Malarial infection induces tissue hypoxia in the host through destruction of red blood cells. Tissue hypoxia in malarial infection may increase the activity of HIF1α through an intracellular oxygen-sensing pathway. Activation of HIF1α may also induce vascular endothelial growth factor (VEGF) to trigger angiogenesis. To investigate whether malarial infection actually generates hypoxia-induced angiogenesis, we analyzed severity of hypoxia, the expression of hypoxia-related angiogenic factors, and numbers of blood vessels in various tissues infected with Plasmodium berghei. Infection in mice was performed by intraperitoneal injection of 2×10⁶ parasitized red blood cells. After infection, we studied parasitemia and survival. We analyzed hypoxia, numbers of blood vessels, and expression of hypoxia-related angiogenic factors including VEGF and HIF1α. We used Western blot, immunofluorescence, and immunohistochemistry to analyze various tissues from Plasmodium berghei-infected mice. In malaria-infected mice, parasitemia was increased over the duration of infection and directly associated with mortality rate. Expression of VEGF and HIF1α increased with the parasitemia in various tissues. Additionally, numbers of blood vessels significantly increased in each tissue type of the malaria-infected group compared to the uninfected control group. These results suggest that malarial infection in mice activates hypoxia-induced angiogenesis by stimulation of HIF1α and VEGF in various tissues.
Angiogenesis Inducing Agents ; Animals ; Anoxia ; Blood Vessels ; Blotting, Western ; Erythrocytes ; Fluorescent Antibody Technique ; Immunohistochemistry ; Injections, Intraperitoneal ; Malaria ; Mice ; Mortality ; Parasitemia ; Plasmodium ; Plasmodium berghei ; Vascular Endothelial Growth Factor A

Anoxia ; Brain ; Brain Ischemia ; Cell Death ; Cognition ; Hippocampus ; Ischemia ; Neuregulin-1 ; Neurons ; Neuroprotection ; Neuroprotective Agents

BACKGROUND: This study was conducted to identify the types and incidence of adverse events associated with midazolam, which is the most widely used drug to induce conscious sedation during gastrointestinal endoscopy, and to analyze the factors associated with hypoxemia and sedation failure.METHODS: Of 87,740 patients who underwent gastrointestinal endoscopy between February 2015 and May 2017, the electronic medical records of 335 who reportedly developed adverse events were retrospectively reviewed, and analysis was performed to determine the risk factors for hypoxemia and sedation failure, the two most frequent adverse events among those manifested during gastrointestinal endoscopy.RESULTS: The overall adverse event rate was 0.38% (n = 335); hypoxemia was most frequent, accounting for 40.7% (n = 90), followed by sedation failure (34.8%, n = 77), delayed discharge from the recovery room (22.1%, n = 49), and hypotension (2.2%, n = 5). Compared with the control group, the hypoxemia group did not show any significant differences in sex and body weight, but mean age was significantly older (P < 0.001) and a significantly lower dose of midazolam was administered (P < 0.001). In the group with sedation failure, the mean rate was higher in men (P < 0.001) and a significantly higher dose of midazolam was administered (P < 0.001), but no age difference was found.CONCLUSIONS: Midazolam-based conscious sedation during gastrointestinal endoscopy can lead to various adverse events. In particular, as elderly patients are at higher risk of developing hypoxemia, midazolam dose adjustment and careful monitoring are required in this group.
Aged ; Anoxia ; Body Weight ; Conscious Sedation ; Electronic Health Records ; Endoscopy, Gastrointestinal ; Humans ; Hypotension ; Incidence ; Male ; Midazolam ; Recovery Room ; Retrospective Studies ; Risk Factors

