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Enzyme systems of detoxication — overview of recent approaches

Enzyme systems of detoxication — overview of recent approaches

The most important enzymes of detoxication are cytochromes P450 of Phase I and UDPglucuronosyltransferases of Phase II of drug metabolism. The conventional division of drug, or xenobiotic, metabolism to two phases has survived almost fifty years and although not perfect, still is rather informative and practical. The recent addition of the next, third phase to the first two (Phase I as yielding a molecule with free functional groups ready for conjugation with another molecule or its part in Phase II) stressed the importance of drug transport across the membranes even if it is not a pure metabolic process (i.e. a process changing the polarity and structure of a compound).

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Radiosensitive effect of curcumin on thyroid cancer cell death induced by radioiodine-131

ABSTRACT

Curcumin is a natural product widely consumed by humans. It has many biological properties. In this study, we investigated the radiosensitive effect of curcumin on thyroid cancer cells against cellular toxicity induced by 131-I. Human thyroid cancer and human non-malignant fibroblast cells (HFFF2) were treated with 131-I and/or curcumin at different concentrations (5, 10 and 25 μg/ml) for 48 h. The cell proliferation was measured by determination of the surviving cells by using MTT assay. Our results showed that curcumin increased the killing effect of 131-I on thyroid cancer cells, while it exerted no toxicity on HFFF2 cells. This result shows a promising effect of curcumin on the enhancement of therapeutic effects of 131-I in patients

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Hemostatic effect and distribution of new rhThrombin formulations in rats

ABSTRACT

Recombinant human thrombin (rhThrombin) is a potential hemostatic alternative to bovine and human plasma-derived thrombin. Hemostatic, liver regeneration effect and plasma concentrations of rhThrombin (SCILL) tested in the form of solution and hydrogels (thermo-sensitive poloxamer gel and carbomer gel; hameln rds) were evaluated. In the bleeding model, rhThrombin was applied locally on the bleeding site. The time to hemostasis was measured. The rhThrombin in liquid form as well as the thermo-sensitive gel forming formulation significantly reduced the bleeding time in comparison to saline. In the regeneration model, a cut in the form “V” was made on the liver and rhThrombin in both formulations was applied at defined concentrations to the wound for 5 min. The rats survived 1, 3 and 5 days after the injury and treatment. Histological examination showed better results in the group treated with rh Thrombin gel in comparison to the liquid form - solution; differences were insignificant. Low [125I]-rhThrombin radioactivity was evaluated in plasma after topical application (solution and both hydrogels) at hemostatic effective doses to partial hepatectomy in rats. Locally applied rh Thrombin on the rat damaged liver tissue never reached pharmacologically active systemic levels. The plasmatic levels and the content of this active protein in injured liver tissue were lower after application of its hydrogels versus solution

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Exposure-dependent variation in cryolite induced lethality in the nontarget insect, Drosophila melanogaster

Abstract

The starting point of toxicity testing of any chemical in an organism is the determination of its Lethal Concentration 50 (LC50). In the present study, LC50 of a fluorinated insecticide cryolite is determined in a non-target insect model, Drosophila melanogaster. Interestingly, the result shows that acute LC50 of cryolite was much greater in comparison to the chronic one in case of Drosophila larvae. Larvae which were exposed to 65,000 to 70,000 μg/ml cryolite through food showed 50% mortality after 18 hours of acute exposure, whereas only 150 to 160 μg/ml cryolite was sufficient to cause 50% mortality in case of chronic exposure. Thus cryolite in a small amount when applied once cannot produce noticeable changes in Drosophila, whereas the same amount when used continuously can be fatal. The non-feeding pupal stage was also seen to be affected by chemical treatment. This suggests that the test chemical affects the developmental fate and results in failure of adult emergence. Absence of chemical-induced mortality in adults assumes that the toxicity of cryolite might be restricted to the preimaginal stages of the organism. Reduction in body size of larvae after ingestion of cryolite (with food) in acute treatment schedule is another interesting finding of this study. Some individuals consuming cryolite containing food cannot survive whereas the few survivors manifest a significant growth retardation which might be due to a tendency of refusal in feeding. Hence the present findings provide a scope of assessment of risk of other similar non-target groups

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Sorption ability of the soil and its impact on environmental contamination

References Adams R, Simmons D, Hartskeerl K, Koehler M. (2004). Surviving suppression: no detectable impacts of Class A foam on soil invertebrates and some Australian native plants. Bushfi re 2004: earth, wind & fi re: fusing the elements: conference proceedings, Department for Environment and Heritage, Adelaide, South Australia. Domene X, Colon J, Uras MV, Izquierdo R, Avila A, Alcaniz JM. (2010). Role of soil properties in sewage sludge toxicity to soil collembolans. Soil Biology and Biochemistry, 42, 1982 - 1990

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The occurrence of Entamoeba gingivalis among patients with periodontal disease

Abstract

According to some studies, the Entamoeba gingivalis colonizing the gingival tissue is an important agent in bringing about periodontitis. Other studies, however, deem it an opportunist that is able to survive in the medium induced by periodontal disease. The aim of this study was to investigate the prevalence of Entamoeba gingivalis infection in patients from the Department of Periodontology, and compare this population with that of healthy people, so as to analyze the relationships between infection and patient sex and age. The result of this work is that in both groups, a correlation (p = 0,19) has been noted between the occurrence of amoebae and other diseases in the oral cavity. Indeed, 81,4% of all patients with some periodontal disease showed the presence of amoeba. Among those who are not afflicted with oral diseases, the presence of amoeba was indicated in 62,5% of the total. In addition, a correlation between the person's age and the presence of protozoa (p = 0,15) was strongly marked among women (p = 0,19). In the three age groups of women in this study (40-49, 60-69, and above 80 years), we observed a 100% presence of protozoa.

Our study leads us to the conclusion that infections with Entamoeba gingivalis should be regarded as an factor that is associated with the pathological changes occurring in patients with periodontal diseases.

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Cardinal temperatures for germination of Salvia leriifolia Benth

Salvia leriifolia. Iran J Basic Med Sci 2009; 12(1):1-8. 5. Hosseinzadeh H, Imanshahidi M. Effect of Salvia leriifolia Benth. aqueous and ethanolic leaf and seed extracts on surviving time of hypoxic mice. Iran J Basic Med Sci 1999; 2:75-81. 6. Khooei AR, Hosseinzadeh H, Imanshahidi M. Pathologic evaluation of anti-ischemic effect of Salvia leriifolia Benth. seed and leaf extracts in rats after global cerebral ischemia. Iran J Basic Med Sci 2003; 5:200-5. 7. Sadeghnia HR, Nassiri Asl M, Haddad Khodaparast MH, Hosseinzadeh

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