scholarly journals Effects of Microplastics on the Feeding Rates of Larvae of a Coastal Fish: Direct Consumption, Trophic Transfer, and Effects on Growth and Survival

2021 ◽  
Author(s):  
Christine Uy ◽  
Darren Johnson
Keyword(s):  
Larval Fish ◽  
Trophic Transfer ◽  
Control Group ◽  
Feeding Rates ◽  
Lower Growth ◽  
Larval Phase ◽  
Coastal Fish ◽  
Growth And Survival ◽  
Low Concentrations ◽  
High Concentrations

Abstract Microplastics are now found throughout the world’s oceans, and although many organisms ingest microplastics, less is known about how plastics in seawater may affect key processes such as feeding rate, growth, and survival. We used a series of laboratory experiments to test whether microplastics in seawater affected the feeding rates of larvae of the California Grunion, Leuresthes tenuis. In addition, we tested whether trophic transfer of microplastics from zooplankton to larval fish can occur and affect growth and survival of fish. We measured feeding rates of grunion larvae at various concentrations of 75–90 µm and 125–250 µm polyethylene microplastics and under both still water and turbulent conditions. In these experiments, exposure to microplastics had modest effects on feeding rates, though responses may be somewhat complex. Low concentrations of microplastics increased feeding rates compared to the control, but at higher concentrations, feeding rates were indistinguishable from those in the control group though effects were small compared to natural variation in feeding rates among individual fish. Experiments to test for trophic transfer of microplastics revealed that grunion larvae that were fed brine shrimp exposed to high concentrations of microplastics had lower growth rates and elevated mortality rates. Overall, our results suggest that the direct effects of microplastics on feeding rates of California Grunion during the early larval phase are minor, while the trophic transfer of microplastics from zooplankton to larval fish may have significant effects on their growth and survival.

NH4Cl affects the expression of Wnt/β-catenin pathway in hepatocytes

2018 ◽  
Vol 96 (3) ◽  
pp. 281-286
Author(s):  
Lu Bai ◽  
Jingjing Li ◽  
Xiaorui Liu ◽  
Shasha Li ◽  
Fulei Li ◽  
...  
Keyword(s):  
Protein Expression ◽  
Control Group ◽  
Cyclin D ◽  
Chang Liver Cell ◽  
Expression Levels ◽  
Low Concentrations ◽  
Short Period ◽  
Mrna And Protein Expression ◽  
High Concentrations ◽  
Chang Liver

We intended to explore whether NH4Cl influences the viability and regulates the expression of Wnt/β-catenin pathway in hepatocytes. The Chang liver cell line was used and cultured with different concentrations of NH4Cl (2.5, 5, 10, 20, 40, and 50 mmol/L) for 12, 24, and 48 h. The viability of hepatocytes was detected by MTT assay. The mRNA and protein expression level was analyzed with qRT–PCR and Western blotting, respectively. NH4Cl concentration significantly affects the viability of hepatocytes. With the increase of NH4Cl concentration, the viability of hepatocytes was decreased, accordingly. The mRNA and protein expression of Wnt1, β-catenin, and cyclin D was significantly increased after treatment with low concentrations of NH4Cl as compared with the control group, whereas their expression levels were decreased after treatment with high concentrations of NH4Cl. The mRNA and protein expression of Wnt1, β-catenin, and cyclin D was also significantly increased after treatment with NH4Cl for a short period as compared with the control group, whereas their expression levels were decreased after treatment with NH4Cl for a long period. In addition, we found NH4Cl treatment significantly reversed the results after RNA silencing of Wnt1 in hepatocytes. NH4Cl influences the viability of hepatocytes and affects the expression of Wnt/β-catenin pathway in hepatocytes.

scholarly journals Plant Contribution to the Remediation of PAH-Contaminated Soil of Dagang Oilfield by Fire Phoenix

2021 ◽  
Author(s):  
Xiaomei Wang ◽  
Jianping Sun ◽  
Rui Liu ◽  
Tingyu Zheng ◽  
Yingnan Tang
Keyword(s):  
Contaminated Soil ◽  
Early Stage ◽  
Removal Rate ◽  
Growth Time ◽  
Control Group ◽  
Total Removal ◽  
Low Concentrations ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Main Factor

