Medical Gas Research最新文献

Acrylonitrile is a potential carcinogen for humans, and exposure to this substance can cause adverse effects for workers. This study aimed to carcinogenic and health risk assessment of acrylonitrile vapor exposure in exposed personnel of a petrochemical complex. This crosssectional study was performed in 2019 in a petrochemical complex. In this study, to sample and determine acrylonitrile's respiratory exposure, the method provided by the National Institute of Occupational Safety and Health (NIOSH 1601) was used, and a total of 45 inhaled air samples were sampled from men workers, aged 39.43 ± 9.37 years. All subjects' mean exposure to acrylonitrile vapors was 71.1 ± 122.8 μg/m³. Also, the mean exposure index among all subjects was 0.02 ± 0.034. The non-carcinogenic risk assessment results showed that the mean Hazard quotient index was 4.04 ± 6.93. The mean lifetime cancer risk index was also 2.1 × 10^-3 ± 3.5 × 10^-3 and was in the definite risk range. Considering that both carcinogenicity and health indicators of exposure to acrylonitrile in the studied petrochemical complex are more than the recommended limits, the necessary engineering and management measures to control and manage the risk to an acceptable level are essential to improving the worker's health.

Nitric oxide can activate neutrophils and macrophages, facilitate the synthesis of collagen, which allows significantly accelerating the regeneration of traumatized tissues. We studied the effects of nitric oxide-containing gas flow generated by plasma-chemical device "Plason" in a rat model of full-thickness wounds. Histological and morphometric analyses revealed that Plason treated wounds expressed significantly fewer signs of inflammation and contained a more mature granulation tissue on day 4 after the operation. Considering the results of the experimental study, we applied the Plason device in sports medicine for the treatment of lower limb bruises of 34 professional soccer players. Athletes were asked to assess the intensity of pain with the Visual Analogue Scale. Girths of their lower limbs were measured over the course of rehabilitation. Nitric oxide therapy of full-thickness wounds inhibited inflammation and accelerated the regeneration of skin and muscle tissues. Compared with the control, we observed a significant reduction in pain syndrome on days 2-7 after injuries, edema, and hematoma, and shortened treatment duration. This pilot study indicates that the use of nitric oxide is a promising treatment method for sports injuries.

Molecular hydrogen (H₂) is an antioxidant and anti-inflammatory agent; however, the molecular mechanisms underlying its biological effects are largely unknown. Similar to other gaseous molecules such as inhalation anesthetics, H₂ is more soluble in lipids than in water. A recent study demonstrated that H₂ reduces radical polymerization-induced cellular damage by suppressing fatty acid peroxidation and membrane permeability. Thus, we sought to examine the effects of short exposure to H₂ on lipid composition and associated physiological changes in SH-SY5Y neuroblastoma cells. We analyzed cells by liquid chromatography-high-resolution mass spectrometry to define changes in lipid components. Lipid class analysis of cells exposed to H₂ for 1 hour revealed transient increases in glycerophospholipids including phosphatidylethanolamine, phosphatidylinositol, and cardiolipin. Metabolomic analysis also showed that H₂ exposure for 1 hour transiently suppressed overall energy metabolism accompanied by a decrease in glutathione. We further observed alterations to endosomal morphology by staining with specific antibodies. Endosomal transport of cholera toxin B to recycling endosomes localized around the Golgi body was delayed in H₂-exposed cells. We speculate that H₂-induced modification of lipid composition depresses energy production and endosomal transport concomitant with enhancement of oxidative stress, which transiently stimulates stress response pathways to protect cells.

Therapeutic use of ozone is becoming increasingly prevalent worldwide. New methods of administration are emerging. One of these emerging techniques, which we refer to as ozone dialysis, uses a dialysis membrane that allows blood to flow against a countercurrent of ozone gas. We found that ozone uptake by continuous countercurrent blood flow is at least 3 times higher than any comparable form of blood ozone administration currently available. This is the first quantitative report of ozone uptake by blood using the ozone dialysis technique.

Diabetic peripheral neuropathy (DPN) is a complex disorder caused by long-standing diabetes. Oxidative stress was considered the critical creed in this DPN pathophysiology. Hydrogen has antioxidative effects on diabetes mellitus and related complications. However, there is still no concern on the beneficial effects of hydrogen in DPN. This paper aimed to evaluate the effects of exogenous hydrogen to reduce the severity of DPN in streptozotocin-induced diabetic rats. Compared with hydrogen-rich saline treatment, hydrogen inhalation significantly reduced blood glucose levels in diabetic rats in the 4^th and 8^th weeks. With regard to nerve function, hydrogen administration significantly attenuated the decrease in the velocity of motor nerve conduction in diabetic animals. In addition, hydrogen significantly attenuated oxidative stress by reducing the level of malondialdehyde, reactive oxygen species, and 8-hydroxy-2-deoxyguanosine and meaningfully enhanced the antioxidant capability by partially restoring the activities of superoxide dismutase. Further studies showed that hydrogen significantly upregulated the expression of nuclear factor erythroid-2-related factor 2 and downstream proteins such as catalase and hemeoxygenase-1 in the nerves of diabetic animals. Our paper showed that hydrogen exerts significant protective effects in DPN by downregulating oxidative stress via the pathway of nuclear factor erythroid-2-related factor 2, which suggests its potential value in clinical applications.

