Carbon dioxide (CO2) is a pivotal environmental signal that influences the physiology, development and pathogenic potential of fungi. Beyond its role as a metabolic by-product, CO2 functions as a conserved signaling molecule that enables fungal pathogens to sense and adapt to host niches. This review synthesizes current knowledge on how fluctuations in CO2 concentration modulate growth dynamics, morphogenesis, virulence-associated attributes and antifungal susceptibility in clinically important yeasts and filamentous fungi. In Candida species, particularly Candida albicans, physiological CO2 levels encountered in host tissues (~5%) act as a potent morphogenetic signal, driving the yeast-to-hypha transition, promoting biofilm formation and inducing metabolic reprogramming; processes tightly linked to tissue invasion and persistence. CO2 exposure also alters membrane composition and stress response pathways, thereby modulating susceptibility to antifungal agents. In Cryptococcus neoformans, elevated CO2 concentrations promote capsule biosynthesis and enlargement, alongside extensive remodeling of surface architecture and membrane composition. These CO2-driven adaptations strengthen resistance to host immune defenses and are associated with increased tolerance to antifungals. In Aspergillus species, CO2 availability influences growth, mycotoxin biosynthesis and developmental trajectories by shifting the balance between asexual and sexual reproduction, with downstream effects on virulence and antifungal responsiveness. In Scedosporium/Lomentospora species, CO2 promotes conidial germination and developmental transitions that may indirectly impact antifungal susceptibility and pathogenic fitness. Collectively, these findings highlight environmental CO2 as a pivotal and dynamic regulator of fungal biology, offering key insights into host-pathogen interactions, informing the prediction of antifungal susceptibility profiles and supporting the rational optimization of therapeutic strategies in clinical settings.

JOURNAL/mgres/04.03/01612956-202609000-00003/figure1/v/2026-01-06T135433Z/r/image-tiff Lumbar disc herniation complicated by lumbar spinal stenosis is a common degenerative condition in spinal surgery, particularly among middle-aged and elderly individuals. Conservative treatments or open surgery are commonly used but often have limited efficacy or significant risks, especially in older patients. Oxygen-ozone therapy, known for its mechanical decompression, anti-inflammatory, analgesic, and neuroprotective effects, is gaining attention as a minimally invasive treatment for lumbar disc herniation, offering an alternative to traditional treatments. Therefore, this study aimed to evaluate the clinical therapeutic effect of computed tomography-guided percutaneous oxygen-ozone injection on lumbar disc herniation complicated by lumbar spinal stenosis. This retrospective study analyzed the clinical outcomes of 47 patients with lumbar disc herniation complicated by lumbar spinal stenosis who were treated between September 2023 and February 2024. Patients were divided into two groups: the ozone group received computed tomography-guided percutaneous oxygen-ozone injection ( n = 25), and the caudal epidural steroid injection group underwent ultrasound-guided ( n = 22). Pain relief and functional outcomes were assessed preoperatively and at 1 day, 1 month, 3 months, and 6 months postoperatively using the visual analog scale, and Oswestry Disability Index and modified MacNab criteria. Both groups showed significant reduction in visual analog scale and Oswestry Disability Index at 1 day and 1 month postoperatively compared with preoperatively ( P < 0.05), with the ozone group demonstrating more pronounced improvements than the caudal epidural steroid injection group. At 3 months, although further improvement was observed in both groups, the differences in visual analog scale and Oswestry Disability Index between the two groups were not statistically significant ( P > 0.05). By 6 months, the ozone group showed significantly greater improvements than the caudal epidural steroid injection group ( P < 0.05). The total effective rate based on modified MacNab criteria increased over time in both groups. Although the ozone group exhibited a slightly higher rate, the difference was not statistically significant ( P > 0.05). Computed tomography-guided oxygen-ozone injection provides sustained pain relief and functional recovery in lumbar disc herniation with lumbar spinal stenosis, demonstrating superior long-term efficacy to epidural steroids.

