scholarly journals Reduced growth in Baltic Sea cod may be due to mild hypoxia

2020 ◽  
Vol 77 (5) ◽  
pp. 2003-2005 ◽  
Author(s):  
Keith Brander
Keyword(s):  
Baltic Sea ◽  
Food Consumption ◽  
Alternative Explanation ◽  
Metabolic Response ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Daily Food ◽  
Lower Production ◽  
Benthic Prey ◽  
Mild Hypoxia

Abstract Daily food consumption by small Baltic Sea cod has declined in recent decades, resulting in reduced growth and biomass. Declining oxygen may cause lower production of benthic prey for small cod, but an alternative explanation presented here is that the mildly hypoxic conditions that small cod experience reduces their rate of digestion and hence food consumption. Better information about the distribution and behaviour of small cod and their metabolic response to low oxygen levels is required.

scholarly journals Connectivity Map Analysis Indicates PI3K/Akt/mTOR Inhibitors as Potential Anti-Hypoxia Drugs in Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2809
Author(s):  
Paolo Uva ◽  
Maria Carla Bosco ◽  
Alessandra Eva ◽  
Massimo Conte ◽  
Alberto Garaventa ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Drug Repurposing ◽  
Enrichment Analysis ◽  
Mtor Inhibitors ◽  
Gene Set Enrichment Analysis ◽  
Low Oxygen ◽  
Connectivity Map ◽  
Hypoxic Conditions ◽  
Connectivity Score

Neuroblastoma (NB) is one of the deadliest pediatric cancers, accounting for 15% of deaths in childhood. Hypoxia is a condition of low oxygen tension occurring in solid tumors and has an unfavorable prognostic factor for NB. In the present study, we aimed to identify novel promising drugs for NB treatment. Connectivity Map (CMap), an online resource for drug repurposing, was used to identify connections between hypoxia-modulated genes in NB tumors and compounds. Two sets of 34 and 21 genes up- and down-regulated between hypoxic and normoxic primary NB tumors, respectively, were analyzed with CMap. The analysis reported a significant negative connectivity score across nine cell lines for 19 compounds mainly belonging to the class of PI3K/Akt/mTOR inhibitors. The gene expression profiles of NB cells cultured under hypoxic conditions and treated with the mTORC complex inhibitor PP242, referred to as the Mohlin dataset, was used to validate the CMap findings. A heat map representation of hypoxia-modulated genes in the Mohlin dataset and the gene set enrichment analysis (GSEA) showed an opposite regulation of these genes in the set of NB cells treated with the mTORC inhibitor PP242. In conclusion, our analysis identified inhibitors of the PI3K/Akt/mTOR signaling pathway as novel candidate compounds to treat NB patients with hypoxic tumors and a poor prognosis.

scholarly journals Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development

2010 ◽  
Vol 70 (2) ◽  
pp. 425-434 ◽  
Author(s):  
WR Barrionuevo ◽  
MN Fernandes ◽  
O Rocha
Keyword(s):  
Danio Rerio ◽  
Anaerobic Metabolism ◽  
Developmental Stages ◽  
Acute Hypoxia ◽  
Lactate Concentration ◽  
Growth Delay ◽  
Hypoxic Conditions ◽  
Aerobic And Anaerobic ◽  
Mild Hypoxia

In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2), critical tensions of oxygen (Pcrit), heart rate (fH) and total body lactate concentration (Lc) were determined for Danio rerio (Hamilton, 1822) raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1) and hypoxic conditions (4.3 mgO2.L-1) and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.

scholarly journals Hypoxia-Induced Gene Expression Occurs Solely through the Action of Hypoxia-Inducible Factor 1α (HIF-1α): Role of Cytoplasmic Trapping of HIF-2α

2003 ◽  
Vol 23 (14) ◽  
pp. 4959-4971 ◽  
Author(s):  
Sang-ki Park ◽  
Agnes M. Dadak ◽  
Volker H. Haase ◽  
Lucrezia Fontana ◽  
Amato J. Giaccia ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Activity ◽  
Hypoxia Inducible Factor ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Show Evidence ◽  
Dependent Protein ◽  
A Cell ◽  
Cell Type Specific ◽  
Inducible Genes