Molecular hydrogen (H₂) has been considered a preventive and therapeutic medical gas in numerous diseases. The study aimed to investigate the potential role of molecular hydrogen as a component of anesthesia in surgical treatment with cardiopulmonary bypass (CPB) of acquired valve defects on the functional state of red blood cells (RBC) and functional indicators of cardiac activity. This clinical trial was conducted with 20 patients referring to the Specialized Cardiosurgical Clinical Hospital, Nizhny Novgorod, Russian Federation, who underwent elective surgery with CPB. Twenty-four patients were randomly assigned to two groups. First group included 12 patients (research group) who received H₂ at a concentration of 1.5-2.0% through a facemask using a breathing circuit of the ventilator together with anesthesia immediately after tracheal intubation and throughout the operation. Second group (control group) included 12 patients who were not given H₂. Blood samples were withdrawn from peripheral veins and radial artery at four stages: immediately after the introduction of anesthesia (stage 1), before the start of CPB (stage 2), immediately after its termination (stage 3) and 24 hours after the operation (the early postoperative period) (stage 4). An increase in electrophoretic mobility, an increase in the metabolism of red blood cells, and a decrease in the aggregation of red blood cells relative to the corresponding indicators of the control group were observed in the research group. Patients in the research group had a decrease in oxidative stress manifestations most pronounced one day after the operation. There was a statistically significant difference between the indicators of myocardial contractile function in the research and control group on the 1^st and 3^rd days after surgery. H₂ inhalation leads to improvement of functional state of red blood cells, which is accompanied by a more favorable course of the early postoperative period. These data show the presence of protective properties of molecular hydrogen.

Most of the drugs used in modern medical treatments are symptomatic treatments and are far from being a cure for the diseases. The adverse effects are unavoidable in the drugs in modern medical treatments. Molecular hydrogen (H₂) has a remarkable therapeutic effect on various diseases, and many clinical studies have reported that H₂ has no adverse effects. Therefore, H₂ is a novel medical gas that is outside the concept of modern medical treatment. H₂, unlike drugs, works on the root of many diseases by scavenging the two kinds of strong reactive oxygen species, hydroxyl radical (·OH) and peroxynitrite (ONOO^-). Since the H₂ alleviates the root of diseases and can treat many diseases at the same time, the medical application of H₂ may be called "machine gun therapy." In this review, we demonstrated that the root of many diseases is based on ·OH-induced oxidative stress in the mitochondria, and at the same time, the root of chronic inflammation is also attributed to ·OH.

Despite the fact that we have reported on the dangers of the explosion of hydrogen gas inhalers, hydrogen gas inhalers with explosive hazards are, as a matter of fact, still being sold today. In this study, we investigated past reports of hydrogen gas inhaler explosion accidents to clarify the causes of these explosion incidents. As a result of this investigation, we found that the central cause was the leakage of hydrogen gas inside the hydrogen gas inhaler. Although it is said that the explosive concentration of hydrogen is between 10% and 75%, and that the gas does not explode above 75% due to the lack of oxygen, we confirmed through a series of ignition experiments that explosions can occur even in hydrogen gas inhalers that produce 100% hydrogen gas. Some manufacturers of such highly concentrated hydrogen gas inhalers claim that the high concentration and purity of hydrogen is safe and that there is no risk of explosion. We believe that manufacturing or selling such products that pose a risk of explosion or detonation is a violation of social justice. This paper presents ideas for selecting safe hydrogen gas inhalers based on a survey of past accident cases.

Ventilation with positive end-expiratory pressure (PEEP) may result in decreased venous return to the heart and therefore decrease cardiac output. We evaluated the influence of PEEP ventilation on arterial blood pressure in the field in 296 posttraumatic intubated patients being treated by a helicopter emergency medical service in a retrospective cohort study. Initial systolic blood pressure on the scene, upon hospital admission and their mean difference were compared between patients being ventilated with no/low PEEP (0-0.3 kPa) and moderate PEEP (0.3-1 kPa). In a subgroup analysis of initially hemodynamic unstable patients (systolic blood pressure < 80 mmHg), systolic blood pressure was compared between patients being ventilated with no/low or moderate PEEP Further, the mean difference between initial systolic blood pressure and upon hospital admission was correlated with the chosen PEEP. Systolic arterial blood pressure of patients being ventilated with no/low PEEP improved from 105 ± 36 mmHg to 112 ± 38 mmHg, and that of patients being ventilated with moderate PEEP improved from 105 ± 38 mmHg to 119 ± 27 mmHg. In initially unstable patients being ventilated with no/low PEEP systolic blood pressure improved from initially 55 ± 36 mmHg to 78 ± 30 mmHg upon hospital admission, and in those being ventilated with moderate PEEP, the systolic blood pressure improved from 43 ± 38 mmHg to 91 ± 27 mmHg. There was no significant correlation between the chosen PEEP and the mean difference of systolic blood pressure (Pearson's correlation, r = 0.07, P = 0.17). Ventilation with moderate PEEP has no adverse effect on arterial systolic blood pressure in this cohort of trauma patients requiring mechanical ventilation. Initially unstable patients being ventilated with moderate PEEP tend to be hemodynamically more stable.