Determining the effect of calcium on cell death rate and perforation formation during leaf development in the novel model system, the lace plant ( Aponogeton madagascariensis )

2020 ◽  
Vol 278 (3) ◽  
pp. 132-144 ◽  
Author(s):  
MEREDITH S. FRASER ◽  
ADRIAN N. DAUPHINEE ◽  
ARUNIKA H.L.A.N. GUNAWARDENA
2016 ◽  
Vol 81 (6) ◽  
pp. 697-705 ◽  
Author(s):  
Xuepeng Yang ◽  
Yan Ji ◽  
Fangfang Wang ◽  
Jia Xu ◽  
Xiangzhen Liu ◽  
...  

Vibrio fischeri bioluminescence inhibition has been widely used to test acute toxicities of metals and organics contaminants. However, the differences of metals and organics acute toxicities to V. fischeri have not been compared. Here, four heavy metals (Zn2+, Cu2+, Cd2+, Cr6+) and five organics (phenol, benzoic acid, p-hydroxy benzoic acid, nitro-benzene and benzene) acute toxicities to V. fischeri were investigated. Heavy metals toxicities to V. fischeri were increased along with the reaction time, while the organics toxicities kept the same level in different reaction times. In order to explain the difference, the relative cell death rate of V. fischeri was detected. In metals toxicities tests, the bioluminescence inhibition rate of V. fischeri was found to be significantly higher than the relative cell death rate (P<0.05), while for the organics toxicities tests, the cell death rate was similar to the bioluminescence inhibition rate. These results indicated that organics acute toxicities to V. fischeri could reflect the death of cell, but metals acute toxicities to V. fischeri may not lead to the death of cell, just represent the bioluminescence inhibition.


2012 ◽  
Vol 38 (3) ◽  
pp. 419-425 ◽  
Author(s):  
Guilherme Fartes ◽  
Fábio Lorenzetti ◽  
Larissa Beloti Salvador ◽  
Valdemar Ortiz ◽  
Miriam Dambros

2004 ◽  
Vol 4 (4) ◽  
pp. 1113-1124 ◽  
Author(s):  
A. Stohl ◽  
O. R. Cooper ◽  
R. Damoah ◽  
F. C. Fehsenfeld ◽  
C. Forster ◽  
...  

Abstract. A forecast system has been developed in preparation for an upcoming aircraft measurement campaign, where the same air parcels polluted by emissions over North America shall be sampled repeatedly as they leave the continent, during transport over the Atlantic, and upon their arrival over Europe. This paper describes the model system in advance of the campaign, in order to make the flight planners familiar with the novel model output. The aim of a Lagrangian strategy is to infer changes in the chemical composition and aerosol distribution occurring en route by measured upwind/downwind differences. However, guiding aircraft repeatedly into the same polluted air parcels requires careful forecasting, for which no suitable model system exists to date. This paper describes a procedure using both Eulerian-type (i.e. concentration fields) and Lagrangian-type (i.e. trajectories) model output from the Lagrangian particle dispersion model FLEXPART to predict the best opportunities for a Lagrangian experiment. The best opportunities are defined as being highly polluted air parcels which receive little or no emission input after the first measurement, which experience relatively little mixing, and which are reachable by as many aircraft as possible. For validation the system was applied to the period of the NARE 97 campaign where approximately the same air masses were sampled on different flights. Measured upwind/downwind differences in carbon monoxide (CO) and ozone (O3) decreased significantly as the threshold values used for accepting cases as Lagrangian were tightened. This proves that the model system can successfully identify Lagrangian opportunities.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6957
Author(s):  
Xinyu Jiang ◽  
Mohammad Aqa Mohammadi ◽  
Yuan Qin ◽  
Zongshen Zhang

Psammosilene tunicoides is a unique perennial medicinal plant species native to the Southwestern regions of China. Its wild population is rare and endangered due to over-excessive collection and extended growth (4–5 years). This research shows that H+-ATPase activity was a key factor for oxalate-inducing programmed cell death (PCD) of P. tunicoides suspension cells. Oxalic acid (OA) is an effective abiotic elicitor that enhances a plant cell’s resistance to environmental stress. However, the role of OA in this process remains to be mechanistically unveiled. The present study evaluated the role of OA-induced cell death using an inverted fluorescence microscope after staining with Evans blue, FDA, PI, and Rd123. OA-stimulated changes in K+ and Ca2+ trans-membrane flows using a patch-clamp method, together with OA modulation of H+-ATPase activity, were further examined. OA treatment increased cell death rate in a dosage-and duration-dependent manner. OA significantly decreased the mitochondria activity and damaged its electron transport chain. The OA treatment also decreased intracellular pH, while the FC increased the pH value. Simultaneously, NH4Cl caused intracellular acidification. The OA treatment independently resulted in 90% and the FC led to 25% cell death rates. Consistently, the combined treatments caused a 31% cell death rate. Furthermore, treatment with EGTA caused a similar change in intracellular pH value to the La3+ and OA application. Combined results suggest that OA-caused cell death could be attributed to intracellular acidification and the involvement of OA in the influx of extracellular Ca2+, thereby leading to membrane depolarization. Here we explore the resistance mechanism of P. tunicoides cells against various stresses endowed by OA treatment.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10592-10592
Author(s):  
J. Jeong ◽  
S. Lee ◽  
S. Yoon ◽  
W. Jung ◽  
H. Lee ◽  
...  

