Low-Flow Nasal Cannula Hydrogen Therapy

Diagnosis, Progress, and Treatment Update of Kawasaki Disease

Kawasaki disease (KD) is an acute inflammatory disorder that primarily affects children and can lead to coronary artery lesions (CAL) if not diagnosed and treated promptly. The original clinical criteria for diagnosing KD were reported by Dr. Tomisaku Kawasaki in 1967 and have been used for decades. However, research since then has highlighted the limitations of relying solely on these criteria, as they might lead to underdiagnosis or delayed diagnosis, potentially increasing the risk of coronary artery complications. This review appears to discuss several important aspects related to KD diagnosis and management. The current diagnostic methods for KD might need updates, especially considering cases that do not fit the typical clinical criteria. Recognizing diagnostic pitfalls and distinguishing KD from other conditions that might have similar clinical presentations is essential. The differences and similarities between KD and Multisystem Inflammatory Syndrome in Children (MIS-C), another inflammatory condition that has been associated with COVID-19, were also reviewed. The review explores the potential role of eosinophil count, new biomarkers, microRNA panels, and scoring systems in aiding the diagnosis of KD. Overall, the review article provides a comprehensive overview of the evolving landscape of KD diagnosis and management, incorporating new diagnostic methods, biomarkers, and treatment approaches to improve patient outcomes and reduce the risk of complications.

Pharmacokinetics of hydrogen administered intraperitoneally as hydrogen-rich saline and its effect on ischemic neuronal cell death in the brain in gerbils

Intraperitoneal administration of hydrogen (H2)-containing saline inhibited neuronal cell death in ischemic stroke in a number of animal models, but it is unknown whether H2 is absorbed from the abdominal cavity into the blood and reaches the brain. In this study, we investigated whether intraperitoneal administration of saline containing H2 inhibits neuronal cell death caused by cerebral ischemia and measured the concentration of H2 in the carotid artery and inferior vena cava (IVC). Gerbils were subjected to transient unilateral cerebral ischemia twice, and saline or H2-rich saline was administered intraperitoneally three or seven times every 12 hours. We evaluated the number of apoptotic cells in the hippocampus and cerebral cortex on day 3 and the number of viable neurons in the hippocampus and cerebral cortex on day 7. In addition, a single dose of saline or H2-rich saline was administered intraperitoneally, and blood H2 levels in the carotid artery and IVC were measured. On day 3 of ischemia/reperfusion, the number of neurons undergoing apoptosis in the cortex was significantly lower in the H2-rich saline group than in the saline group, and on day 7, the number of viable neurons in the hippocampus and cerebral cortex was significantly higher in the H2-rich saline group. Intraperitoneal administration of H2-rich saline resulted in large increases in H2 concentration in the IVC ranging from 0.00183 mg/L (0.114%) to 0.00725 mg/L (0.453%). In contrast, carotid H2 concentrations remained in the range of 0.00008 mg/L (0.0049%) to 0.00023 (0.0146%). On average, H2 concentrations in carotid artery were 0.04 times lower than in IVC. These results indicate that intraperitoneal administration of H2-rich saline significantly suppresses neuronal cell death after cerebral ischemia, even though H2 hardly reaches the brain.

Molecular Hydrogen Positively Affects Physical and Respiratory Function in Acute Post-COVID-19 Patients: A New Perspective in Rehabilitation

Molecular hydrogen (H₂) is potentially a novel therapeutic gas for acute post-coronavirus disease 2019 (COVID-19) patients because it has antioxidative, anti-inflammatory, anti-apoptosis, and antifatigue properties. The aim of this study was to determine the effect of 14 days of H₂ inhalation on the respiratory and physical fitness status of acute post-COVID-19 patients. This randomized, single-blind, placebo-controlled study included 26 males (44 ± 17 years) and 24 females (38 ± 12 years), who performed a 6-min walking test (6 MWT) and pulmonary function test, specifically forced vital capacity (FVC) and expiratory volume in the first second (FEV1). Symptomatic participants were recruited between 21 and 33 days after a positive polymerase chain reaction test. The experiment consisted of H₂/placebo inhalation, 2 × 60 min/day for 14 days. Results showed that H₂ therapy, compared with placebo, significantly increased 6 MWT distance by 64 ± 39 m, FVC by 0.19 ± 0.24 L, and, in FEV1, by 0.11 ± 0.28 L (all p ≤ 0.025). In conclusion, H₂ inhalation had beneficial health effects in terms of improved physical and respiratory function in acute post-COVID-19 patients. Therefore, H₂ inhalation may represent a safe, effective approach for accelerating early function restoration in post-COVID-19 patients.

H2 Inhibits the Formation of Neutrophil Extracellular Traps

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NETs have been implicated as therapeutic targets to address inflammation and thrombotic tissue damage in conditions such as sepsis, acute respiratory disease syndrome, COVID-19, and CVDs.

