Medical Gas Research最新文献

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.

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.

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.

Demyelination of the cerebral white matter is the most common pathological change after carbon monoxide (CO) poisoning. Notch signaling, the mechanism underlying the differentiation of astrocytes and oligodendrocytes, is critical to remyelination of the white matter after brain lesion. The purpose of this work was to determine the effects of hyperbaric oxygen (HBO) on Notch signaling pathway after CO poisoning for the explanation of the protective effects of HBO on CO-poisoning-related cerebral white matter demyelination. The male C57 BL/6 mice with severe CO poisoning were treated by HBO. And HBO therapy shortened the escape latency and improved the body mass after CO poisoning. HBO therapy also significantly suppressed protein and mRNA levels of Notch1 and Hes5 after CO poisoning. Our findings suggested that HBO could suppress the activation of Notch signaling pathway after CO poisoning, which is the mechanism underlying the neuroprotection of HBO on demyelination after severe CO poisoning.

Cerebral ischemia/reperfusion injury is an important factor leading to poor prognosis in ischemic stroke patients. Therefore, it is particularly important to find effective remedial measures to promote the health of patients to return to society. Isoflurane is a safe and reliable anesthetic gas with a long history of clinical application. In recent years, its protection function to human body has been widely recognized, and nowadays isoflurane for cerebral protection has been widely studied, and the stable effect of isoflurane has satisfied many researchers. Basic studies have shown that isoflurane's protection of brain tissue after ischemia/reperfusion involves a variety of signaling pathways and effector molecules. Even though many signaling pathways have been described, more and more studies focus on exploring their mechanisms of action, in order to provide strong evidence for clinical application. This could prompt the introduction of isoflurane therapy to clinical patients as soon as possible. In this paper, several confirmed signaling pathways will be reviewed to find possible strategies for clinical treatment.

This trial-based paper strives to address the comparative efficacy of some ropivacaine adjuvant options, comprising dexmedetomidine, granisetron, and nitroglycerin, on pain and hemodynamic changes in intravenous anesthesia for forearm surgeries. This double-blind, placebo-controlled study enrolled four block-randomized eligible groups with patients (overall, n=128) undergoing orthopedic forearm surgeries in the dexmedetomidine, nitroglycerin, granisetron, and placebo groups. Intra- and post-operative vital signs (mean arterial pressure/heart rate/ oxygen saturation) were monitored at baseline and captured every 10 minutes until the end of the surgery, as well as the onset of sensory and motor block and length and duration of the block and mean opioid use within 24 hours. Lastly, pain was noted after tourniquet inflation (at 15, 30, and 45 minutes every 15 minutes until the end of surgery) and after deflation (every 30 minutes to 2 hours at 30, 60, 90, and 120 minutes), as well as 6, 12, and 24 hours after the tourniquet was deflated. The dexmedetomidine-sedated subjects appeared to demonstrate quicker onset and longer length and duration of sensory and motor block, plus less pain and opioid use at all scheduled times (both P = 0.0001). Dexmedetomidine is recommended as an adjuvant to regional anesthesia (Bier's block), while being coupled with the rapid onset and prolonged length and duration of sensory and motor blocks, in addition to soothed pain and diminished opioid use within postoperative 24 hours. The study was approved by Ethics Committee of Arak University of Medical Sciences (approval No. IR.ARAKMU.REC.1398.112) on July 21, 2019, and registered at Iranian Registry of Clinical Trials (registration number IRCT20141209020258N123) on November 2, 2019.

This study was aimed to investigate the effects of different fresh gas (oxygen + air) flow rates and different anesthetics on airway temperature and humidity when using the same anesthesia machine in patients undergoing general anesthesia. In this prospective, observational study, 240 patients with American Society of Anesthesiologists (ASA) I-II between the age of 18-65 years to be operated under general anesthesia were enrolled and divided into two groups according to the fresh gas flow rate (3-6 L/min). Each of the two main groups was further divided into three subgroups according to the administered anesthetic gases and drugs. The resulting six groups were further divided into two subgroups according to whether the heat and humidity exchanger filter (HME) was attached to the breathing circuit, and the study was carried out on a total of 12 groups. The temperature and humidity of the inspired air were recorded every 10 minutes using an electronic thermo-hygrometer. The inspired temperature and humidity were greater in patients ventilated at 3 L/min compared to the 6 L/min group and in HME (+) patients compared to HME (-), regardless of the type of anesthetics. HME application makes the air more physiological for the respiratory tract by increasing the temperature and humidity of the air regardless of the anesthetic agent. This study was approved by Ethics Committee Review of Selcuk University Faculty of Medicine (No. 2017/261) in September 2017, and was registered in the Clinical Trial Registry (identifier No. NCT04204746) on December 19, 2019.