Acute and long-term effects of X-irradiation on skeletal growth in the rat

1964 ◽  
Vol 207 (6) ◽  
pp. 1447-1451 ◽  
Author(s):  
Richard D. Phillips ◽  
Donald J. Kimeldorf

The early and long-term effects of X-irradiation on skeletal growth were investigated with respect to the age at exposure. Rats exposed at a juvenile age (37 days) to a sublethal dose (430 rad) exhibited a retardation in femur, tibia, and tail growth within 14 days after exposure. The maximal deficit was attained within 30 days after exposure and remained approximately constant for the next 300 days. In animals which were exposed to X-rays as young adults (101 days of age), femur and tibia length did not differ from those of controls for the first 2 months after exposure. However, there was a deficit in femur and tibia length in these animals at the end of life span. The magnitude of the bone length reduction at the end of life span was dose dependent. The two major differences in response between the two age groups were the time course of the radiation effect on growth and the magnitude of the deficit. The reduction in bone length occurred faster and was greater in the younger irradiated group.

1985 ◽  
Vol 1985 (1) ◽  
pp. 547-551 ◽  
Author(s):  
Anthony H. Knap ◽  
Sheila C. Wyers ◽  
Richard E. Dodge ◽  
Thomas D. Sleeter ◽  
Harold R. Frith ◽  
...  

ABSTRACT The Coroil project in Bermuda has been an intensive, multidisciplinary study of the effects of physically and chemically dispersed Arabian light crude oil on the main reef-building coral in Bermuda, Diploria strigosa. This paper reviews the results of this three year study. Corals were exposed to dispersed oil in a flow system, using spectrofluorimetry and gas chromatography to characterize and quantify the dose. Appropriate controls were included in all experiments. The studies included effects of dispersed oil on survival and behavior, the uptake and depuration of petroleum hydrocarbons, photosynthesis by symbiotic zoo-xanthellae, and skeletal growth. In behavioral and growth studies, corals were dosed in the laboratory or in the field. Laboratory-dosed colonies were returned to the field to determine long-term effects. Exposure to 20 ppm of chemically dispersed oil for 24 hours induced various behavioral reactions, including tentacle retraction, tissue contraction and mesenterial filament extrusion. However, effects were typically sublethal, and recovery was usually evident within four days. These symptoms were not significant in long-term transplants. Using the alizarin red staining technique, no long-term effects on skeletal growth could be detected following any of our treatments. Depuration studies using (9-I4C) -phenanthrene and gas chromatographic analysis showed that the uptake of petroleum hydrocarbons by the tissue of Diploria was rapid, but 75 percent of the hydrocarbon dose was eliminated within 14 days. Photosynthesis studies showed a short-term inhibition of photosynthesis only by chemically dispersed oil, with lipid synthesis being most severely affected. Total recovery occurred within 24 hours of exposure.


2021 ◽  
Vol 29 (3) ◽  
pp. 127-131
Author(s):  
MATHEUS GARCIA LOPES MERINO ◽  
VICTOR MORALE ◽  
GUILHERME PEREIRA OCAMPOS ◽  
MARIA CÂNDIDA MIRANDA LUZO ◽  
OLAVO PIRES DE CAMARGO ◽  
...  

ABSTRACT Objective: To compare the long-term effects of a brace designed to stabilize the patellofemoral (PF) joint in comparison to a standard neoprene sleeve for the knee with patellar hole in patients with patellofemoral osteoarthritis (PFOA). Methods: 38 patients with PFOA and comorbidities received either a functional PF brace (Study Group, SG) or a neoprene sleeve for the knee (Control Group, CG). Both groups received clinical treatment to OA and comorbidities according to a program from the institution. Patients were evaluated with Western Ontario and MacMaster (WOMAC) and Lequesne questionnaires, 30-second chair stand test (30CST), Timed Up and Go (TUG), anthropometric measures and self-reported physical activity in minutes/week at inclusion, one, three and twelve months after placing the brace. X-Rays were taken to measure the angles. Results: At one year there was more abandonment in the CG without differences in weight and body mass index between groups during the study. The SG maintained improvements in Lequesne and WOMAC total and subsets during the year, whereas the CG returned to baseline values for pain, function and total (p < 0.01). TUG and 30CST results were always better in the study group without any clinically important improvement in both groups. Conclusion: Long-term use of functional brace added to self-management program improves pain and function in patients with PFOA. Level of Evidence II, Lesser quality RCT (eg, < 80% followup, no blinding, or improper randomization).


2021 ◽  
Vol 9 (A) ◽  
pp. 1097-1103
Author(s):  
Akerke Chayakova ◽  
Marzhan Myrzakhanova ◽  
S. O. Rakhyzhanova ◽  
Ainur Kydyrmoldina ◽  
Elmira Omarkhanova ◽  
...  

