Relationship between severity of adult community-acquired pneumonia and impairment of the antioxidant defense system

Bioavailability of bioactive phytochemicals in selected tissues and excreta from goats fed hempseed cake (Cannabis sativa L.) finisher diets

Hempseeds are rich in bioactive phytochemicals, yet little is known about their bioavailability in tissues and excreta of animals fed hemp seed cake. The study evaluated the bioactive phytochemicals and their antioxidant activity in the blood, liver, meat, feces, and urine from goats fed finishing diets containing graded inclusions of hempseed cake (HSC). Twenty-five wether goats (26.8 ± 2.9 kg) of 4-5 months were randomly allocated to five experimental diets containing increasing levels of HSC (0, 25, 50, 75, 100 g/kg DM) substituted for soybean meal (SBM) as the main protein source. Goats were allowed for period of 21 days for adaptation, and blood, fecal, and urine samples were collected on the 28th day of the experiment. The liver and right longissimus thoracis et lumborum were respectively collected at 60 min and 24 h after slaughter. Linear increases (P ≤ 0.05) in blood, liver, and urine magnesium; fecal manganese; and fecal copper were observed with increasing HSC inclusion in the diet. Liver and fecal selenium exhibited a decreasing linear trend (P ≤ 0.05) with HSC increment in diets. Diet did not affect (P > 0.05) meat and urine mineral contents, except urine magnesium. The 2,2-diphenyl-1-picrylhydrazyl, and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) of the blood, liver, and meat linearly increased (P ≤ 0.05) with dietary inclusion of HSC. Blood and liver ferric reducing antioxidant power quadratically increased (P ≤ 0.05) with HSC inclusion reaching a maximum at 50 g/kg dry matter. Current results suggest that inclusion of HSC up to 100 g/kg substituting SBM in goat diets can improve bioavailability of bioactive phytochemicals in the blood, liver, and meat.

Pneumonia-Induced Inflammation, Resolution and Cardiovascular Disease: Causes, Consequences and Clinical Opportunities

Pneumonia is inflammation in the lungs, which is usually caused by an infection. The symptoms of pneumonia can vary from mild to life-threatening, where severe illness is often observed in vulnerable populations like children, older adults, and those with preexisting health conditions. Vaccines have greatly reduced the burden of some of the most common causes of pneumonia, and the use of antimicrobials has greatly improved the survival to this infection. However, pneumonia survivors do not return to their preinfection health trajectories but instead experience an accelerated health decline with an increased risk of cardiovascular disease. The mechanisms of this association are not well understood, but a persistent dysregulated inflammatory response post-pneumonia appears to play a central role. It is proposed that the inflammatory response during pneumonia is left unregulated and exacerbates atherosclerotic vascular disease, which ultimately leads to adverse cardiac events such as myocardial infarction. For this reason, there is a need to better understand the inflammatory cross talk between the lungs and the heart during and after pneumonia to develop therapeutics that focus on preventing pneumonia-associated cardiovascular events. This review will provide an overview of the known mechanisms of inflammation triggered during pneumonia and their relevance to the increased cardiovascular risk that follows this infection. We will also discuss opportunities for new clinical approaches leveraging strategies to promote inflammatory resolution pathways as a novel therapeutic target to reduce the risk of cardiac events post-pneumonia.

Serum Level of 4-Hydroxynonenal in Community-Acquired Pneumonia: A Potential Biomarker for Severity and Prognosis

Background

Four-hydroxynonenal (4-HNE) exerts a central role in the pathophysiological process of pulmonary diseases. The aim of this project was to evaluate the correlations between serum 4-HNE with severity and prognosis in patients with community-acquired pneumonia (CAP) by a prospective cohort study.

Materials and Methods

A total of 239 patients with CAP and healthy volunteers were recruited. Fasting blood was collected. Serum 4-HNE was measured with ELISA. Clinical characteristics and demographic information were obtained. The relationships between serum 4-HNE and clinical characteristics were evaluated through the Spearman or Pearson correlation coefficient. The associations of serum 4-HNE with severity and prognosis were estimated through logistic regression analysis.

Results

On admission, serum 4-HNE was upregulated in patients with CAP compared with healthy volunteers. Serum 4-HNE was gradually increased in line with CAP scores. Additionally, elderly patients with CAP were more prone to suffer from 4-HNE elevation. Moreover, serum 4-HNE was positively correlated with CAP severity scores. Meanwhile, the poor prognostic outcomes were tracked among patients with CAP. Higher serum 4-HNE on admission increased the risks of mechanical ventilation, vasoactive agent usage, and death in patients with CAP during hospitalization. The predictive powers for severity and death were increased in serum 4-HNE compared with CAP severity scores and inflammatory cytokines.

