scholarly journals BIOLOGICAL EFFECTS OF SMALL DOSES OF RADIATION.

1971 ◽  
Author(s):  
J Fabrikant
Keyword(s):  
Biological Effects ◽  
Small Doses

Influence of small doses of various drug vehicles on acetaminophen-induced liver injury

2010 ◽  
Vol 88 (10) ◽  
pp. 960-967 ◽  
Author(s):  
Tomislav Kelava ◽  
Ivan Ćavar ◽  
Filip Čulo
Keyword(s):  
Liver Injury ◽  
Propylene Glycol ◽  
Reduced Glutathione ◽  
Biological Effects ◽  
Tween 20 ◽  
Histopathological Changes ◽  
Acetaminophen Toxicity ◽  
Small Doses ◽  
Injury Assessment ◽  
Drug Vehicle

The biological effects of drug vehicles are often overlooked, often leading to artifacts in acetaminophen-induced liver injury assessment. Therefore, we decided to investigate the effect of dimethylsulfoxide, dimethylformamide, propylene glycol, ethanol, and Tween 20 on acetaminophen-induced liver injury. C57BL/6 male mice received a particular drug vehicle (0.6 or 0.2 mL/kg, i.p.) 30 min before acetaminophen administration (300 mg/kg, i.p.). Control mice received vehicle alone. Liver injury was assessed by measuring the concentration of alanine aminotransferase in plasma and observing histopathological changes. The level of reduced glutathione (GSH) was assessed by measuring total nonprotein hepatic sulfhydrils. Dimethylsulfoxide and dimethylformamide (at both doses) almost completely abolished acetaminophen toxicity. The higher dose of propylene glycol (0.6 mL/kg) was markedly protective, but the lower dose (0.2 mL/kg) was only slightly protective. These solvents also reduced acetaminophen-induced GSH depletion. Dimethylformamide was protective when given 2 h before or 1 h after acetaminophen administration, but was ineffective if given 2.5 h after acetaminophen. Ethanol at the higher dose (0.6 mL/kg) was partially protective, whereas ethanol at the lower dose (0.2 mL/kg) as well as Tween 20 at any dose had no influence. None of the vehicles (0.6 mL/kg) was hepatotoxic per se, and none of them was protective in a model of liver injury caused by d-galactosamine and lipopolysaccharide.

Effects of Ultrasonic on Ability of Learning and Memory in Kunming Mice

2011 ◽  
Vol 295-297 ◽  
pp. 1369-1372
Author(s):  
Bao Qiang Wang ◽  
Liang Liang Yang
Keyword(s):  
Learning And Memory ◽  
Ultrasonic Irradiation ◽  
Water Maze ◽  
Irradiation Time ◽  
Biological Effects ◽  
Ultrasonic Method ◽  
Discrete Distribution ◽  
Memory Ability ◽  
Cavitation Effect ◽  
Small Doses

Objective:to study the effects and mechanisms of ultrasonic on ability of learning and memory in Kunming mice.Methods:changing the time of irradiation can get different dose of ultrasonic. Using Morris water maze analyzes the activity of Kunming mice on different time points. Remain the same ultrasonic irradiation time, and find the rule of platform latency by comparing the ultrasonic method with no ultrasonic. According to statistics analyzing related experiments data by SPSS and the theory of ultrasonic biological effects, how ultrasonic affects the ability of learning and memory in mice can be found. Results: small doses of ultrasonic have positive significance on the learning and memory ability in mice .But more than regular doses, the ability of learning and memory will be badly damage. After ultrasonic irradiation, the latency is discrete distribution while no ultrasonic irradiation the latency is stable.Conclusion:ultrasonic has certain effects on the learning and memory ability in Kuming mice. Its mechanism is the mechanical, thermal, cavitation effect of ultrasonic.

