preventing Biofilm Formation In Vitro and in a Rodent Central Venous Catheter Model

Candida albicansis a leading nosocomial pathogen. Today, candidal biofilms are a significant cause of catheter infections, and such infections are becoming increasingly responsible for the failure of medical-implanted devices.C. albicansforms biofilms in which fungal cells are encased in an autoproduced extracellular polysaccharide matrix. Consequently, the enclosed fungi are protected from antimicrobial agents and host cells, providing a unique niche conducive to robust microbial growth and a harbor for recurring infections. Here we demonstrate that a recently developed platform comprised of nanoparticles that release therapeutic levels of nitric oxide (NO-np) inhibits candidal biofilm formation, destroys the extracellular polysaccharide matrices of mature fungal biofilms, and hinders biofilm development on surface biomaterials such as the lumen of catheters. We found NO-np to decrease both the metabolic activity of biofilms and the cell viability ofC. albicansin vitroandin vivo Furthermore, flow cytometric analysis found NO-np to induce apoptosis in biofilm yeast cellsin vitro Moreover, NO-np behave synergistically when used in combination with established antifungal drug therapies. Here we propose NO-np as a novel treatment modality, especially in combination with standard antifungals, for the prevention and/or remediation of fungal biofilms on central venous catheters and other medical devices.

Nitric oxide generating/releasing materials

Harnessing the impressive therapeutic potential of nitric oxide (NO) remains an ongoing challenge. This paper describes several of the current strategies both with respect to the underlying chemistry and physics and to the applications where they have shown promise. Included in this overview are molecular systems such as NONOates that release NO through chemical reactions and delivery vehicles such as nanoparticles that can generate, store, transport and deliver NO and related bioactive forms of NO such as nitrosothiols. Although there has been much positive movement, it is clear that we are only at the early stages of knowing how to precisely produce, transport and deliver to targeted sites therapeutic levels of NO and related molecules.

Design, Synthesis, and Investigation of Novel Nitric Oxide (NO)-Releasing Prodrugs as Drug Candidates for the Treatment of Ischemic Disorders: Insights into NO-Releasing Prodrug Biotransformation and Hemoglobin-NO Biochemistry

We have developed novel nitric oxide (NO)-releasing prodrugs of efaproxiral (RSR13) for their potential therapeutic applications in a variety of diseases with underlying ischemia. RSR13 is an allosteric effector of hemoglobin (Hb) that decreases the protein's affinity for oxygen, thereby increasing tissue oxygenation. NO, because of its vasodilatory property, in the form of ester prodrugs has been found to be useful in managing several cardiovascular diseases by increasing blood flow and oxygenation in ischemic tissues. We synthesized three NO-donor ester derivatives of RSR13 (DD-1, DD-2, and DD-3) by attaching the NO-releasing moieties nitrooxyethyl, nitrooxypropyl, and 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate, respectively, to the carboxylate of RSR13. In vitro studies demonstrated that the compounds released NO in a time-dependent manner upon being incubated with l-cysteine (1.8-9.3%) or human serum (2.3-52.5%) and also reduced the affinity of Hb for oxygen in whole blood (ΔP50 of 4.9-21.7 mmHg vs ΔP50 of 25.4-32.1 mmHg for RSR13). Crystallographic studies showed RSR13, the hydrolysis product of the reaction between DD-1 and deoxygenated Hb, bound to the central water cavity of Hb. Also, the hydrolysis product, NO, was observed exclusively bound to the two α hemes, the first such HbNO structure to be reported, capturing the previously proposed physiological bis-ligated nitrosylHb species. Finally, nitrate was observed bound to βHis97. Ultraperformance liquid chromatography-mass spectrometry analysis of the compounds incubated with matrices used for the various studies demonstrated the presence of the predicted reaction products. Our findings, beyond the potential therapeutic application, provide valuable insights into the biotransformation of NO-releasing prodrugs and their mechanism of action and into hemoglobin-NO biochemistry at the molecular level.

