scholarly journals Comparison of growth and toxicity responses between non-toxic and toxic strains of Prorocentrum hoffmannianum

2020 ◽  
Vol 29 ◽  
pp. 59-70
Author(s):  
TCH Lee ◽  
PL Chan ◽  
SJL Xu ◽  
FWF Lee
Keyword(s):  
Correlation Analysis ◽  
Cell Density ◽  
Okadaic Acid ◽  
Comparative Studies ◽  
Growth Response ◽  
Phosphate Metabolism ◽  
Cellular Concentration ◽  
Phosphate Depletion ◽  
Delayed Growth

We aimed to study the growth and toxicity responses of non-toxic (CCMP683) and toxic (CCMP2804) strains of Prorocentrum hoffmannianum under various nitrate and phosphate concentrations. The 2 strains were cultured in L1-Si medium with standard, depleted or 10-fold repleted nitrate or phosphate. CCMP683 cultured in standard L1-Si medium exhibited delayed growth. Nitrate or phosphate depletion decreased the cell density of both strains. Repletion of nitrate slightly increased the cell density of both strains. Repletion of phosphate also slightly increased the cell density of CCMP2804 but surprisingly decreased the cell density of CCMP683. Okadaic acid (OA) and its derivatives were not detected in CCMP683. OA was detected only in CCMP2804. Depletion of nitrate or phosphate increased the cellular concentration of OA, and repletion of nitrate or phosphate had no effect on the cellular concentration of OA. Correlation analysis indicated that the cellular concentration of OA was negatively correlated with cell density. Differences in the growth response to phosphate repletion and in the ability to produce OA suggest that the 2 strains may be good candidates for comparative studies related to phosphate metabolism and OA toxicity.

Impact of Pre- and Intraoperative Factors on Endothelial Cell Density in the Early and Late Stage after Penetrating Keratoplasty

2021 ◽  
Author(s):  
Jessica Brand ◽  
Achim Langenbucher ◽  
Elena Zemova ◽  
Tanja Stachon ◽  
Melanie Weber ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Endothelial Cell ◽  
Correlation Analysis ◽  
Cell Density ◽  
Penetrating Keratoplasty ◽  
Endothelial Cell Density ◽  
Donor Age ◽  
Triple Procedure ◽  
Recipient Age ◽  
Weak Negative Correlation

Abstract Aim This retrospective investigated the impact of donor age, recipient age, donor endothelial cell density, vis-à-tergo, and additional intraoperative lens exchange (triple-procedure) on overall early and late phase postoperative endothelial cell density (ECD) following penetrating keratoplasty (PKP) in various diagnosis groups. Patients and Methods In 590 cases with diagnosed keratoconus (KC), Fuchs dystrophy (FD) and herpes simplex virus infection (HSV) who underwent PKP or triple surgery, the ECD in cells/mm2 was analysed, both preoperatively, with all-sutures-in (early postoperative stage), and after last suture removal. The factors were tested by Mann-Whitney U-test, correlation analysis and linear regression analysis. Outcome Correlation analysis demonstrated a weak negative correlation between the patientʼs ECD and donor age (early postoperative stage: r = − 0.25, p < 0.001; after last suture removal: r = − 0.16; p = 0.003). Regression analysis revealed that donor age did not impact postoperative patient ECD. There was a weak negative correlation between postoperative ECD and recipient age (early postoperative stage: r = − 0.31, p < 0.001; after last suture removal: r = − 0.34, p < 0.001). Regression analysis confirmed the negative impact of recipient age on patient ECD (early postoperative stage: β = − 13.2, p = 0.001; after last suture removal: β = − 4.6, p < 0.001). Correlation analysis determined a weak positive correlation between postoperative ECD and donor endothelial cell density (early postoperative stage: r = 0.37, p < 0.001; after last suture removal: r = 0.32, p < 0.001). Regression analysis also determined that donor endothelial cell density had a positive impact on postoperative ECD following last suture removal (β = 0.4, p < 0.001). Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD (p > 0.05). This was also confirmed by the results of the regression analysis after last suture removal. Conclusion Recipient age and donor endothelial cell density have a significant impact on postoperative ECD following PKP. Not all of the statistical tests proved donor age to be a significant influencing factor. Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD following PKP.

Comparative studies of the actin cytoskeleton response to maitotoxin and okadaic acid

1995 ◽  
Vol 9 (1) ◽  
pp. 1-10 ◽  
Author(s):  
G. Diogène ◽  
V. Fessard ◽  
A. Dubreuil ◽  
S. Puiseux-Dao
Keyword(s):  
Actin Cytoskeleton ◽  
Okadaic Acid ◽  
Comparative Studies

Analysis of a Crowley-Martin Type Chemostat with Delayed Growth Response and Pulsed Input

2014 ◽  
Vol 556-562 ◽  
pp. 4333-4337
Author(s):  
Ming Juan Sun ◽  
Hua Xin Zhao ◽  
Qing Lai Dong
Keyword(s):  
Differential Equation ◽  
Growth Response ◽  
Global Attractivity ◽  
Computational Techniques ◽  
Chemostat Model ◽  
Delayed Differential Equation ◽  
Delayed Growth

In this paper, we introduce and study a Crowley-Martin type Chemostat model with delayed growth response and pulsed input. We get that the existence and the global attractivity of a ‘microorganism-extinction’periodic solution. We prove that the system is permanent under appropriate conditions, by use of new computational techniques for impulsive and delayed differential equation.

Transient oscillations induced by delayed growth response in the chemostat

2005 ◽  
Vol 50 (5) ◽  
pp. 489-530 ◽  
Author(s):  
Huaxing Xia ◽  
Gail S.K. Wolkowicz ◽  
Lin Wang
Keyword(s):  
Growth Response ◽  
Delayed Growth ◽  
Transient Oscillations
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