ABSTRACT The hypoxia-inducible factors 1α (HIF-1α) and 2α (HIF-2α) have extensive structural homology and have been identified as key transcription factors responsible for gene expression in response to hypoxia. They play critical roles not only in normal development, but also in tumor progression. Here we report on the differential regulation of protein expression and transcriptional activity of HIF-1α and -2α by hypoxia in immortalized mouse embryo fibroblasts (MEFs). We show that oxygen-dependent protein degradation is restricted to HIF-1α, as HIF-2α protein is detected in MEFs regardless of oxygenation and is localized primarily to the cytoplasm. Endogenous HIF-2α remained transcriptionally inactive under hypoxic conditions; however, ectopically overexpressed HIF-2α translocated into the nucleus and could stimulate expression of hypoxia-inducible genes. We show that the factor inhibiting HIF-1 can selectively inhibit the transcriptional activity of HIF-1α but has no effect on HIF-2α-mediated transcription in MEFs. We propose that HIF-2α is not a redundant transcription factor of HIF-1α for hypoxia-induced gene expression and show evidence that there is a cell type-specific modulator(s) that enables selective activation of HIF-1α but not HIF-2α in response to low-oxygen stress.

Ventilatory and metabolic responses to hypoxia in the smallest simian primate, the pygmy marmoset

2002 ◽  
Vol 92 (1) ◽  
pp. 202-210 ◽  
Author(s):  
Glenn J. Tattersall ◽  
James L. Blank ◽  
Stephen C. Wood
Keyword(s):  
Body Temperature ◽  
Metabolic Response ◽  
World Monkey ◽  
Minute Ventilation ◽  
Metabolic Depression ◽  
Hypoxic Conditions ◽  
Pygmy Marmoset ◽  
Average Body Mass ◽  
Average Body ◽  
Ventilatory Response To Hypoxia

The pygmy marmoset ( Cebuella pygmaea) is the smallest New World Monkey (average body mass of 120–130 g). As such, it faces possible challenges to thermoregulation. Small mammals (e.g., rats) are well known to lower body temperature and metabolism in response to hypoxia; however, small primates have not been studied in this respect nor have, in general, the interactions between metabolism and ventilation. Because little is known about these responses in small primates, it seemed of great interest to assess the hypoxia-induced metabolic depression and drop in body temperature and the associated ventilatory requirements in this species under hypoxic conditions. Exposure to graded hypoxia (30 min at each of 18, 16, 14, 12, and 10% O2) caused body temperature to drop from the normoxic value of 39 to 37°C. This was accompanied by a marked metabolic depression (O2 consumption was ∼68% of the normoxic value, implying a suppression of metabolism greater than that predicted from a typical value of the effect of 10°C change on metabolism of 2–3 times). Minute ventilation declined in parallel to metabolism, maintaining a constant air-convection requirement during hypoxia; thus this species did not show the typical mammalian hyperventilation. Acute exposure to 10% O2 led to a similar overall decline in metabolism and body temperature and qualitative differences in the timing of these changes. The pygmy marmoset shares some similarities in its hypoxic metabolic response with other mammals of similar size yet appears to be unique in its much diminished ventilatory response to hypoxia.

Feeding Schedule and Daily Food Consumption in Red-Throated Loons (Gavia stellata) over the Prefledging Period

The Auk ◽  
1984 ◽  
Vol 101 (3) ◽  
pp. 593-599 ◽  
Author(s):  
T. E. Reimchen ◽  
Sheila Douglas
Keyword(s):  
British Columbia ◽  
Food Consumption ◽  
Marine Fish ◽  
Average Duration ◽  
Fish Populations ◽  
Feeding Schedule ◽  
Parental Feeding ◽  
Daily Food ◽  
Feeding Activities ◽  
Coastal British Columbia