OBJECTIVE: Assessing the severity of injury and predicting outcomes are essential in traumatic brain injury (TBI). However, the respiratory rate and Glasgow Coma Scale (GCS) of the Revised Trauma Score (RTS) are difficult to use in the prehospital setting. This investigation aimed to develop a new prehospital trauma score for TBI (NTS-TBI) to predict mortality and disability.METHODS: We used a nationwide trauma database on severe trauma cases transported by fire departments across Korea in 2013 and 2015. NTS-TBI model 1 used systolic blood pressure < 90 mmHg, peripheral capillary oxygen saturation < 90% measured via pulse oximeter, and motor component of GCS. Model 2 comprised variables of model 1 and age >65 years. We assessed discriminative power via area under the curve (AUC) value for in-hospital mortality and disability defined according to the Glasgow Outcome Scale with scores of 2 or 3. We then compared AUC values of NTS-TBI with those of RTS.RESULTS: In total, 3,642 patients were enrolled. AUC values of NTS-TBI models 1 and 2 for mortality were 0.833 (95% confidence interval [CI], 0.815 to 0.852) and 0.852 (95% CI, 0.835 to 0.869), respectively, while AUC values for disability were 0.772 (95% CI, 0.749 to 0.796) and 0.784 (95% CI, 0.761 to 0.807), respectively. AUC values of NTS-TBI model 2 for mortality and disability were higher than those of RTS (0.819 and 0.761, respectively) (P < 0.01).CONCLUSION: Our NTS-TBI model using systolic blood pressure, motor component of GCS, oxygen saturation, and age was feasible for prehospital care and showed outstanding discriminative power for mortality.
Anoxia ; Area Under Curve ; Blood Pressure ; Brain Injuries ; Capillaries ; Fires ; Glasgow Coma Scale ; Glasgow Outcome Scale ; Hospital Mortality ; Humans ; Hypotension ; Korea ; Mortality ; Observational Study ; Oxygen ; Quality Improvement ; Respiratory Rate

Oxygen is required to sustain aerobic organisms. Reactive oxygen species (ROS) are constantly released during mitochondrial oxygen consumption for energy production. Any imbalance between ROS production and its scavenger system induces oxidative stress. Oxidative stress, a critical contributor to tissue damage, is well-known to be associated with various diseases. The kidney is susceptible to hypoxia, and renal hypoxia is a common final pathway to end stage kidney disease, regardless of the underlying cause. Renal hypoxia aggravates oxidative stress, and elevated oxidative stress, in turn, exacerbates renal hypoxia. Oxidative stress is also enhanced in chronic kidney disease, especially diabetic kidney disease, through various mechanisms. Thus, the vicious cycle between oxidative stress and renal hypoxia critically contributes to the progression of renal injury. This review examines recent evidence connecting chronic hypoxia and oxidative stress in renal disease and subsequently describes several promising therapeutic approaches against oxidative stress.
Anoxia ; Diabetic Nephropathies ; Kidney ; Kidney Failure, Chronic ; Oxidative Stress ; Oxygen ; Oxygen Consumption ; Reactive Oxygen Species ; Renal Insufficiency, Chronic

High-flow nasal oxygenation (HFNO) is a promising new technique for anesthesiologists. The use of HFNO during the induction of anesthesia and during upper airway surgeries has been initiated, and its applications have been rapidly growing ever since. The advantages of this technique include its easy set-up, high tolerability, and its abilities to produce positive airway pressure and a high fraction of inspired oxygen and to influence the clearance of carbon dioxide to some extent. HFNO, via a nasal cannula, can provide oxygen both to patients who can breathe spontaneously and to those who are apneic; further, this technique does not interfere with bag-mask ventilation, attempts at laryngoscopy for tracheal intubation, and surgical procedures conducted in the airway. In this review, we describe the techniques associated with HFNO and the advantages and disadvantages of HFNO based on the current state of knowledge.
Airway Management ; Anesthesia ; Anoxia ; Carbon Dioxide ; Catheters ; Humans ; Intubation ; Intubation, Intratracheal ; Laryngoscopy ; Oxygen ; Ventilation

OBJECTIVES: Hypoxia—a characteristic of almost all types of solid tumors—has been associated with poor outcomes in several human malignancies. Genipin—an active constituent of Gardenia fruit— has been reported to exert an anti-tumor effect in several cancers. In this study, we investigated inhibition of angiogenesis using Genipin-mediated hypoxia-induced hypoxia inducible factor (HIF-1) and VEGF expression in human cervical cancer cells.METHODS: Under normoxic and hypoxic conditions, the expression of HIF-1α and VEGF in cervical cancer HeLa cells was detected by quantitative reverse transcription polymerase chain reaction and western blotting. Luciferase reporter assays were used to investigate the molecular mechanisms underlying the hypoxia-induced survivin activation.RESULTS: Surprisingly, we found that Genipin suppressed the HIF-1α accumulation during hypoxia in human liver cancer cell line (HepG2), human prostate cancer cell line (LNCaP), colon cancer cell line (HCT116), and breast cancer cell line (MDA231). Genipin treatment also significantly reduced hypoxia-induced secretion of VEGF.CONCLUSIONS: Suppression of HIF-1α accumulation following treatment with Genipin under hypoxia was associated with PI3K and MAPK pathways. Taken together, these results suggested that Genipin inhibits HIF-1α expression through inhibition of PI3K and MAPK signaling pathways. These results provide new insights into a potential mechanism of the anticancer properties of Genipin.
Anoxia ; Blotting, Western ; Breast Neoplasms ; Cell Line ; Colonic Neoplasms ; Gardenia ; HeLa Cells ; Humans ; Liver Neoplasms ; Luciferases ; Polymerase Chain Reaction ; Prostatic Neoplasms ; Reverse Transcription ; Uterine Cervical Neoplasms ; Vascular Endothelial Growth Factor A

