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Fulltext Mechanisms for Combined Hypoxic Conditioning and Divergent Exercise Modes to Regulate Inflammation, Body Composition, Appetite, and Blood Glucose Homeostasis in Overweight and Obese Adults: A Narrative Review

Tee CCL, Cooke MB, Chong MC, Yeo WK, Camera DM

Sports Med, 2023 Feb;53(2):327-348.
PMID: 36441492 DOI: 10.1007/s40279-022-01782-0

Obesity is a major global health issue and a primary risk factor for metabolic-related disorders. While physical inactivity is one of the main contributors to obesity, it is a modifiable risk factor with exercise training as an established non-pharmacological treatment to prevent the onset of metabolic-related disorders, including obesity. Exposure to hypoxia via normobaric hypoxia (simulated altitude via reduced inspired oxygen fraction), termed hypoxic conditioning, in combination with exercise has been increasingly shown in the last decade to enhance blood glucose regulation and decrease the body mass index, providing a feasible strategy to treat obesity. However, there is no current consensus in the literature regarding the optimal combination of exercise variables such as the mode, duration, and intensity of exercise, as well as the level of hypoxia to maximize fat loss and overall body compositional changes with hypoxic conditioning. In this narrative review, we discuss the effects of such diverse exercise and hypoxic variables on the systematic and myocellular mechanisms, along with physiological responses, implicated in the development of obesity. These include markers of appetite regulation and inflammation, body conformational changes, and blood glucose regulation. As such, we consolidate findings from human studies to provide greater clarity for implementing hypoxic conditioning with exercise as a safe, practical, and effective treatment strategy for obesity.

Matched MeSH terms: Anoxia
Fulltext Molybdenum cofactor deficiency in a Malaysian child

Ngu LH, Afroze B, Chen BC, Affandi O, Zabedah MY

Singapore Med J, 2009 Oct;50(10):e365-7.
PMID: 19907877

Molybdenum cofactor deficiency is a rare autosomal recessive disorder with devastating neurological manifestations, characterised by neonatal-onset encephalopathy mimicking hypoxic-ischaemic insult, intractable seizure, and feeding and respiratory difficulties. It is often fatal in the early life. We report an affected 8-year-old boy, who presented with severe neurological manifestations since birth, but without clinically-significant seizure. Molybdenum cofactor deficiency must be included in the differential diagnosis of patients presenting with unexplained encephalopathy in the newborn period, and whose neuroimaging findings are consistent with hypoxic ischaemic encephalopathy. The classic laboratory hallmark of this disorder is low serum uric acid, positive urine sulphite dipstick test, and elevated urinary S-sulphocysteine, hypoxanthine and xanthine.

Matched MeSH terms: Anoxia/pathology
Fulltext Association of Unrecognized Obstructive Sleep Apnea With Postoperative Cardiovascular Events in Patients Undergoing Major Noncardiac Surgery

Chan MTV, Wang CY, Seet E, Tam S, Lai HY, Chew EFF, et al.

JAMA, 2019 May 14;321(18):1788-1798.
PMID: 31087023 DOI: 10.1001/jama.2019.4783

IMPORTANCE: Unrecognized obstructive sleep apnea increases cardiovascular risks in the general population, but whether obstructive sleep apnea poses a similar risk in the perioperative period remains uncertain.
OBJECTIVES: To determine the association between obstructive sleep apnea and 30-day risk of cardiovascular complications after major noncardiac surgery.
DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study involving adult at-risk patients without prior diagnosis of sleep apnea and undergoing major noncardiac surgery from 8 hospitals in 5 countries between January 2012 and July 2017, with follow-up until August 2017. Postoperative monitoring included nocturnal pulse oximetry and measurement of cardiac troponin concentrations.
EXPOSURES: Obstructive sleep apnea was classified as mild (respiratory event index [REI] 5-14.9 events/h), moderate (REI 15-30), and severe (REI >30), based on preoperative portable sleep monitoring.
MAIN OUTCOMES AND MEASURES: The primary outcome was a composite of myocardial injury, cardiac death, heart failure, thromboembolism, atrial fibrillation, and stroke within 30 days of surgery. Proportional-hazards analysis was used to determine the association between obstructive sleep apnea and postoperative cardiovascular complications.
RESULTS: Among a total of 1364 patients recruited for the study, 1218 patients (mean age, 67 [SD, 9] years; 40.2% women) were included in the analyses. At 30 days after surgery, rates of the primary outcome were 30.1% (41/136) for patients with severe OSA, 22.1% (52/235) for patients with moderate OSA, 19.0% (86/452) for patients with mild OSA, and 14.2% (56/395) for patients with no OSA. OSA was associated with higher risk for the primary outcome (adjusted hazard ratio [HR], 1.49 [95% CI, 1.19-2.01]; P = .01); however, the association was significant only among patients with severe OSA (adjusted HR, 2.23 [95% CI, 1.49-3.34]; P = .001) and not among those with moderate OSA (adjusted HR, 1.47 [95% CI, 0.98-2.09]; P = .07) or mild OSA (adjusted HR, 1.36 [95% CI, 0.97-1.91]; P = .08) (P = .01 for interaction). The mean cumulative duration of oxyhemoglobin desaturation less than 80% during the first 3 postoperative nights in patients with cardiovascular complications (23.1 [95% CI, 15.5-27.7] minutes) was longer than in those without (10.2 [95% CI, 7.8-10.9] minutes) (P