Conclusion

Serum 4-HNE on admission is positively correlated with the severity and poor prognosis among patients with CAP, indicating that 4-HNE participates in the pathophysiology of CAP. Serum 4-HNE may be used as an earlier biomarker for diagnosis and prognosis in patients with CAP.

Pathophysiology of Acute Respiratory Failure by CoV-2 Infection: Role of Oxidative Stress, Endothelial Dysfunction and Obesity

Coronavirus disease 2019 (COVID-19) due to CoV-2 (coronavirus type 2) virus possess a particular risk of developing acute respiratory distress syndrome (ARDS) or SARS (severe acute respiratory syndrome coronavirus 2)-CoV2 in people with pre-existing conditions related to endothelial dysfunction and increased pro-inflammatory and pro-oxidant state. In between these conditions, chronic systemic inflammation related to obese patients is associated with the development of atherosclerosis, type 2 diabetes, and hypertension, comorbidities that adversely affect the clinical outcome in critical patients with COVID-19. Obesity affects up to 40% of the general population in the USA and more than 30% of the adult population in Chile. Until April 2021, 1,019,478 people have been infected, with 23,524 deaths. Given the coexistence of this worldwide obesity epidemic, COVID-19 negative outcomes are seriously enhanced in the current scenario. On the other hand, obesity is characterized by endothelial dysfunction observed in different vascular beds, an alteration which can be associated with impaired vasodilation, oxidative stress, and inflammatory events. Emerging evidence shows that obesity-related conditions such as endothelial dysfunction are associated with detrimental outcomes for COVID-19 evolution, especially if the patient derives to Intensive Care Units (ICU). This implies the need to understand the pathophysiology of the infection in the obese population, in order to propose therapeutic alternatives and public health policies, especially if the virus remains in the population. In this review, we summarize evidence about the pathogeny of Cov-2 infection in obese individuals and discuss how obesity-associated inflammatory and prooxidant status increase the severity of COVID-19.

Diabetes and COVID-19: Mechanism of pneumonia, treatment strategy and vaccine

As of August 5, 2021, there were about 200,000,000 global confirmed patients of COVID-19, with more than 4,250,000 deaths. The COVID-19 disease which is a tremendous public health threat, jumps unpredictably and outbreaks very quickly. The overall mortality rate of COVID-19 infection is 1%-15% but reaches up to 17-38% in older cases with chronic disorders and in intensive care unit (ICU) subjects. Diabetic patients, particularly those whose disease is not well controlled can be more susceptible to COVID-19. Although diabetes was present in 5.3%-42.3% of fatalities from COVID-19, the underlying pathophysiological mechanisms of action of novel coronavirus in diabetic patients are unknown. Based on the elevating of global prevalence, diabetes is the main medical problem associated with COVID-19. It is plausible that diabetes can forecast elevated severity of pneumonia. The mortality of lung infection among diabetes is remarkably higher compared with non-diabetic patients. Mechanisms responsible for severe pneumonia in the diabetic patients as well as treatment of diabetic patients infected with COVID-19 are largely speculative. Hence, this paper will summarize the recent findings related to the mechanisms of pneumonia and treatment strategies in diabetic patients.