10592 Background: The response to chemotherapeutic agents of breast cancer is heterogeneous from patient to patient. Several methods were developed to decide chemotherapeutic agents which were sensitive to individual patients but so far, there are no ways which is commonly used in the clinic to tailor the treatment. In this study, we performed the chemotherapy response assay using adenosine triphosphate (ATP-CRA) in breast cancer patients and assessed the clinical availability. Methods: From March 2004 to February 2005, 65 breast cancer patients were enrolled in this study. After elimination of normal contaminated cells, cancer cells were evenly divided and treated with commonly used chemotherapeutic drugs in breast cancer(doxorubicin, epirubicin, 5-FU, paclitaxel, docetaxel, vinorelbine, and gemcitabine). 7 Drug-treated cancer cells and untreated cancer cells were cultured for 48 hours and then ATP was measured. To verify in vitro ATP-CRA indirectly, we analyzed the correlation between cell death rate of doxorubicin and epirubicin, and between doxorubicin and paclitaxel. We also analyzed the mean death rate of doxorubicin, epirubicin and paclitaxel by HER-2 status. Results: The ATP-CRA was performed sucessfully in 62 patients. (95.4%) In all cases, we can get the results within 7 days. The range of cell death rate was very wide, from 0 to more than 50%, except gemcitabine. Epirubicin showed the highest mean cell death rate (35.7%) and doxorubicin, paclitaxel in order. According to the chemosensitivity index, paclitaxel is the most frequently first-ranked and doxorubicin, epirubicin in order. Correlation coefficient between the cell death rate of doxorubicin and epirubicin is 0.58 and 0.2 between paclitaxel and epirubicin. In HER-2 positive group, mean cell death rate of epirubicin and paclitaxel was significantly higher than in HER-2 negative group (p = 0.017, p = 0.036) and same trend was seen in doxorubicin but not statistically significant (p = 0.060). Conclusions: ATP-CRA showed heterogeneous results in individual patients. ATP-CRA was successful and can be performed within short time period. With indirect comparison, it showed similar results with in vivo studies but for clinical use, the prospective randomized controlled trial should be preceded. No significant financial relationships to disclose.


2011 ◽  
Vol 268-270 ◽  
pp. 1205-1210 ◽  
Author(s):  
Xiao Dan Qi ◽  
Jin Cai Hou ◽  
Hai Tao Yu ◽  
Chun Jing Zhang

To study the underlying mechanism of 20 (S)-Ginsenoside-Rh2 and 20 (R)-Ginsenoside-Rh2 inducing apoptosis of human lung adenocarcinoma A549 cells. In this study, cell death rate and cell survival rate were obtained using typan blue staining cell viability assay, and transmission electron microscopy was used to detect cell apoptosis. Meanwhile, IkappaB phosphorylation expression was analysed by western blotting. Results showed that after A549 cells were treated with 30 μg/mL 20(S)-Rh2 and 20(R)-Rh2 for 48h, cell death rate increased significantly compared with the control group (P<0.05), and nuclear condensation, fragmentation, karyopycnosis and apoptotic bodies were found under transmission electron microscope. There were no significant changes of IkappaB expression after treated with 20(S)-Rh2 and 20(R)-Rh2 (P>0.05). After treated with 20(R)-Rh2, p-IkappaB expression increased obviously between 4h-6h (P<0.05). After treated with 20(S)-Rh2, p-IkappaB expression increased obviously between 1h-2h (P<0.05), back to normal over time after 3h, increased significantly again between 4h-6h (P<0.05), which indicated the activation of IkappaB participated in A549 cell apoptosis induced by Rh2. These results demonstrated that 20(S)-Rh2 and 20(R)-Rh2 both have the functions of activating I-kappaB/NF-kappaB signaling pathway, thus promoting A549 cell apoptosis.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Tomohito Sato ◽  
Yoko Karasawa ◽  
Sho Ishikawa ◽  
Manzo Taguchi ◽  
Tadashi Muraoka ◽  
...  

Indocyanine green (ICG) angiography is an indispensable inspection to diagnose and treat for chorioretinal diseases. In this study, we investigated the phototoxicity of ICG on RPE cells at the levels of residual ICG after angiography under ambient light. After incubation of ARPE-19 cells in a colorless medium containing 0 to 10 μg/mL ICG for 24 hours in the dark or under 2000 lx illumination from a fluorescent lamp, cell viability decreased and cell death rate increased in cultures with more than 5.0 μg/mL ICG under illumination. In culture with 10 μg/mL ICG under illumination, morphology of cells changed to be oval and TUNEL- and malondialdehyde-positive cells increased compared to other cultures with ICG in the dark or without ICG under illumination. Furthermore, the level of intracellular reactive oxygen species was also elevated. On the other hand, toxicity of ICG denatured by illumination was not observed. Blocking green to red light overlapping wavelengths of ICG absorbance exhibited decreased cell death rate. The present study indicated that ICG at the estimated intravenous concentrations after ICG angiography induces potential phototoxicity on human RPE cells via oxidative damage under continuous ambient illumination and that the cytotoxicity is reduced by blocking green to red light wavelengths.


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