Transformation of RAFT Polymer End Groups into Nitric Oxide Donor Moieties: En Route to Biochemically Active Nanostructures

Polymers with a terminal S-nitrosothiol moiety were synthesized by modifying the thiocarbonylthio end group formed by reversible addition-fragmentation chain transfer polymerization. Specifically, benzodithioate-terminated poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) was first synthesized by polymerizing OEGMA in the presence of 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid. Sequential treatment with hydrazine hydrate and a stoichiometric amount of nitrous acid resulted in the formation of S-nitrosothiol-terminated polymers. A similar approach was applied to block copolymers of POEGMA incorporating a domain of poly[(N,N-diisopropylamino)ethyl methacrylate], thus, enabling the preparation of pH responsive nitric oxide (NO)-releasing micelles. The micelles possessed substantially modified S-nitrosothiol loss kinetics compared to the hydrophilic homopolymer analogue. Moreover, thiol-triggered degradation of the S-nitrosothiol was significantly slower when the S-nitrosothiol was embedded in a micellar structure. These results demonstrate that it is possible to incorporate nitric oxide donor moieties directly onto a polymer chain end, enabling simple synthesis of biochemically active nanostructures.

Pre-Hypertension in Apparently Healthy Young Adults: Incidence and Influence of Haemoglobin Level

INTRODUCTION

Prehypertension is a precursor of clinical hypertension and consequently of the cardiovascular disease. Recent studies have found positive correlation between Haemoglobin Level (Hb) and Blood Pressure (BP). But the presumed association between Hb and BP has not been investigated in healthy young adults.

AIM

This study aimed to estimate the incidence of prehypertension and the influence of Hb level on BP in healthy young adults.

MATERIALS AND METHODS

This was a cross-sectional study done in 84 apparently healthy undergraduate medical students aged between 18-23 years, of either sex. In study subjects, BP and haemoglobin content was measured. Prehypertension was defined as BP levels of 120 to 139/80 to 89 mm Hg. Statistical analysis was done by unpaired t-test and Pearson correlation Coefficient tests.

RESULTS

Incidence of prehypertension was 50%. In 24% of the study subjects both systolic and diastolic BP was in prehypertensive state. In another 26% of study subjects only systolic BP was above normal. There was positive correlation between systolic BP and Hb level (p = 0.0015).

CONCLUSION

High incidence of prehypertension especially systolic prehypertension prevails inapparently healthy medical undergraduate students. In them, positive correlation between Hb and systolic BP persists.

NO supplementation for transfusion medicine and cardiovascular applications

Blood transfusions are used to treat reduced O₂-carrying capacity consequent to anemia. In many cases anemia is caused by a major blood loss, which also creates a state of hypovolemia. Whereas O₂ transport capacity is restored by increasing levels of circulating Hb, transfusion does not resolve the hypoperfusion, the hypoxia and the inflammatory cascades initiated during the anemia and hypovolemia. This explains why blood transfusion is not always an effective treatment and why transfusion of stored blood has been associated with increased morbidity and mortality, especially in patient populations receiving multiple transfusions. Epidemiologic data indicate that adverse events after transfusion are relatively common, having a great impact on the patients outcome and on the costs of public health. In this chapter, we explain why classical transfusion strategies target the reversal of hypoxia only, but do not address the inflammatory cascades initiated during anemic states and the importance of the flow and vascular endothelium interactions. We also establish the relation between red blood cells storage lesions, limited NO bioavailability and transfusion-associated adverse events. Lastly, we explain the potential use of long-lived sources of bioactive NO to reverse the hypoxic inflammatory cascades, promote a sustained increase in tissue perfusion and thereby allow transfusions to achieve their intended goal. The underlying premise is that adverse effects associated with transfusions are intimately linked to vascular dysfunction. Understanding of these mechanisms would lead to novel transfusion medicine strategies to preserve red cell function and to correct for functional changes induced by hemoglobinopathies that affect cell structure and function.

Evaluating the capacity to generate and preserve nitric oxide bioactivity in highly purified earthworm erythrocruorin: a giant polymeric hemoglobin with potential blood substitute properties

The giant extracellular hemoglobin (erythrocruorin) from the earth worm (Lumbricus terrestris) has shown promise as a potential hemoglobin-based oxygen carrier (HBOC) in in vivo animal studies. An important beneficial characteristic of this hemoglobin (LtHb) is the large number of heme-based oxygen transport sites that helps overcome issues of osmotic stress when attempting to provide enough material for efficient oxygen delivery. A potentially important additional property is the capacity of the HBOC either to generate nitric oxide (NO) or to preserve NO bioactivity to compensate for decreased levels of NO in the circulation. The present study compares the NO-generating and NO bioactivity-preserving capability of LtHb with that of human adult hemoglobin (HbA) through several reactions including the nitrite reductase, reductive nitrosylation, and still controversial nitrite anhydrase reactions. An assignment of a heme-bound dinitrogen trioxide as the stable intermediate associated with the nitrite anhydrase reaction in both LtHb and HbA is supported based on functional and EPR spectroscopic studies. The role of the redox potential as a factor contributing to the NO-generating activity of these two proteins is evaluated. The results show that LtHb undergoes the same reactions as HbA and that the reduced efficacy for these reactions for LtHb relative to HbA is consistent with the much higher redox potential of LtHb. Evidence of functional heterogeneity in LtHb is explained in terms of the large difference in the redox potential of the isolated subunits.