Infectious Lung Diseases and Endogenous Oxidative Stress

Lower respiratory tract infections, according to the World Health Organization, account for nearly one third of all deaths from infectious diseases. They account for approximately 4 million deaths annually including children and adults and provide a greater disease burden than HIV and malaria. Among the common respiratory diseases, tuberculosis, influenza, and pneumonia are very common and can be life threatening if not treated properly. The causative agent of tuberculosis is the slow-growing bacilli Mycobacterium tuberculosis, while the causative agent of influenza is a segmented genome RNA virus. Pneumonia can be caused by a number of different microorganisms like bacteria, virus, and mycoplasma. In case of the entry of a pathogen in our body, the immune system gets activated, and the phagocytic cells try to eliminate it by generating reactive oxygen and nitrogen species (ROS and RNS) inside the phagosome. These reactive species or respiratory bursts are sufficient to eliminate most of the pathogens, except a few. M. tuberculosis is one such microorganism that has evolved mechanisms to escape this respiratory burst-mediated killing and thus survive and grow inside the macrophages. Infection with M. tuberculosis leads to the destruction of macrophages and release of cytokines, which lead to prolonged immune activation and oxidative stress. In some cases, the bacilli remain dormant inside macrophages for a long time. Flu viruses infect the epithelial cells present in respiratory tract, and the infection site is dependent on the hemagglutinin protein present on their capsid. Destruction of epithelial cells promotes secretion of mucus and activation of immune system leading to the oxidative damage. Community-acquired pneumonia is more serious and difficult to treat. In all these infections, ROS/RNS are developed as a defense mechanism against the pathogen. Persistence of the pathogen for a long time would lead to the uncontrolled production of ROS/RNS which will lead to oxidative stress and tissue damage to the host. Administration of antioxidants along with conventional treatments can be useful in the elimination of the reactive oxygen and nitrogen species.

N-acetylcysteine improves oxidative stress and inflammatory response in patients with community acquired pneumonia: A randomized controlled trial

Oxidative stress is considered to be part of the pathogenic mechanism for community-acquired pneumonia (CAP) and is closely linked to inflammation. Attenuation of oxidative stress would be expected to reduce pulmonary damage. Antioxidants have been found to be effective in alleviating lung injury and protecting against damage of other organs.The aim of the study was to compare the effect of adding N-acetylcysteine (NAC) to conventional treatment versus conventional treatment on oxidative stress, inflammatory factors, and radiological changes in CAP patients.Eligible CAP patients at Weihai Municipal Hospital were stratified and randomly assigned to either NAC group or non-NAC group between August 2016 and March 2017. The NAC group received conventional treatment for pneumonia and NAC (1200 mg/d). Thenon-NAC group received conventional therapy. malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAOC), tumor necrosis factor-α (TNF-α), and computed tomography (CT) images were evaluated at baseline and after treatment. The primary endpoint indicators were the changes in oxidative stress parameters (MDA, TAOC, SOD) and TNF-α after treatment in the NAC group compared with those in the non-NAC group. The secondary endpoint indicator was any difference in CT scores after treatment in the NAC group compared with the non-NAC group.Baseline levels of MDA, TAOC, SOD, and TNF-α were similar between the 2 groups before treatment. Plasma levels of MDA and TNF-α decreased more (P < .05 MDA:p 0.004, TNF-α:p <0.001) in the NAC group than the non-NAC group, and there was a reliable increase in TAOC content (p 0.005). There was no significant difference in increased plasma SOD activity between the groups (p 0.368), and the NAC group did not show a greater improvement from CT scores. No NAC-related adverse effects were observed.Addition of NAC therapy for CAP patients reduced MDA and TNF-α and increased TAOC. Treatment with NAC may help to reduce oxidative and inflammatory damage in pneumonia patients.

Evaluation of dynamic thiol/disulfide redox state in community-acquired pneumonia

Objectives

To compare dynamic thiol/disulfide homeostasis between patients with community-acquired pneumonia (CAP) and healthy controls.

Methods

This prospective, case-control study was conducted in the Department of Pulmonary Diseases, Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, Ankara, Turkey, between August 2016 and August 2017. In total, 50 hospitalized patients with CAP and 35 healthy individuals were enrolled. Patients with comorbidities and smokers were excluded. The thiol/disulfide state was evaluated in each group. Thiol levels (native/total) and % polymorhonuclear leukocytes and C-reactive protein levels association were evaluated in patients with CAP.

Results

There was no significant difference between the CAP and control groups in age or gender (both, p>0.05). The disulfide (SS) levels were similar between the 2 groups (p=0.148). The total thiol (TT) and native thiol (SH) levels were significantly lower (all, p=0.001) and the SS/TT levels were significantly higher (p=0.019) in the CAP group compared with the controls.

Conclusions

This study showed that the oxidant/antioxidant ratio was shifted to the oxidative side in CAP patients. An abnormal thiol/disulfide state may be an important factor in the pathogenesis and monitoring the treatment response. The thiol resources may use for treatment in CAP and may positively affect the prognosis.

Evaluation of dynamic thiol/disulfide homeostasis in adult patients with community-acquired pneumonia

Background:

Community-acquired pneumonia is an important cause of mortality and morbidity in all age groups. Oxidant and antioxidant mechanisms play an important role in the pathogenesis and mortality of community-acquired pneumonia.