Abstract Pot experiments were conducted to evaluate plant contribution during remediation of the polycyclic aromatic hydrocarbons (PAH)-contaminated soil of Dagang Oilfield by Fire Phoenix. The results showed that Fire Phoenix could grow in soil contaminated by high and low concentrations of PAHs. After being planted for 150 days, the total removal rate of six PAHs in the high and low PAH concentrations was 80.36% and 79.79%, significantly higher than the 58.79% and 53.29% of the unplanted control group, respectively. Thus, Fire Phoenix can effectively repair the soil contaminated by different concentrations of PAHs. In high concentrations of PAHs, the results indicated a positive linear relationship between PAH absorption in tissues of Fire Phoenix and the growth time in the early stage. In contrast, the contents of PAHs were just slightly increased in the late period of plant growth. The main factor for the dissipation of PAHs was plant-promoted biodegradation (99.04–99.93%), suggesting a low contribution of PAH uptake and transformation (0.07–0.96%). The results revealed that Fire Phoenix did not remove the PAHs in the soil by accumulation but promoted PAH dissipation in the soil by stimulating the microbial metabolism in the rhizosphere.

scholarly journals Histological Effects of Titanium Dioxide Nanoparticles Size 10 Nm in Mice Testes

2017 ◽  
Vol 5 (2) ◽  
pp. 158 ◽  
Author(s):  
Imad Taher Abdulla
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Testicular Tissue ◽  
Germinal Epithelium ◽  
Seminiferous Tubules ◽  
Control Group ◽  
Histological Changes ◽  
Low Concentrations ◽  
High Concentrations ◽  
Histological Effect

In the present study, the histological effect of titanium dioxide nanoparticles (TDN) on testicular tissue of mature Mus musculus mice was investigated. The animals were divided into six groups, control group treated with TDN free saline and five groups treated with TDN as follow 5, 10, 50, 100 and 150 mg/kg B.W. The results showed that TDN has histological effects on testicular tissue like sever congestion, mild edema between seminiferous tubules (STs) and decrease the thickness of germinal epithelium at low concentrations, While, the histological changes at high concentrations involved disturbance in STs diameters, sever edema between STs, sever vaculation in the germinal epithelium and necrosis in spermatogonia, germinal epithelium and Sertoli cells.

The effect of nicotine and cotinine on human gingival fibroblasts attachment to root surfaces

2015 ◽  
Vol 26 (5) ◽  
Author(s):  
Zeinab Rezaei Esfahrood ◽  
Amirhosein Zamanian ◽  
Maryam Torshabi ◽  
Maryam Abrishami
Keyword(s):  
Cell Adhesion ◽  
Adverse Effects ◽  
Control Group ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Initial Cell ◽  
Low Concentrations ◽  
High Concentrations ◽  
Root Surfaces ◽  
Initial Cell Adhesion

AbstractDifferent compounds of smoking (e.g., nicotine and cotinine) are risk factors for various diseases such as oral cancer and periodontal diseases. Some studies reported the negative effects of nicotine on cell proliferation and differentiation. The present in vitro study assessed the effects of nicotine and cotinine (long-acting metabolite of nicotine) on the attachment and viability of human gingival fibroblast (HGF) cells to tooth root surfaces.A total of 70 teeth specimens were placed into 48-well culture plates and covered with HGF cell suspension, in complete Dulbecco’s modified Eagle’s medium culture medium containing 1 nM, 1 μm, 1 mM, and 5 mM of nicotine and cotinine concentrations. Cellular attachment and viability measured using an MTT assay and a scanning electron microscope were used for cell morphological evaluation.After 24 h, low (nanomolar and micromolar) and high concentrations (millimolar) of nicotine and cotinine caused a significant reduction in the initial cell adhesion in comparison with the control group, but no significant difference was observed between the nicotine and the cotinine groups (p<0.05). Dentally attached cells with low concentrations of nicotine and cotinine proliferated 48 h after exposure, the same as the control group. However, dentally attached cells with high concentrations of nicotine and cotinine (especially 5 mM) did not proliferate 24 h after exposure (p<0.05).Low concentrations of nicotine and cotinine caused a reduction in the initial cell adhesion. However, no significant adverse effects on the proliferation of attached cells were seen in the longer period. High concentrations of nicotine and cotinine have adverse effects on the cell adhesion and proliferation of HGF cells.

scholarly journals Indirect versus Direct Effects of Freshwater Browning on Larval Fish Foraging