Matched MeSH terms: Anoxia/complications
Fulltext The oncolytic activity of Newcastle disease virus in clear cell renal carcinoma cells in normoxic and hypoxic conditions: the interplay between von Hippel-Lindau and interferon-β signaling

Ch'ng WC, Stanbridge EJ, Yusoff K, Shafee N

J Interferon Cytokine Res, 2013 Jul;33(7):346-54.
PMID: 23506478 DOI: 10.1089/jir.2012.0095

Viral-mediated oncolysis is a promising cancer therapeutic approach offering an increased efficacy with less toxicity than the current therapies. The complexity of solid tumor microenvironments includes regions of hypoxia. In these regions, the transcription factor, hypoxia inducible factor (HIF), is active and regulates expression of many genes that contribute to aggressive malignancy, radio-, and chemo-resistance. To investigate the oncolytic efficacy of a highly virulent (velogenic) Newcastle disease virus (NDV) in the presence or absence of HIF-2α, renal cell carcinoma (RCC) cell lines with defective or reconstituted wild-type (wt) von Hippel-Lindau (VHL) activity were used. We show that these RCC cells responded to NDV by producing only interferon (IFN)-β, but not IFN-α, and are associated with increased STAT1 phosphorylation. Restoration of wt VHL expression enhanced NDV-induced IFN-β production, leading to prolonged STAT1 phosphorylation and increased cell death. Hypoxia augmented NDV oncolytic activity regardless of the cells' HIF-2α levels. These results highlight the potential of oncolytic NDV as a potent therapeutic agent in the killing of hypoxic cancer cells.

Matched MeSH terms: Anoxia/immunology; Anoxia/therapy*
Fulltext Evidence of Coronavirus (CoV) Pathogenesis and Emerging Pathogen SARS-CoV-2 in the Nervous System: A Review on Neurological Impairments and Manifestations

Jha NK, Ojha S, Jha SK, Dureja H, Singh SK, Shukla SD, et al.

J Mol Neurosci, 2021 Nov;71(11):2192-2209.
PMID: 33464535 DOI: 10.1007/s12031-020-01767-6

The coronavirus disease 2019 (COVID-19) pandemic is an issue of global significance that has taken the lives of many across the world. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for its pathogenesis. The pulmonary manifestations of COVID-19 have been well described in the literature. Initially, it was thought to be limited to the respiratory system; however, we now recognize that COVID-19 also affects several other organs, including the nervous system. Two similar human coronaviruses (CoV) that cause severe acute respiratory syndrome (SARS-CoV-1) and Middle East respiratory syndrome (MERS-CoV) are also known to cause disease in the nervous system. The neurological manifestations of SARS-CoV-2 infection are growing rapidly, as evidenced by several reports. There are several mechanisms responsible for such manifestations in the nervous system. For instance, post-infectious immune-mediated processes, direct virus infection of the central nervous system (CNS), and virus-induced hyperinflammatory and hypercoagulable states are commonly involved. Guillain-Barré syndrome (GBS) and its variants, dysfunction of taste and smell, and muscle injury are numerous examples of COVID-19 PNS (peripheral nervous system) disease. Likewise, hemorrhagic and ischemic stroke, encephalitis, meningitis, encephalopathy acute disseminated encephalomyelitis, endothelialitis, and venous sinus thrombosis are some instances of COVID-19 CNS disease. Due to multifactorial and complicated pathogenic mechanisms, COVID-19 poses a large-scale threat to the whole nervous system. A complete understanding of SARS-CoV-2 neurological impairments is still lacking, but our knowledge base is rapidly expanding. Therefore, we anticipate that this comprehensive review will provide valuable insights and facilitate the work of neuroscientists in unfolding different neurological dimensions of COVID-19 and other CoV associated abnormalities.

