scholarly journals Change in Dose-survival Time Relationship after X-irradiation during Embryonic Development in the Fish, Oryzias Iatipes

1969 ◽  
Vol 10 (3-4) ◽  
pp. 121-125 ◽  
Author(s):  
Yasuko HYODO-TAGUCHI ◽  
Nobuo EGAMI
Keyword(s):  
Embryonic Development ◽  
Survival Time ◽  
Time Relationship ◽  
X Irradiation

Concentration-Survival Time Relationship for Roaches Injected with Arsenicals

1945 ◽  
Vol 38 (6) ◽  
pp. 634-642 ◽  
Author(s):  
Sam C. Munson ◽  
J. Franklin Yeager
Keyword(s):  
Survival Time ◽  
Time Relationship

Enhancement of the efficacy of x-irradiation by pentobarbital in a rodent brain-tumor model

1990 ◽  
Vol 72 (5) ◽  
pp. 745-748 ◽  
Author(s):  
Jeffrey J. Olson ◽  
Robert Friedman ◽  
Kathryn Orr ◽  
Thomas Delaney ◽  
Edward H. Oldfield
Keyword(s):  
Brain Tumor ◽  
Survival Time ◽  
Radiation Treatment ◽  
Normal Brain ◽  
Content Type ◽  
Tumor Bearing ◽  
X Irradiation ◽  
Group 3 ◽  
Group 2 ◽  
Fine Print

✓ Radiation therapy is an important component of brain tumor treatment, but its efficacy is limited by its toxicity to the surrounding normal tissue. Pentobarbital acts as a cerebral radioprotectant, but the selectivity of its protection for the central nervous system has not been demonstrated. To determine if pentobarbital also protects tumor against ionizing radiation, five groups of Fischer 344 rats were observed after exposure to varying combinations of the presence or absence of implanted tumor, pentobarbital, and radiation treatment. The first three groups underwent cerebral implantations of a suspension of 9L gliosarcoma cells. Group 1 was left untreated and served as tumor-bearing controls. Group 2 received 30 Gy of whole-brain x-irradiation without anesthesia 8 days after tumor implantation. Group 3 received the same radiation treatment 15 minutes after pretreatment with 60 mg/kg of pentobarbital intraperitoneally. Groups 4 and 5 served as radiation controls, receiving 30 Gy of x-irradiation while awake and 30 Gy of x-irradiation after pentobarbital administration, respectively. Survival was calculated from the death of the last tumor-bearing rat. The mean survival time in tumor-bearing control rats was 20.8 ± 2.6 days (± standard deviation). X-irradiation alone significantly enhanced the period of survival in rats implanted with the 9L tumor (29.7 ± 5.6 days, p < 0.003). Further significant prolongation of survival was seen with the addition of pentobarbital to the treatment regimen (39.9 ± 13.5 days, p < 0.01). Nontumor-bearing rats irradiated while awake (Group 4) survived 30.9 ± 2.3 days. All of their pentobarbital-anesthetized counterparts in Group 5 survived. If pentobarbital had offered radioprotection to the tumor, then Group 3 would have had a shorter survival period than Group 2. This implies that the enhancement of survival time after irradiation results from selective protection of normal brain in this model.

scholarly journals Egg morphology, larval development and description of the oncomiracidium of Heterobothrium ecuadori (Monogenea: Diclidophoridae) parasitising the bullseye pufferfish, Sphoeroides annulatus

2011 ◽  
Vol 48 (1) ◽  
pp. 51-55 ◽  
Author(s):  
M. Grano-Maldonado ◽  
A. Roque ◽  
H. Aguirre ◽  
E. Fajer-Avila
Keyword(s):  
Embryonic Development ◽  
Survival Time ◽  
The Body ◽  
Full Description ◽  
Valuable Data ◽  
Precise Information ◽  
Mean Survival Time ◽  
Hatching Time ◽  
Egg Morphology ◽  
Time Required

AbstractThe present study is the first description of the egg morphology, embryonic development, and time required for hatching, and longevity of the oncomiracidium of Heterobothrium ecuadori (Meserve, 1938) Sproston, 1946. Experiments found that hatching time fluctuated between 7 and 10 days with a mean of 7.5 ± 1 days at 23 ± 1° C and 35 ‰. Eggs were provided with a polar filamentous appendage. The body of the oncomiracidium was flattened dorso-ventrally, 156 ± 9 μm long and 65 ± 8 μm wide. A full description of the egg development and morphology of the oncomiracidium is provided. The longevity of the oncomiracidia was 4–7 days at 21 ± 1°C, with a mean survival time of 121.8h. The ability to rear diclidophorids like H. ecuadori and to record precise information on their development provides valuable data for further studies.

scholarly journals Studies in the dynamics of disinfection: XIII. The nature of the probit-log survival-time relationship in disinfections of standard cultures of Bact. coli at 51°C. under various conditions of pH

1948 ◽  
Vol 46 (3) ◽  
pp. 280-288 ◽  
Author(s):  
R. C. Jordan ◽  
S. E. Jacobs
Keyword(s):  
Survival Time ◽  
Bilinear Form ◽  
Experimental Error ◽  
Line Treatment ◽  
Continuous Curve ◽  
Close Approximation ◽  
Percentage Mortality ◽  
Ph Values ◽  
Time Relationship ◽  
Straight Line

1. The nature of the probit-log survival-time relationship in the disinfection of standard cultures of Bact. coli at 51° C. at pH values ranging from 2·8 to 8·8 has been studied.2. It is concluded that there is a very close approximation to a bilinear form in all cases, though there was evidence that a continuous curve concave upwards and to the left would provide a better fit.3. Probit limits, corresponding to the range of percentage mortality within which, having regard to the experimental error involved, an observation might lie, have been worked out. The range covered by these probit limits decreases as the percentage mortality rises.4. These limits have been used to decide whether a bilinear or a single straight line treatment should be applied to certain sets of data. It is suggested that they would often materially assist in deciding the range over which linearity may be assumed in any given case.

scholarly journals Studies in the dynamics of disinfection IX. The effect of lethal temperatures on standard cultures of Bact. Coli. I. The nature of the probit-log survival-time relationship at pH 7·0

1947 ◽  
Vol 45 (2) ◽  
pp. 144-148 ◽  
Author(s):  
R. C. Jordan ◽  
S. E. Jacobs ◽  
H. E. F. Davies
Keyword(s):  
Survival Time ◽  
Financial Assistance ◽  
Full Time ◽  
Time Curve ◽  
Lethal Temperatures ◽  
Time Relationship ◽  
The Relationship

1. A study has been made of the probit-log survival-time relationship in a number of experiments in which whole standard cultures of Bact. coli were subjected to heat at temperatures ranging from 47 to 55° C.2. It is concluded that the whole mortality up to 99·99 % could not be covered by a single straightline relationship since the graphs are curves concave upwards and to the left.3. Between 95 and 99·99 % mortality the relationship approximated closely to linearity.4. Several individual experiments showed ‘humps’ in their curves. These, although always occurring at the same stage in time in the disinfections, varied in their probit levels.5. By combining the data for all experiments, an idealized probit-log survival-time curve was obtained in which the changes of slope were less marked than in the curve representing the disinfection of similar cultures by phenol.The authors wish to express their gratitude to Messrs I.C.I. (Pharmaceuticals) Ltd. for their valuable financial assistance, which has enabled one of us (H. E. F. D.) to devote his full time to this work.

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