JOURNAL/mgres/04.03/01612956-202606000-00006/figure1/v/2025-08-18T154854Z/r/image-tiff Although mitochondria and related proteins are essential for mitochondrial preservation, the functions of some of these proteins remain unknown. The novel protein oxidoreductase-like domain containing 1 (OXLD1/C17orf90, UniProtKB Q5BKU9) have attracted our attention because of its correlation with mitochondria. This study revealed a decrease in OXLD1 levels in cardiomyocytes cultured in 1% oxygen for 24 hours. Suppressing OXLD1 increases mitochondrial injury under both normoxic and hypoxic conditions. This is evidenced by decreased mitochondrial membrane potential and increased reactive oxygen species production. Meanwhile, suppressing OXLD1 decreased mitochondrial oxidative phosphorylation. Overexpression of OXLD1 decreased mitochondrial injury under normoxia and hypoxia, as indicated by an increase in the mitochondrial membrane potential and a decrease in reactive oxygen species production. Moreover, overexpression of OXLD1 enhanced mitochondrial oxidative phosphorylation. Additionally, we found that OXLD1 regulates mitochondrial oxidative phosphorylation by affecting mitochondrial complexes I and V. OXLD1 plays a crucial role in protecting cardiomyocytes by improving mitochondrial function under low-oxygen conditions. OXLD1 achieves this protection through interactions with mitochondrial complexes I and V. Therefore, OXLD1 may serve as a new and important regulator of mitochondrial function.

Gas-induced spinal cord compression, also known as intraspinous pneumorrhachis, is a rare condition in which the presence of gas in the spinal canal generally does not result in any symptoms. However, in certain cases, gas can compress the spinal cord, leading to severe neurological dysfunction. This underscores the importance of early recognition and intervention. Herein, we conduct a comprehensive analysis of the literature on pneumorrhachis by searching databases such as PubMed, ClinicalKey, Web of Science, and CNKI. We discuss the etiology, pathophysiology, clinical manifestations, imaging features, differential diagnosis, treatment strategies, and prognosis of these patients. Our findings indicate that the occurrence of intraspinous pneumorrhachis is associated with various factors, including medical conditions, trauma, and infection. While most cases are limited in extent and resolve spontaneously, a subset of cases may signal a serious underlying condition.

JOURNAL/mgres/04.03/01612956-202603000-00002/figure1/v/2025-06-28T140100Z/r/image-tiff Paroxysmal sympathetic hyperactivity syndrome (PSH) is common in patients with severe craniocerebral injuries. Carbon monoxide poisoning (ACOP) may lead to secondary PSH, and hyperbaric oxygen (HBO) is an important treatment method for ACOP that can promote the dissociation of carboxyhemoglobin and reduce the long-term sequelae of ACOP. To explore the risk factors and clinical characteristics of PSH secondary to acute ACOP and to investigate the efficacy of HBO treatment, a retrospective analysis was performed on patients with moderate to severe ACOP admitted to the Hyperbaric Oxygen Department of Beijing Chaoyang Hospital, Capital Medical University, from January 1, 2018 to December 31, 2024. Three patients developed PSH during hospitalization and were classified into the PSH group, while the remaining 50 patients were in the non-PSH group. Univariate Fisher's exact test indicated that a coma duration of more than 72 hours was related to the occurrence of PSH after ACOP, and irregular HBO treatment after onset might be associated with the occurrence of PSH after ACOP. All three PSH patients developed paroxysmal postural or dystonic disorders after onset, accompanied by sympathetic excitation manifestations such as increased heart rate, respiratory rate, elevated blood pressure, and fever. Antiepileptic drugs had poor effects, and the attacks were effectively controlled after HBO treatment combined with adjusted drug therapy. The results indicate that for patients with severe carbon monoxide poisoning, especially those with a long coma duration or irregular HBO treatment after onset, if epileptic seizures occur during the disease course and are accompanied by sympathetic excitation manifestations, the possibility of PSH should be considered. Regular HBO treatment is of great significance for controlling the onset of symptoms.

Numerous physiological processes in the human skin are mediated by nitric oxide, a gaseous signalling molecule. Almost every type of skin cell may produce nitric oxide, it is possible to generate nitric oxide without the need of enzymes. Nitric oxide plays a crucial role in regulating apoptosis, keratinocyte differentiation and proliferation, the protective properties of the epidermal barrier, and the structure and functions of the microcirculatory bed. Nitric oxide is involved in immunological and inflammatory responses, hair growth regulation, and wound healing processes. It mediates ultraviolet-induced processes such as erythema and edema development and participates in melanogenesis. Furthermore, the ability of nitric oxide to bind reactive oxygen species and prevent lipid peroxidation gives it antioxidant qualities. This coordinated action of nitric oxide on gene expression and membrane integrity effectively protects cells from ultraviolet A-induced apoptosis and necrosis. Furthermore, nitric oxide can be considered as a molecule that inhibits the development of cancer and photoaging. It directly harms microorganisms and indirectly activates the immune system, exhibiting antibacterial, antiviral, and antifungal qualities. Notably, nitric oxide is effective against antibiotics-resistant bacteria. All of the aforementioned findings suggest that nitric oxide is a gaseous mediator that can protect skin function.