Abstract We describe parental feeding activities of Red-throated Loons (Gavia stellata) throughout the prefledging period at two freshwater nesting territories in coastal British Columbia. The nesting lake contained resident fish populations, but adult loons fed marine fish to their young, making an average of 11 flights per day (average duration 60 min per flight) to the ocean and returning each time with a single fish. Small shallow-bodied fish (Ammodytidae, Pholidae), which were easily swallowed by chicks, predominated in the diet during the 3 days following hatching. The total weight of fish fed to the chicks per day (8-194 g) increased over the prefledging period: adults returned fewer but larger fish (Embiotocidae) as the chick aged. Of the fish offered, 4% were too large for the chick to swallow.

Jasus lalandii 'walkouts' or mass strandings in South Africa during the 1990s: an overview

2001 ◽  
Vol 52 (8) ◽  
pp. 1085 ◽  
Author(s):  
Andrew C. Cockcroft
Keyword(s):  
South Africa ◽  
West Coast ◽  
The Other ◽  
Fishing Industry ◽  
Low Oxygen ◽  
Rock Lobster ◽  
The West ◽  
Hypoxic Conditions ◽  
Oxygen Conditions ◽  
Mass Mortalities

Faunal mass mortalities are a sporadic, but not uncommon, feature of the West and South coasts of South Africa. Five mass mortalities of West Coast rock lobsterJasus lalandii, including three of the most severe ever recorded in South Africa, occurred in the 1990s and resulted in the stranding of about 2263 tonnes of lobster. The bulk (97%) of the loss occurred in the last three years of the decade. The five events occurred within an 80 km stretch of coastline that straddled two fishing zones and resulted from hypoxic conditions associated with highbiomass dinoflagellate blooms. In each case, the quantity of lobsters stranded was directly related to the extent or duration of low-oxygen conditions. Small females constituted the bulk of the lobster stranded in most events. The lobster fisheries in the affected fishing zones suffered severe impacts. Recovery in one zone appears to be extremely slow, whereas the other zone is more resilient. Not only would a continuation of the trend of increasing frequency and severity of lobster strandings devastate the rock-lobster fishing industry and the employment prospects of small fishing communities, but it could also seriously affect the ecology of the region.

scholarly journals The Response of Macrophages and Neutrophils to Hypoxia in the Context of Cancer and Other Inflammatory Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Antje Egners ◽  
Merve Erdem ◽  
Thorsten Cramer
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Diseases ◽  
Neutrophil Function ◽  
Proper Function ◽  
Low Oxygen ◽  
Bacterial Killing ◽  
Molecular Responses ◽  
Chronic Inflammatory Diseases ◽  
Hypoxic Conditions ◽  
Cellular Components

Lack of oxygen (hypoxia) is a hallmark of a multitude of acute and chronic diseases and can be either beneficial or detrimental for organ restitution and recovery. In the context of inflammation, hypoxia is particularly important and can significantly influence the course of inflammatory diseases. Macrophages and neutrophils, the chief cellular components of innate immunity, display distinct properties when exposed to hypoxic conditions. Virtually every aspect of macrophage and neutrophil function is affected by hypoxia, amongst others, morphology, migration, chemotaxis, adherence to endothelial cells, bacterial killing, differentiation/polarization, and protumorigenic activity. Prominent arenas of macrophage and neutrophil function, for example, acute/chronic inflammation and the microenvironment of solid tumors, are characterized by low oxygen levels, demonstrating the paramount importance of the hypoxic response for proper function of these cells. Members of the hypoxia-inducible transcription factor (HIF) family emerged as pivotal molecular regulators of macrophages and neutrophils. In this review, we will summarize the molecular responses of macrophages and neutrophils to hypoxia in the context of cancer and other chronic inflammatory diseases and discuss the potential avenues for therapeutic intervention that arise from this knowledge.