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H₂ has been clinically and experimentally proven to ameliorate inflammation; however, the underlying molecular mechanisms remain elusive.

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Compared with control neutrophils, PMA-stimulated human neutrophils exposed to H₂ exhibited reduced citrullination of histones and release of NET components; mechanistically, H₂-mediated neutralization of HOCl produced during oxidative bursts suppresses DNA damage.

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Inhalation of H₂ inhibited the formation and release of NET components in the blood and BAL of the LPS-induced sepsis in mice and aged mini pigs.

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H₂ therapy is potentially a new therapeutic strategy for inflammatory diseases involving NETs associated with excessive neutrophil activation.

Neutrophil extracellular traps (NETs) contribute to inflammatory pathogenesis in numerous conditions, including infectious and cardiovascular diseases, and have attracted attention as potential therapeutic targets. H₂ acts as an antioxidant and has been clinically and experimentally proven to ameliorate inflammation. This study was performed to investigate whether H₂ could inhibit NET formation and excessive neutrophil activation. Neutrophils isolated from the blood of healthy volunteers were stimulated with phorbol-12-myristate-13-acetate (PMA) or the calcium ionophore A23187 in H₂-exposed or control media. Compared with control neutrophils, PMA- or A23187-stimulated human neutrophils exposed to H₂ exhibited reduced neutrophil aggregation, citrullination of histones, membrane disruption by chromatin complexes, and release of NET components. CXCR4^high neutrophils are highly prone to NETs, and H₂ suppressed Ser-139 phosphorylation in H2AX, a marker of DNA damage, thereby suppressing the induction of CXCR4 expression. H₂ suppressed both myeloperoxidase chlorination activity and production of reactive oxygen species to the same degree as N-acetylcysteine and ascorbic acid, while showing a more potent ability to inhibit NET formation than these antioxidants do in PMA-stimulated neutrophils. Although A23187 formed NETs in a reactive oxygen species–independent manner, H₂ inhibited A23187-induced NET formation, probably via direct inhibition of peptidyl arginine deiminase 4-mediated histone citrullination. Inhalation of H₂ inhibited the formation and release of NET components in the blood and bronchoalveolar lavage fluid in animal models of lipopolysaccharide-induced sepsis (mice and aged mini pigs). Thus, H₂ therapy can be a novel therapeutic strategy for NETs associated with excessive neutrophil activation.

Pharmacokinetics of hydrogen after ingesting a hydrogen-rich solution: A study in pigs

Drinking hydrogen (H₂)-rich water is a common way to consume H₂. Although many studies have shown efficacy of drinking H₂-rich water in neuropsychiatric and endocrine metabolic disorders, their authenticity has been questioned because none examined the associated pharmacokinetics of H₂. Therefore, we performed the first study to investigate the pharmacokinetics of H₂ in pigs given an H₂-rich glucose solution with the aim to extrapolate the findings to humans. We inserted blood collection catheters into the jejunal and portal veins, suprahepatic inferior vena cava, and carotid artery of 4 female pigs aged 8 weeks. Then, within 2 min we infused 500 ml of either H₂-rich or H₂-free glucose solution into the jejunum via a percutaneous gastrostomy tube and measured changes in H₂ concentration in venous and arterial blood over 120 min. After infusion of the H₂-rich glucose solution, H₂ concentration in the portal vein peaked at 0.05 mg/L and remained at more than 0.016 mg/L (H₂ saturation level, 1%) after 1 h; it also increased after infusion of H₂-free glucose solution but remained below 0.001 mg/L (H₂ saturation level, 0.06%). We assume that H₂ was subsequently metabolized in the liver or eliminated via the lungs because it was not detected in the carotid artery. In conclusion, drinking highly concentrated H₂-rich solution within a short time is a good way to increase H₂ concentration in portal blood and supply H₂ to the liver.

Chemical and Biochemical Aspects of Molecular Hydrogen in Treating Kawasaki Disease and COVID-19

Kawasaki disease (KD) is a systemic vasculitis and is the most commonly acquired heart disease among children in many countries, which was first reported 50 years ago in Japan. The 2019 coronavirus disease (COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) has been a pandemic in most of the world since 2020, and since late 2019 in China. Kawasaki-like disease caused by COVID-19 shares some symptoms with KD, referred to as multisystem inflammatory syndrome in children, and has been reported in the United States, Italy, France, England, and other areas of Europe, with an almost 6-10 times or more increase compared with previous years of KD prevalence. Hydrogen gas is a stable and efficient antioxidant, which has a positive effect on oxidative damage, inflammation, cell apoptosis, and abnormal blood vessel inflammation. This review reports the chemical and biochemical aspects of hydrogen gas inhalation in treating KD and COVID-19.