Objectives:

In this study, the role of thiol/disulfide homeostasis in the diagnosis and prognosis of community-acquired pneumonia was investigated.

Methods:

This was a prospective, controlled, observational study involving 73 community-acquired pneumonia patients and 68 healthy volunteers.

Results:

The native thiol and total thiol, which are thiol/disulfide homeostasis components, were significantly lower in the community-acquired pneumonia group. It was also found that the native thiol was lower in the high-risk community-acquired pneumonia group and that the native thiol and total thiol were associated with the Pneumonia Severity Index, CRB65 (confusion, respiratory rate, blood pressure, ⩾65 years old), and CURB65 (confusion, uremia, respiratory rate, blood pressure, ⩾65 years old) scores. The thiol compound levels were also associated with the C-reactive protein and procalcitonin levels. However, there was no significant difference between the survivors and non-survivors in terms of the thiol/disulfide homeostasis parameters.

Conclusion:

This study demonstrated the important role that oxidative stress plays in the pathogenesis of community-acquired pneumonia. The thiol/disulfide homeostasis biomarkers especially the native thiol and index-1 levels were significantly lower in patients with community-acquired pneumonia. Further studies are needed to investigate the diagnostic and prognostic value of thiol/disulfide homeostasis parameters in community-acquired pneumonia.

Characteristic of the Oxidative Stress in Blood of Patients in Dependence of Community-Acquired Pneumonia Severity

BACKGROUND

At the present time the alternation of the oxidative metabolism is considered as one of the leading pathogenic mechanisms in the development and progression of community-acquired pneumonia (CAP). However the nature and direction of the oxidative protein changes in CAP patient's blood had been almost unexplored.

AIM

To define oxidative and modified proteins in erythrocytes and blood plasma of CAP patients.

MATERIAL AND METHODS

Blood plasma and erythrocytes obtained from: 42 patients with moderate severity pneumonia, 12 patients with grave severity pneumonia and 32 healthy volunteers. Content of advanced oxidation protein products, malondialdehyde and reactive carbonyl derivatives were estimated as indicators of the oxidative stress and oxidative damage of proteins.

RESULTS

In patients with grave severity the level of oxidative proteins and MDA in erythrocytes exceeded both: control values and similar meanings in CAP patients with moderate severity. The further growth of MDA in this group patients' blood plasma was observed, but the level of oxidative proteins decreased in comparison with those in CAP patients with moderate severity.

CONCLUSION

To sum up, our derived data show, that injury of erythrocytes' redox-status and blood plasma components plays an essential role in development and progression CAP.

Oxidative stress and inflamatory plasma biomarkers in respiratory syncytial virus bronchiolitis

INTRODUCTION

Oxidative stress (OS) plays a crucial role in the pathogenesis of inflammatory lung diseases.

OBJECTIVES

(i) We determined whether acute bronchiolitis (AB) caused by respiratory syncytial virus (RSV) induced OS; (ii) assessed whether OS biomarkers correlated with the severity of RSV-AB; and (iii) studied whether the levels of interleukins are associated with OS biomarkers.

METHODS

We performed an observational study by comparing healthy infants (Group 1) with RSV-AB infants, classified as Group 2 (pulse oximetry (SpO₂ ) >93%), and Group 3 (SpO₂  ≤ 92%), which needed oxygen therapy. Blood samples were collected to determine the levels of lipid peroxidation (LPO) products (LPO), total glutathione (TG), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), interleukins (ILs) IL-10, IL-6, IL-8, interferon-gamma (IFNγ), tumour necrosis factor-alpha (TNFα) and macrophage inflammatory proteins (MIP α and MIP β).

RESULTS

Forty-six RSV-AB infants (47% needed oxygen therapy) and 27 healthy infants were included. The GSH/GSSG ratio was lower in RSV-AB infants than in Group 1 (P<0.001). GSSG and GPx were significantly higher in Group 3. GSSG predicted the need for oxygen therapy with an optimal cut-off point of 15 µM/g for haemoglobin. The GSH/GSSG ratio negatively correlated with IL-6 (P: 0.014), IL-8 (P: 0.014) and IL-10 (P: 0.033). Group 3 exhibited a direct correlation between GPx and IL-10 levels (P: 0.024) and between LPO and MIP β (P: 0.003).

CONCLUSIONS

RSV induced OS in AB. An increase in GSSG correlated with the disease severity in the infants. OS may contribute to the pathogenesis of RSV-AB.