Mesozooplankton community in a seasonally hypoxic and highly eutrophic bay

2015 ◽  
Vol 66 (8) ◽  
pp. 719 ◽  
Author(s):  
Min-Chul Jang ◽  
Kyoungsoon Shin ◽  
Pung-Guk Jang ◽  
Woo-Jin Lee ◽  
Keun-Hyung Choi
Keyword(s):  
High Temperature ◽  
Bottom Water ◽  
Oxygen Solubility ◽  
Low Oxygen ◽  
Negative Effects ◽  
Mesozooplankton Community ◽  
Seawater Chemistry ◽  
Hypoxic Conditions ◽  
Bottom Waters ◽  
Major Factors

A 2-year survey of seawater chemistry and mesozooplankton abundance was carried out in Masan Bay, South Korea, one of the most eutrophic coastal ecosystems known. The study aimed to identify the major factors contributing to the seasonally persistent hypoxia in the bay, to characterise the Bay’s mesozooplankton community and to examine the effects of low oxygen on the distribution of mesozooplankton. Hypoxia (<2mgO2L–1) was present only in summer, with ultrahypoxia (<0.2mg O2 L–1) in the bottom waters of the inner bay in both years. Low summer oxygen can be attributed to high summer phytoplankton stocks, together with reduced oxygen solubility at high temperature and stratification of the water column that limits downward diffusion of oxygen. A seasonally and spatially distinct mesozooplankton community was identified in summer when there was greater influence of freshwater discharge in the inner bay. Marine cladocerans were very abundant, with a population outburst of Penilia avirostris in the inner bay (>4000 individuals m–3) during summer. During hypoxic events, the abundance of Penilia avirostris was positively related to oxygen levels in the bottom water, suggesting that hypoxic conditions may cause mortality or have sublethal negative effects on population growth of this filter-feeding cladoceran.

scholarly journals Development of a foraging model framework to reliably estimate daily food consumption by young fishes

2017 ◽  
Vol 74 (10) ◽  
pp. 1668-1681 ◽  
Author(s):  
David Deslauriers ◽  
Alex J. Rosburg ◽  
Steven R. Chipps
Keyword(s):  
Water Temperature ◽  
Food Consumption ◽  
Prey Density ◽  
Handling Time ◽  
Prey Type ◽  
Daily Consumption ◽  
Model Framework ◽  
Fish Feeding ◽  
Daily Food Consumption ◽  
Daily Food

We developed a foraging model for young fishes that incorporates handling and digestion rate to estimate daily food consumption. Feeding trials were used to quantify functional feeding response, satiation, and gut evacuation rate. Once parameterized, the foraging model was then applied to evaluate effects of prey type, prey density, water temperature, and fish size on daily feeding rate by age-0 (19–70 mm) pallid sturgeon (Scaphirhynchus albus). Prey consumption was positively related to prey density (for fish >30 mm) and water temperature, but negatively related to prey size and the presence of sand substrate. Model evaluation results revealed good agreement between observed estimates of daily consumption and those predicted by the model (r2 = 0.95). Model simulations showed that fish feeding on Chironomidae or Ephemeroptera larvae were able to gain mass, whereas fish feeding solely on zooplankton lost mass under most conditions. By accounting for satiation and digestive processes in addition to handling time and prey density, the model provides realistic estimates of daily food consumption that can prove useful for evaluating rearing conditions for age-0 fishes.

Enhancing the Mechanical Properties of Articular Cartilage Through Enzyme-Mediated Collagen Crosslinking as Regulated by Low Oxygen Tension

2012 ◽  
Author(s):  
Eleftherios A. Makris ◽  
Jerry Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Articular Cartilage ◽  
Oxygen Tension ◽  
Low Oxygen ◽  
Healthy Human ◽  
Collagen Crosslinking ◽  
Human Knee ◽  
Hypoxic Conditions ◽  
The Poor ◽  
Human Knee Joint ◽  
Low Oxygen Tension

The poor ability of articular cartilage to repair following disease and injury makes the tissue a key target for reparative and regenerative medicine strategies. It has been shown that human knee joint resides under hypoxic conditions. Oxygen tension in healthy human synovium is between 7 and 11% and in articular cartilage may therefore be as low as 1–2.5% [1].

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