The capacity of red blood cells to reduce nitrite determines nitric oxide generation under hypoxic conditions

Nitric oxide (NO) is a key regulator of vascular tone. Endothelial nitric oxide synthase (eNOS) is responsible for NO generation under normoxic conditions. Under hypoxia however, eNOS is inactive and red blood cells (RBC) provide an alternative NO generation pathway from nitrite to regulate hypoxic vasodilation. While nitrite reductase activity of hemoglobin is well acknowledged, little is known about generation of NO by intact RBC with physiological hemoglobin concentrations. We aimed to develop and apply a new approach to provide insights in the ability of RBC to convert nitrite into NO under hypoxic conditions. We established a novel experimental setup to evaluate nitrite uptake and the release of NO from RBC into the gas-phase under different conditions. NO measurements were similar to well-established clinical measurements of exhaled NO. Nitrite uptake was rapid, and after an initial lag phase NO release from RBC was constant in time under hypoxic conditions. The presence of oxygen greatly reduced NO release, whereas inhibition of eNOS and xanthine oxidoreductase (XOR) did not affect NO release. A decreased pH increased NO release under hypoxic conditions. Hypothermia lowered NO release, while hyperthermia increased NO release. Whereas fetal hemoglobin did not alter NO release compared to adult hemoglobin, sickle RBC showed an increased ability to release NO. Under all conditions nitrite uptake by RBC was similar. This study shows that nitrite uptake into RBC is rapid and release of NO into the gas-phase continues for prolonged periods of time under hypoxic conditions. Changes in the RBC environment such as pH, temperature or hemoglobin type, affect NO release.

Interaction of body mass index and hemoglobin concentration on blood pressure among pregnant women in Guangxi, China

Background

Body mass index (BMI) and hemoglobin (Hb) are positively associated with hypertensive disorders among pregnant women. The aim of this study was to estimate a potential interaction between high BMI and high Hb concentrations on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in pregnancy.

Methods

We recruited 4497 single-birth women aged 18–43 years who received routine antenatal care at three hospitals of Guigang, Guangxi, China, from December 2007 to January 2011. Of 4497 participants, 3472 women were in the first trimester, with following up, 2986 women and 2261 women were left in the second and third trimester, respectively. Clinical data were derived from medical records of each woman. We used multivariable linear regression, by trimesters of pregnancy, to evaluate the associations of high BMI and high Hb concentrations with SBP and DBP according to cross-sectional design.

Results

In multivariable analyses, BMI was positively associated with SBP throughout all trimesters, but the corresponding association for Hb concentrations only in the first trimester, whereas both BMI and Hb concentrations were positively associated with DBP in the first and third trimesters. After full adjustment for confounding, the average differences in SBP and DBP comparing women with high BMI and high Hb to those with non-high BMI and non-high Hb were 2.9 mmHg (95% CI: 0.8 to 5.0 mmHg) and 3.9 mmHg (95% CI: 1.5 to 6.3 mmHg) in the first trimester, 2.6 mmHg (95% CI: 0.4 to 4.8 mmHg) and 1.5 mmHg (95% CI: -1.3 to 4.3 mmHg) in the second trimester, and 4.8 mmHg (95% CI: 2.3 to 7.4 mmHg) and 5.7 mmHg (95% CI: 3.2 to 8.3 mmHg) in the third trimester, respectively. With respect to the interaction, significant combined effects between high BMI and high Hb were confirmed on SBP (P = 0.02) and DBP (P = 0.004) in the third trimester, and the amount of interaction on SBP and DBP were 2.0 mmHg (95% CI: 0.1 to 3.9 mmHg) and 2.3 mmHg (95% CI: 0.4 to 4.3 mmHg), respectively.

Conclusion

Our findings suggest that high BMI and high Hb concentrations may have a synergistic effect on blood pressure in late stage of pregnancy.

Hemoglobin in normal range, the lower the better?-Evidence from a study from Chinese community-dwelling participants

OBJECTIVE

To examine the association between hemoglobin (Hb) levels and cardiovascular risk factors in a large community-dwelling cohort.