Review of the Radiation Damage Problem of Organic Specimens in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 476-477
Author(s):  
L. Reimer
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Irradiation Time ◽  
Dose Effect ◽  
Primary Process ◽  
Thin Specimen ◽  
Secondary Damage ◽  
Small Doses ◽  
Micro Organisms ◽  
Damage Processes

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

Genomic analysis of C-type lectins

2002 ◽  
Vol 69 ◽  
pp. 59-72 ◽  
Author(s):  
Kurt Drickamer ◽  
Andrew J. Fadden
Keyword(s):  
Biological Effects ◽  
Cell Signalling ◽  
Genomic Analysis ◽  
Binding Activity ◽  
Immunoglobulin Superfamily ◽  
Carbohydrate Binding ◽  
Carbohydrate Recognition ◽  
Calcium Dependent ◽  
Binding Domains ◽  
Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

Lauric Acid-Induced Thrombocytopenia and Thrombosis in Rabbits

1967 ◽  
Vol 18 (01/02) ◽  
pp. 057-065 ◽  
Author(s):  
G Zbinden
Keyword(s):  
Acid Solution ◽  
Intravenous Injection ◽  
Lauric Acid ◽  
Repeated Administration ◽  
Intravenous Dose ◽  
Acid Injection ◽  
Small Doses ◽  
High Doses

SummaryIntravenous injection of 0.5% lauric acid solution into rabbits caused moderate to marked thrombocytopenia. With small doses (2.5 mg/kg) this thrombocyte decrease was reversible and microscopically demonstrable thrombosis in the lungs was only seen or suspected in a small number of rabbits 10 to 30 min after lauric acid injection. High doses were followed by partly reversible thrombocytopenia and by moderate to marked, sometimes lethal, thrombosis in the lungs still demonstrable 24 hrs after injection. Repeated administration of small doses of lauric acid did not lead to a depletion of the circulating thrombocytes. Thrombocytopenic response, however, appeared to be less pronounced after the second and subsequent injections. Studies with Cr51-labeled platelets indicate that during the reversible thrombocytopenia following a small intravenous dose of lauric acid platelets are retained in various organs, particularly the lungs.

Functional Fractionation of Platelets: Aggregation Kinetics and Glycoprotein Labeling of Differing Platelet Populations

1982 ◽  
Vol 48 (02) ◽  
pp. 211-216 ◽  
Author(s):  
V M Haver ◽  
A R L Gear
Keyword(s):  
Galactose Oxidase ◽  
Aggregation Kinetics ◽  
Maximal Rate ◽  
Membrane Glycoproteins ◽  
Whole Cells ◽  
Reversible Aggregation ◽  
Significant Difference ◽  
Small Doses ◽  
Major Loss ◽  
Kinetics Of

SummaryPlatelet heterogeneity has been studied with a technique called functional fractionation which employs gentle centrifugation to yield subpopulations (“reactive” and “less-reactive” platelets) after exposure to small doses of aggregating agent. Aggregation kinetics of the different platelet populations were investigated by quenched-flow aggregometry. The large, “reactive” platelets were more sensitive to ADP (Ka = 1.74 μM) than the smaller “less-reactive” platelets (Ka = 4.08 μM). However, their maximal rate of aggregation (Vmax, % of platelets aggregating per sec) of 23.3 was significantly lower than the “less-reactive” platelets (Vmax = 34.7). The “reactive” platelets had a 2.2 fold higher level of cyclic AMP.Platelet glycoproteins were labeled using the neuraminidase-galactose oxidase – [H3]-NaBH4 technique. When platelets were labeled after reversible aggregation, the “reactive” platelets showed a two-fold decrease in labeling efficiency (versus control platelets). However, examination of whole cells or membrane preparations from reversibly aggregated platelets revealed no significant difference in Coomassie or PAS (Schiff) staining.These results suggest that the large, “reactive” platelets are more sensitive to ADP but are not hyperaggregable in a kinetic sense. Reversible aggregation may cause a re-orientation of membrane glycoproteins that is apparently not characterized by a major loss of glycoprotein material.

Platelet Behavior in Classic Migraine: Responsiveness to Small Doses of Aspirin

1983 ◽  
Vol 49 (02) ◽  
pp. 153-153 ◽  
Author(s):  
G D’Andrea ◽  
A Cananzi ◽  
M Toldo ◽  
S Cortelazzo ◽  
F Ferro-Milone
Keyword(s):  
Small Doses
Sign in / Sign up

Export Citation Format

Share Document