Abstract BACKGROUND: Recently, the problem of changes in immunological reactivity has become important with the growth of immunodeficiency states of a different nature. [4]. High radiosensitivity of the immune system, its stability in time and the irreversibility of some post-radiation changes can contribute to the development of long-term effects of radiation [2,3,6]. One of the tasks of modern medicine and biology is to study the effect of chronic or fractionated ionizing effects on the body's immune system both in the early and late periods of irradiation and their 1st generation descendants [1,2,3,11,12].  Therefore, it is necessary to study the long-term effects of sublethal and fractionated effects of g-radiation on the immunological reactivity of the organism, nonspecific phagocytic resistance and their 1st generation descendants. AIM: The aim of this study was to study the long-term effects of sublethal and fractionated effects of g-radiation on the immunological reactivity of the organism, nonspecific phagocytic resistance and their 1st generation descendants.. METHODS: 7 series of experiments were performed on 105 white outbred sexually mature rats. 1-series intact (n=15), 2nd series - (n = 15) irradiated with a sublethal dose of 6 Gr. (1 month), 3rd series - irradiated with a sublethal dose (3 months, n = 20), 4 - descendants 1 - generations after sublethal dose, 5 series - irradiated with a fractionated dose (1 month), 6 series - irradiated with a fractionated dose (3 months), 7 - descendants of the 1st generation after fractionated -irradiation. Each series used 15 animals.     Irradiation of animals 2 - 3 - 4 series was carried out on the Russian radiotherapy device "Agat-RM" -rays 60Co, the dose of sublethal irradiation is 6 Gr. Irradiation of animals of 5-6-7 series was carried out on the Russian radiotherapy device "Agat-RM" with 60Co-rays with topometric and dosimetric preparation of experimental animals, which facilitates the administration of a fractionated dose of 2 Gr. to animals three times within 3 weeks. RESULTS: In the long-term period after fractionated g-irradiation in the T-system of immunity, the following changes occur: against the background of an increase in the total number of lymphocytes, there is a decrease in the pool of CD3 +, CD4 + lymphocytes, immunoregulatory index, normalization of the lymphokine-producing ability of lymphocytes and a decrease in the pool of CD8 + lymphocytes. In the long-term period after fractionated g-irradiation in the humoral link of immunity, an increase in the absolute amount of CD19 + by 3.5 times was noted, which significantly exceeded the indicators of both control and intact animals. The percentage of this pool of cells exceeded the data of intact ones by 1.7 times. In the studied time period, the antibody-producing ability in the spleen increased from 22 ± 1.3 to 45 ± 2.6, without reaching, however, the level of intact animals. At the same time, there was a significant decrease in the suppression index to 13% (P<0.001) and the CIC concentration by 14 times (P<0.001) in the blood serum. The indicators of F/n and NST-test were high by 1.43 and 2.46 times, respectively. So, in the long-term period after exposure to a fractionated dose of g-radiation, the nonspecific phagocytic resistance of the organism is increased. CONCLUSIONS: The tension in the humoral link of immunity is manifested by a decrease in the quantitative and qualitative indicators and an increase in the functional and metabolic activity of neutrophils.  


1970 ◽  
Vol 48 (5) ◽  
pp. 1017-1021
Author(s):  
G. B. Friedmann ◽  
H. M. McCurdy ◽  
F. T. Algard

Graded doses of from 200 to 2000 rad of x-rays were administered to premetamorphic Taricha torosa larvae of various ages. General stunting, specific malformation, pigmentary damage, and a very shortened life-span occurred at all doses. There is an age-dependent dose response; some animals exposed to 200 and 600 rad survived to complete metamorphosis. Evidence is presented supporting a view that postmetamorphic epidermal melanocytes may be derived largely by division of an unpigmented progenitor cell type.


1974 ◽  
Vol 58 (3) ◽  
pp. 417 ◽  
Author(s):  
D. F. Nelson ◽  
J. T. Chaffey ◽  
S. Hellman

A systematic study has been made of the reduction of life span in mice exposed to a single whole-body dose of 15 MeV X-rays. 4604 mice of an inbred A substrain were used, all of the same age, 30 days, when irradiated. Nine dose groups, from 50 to 780 r, were used, with a large number of control mice, which were kept to the end of their lives under the same conditions as the irradiated animals. An analysis of the survival curves has revealed two effects of radiation: a reduction in the median age and an increase in standard deviation of the distribution of ages at death. The latter was found to be a quadratic function of dose and it is suggested that the increase is the result of the larger spread in the ages of onset of diseases in irradiated animals. The reduction of life span was found to be proportional to dose, with no threshold. It amounts to 5∙66 ± 0∙18 weeks per 100 r, or to 38 % of the median life span for a dose equal to the LD 50 (698 r). The difference between the life-shortening in males and females was not statistically significant. The data have also been analyzed in terms of Gompertz plots and it was found that they cannot be represented by straight lines, although the displacement of the curves caused by radiation is roughly proportional to dose. The fact that after correcting for the change in standard deviation, all survival curves are parallel to each other, suggests that the effect of exposure is to ‘age' the animal, by the removal of a few weeks of its early life.


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