METHODS

A total of 4,186 women and 4,851 men were enrolled in the study. Data on personal history, physical examination and biochemical parameters were collected. Subjects were categorized by gender and divided into different group according to the level of Hb or blood pressure, and the association between Hb levels and cardiovascular risk factors was examined using Pearson's correlation analysis.

RESULTS

In both men and women even with normal Hb level, tertiles of Hb levels were positively associated with body mass index (BMI), total-cholesterol (TC), triglyceride (TG), uric acid (UA), diastolic blood pressures (DBP) and fasting plasma glucose (FPG) (all P=0.000 in men and women). Furthermore, significantly increased incidence of hyperuricemia (P=0.000 both in men and women) and obesity (P=0.000 both in men and women) were observed with the gradually increased Hb level. In addition, Pearson's correlation analysis revealed obvious correlation between Hb level and various cardiovascular risk factors including blood pressure and UA. Binary logistic regression analysis further demonstrated that the level of Hb was an important risk factor for elevated blood pressure (OR =1.216; 95% CI: 1.138-1.293, P=0.000 in men; OR =1.287; 95% CI: 1.229-1.363, P=0.000 in women).

CONCLUSIONS

Increasing Hb levels, even in subjects with normal level were associated with increasing prevalence of cardiovascular risk factors, suggesting that a slightly low Hb level might be beneficial to Chinese community-dwelling individuals.

Blood substitutes: evolution from noncarrying to oxygen- and gas-carrying fluids

The development of oxygen (O2)-carrying blood substitutes has evolved from the goal of replicating blood O2 transport properties to that of preserving microvascular and organ function, reducing the inherent or potential toxicity of the material used to carry O2, and treating pathologies initiated by anemia and hypoxia. Furthermore, the emphasis has shifted from blood replacement fluid to "O2 therapeutics" that restore tissue oxygenation to specific tissues regions. This review covers the different alternatives, potential and limitations of hemoglobin-based O2 carriers (HBOCs) and perfluorocarbon-based O2 carriers (PFCOCs), with emphasis on the physiologic conditions disturbed in the situation that they will be used. It describes how concepts learned from plasma expanders without O2-carrying capacity can be applied to maintain O2 delivery and summarizes the microvascular responses due to HBOCs and PFCOCs. This review also presents alternative applications of HBOCs and PFCOCs namely: 1) How HBOC O2 affinity can be engineered to target O2 delivery to hypoxic tissues; and 2) How the high gas solubility of PFCOCs provides new opportunities for carrying, dissolving, and delivering gases with biological activity. It is concluded that the development of current blood substitutes has amplified their applications horizon by devising therapeutic functions for O2 carriers requiring limited O2 delivery capacity restoration. Conversely, full, blood-like O2-carrying capacity reestablishment awaits the control of O2 carrier toxicity.

Generating S-nitrosothiols from hemoglobin: mechanisms, conformational dependence, and physiological relevance

In vitro, ferrous deoxy-hemes in hemoglobin (Hb) react with nitrite to generate nitric oxide (NO) through a nitrite reductase reaction. In vivo studies indicate Hb with nitrite can be a source of NO bioactivity. The nitrite reductase reaction does not appear to account fully for this activity because free NO is short lived especially within the red blood cell. Thus, the exporting of NO bioactivity both out of the RBC and over a large distance requires an additional mechanism. A nitrite anhydrase (NA) reaction in which N2O3, a potent S-nitrosating agent, is produced through the reaction of NO with ferric heme-bound nitrite has been proposed (Basu, S., Grubina, R., Huang, J., Conradie, J., Huang, Z., Jeffers, A., Jiang, A., He, X., Azarov, I., Seibert, R., Mehta, A., Patel, R., King, S. B., Hogg, N., Ghosh, A., Gladwin, M. T., and Kim-Shapiro, D. B. (2007) Nat. Chem. Biol. 3, 785-794) as a possible mechanism. Legitimate concerns, including physiological relevance and the nature of the mechanism, have been raised concerning the NA reaction. This study addresses these concerns demonstrating NO and nitrite with ferric hemes under near physiological conditions yield an intermediate having the properties of the purported NA heme-bound N2O3 intermediate. The results indicate that ferric heme sites, traditionally viewed as a source of potential toxicity, can be functionally significant, especially for partially oxygenated/partially met-R state Hb that arises from the NO dioxygenation reaction. In the presence of low levels of nitrite and either NO or a suitable reductant such as L-cysteine, these ferric heme sites can function as a generator for the formation of S-nitrosothiols such as S-nitrosoglutathione and, as such, should be considered as a source of RBC-derived and exportable bioactive NO.