DOSE FRACTIONATION AND RECOVERY FROM X RAYS IN RHODNIUS

1964 ◽  
Vol 42 (4) ◽  
pp. 515-518 ◽  
Author(s):  
W. F. Baldwin ◽  
Evelyn L. Shaver
Keyword(s):  
Total Dose ◽  
Recovery Period ◽  
Rhodnius Prolixus ◽  
Fourth Instar ◽  
Full Recovery ◽  
Dose Fractionation ◽  
X Rays ◽  
Single Exposure ◽  
Radiation Induced

Recovery from radiation-induced damage has been studied in Rhodnius prolixus by comparing the effects of single exposures with those of fractionated exposures to the same total dose (6000 r). Immature fourth-instar nymphs, irradiated as above, showed an equal amount of recovery from molting delay (in days) with intervals ranging from 0 to 250 hours between irradiation and feeding. Recovery was most rapid during the first 16 hours. In the case of the single exposure of 6000 r, molting was reduced almost to control levels within the full recovery period of 2048 hours.

RADIATION-INDUCED STERILITY IN THE INSECT RHODNIUS PROLIXUS

1963 ◽  
Vol 41 (4) ◽  
pp. 637-648 ◽  
Author(s):  
W. F. Baldwin ◽  
Evelyn L. Shaver
Keyword(s):  
Population Growth ◽  
Mating Behavior ◽  
Adult Stage ◽  
Substantial Reduction ◽  
Rhodnius Prolixus ◽  
The Other ◽  
High Dose ◽  
X Rays ◽  
Radiation Induced ◽  
Very High

Immature fifth instar Rhodnius nymphs and adults of both sexes were exposed to various doses of 2 MVP X-rays, chosen to produce reductions in fertility up to and including complete sterility. In male insects irradiated as fifth instar nymphs and reared to the adult stage, sterilizing doses interfered with mating, thus making these males useless as a means of inhibiting the growth of populations into which they are introduced. Exposure in the adult stage, on the other hand, had less effect on mating behavior. Thus, with a very high dose (17,500 r) and high ratios of sterile to fertile males, a substantial reduction occurred in percentage of viable eggs from normal females. However, this was true for the first month only. In the second and third months, the effect on population fertility disappeared, a result of the early deaths of irradiated males. Greater effectiveness in limiting population growth over extended periods might be expected to result from the introduction of males that had been partially sterilized by exposure to lower doses.

scholarly journals Factors Limiting the Number of Radiation-Induced Chromosome Exchanges

1958 ◽  
Vol 4 (4) ◽  
pp. 365-372 ◽  
Author(s):  
Sheldon Wolff ◽  
K. C. Atwood ◽  
M. L. Randolph ◽  
H. E. Luippold
Keyword(s):  
Dose Fractionation ◽  
Fast Neutrons ◽  
Root Tip ◽  
X Rays ◽  
X Ray ◽  
Linear Dose ◽  
Radiation Induced ◽  
Short Fractionation ◽  
Chromosome Exchanges ◽  
Aberration Yield

Soaked seeds of Vicia faba were exposed to fractionated doses of x-rays or x-rays and fast neutrons. When the two-hit (exchange) chromosome aberrations were scored at the first mitosis of the root tip, it was observed that with short fractionation times the radiation-induced breaks from the two x-ray doses could rejoin with one another to form exchanges in proportion to the square of the total dose. If, however, one dose was x-rays and the second neutrons, then no quantitatively determinable interaction occurred between the breaks induced by each of the doses, and the aberration yield was simply the sum of that induced by each fraction. The phenomenon of non-interaction as observed by these dose fractionation studies and also by the linear dose response curve for two-break aberrations induced by neutrons has led to calculations of the distance over which two breaks can rejoin. The distance is evidently much smaller than the previously accepted value of 1 µ.

scholarly journals Immunomodulatory Effects of Radiotherapy

2020 ◽  
Vol 21 (21) ◽  
pp. 8151
Author(s):  
Sharda Kumari ◽  
Shibani Mukherjee ◽  
Debapriya Sinha ◽  
Salim Abdisalaam ◽  
Sunil Krishnan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Carbon Particle ◽  
Dna Lesions ◽  
X Rays ◽  
Adaptive Immune ◽  
High Let Radiation ◽  
Different Types ◽  
High Let ◽  
Radiation Induced ◽  
Tumor Death

