Incorporating the Host-Pathogen Kinetics of Time-Dose-Response into Epidemic Outbreak Models

2021 ◽  
Author(s):  
Bidya Prasad
Keyword(s):  
Dose Response ◽  
Epidemic Outbreak ◽  
Host Pathogen ◽  
Kinetics Of ◽  
Time Dose

Kinetics of DNA Repair Under Chronic Irradiation at Low and Medium Dose Rates in Repair Proficient and Repair Compromised Normal Fibroblasts

2021 ◽  
Author(s):  
Elena K. Zaharieva ◽  
Megumi Sasatani ◽  
Kenji Kamiya
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dose Rate ◽  
Dose Response ◽  
Chronic Irradiation ◽  
Dose Rates ◽  
Chronic Radiation ◽  
Damage Repair ◽  
Kinetics Of ◽  
Medium Dose

We present time and dose dependencies for the formation of 53BP1 and γH2AX DNA damage repair foci after chronic radiation exposure at dose rates of 140, 250 and 450 mGy/day from 3 to 96 h, in human and mouse repair proficient and ATM or DNA-PK deficient repair compromised cell models. We describe the time/dose-response curves using a mathematical equation which contains a linear component for the induction of DNA damage repair foci after irradiation, and an exponential component for their resolution. We show that under conditions of chronic irradiation at low and medium dose rates, the processes of DNA double-strand breaks (DSBs) induction and repair establish an equilibrium, which in repair proficient cells manifests as a plateau-shaped dose-response where the plateau is reached within the first 24 h postirradiation, and its height is proportionate to the radiation dose rate. In contrast, in repair compromised cells, where the rate of repair may be exceeded by the DSB induction rate, DNA damage accumulates with time of exposure and total absorbed dose. In addition, we discuss the biological meaning of the observed dependencies by presenting the frequency of micronuclei formation under the same irradiation conditions as a marker of radiation-induced genomic instability. We believe that the data and analysis presented here shed light on the kinetics of DNA repair under chronic radiation and are useful for future studies in the low-to-medium dose rate range.

scholarly journals Time–dose response of oxygen delivery during cardiopulmonary bypass predicts acute kidney injury

2019 ◽  
Vol 158 (2) ◽  
pp. 492-499 ◽  
Author(s):  
Hiroshi Mukaida ◽  
Satoshi Matsushita ◽  
Kenji Kuwaki ◽  
Takahiro Inotani ◽  
Yuki Minami ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Cardiopulmonary Bypass ◽  
Dose Response ◽  
Oxygen Delivery ◽  
Kidney Injury ◽  
Time Dose

scholarly journals A method for incorporating a time-dose-response model into a Giardia lamblia outbreak

2017 ◽  
Vol 15 (4) ◽  
pp. 490-504
Author(s):  
Bidya Prasad ◽  
Michael O. Ryan ◽  
Charles N. Haas
Keyword(s):  
Dose Response ◽  
Giardia Lamblia ◽  
Probability Model ◽  
Infectious Agent ◽  
Likelihood Estimation ◽  
Dependency Model ◽  
Using Data ◽  
Best Fit ◽  
Time Dose

Experimental time-to-infection data is a useful, but often underutilized, material for examining the mechanics of in vivo pathogen growth. In this paper, the authors attempt to incorporate a time-dose-response (TDR) equation into a model which predicts the number of ill persons per day in a Giardia lamblia epidemic using data collected from a Pittsfield, Massachusetts outbreak. To this end, dose-response and TDR models were generated for Giardia exposure to beaver and human volunteers, and a maximum likelihood estimation approach was used to ensure that the models provided acceptable fits. The TDR equation that best-fit the human data was the beta-Poisson with exponential-reciprocal dependency model, and this was chosen to be incorporated into the outbreak model. The outbreak model is an expanded probability model that convolutes an assumed incubation distribution of the infectious agent with an exposure distribution. Since the beta-Poisson with exponential-reciprocal dependency models the time-to-infection density distribution, it is input as the incubation distribution. Several density functions, including the Weibull, lognormal, gamma, and uniform functions served as exposure distributions. The convolution of the time-dependent probability distribution with the lognormal distribution yielded the best-fit for the outbreak model.

scholarly journals A human time dose response model for Q fever

Epidemics ◽  
2017 ◽  
Vol 21 ◽  
pp. 30-38 ◽  
Author(s):  
Charles W. Heppell ◽  
Joseph R. Egan ◽  
Ian Hall
Keyword(s):  
Dose Response ◽  
Q Fever ◽  
Response Model ◽  
Time Dose
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