BACKGROUND: Low temperature plasma (LTP) was recently shown to be potentially useful for biomedical applications such as bleeding cessation, cancer treatment, and wound healing, among others. Keratinocytes are a major cell type that migrates directionally into the wound bed, and their proliferation leads to complete wound closure during the cutaneous repair/regeneration process. However, the beneficial effects of LTP on human keratinocytes have not been well studied. Therefore, we investigated migration, growth factor production, and cytokine secretion in primary human keratinocytes after LTP treatment.METHODS: Primary cultured keratinocytes were obtained from human skin biopsies. Cell viability was measured with the EZ-Cytox cell viability assay, cell migration was evaluated by an in vitro wound healing assay, gene expression was analyzed by quantitative real-time polymerase chain reaction, and protein expression was measured by enzyme-linked immunosorbent assays and western blotting after LTP treatment.RESULTS: Cell migration, the secretion of several cytokines, and gene and protein levels of angiogenic growth factors increased in LTP-treated human keratinocytes without associated cell toxicity. LTP treatment also significantly induced the expression of hypoxia inducible factor-1α (HIF-1α), an upstream regulator of angiogenesis. Further, the inhibition of HIF-1α expression blocked the production of angiogenic growth factors induced by LTP in human keratinocytes.CONCLUSION: Our results suggest that LTP treatment is an effective approach to modulate wound healing-related molecules in epidermal keratinocytes and might promote angiogenesis, leading to improved wound healing.
Anoxia ; Biopsy ; Blotting, Western ; Cell Migration Assays ; Cell Movement ; Cell Survival ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; Hemorrhage ; Humans ; In Vitro Techniques ; Intercellular Signaling Peptides and Proteins ; Keratinocytes ; Plasma ; Real-Time Polymerase Chain Reaction ; Skin ; Wound Healing ; Wounds and Injuries

BACKGROUND: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. METHODS: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). RESULTS: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen (FiO2) ratio was higher (97 vs. 61, p<0.001) while the median FiO2 was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02–0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. CONCLUSION: Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.
Adult ; Anoxia ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Humans ; Intensive Care Units ; Korea ; Lung ; Mortality ; Multicenter Studies as Topic ; Multivariate Analysis ; Oxygen ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Retrospective Studies ; Ventilation ; Ventilators, Mechanical

PURPOSE: The aim of this study was to investigate whether propofol could attenuate hypoxia/reoxygenation-induced apoptosis and autophagy in human renal proximal tubular cells (HK-2) by inhibiting JNK activation. MATERIALS AND METHODS: HK-2 cells were treated with or without propofol or JNK inhibitor SP600125 for 1 hour and then subjected to 15 hours of hypoxia and 2 hours of reoxygenation (H/R). Cell viability and LDH release were measured with commercial kits. Cell apoptosis was evaluated by flow cytometry. The expressions of p-JNK, cleaved-caspase-3, Bcl-2, and autophagy markers LC3 and p62 were measured by Western blot or immunofluorescence. RESULTS: HK-2 cells exposed to H/R insult showed higher cell injury (detected by increased LDH release and decreased cell viability), increased cell apoptosis index and expression of cleaved-caspase-3, a decrease in the expression of Bcl-2 accompanied by increased expression of p-JNK and LC3II, and a decrease in expression of p62. All of these alterations were attenuated by propofol treatment. Similar effects were provoked upon treatment with the JNK inhibitor SP600125. Moreover, the protective effects were more obvious with the combination of propofol and SP600125. CONCLUSION: These results suggest that propofol could attenuate hypoxia/reoxygenation induced apoptosis and autophagy in HK-2 cells, probably through inhibiting JNK activation.
Anoxia ; Apoptosis ; Autophagy ; Blotting, Western ; Cell Survival ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Propofol