2019 ◽  
Author(s):  
Dina M. Leech ◽  
Troy L. Clift ◽  
Jessica L. Littlefield ◽  
Nicholas R. Ravagli ◽  
Jacob E. Spain
Keyword(s):  
Largemouth Bass ◽  
Indirect Effects ◽  
Prey Availability ◽  
Larval Fish ◽  
Light Availability ◽  
Direct Effects ◽  
Feeding Rates ◽  
Growth And Survival ◽  
Feeding Experiments ◽  
Fish Spawning

ABSTRACTFish foraging and energy flow are both predicted to decline with freshwater ‘browning’ due to reductions in light availability. Studies investigating these predictions have focused on juveniles and adults; however, the larval stage represents a ‘critical period’ in fish development. We investigated the indirect versus direct effects of browning on zooplankton-larval fish interactions by altering water color with SuperHume (absorbance at 440 nm = 1.6 – 10.8 m−1). Phytoplankton and zooplankton densities were monitored across experimental tanks in the laboratory for one month leading up to fish spawning. Larval largemouth bass were then introduced to assess indirect effects on fish feeding rates and growth. Direct effects on foraging of largemouth bass and bluegill were determined with separate short-term feeding experiments. Browning did not directly alter the ability of larval fish to capture prey. However, significant indirect effects on larval fish foraging, growth, and survival were observed as phytoplankton and zooplankton decreased with increased browning. Our data suggest lake browning will reduce energy transfer to larval fish due to a reduction in prey availability but not visual foraging.

scholarly journals Effects of Artifical Substrate on Rearing of Macrobrachium Rosenbergii Post-larvae in Pond Net Cage

2021 ◽  
Vol 24 (2) ◽  
pp. 95-106
Author(s):  
H Thapa ◽  
SM Rafiquzzaman ◽  
MM Rahman ◽  
MJ Alam
Keyword(s):  
Survival Rate ◽  
Surface Area ◽  
Macrobrachium Rosenbergii ◽  
Freshwater Prawn ◽  
Control Group ◽  
Lower Growth ◽  
Growth And Survival ◽  
Randomized Design ◽  
Net Cage ◽  
Substrate Group

Two experiments were carried out to evaluate the effects of addition of net piece substrates in cages for nursery rearing of freshwater prawn, Macrobrachium rosenbergii post-larvae. In the first experiment, net piece substrates were added with an arrangement to increase the surface area of nursery cages to 50% and 75% and compared with cages without any substrate (control). In the second experiment, maintaining surface area increment at 75% in all cages, the net piece substrates were arranged in three different orientations of horizontal, vertical, and 45o angle sloping. Experiments were conducted in a pond of Faculty of Fisheries, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh for a period of 45 days in June –August of 2015 and 2016. A completely randomized design was followed to assign the treatments with three replications. The 75% area increment group showed significantly higher (P < 0.05) growth (1.02 ± 0.09 g) and survival rate (79.43 ± 1.63%), compared to 50% area increment (0.96 ± 0.05 g and 75.03 ± 2.45%) and control group (0.79 ± 0.06 g and 66.66 ± 3.57%). The vertically oriented substrate group showed significantly lower growth 0.95 ± 0.04 g) and survival (76.33 ± 1.15%), compared to the horizontal (1.06 ± 0.05 g and 77.12 ± 1.20%) and sloping (1.16 ± 0.10 g and 79.33 ± 0.57 %) substrate group. However, there were no differences between horizontal and sloping substrate groups regarding final length, final weight, specific growth rate (SGR), and survival rate except food conversion ratio (FCR). The overall results suggested that modification of net cage nursery structure of M. rosenbergii might have significant effects on growth and survival of post-larvae by the manipulation of their behaviour in culture system. Ann. Bangladesh Agric. (2020) 24(2) : 95-106

scholarly journals Inhibin A, B and pro-alphaC in serum and peritoneal fluid in postmenopausal patients with ovarian tumors

2000 ◽  
pp. 334-339 ◽  
Author(s):  
SL Ala-Fossi ◽  
J Maenpaa ◽  
M Blauer ◽  
P Tuohimaa ◽  
R Punnonen
Keyword(s):  
Peritoneal Fluid ◽  
Ovarian Tumors ◽  
Ca 125 ◽  
Control Group ◽  
Peritoneal Cytology ◽  
Low Grade ◽  
Inhibin A ◽  
Gynecology And Obstetrics ◽  
Low Concentrations ◽  
High Concentrations