Matched MeSH terms: Anoxia/etiology; Anoxia/physiopathology
Fulltext Tolerance and safety to colonoscopy with conscious sedation in Malaysian adults

Ma WT, Mahadeva S, Quek KF, Goh KL

Med J Malaysia, 2007 Oct;62(4):313-8.
PMID: 18551936 MyJurnal

Tolerance to colonoscopy varies between populations and data from the South East Asian region is lacking. We aimed to determine tolerance and safety with to colonoscopy; conscious sedation and identify risk factors for complications in Malaysian adults. Consecutive outpatients undergoing colonoscopy were enrolled prospectively. A combination of pethidine and midazolam were used and tolerance to colonoscopy assessed three hours post-procedure using a validated scale. All patients were monitored for cardiorespiratory depression and risk factors for complications were identified. Two hundred and eight patients (mean age 57.2 +/- 14.8 years, 48% female) were enrolled. The population ethnicity consisted of 45 (21.63%) Malays, 101 (48.56%) Chinese and 56 (26.92%) Indians. Conscious sedation was achieved with 5.0 +/- 1.1 mg of midazolam and 43.3 +/- 14.0 mg of pethidine. Thirty (14.4%) patients tolerated the procedure poorly and independent predictors included female gender (OR 2.93, 95% CI = 1.22 to 7.01) and a prolonged duration of procedure (OR 2.85, 95% CI = 1.08 to 7.48). Hypotension occurred in 13 (6.25%) patients, with age > 65 years as the only risk factor (OR 13.17, 95% CI = 1.28 to 137.92). A prolonged duration was the main cause of hypoxia (OR 5.49, 95% CI = 1.54 to 19.49), which occurred in 6 (2.88%) patients. No major complications occurred during the study period. The current practice of conscious sedation is safe and tolerated well by most adults in our population. However, poor tolerance in a notable minority may have significant clinical implications.

Study site: Division of Gastroenterology, Department of Medicine, University Malaya Medical Centre (UMMC)

Matched MeSH terms: Anoxia/etiology
Drawbacks in using hypercapnic acidosis in preoperative children with single ventricle physiology

Prakash ES

J Appl Physiol (1985), 2008 06;104(6):1841.
PMID: 18584792 DOI: 10.1152/japplphysiol.zdg-7979-pcpcomm.2008
Matched MeSH terms: Anoxia/physiopathology
The combined effect of hypoxia and nutritional status on metabolic and ionoregulatory responses of common carp (Cyprinus carpio)

Moyson S, Liew HJ, Diricx M, Sinha AK, Blust R, De Boeck G

Comp Biochem Physiol A Mol Integr Physiol, 2015 Jan;179:133-43.
PMID: 25263807 DOI: 10.1016/j.cbpa.2014.09.017

In the present study, the combined effects of hypoxia and nutritional status were examined in common carp (Cyprinus carpio), a relatively hypoxia tolerant cyprinid. Fish were either fed or fasted and were exposed to hypoxia (1.5-1.8mg O2L(-1)) at or slightly above their critical oxygen concentration during 1, 3 or 7days followed by a 7day recovery period. Ventilation initially increased during hypoxia, but fasted fish had lower ventilation frequencies than fed fish. In fed fish, ventilation returned to control levels during hypoxia, while in fasted fish recovery only occurred after reoxygenation. Due to this, C. carpio managed, at least in part, to maintain aerobic metabolism during hypoxia: muscle and plasma lactate levels remained relatively stable although they tended to be higher in fed fish (despite higher ventilation rates). However, during recovery, compensatory responses differed greatly between both feeding regimes: plasma lactate in fed fish increased with a simultaneous breakdown of liver glycogen indicating increased energy use, while fasted fish seemed to economize energy and recycle decreasing plasma lactate levels into increasing liver glycogen levels. Protein was used under both feeding regimes during hypoxia and subsequent recovery: protein levels reduced mainly in liver for fed fish and in muscle for fasted fish. Overall, nutritional status had a greater impact on energy reserves than the lack of oxygen with a lower hepatosomatic index and lower glycogen stores in fasted fish. Fasted fish transiently increased Na(+)/K(+)-ATPase activity under hypoxia, but in general ionoregulatory balance proved to be only slightly disturbed, showing that sufficient energy was left for ion regulation.