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.

scholarly journals Differential Effects of Gold Nanoparticles and Ionizing Radiation on Cell Motility between Primary Human Colonic and Melanocytic Cells and Their Cancerous Counterparts

2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Colorectal Adenocarcinoma ◽  
X Rays ◽  
Cell Adherence ◽  
Cancerous Cell ◽  
Primary Colon ◽  
Radiation Induced

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

A review on radiation induced nausea and vomiting: “Current management strategies and prominence of radio sensitizers”

2021 ◽  
pp. 107815522110115
Author(s):  
Meenu Vijayan ◽  
Sherin Joseph ◽  
Emmanuel James ◽  
Debnarayan Dutta
Keyword(s):  
Radiation Therapy ◽  
Cell Damage ◽  
Genetic Material ◽  
High Energy ◽  
Concurrent Chemotherapy ◽  
Nausea And Vomiting ◽  
Dose Fractionation ◽  
Psychological State ◽  
Related Factors ◽  
Radiation Induced

Radiations dissipated are high energy waves used mostly as treatment intervention in controlling the unwanted multiplication of cell. About 60%–65% of cancer treatment requires radiation therapy and 40%–80% of radiation therapy causes RINV which are true troublemakers. Radiation therapy (RT) is targeted therapy mostly used to treat early stages of tumour and prevent their reoccurrence. They mainly destroy the genetic material (DNA) of cancerous cells to avoid their unwanted growth and division. The RINV affects the management and quality of life of patients which further reduces the patient outcome. RINV depends on RT related factors (dose, fractionation, irradiation volume, RT techniques) and patient related factors like (gender, health conditions, age, concurrent chemotherapy, psychological state, and tumour stage). RT is an active area of research and there is only limited progress in tackling the RINV crisis. Advanced technological methods are adopted that led to better understanding of total lethal doses. Radiation therapy also affects the immunity system that leads to radiation induced immune responses and inflammation. Radio sensitizers are used to sensitize the tumour cells to radiations that further prevent the normal cell damage from radiation exposure. There is a need for future studies and researches to re-evaluate the data available from previous trials in RINV to make better effective antiemetic regimen. The article focuses on radiation therapy induced nausea and vomiting along with their mechanism of action and treatment strategies in order to have a remarkable patient care.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

scholarly journals Low-Dose Radiation Activates Akt and Nrf2 in the Kidney of Diabetic Mice: A Potential Mechanism to Prevent Diabetic Nephropathy

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Xiao Xing ◽  
Chi Zhang ◽  
Minglong Shao ◽  
Qingyue Tong ◽  
Guirong Zhang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Low Dose ◽  
X Rays ◽  
Diabetic Mice ◽  
Low Dose Radiation ◽  
Single Exposure ◽  
Akt Phosphorylation ◽  
And Function ◽  
Nrf2 Expression ◽  
Dose Radiation

Repetitive exposure of diabetic mice to low-dose radiation (LDR) at 25 mGy could significantly attenuate diabetes-induced renal inflammation, oxidative damage, remodeling, and dysfunction, for which, however, the underlying mechanism remained unknown. The present study explored the effects of LDR on the expression and function of Akt and Nrf2 in the kidney of diabetic mice. C57BL/6J mice were used to induce type 1 diabetes with multiple low-dose streptozotocin. Diabetic and age-matched control mice were irradiated with whole body X-rays at either single 25 mGy and 75 mGy or accumulated 75 mGy (25 mGy daily for 3 days) and then sacrificed at 1–12 h for examining renal Akt phosphorylation and Nrf2 expression and function. We found that 75 mGy of X-rays can stimulate Akt signaling pathway and upregulate Nrf2 expression and function in diabetic kidneys; single exposure of 25 mGy did not, but three exposures to 25 mGy of X-rays could offer a similar effect as single exposure to 75 mGy on the stimulation of Akt phosphorylation and the upregulation of Nrf2 expression and transcription function. These results suggest that single 75 mGy or multiple 25 mGy of X-rays can stimulate Akt phosphorylation and upregulate Nrf2 expression and function, which may explain the prevention of LDR against the diabetic nephropathy mentioned above.

Sign in / Sign up

Export Citation Format

Share Document