OBJECTIVE: To compare serum and peritoneal fluid concentrations of inhibin A, B, and pro-alphaC in women with ovarian tumors. METHODS: Serum and peritoneal fluid samples were taken from 41 postmenopausal women operated on for an ovarian tumor. Twenty-one patients with endometrial cancer formed a control group. Serum and peritoneal fluid inhibin A, B, and pro-alphaC concentrations, and serum FSH and tumor marker CA 125 (study group only) concentrations were analyzed. RESULTS: Inhibin A was found in low concentrations (median 4.1pg/ml, range <2-29pg/ml) in serum in most postmenopausal patients with epithelial ovarian carcinoma, whereas inhibin B was not measurable. Inhibin pro-alphaC circulated in high concentrations (median 125pg/ml, range 37->1000pg/ml). All inhibins were found in clearly greater concentrations in the peritoneal fluid than in serum. International Federation of Gynecology and Obstetrics (FIGO) stage III-IV and poor differentiation grade were associated with significantly lower concentrations of inhibin A and pro-alphaC in the peritoneal fluid compared with stages I-II or low grade. This correlation was not found in the serum concentrations of inhibin A or pro-alphaC. In the control group, no dimeric inhibins were found in serum, and pro-alphaC circulated in median concentrations of 47pg/ml (range 12-174pg/ml). CONCLUSIONS: Postmenopausal patients with epithelial ovarian tumors had low concentrations of inhibin A and relatively high concentrations of inhibin pro-alphaC in serum. The peritoneal fluid concentrations of all inhibins far exceeded those in the serum. Relatively low concentrations of inhibin A and pro-alphaC in the peritoneal fluid of patients with ovarian cancer seem to be associated with high stage and grade and, to a lesser degree, with positive peritoneal cytology.

Neutrophil Elastase Potentiates Cathepsin G-lnduced Platelet Activation

1992 ◽  
Vol 68 (05) ◽  
pp. 570-576 ◽  
Author(s):  
Mary A Selak
Keyword(s):  
Neutrophil Elastase ◽  
Cell Activation ◽  
Thromboxane A2 ◽  
Creatine Phosphate ◽  
Dense Granule ◽  
Cathepsin G ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Low Concentrations ◽  
High Concentrations

SummaryWe have previously demonstrated that human neutrophil cathepsin G is a strong platelet agonist that binds to a specific receptor. This work describes the effect of neutrophil elastase on cathepsin G-induced platelet responses. While platelets were not activated by high concentrations of neutrophil elastase by itself, elastase enhanced aggregation, secretion and calcium mobilization induced by low concentrations of cathepsin G. Platelet aggregation and secretion were potentiated in a concentration-dependent manner by neutrophil elastase with maximal responses observable at 200 nM. Enhancement was observed when elastase was preincubated with platelets for time intervals of 10–60 s prior to addition of a low concentration of cathepsin G and required catalytically-active elastase since phenylmethanesulphonyl fluoride-inhibited enzyme failed to potentiate cell activation. Neutrophil elastase potentiation of platelet responses induced by low concentrations of cathepsin G was markedly inhibited by creatine phosphate/creatine phosphokinase and/or indomethacin, indicating that the synergism between elastase and cathepsin G required the participation of ADP and thromboxane A2. On the other hand, platelet responses were not attenuated by the PAF antagonist BN 52021, signifying that PAF-acether did not play a role in elastase potentiation. At higher concentrations porcine pancreatic elastase exhibits similar effects to neutrophil elastase, demonstrating that the effect of elastase was not unique to the neutrophil protease. While neutrophil elastase failed to alter the ability of cathepsin G to hydrolyze a synthetic chromogenic substrate, preincubation of platelets with elastase increased the apparent affinity of cathepsin G binding to platelets. In contrast to their effect on cathepsin G-induced platelet responses, neither neutrophil nor pancreatic elasatse potentiated aggregation or dense granule release initiated by ADP, PAF-acether, arachidonic acid or U46619, a thromboxane A2 mimetic. Moreover, unlike its effect on cathepsin G, neutrophil elastase inhibited thrombin-induced responses. The current observations demonstrate that elastase can potentiate platelet responses mediated by low concentrations of cathepsin G, suggesting that both enzymes may function synergistically to activate platelets under conditions where neutrophil degranulation occurs.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

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