Matched MeSH terms: Anoxia/metabolism*
Involvement of TRPM2 Channel on Hypoxia-Induced Oxidative Injury, Inflammation, and Cell Death in Retinal Pigment Epithelial Cells: Modulator Action of Selenium Nanoparticles

Özkaya D, Nazıroğlu M, Vanyorek L, Muhamad S

Biol Trace Elem Res, 2021 Apr;199(4):1356-1369.
PMID: 33389617 DOI: 10.1007/s12011-020-02556-3

Hypoxia (HYPX) in several eye diseases such as glaucoma and diabetic retinopathy causes oxidative cell death and inflammation. TRPM2 cation channel is activated by HYPX-induced ADP-ribose (ADPR) and oxidative stress. The protective role of selenium via inhibition of TRPM2 on the HYPX-induced oxidative cytotoxicity and inflammation values in the human kidney cell line was recently reported. However, the protective role of selenium nanoparticles (SeNP) on the values in the retinal pigment epithelial (ARPE-19) cells has not been clarified yet. In the current study, we investigated two subjects. First, we investigated the involvement of TRPM2 channel on the HYPX-induced oxidative injury, inflammation, and apoptosis in the ARPE-19 cells. Second, we investigated the protective role of SeNP via inhibition of TRPM2 channel on the HYPX-induced oxidative injury and apoptosis in the ARPE-19 cells. For the aims, the ARPE-19 cells were divided into four main groups as follows: Control (Ctr), SeNP (2.5 μg/ml for 24 h), HYPX (200 μM CoCl2 for 24 h), and HYPX+SeNP. The TRPM2 current density and Ca2+ fluorescence intensity with an increase of mitochondrial membrane depolarization and oxygen free radical (OFR) generations were increased in the ARPE-19 cells by the treatment of HYPX. There was no increase of Ca2+ fluorescence intensity in the pre-treated cells with PARP-1 inhibitors (DPQ and PJ34) or in the presence of Ca2+-free extracellular buffer. When HYPX-induced TRPM2 activity was treated by SeNP and TRPM2 (2-APB and ACA) blockers, the increases of OFR generation, cytokine (TNF-α and IL-1β) levels, TRPM2, and PARP-1 expressions were restored. In conclusion, the exposure of HYPX caused mitochondrial oxidative cell cytotoxicity and cell death via TRPM2-mediated Ca2+ signaling and may provide an avenue for treating HYPX-induced retinal diseases associated with the excessive OFR and Ca2+ influx.

Matched MeSH terms: Anoxia
Fulltext Anaemia and cancer treatment: a conceptual change

Khan FA, Shukla AN, Joshi SC

Singapore Med J, 2008 Oct;49(10):759-64.
PMID: 18946607

Anaemia is the most common haematological abnormality in cancer patients, and unfortunately, it is often under-recognised and undertreated. The aetiopathology of anaemia in cancer patients is complex and is usually multifactorial. There is enough evidence suggesting that tumour hypoxia in anaemic patients has a negative impact on the treatment outcomes in cancer patients. The use of recombinant human erythropoietin is becoming a new standard of care in cancer patients. Various well-controlled studies have shown that the use of erythropoietin (EPO) increases the haemoglobin level, thereby decreasing the need for frequent transfusions and improving the tumour responses, cancer-free survival and quality-of-life parameters in cancer patients. However, a few recent clinical trials failed to replicate the survival benefit. Hence, a free unrestricted use of EPO is to be avoided. The past belief that anaemia does not matter in cancer patients is now considered invalid and is being seriously challenged. This article aims to present some recent findings on the impact of anaemia on outcomes, with discussion on the possible causes and effects. The benefits of the use of EPO analogues in cancer-related anaemia are also presented.

Matched MeSH terms: Anoxia
Fulltext The JCR:LA-cp rat: a novel rodent model of cystic medial necrosis

Pung YF, Chilian WM, Bennett MR, Figg N, Kamarulzaman MH

Am J Physiol Heart Circ Physiol, 2017 Mar 01;312(3):H541-H545.
PMID: 27986661 DOI: 10.1152/ajpheart.00653.2016

Although there are multiple rodent models of the metabolic syndrome, very few develop vascular complications. In contrast, the JCR:LA-cp rat develops both metabolic syndrome and early atherosclerosis in predisposed areas. However, the pathology of the normal vessel wall has not been described. We examined JCR:LA control (+/+) or cp/cp rats fed normal chow diet for 6 or 18 mo. JCR:LA-cp rats developed multiple features of advanced cystic medial necrosis including "cysts," increased collagen formation and proteoglycan deposition around cysts, apoptosis of vascular smooth muscle cells, and spotty medial calcification. These appearances began within 6 mo and were extensive by 18 mo. JCR:LA-cp rats had reduced medial cellularity, increased medial thickness, and vessel hypoxia that was most marked in the adventitia. In conclusion, the normal chow-fed JCR:LA-cp rat represents a novel rodent model of cystic medial necrosis, associated with multiple metabolic abnormalities, vascular smooth muscle cell apoptosis, and vessel hypoxia.NEW & NOTEWORTHY Triggers for cystic medial necrosis (CMN) have been difficult to study due to lack of animal models to recapitulate the pathologies seen in humans. Our study is the first description of CMN in the rat. Thus the JCR:LA-cp rat represents a useful model to investigate the underlying molecular changes leading to the development of CMN.

Matched MeSH terms: Anoxia

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