The consequences of the effects of the chemotherapeutic drug (vincristine) in organs and the influence on the bioavailability of two radio-biocomplexes used for bone evaluations in balb/c female mice

The development of animal model to evaluate the toxicological action of compounds used as pharmaceutical drugs is desired. The model described in this work is based on the capability of drugs to alter the bioavailability of radiopharmaceuticals (radiobiocomplexes) labeled with technetium-99 m(99mTc). There are evidences that the bioavailability or the pharmacokinetic of radiobiocomplexes can be modified by some factors, as drugs, due to their toxicological action in specific organs. Vincristine is anatural product that has been utilized in oncology. The vincristine effect on the bioavailability of the radiobiocomplexes 99mTc- ethylenediphosphonic acid (99mTc-MDP) and 99mTc-pyrophosphate (99mTc- PYP) in Balb/c female mice was evaluated. The fragments of kidney were processed to light microscopy and transmission electron microscopy. The aim of this work was to study at structural and ultrastructural levels the alterations caused by vincristine in organs. One hour after the last dose ofvincristine, 99mTc-PYP or 99mTc-MDP was injected, the animals were sacrificed and the percentage of radioactivity (%ATI) was determined in the isolated organs. Concerning 99mTc-PYP, the %ATI (i) decreased in spleen, thymus, lymph nodes (inguinal and mesentheric), kidney, lung, liver, pancreas, stomach, heart and brain and (ii) increased in bone and thyroid. Concerning 99mTc-MDP, the %ATI (iii) decreased in spleen, thymus, lymph nodes (inguinal and mesentheric), kidney, liver, pancreas,stomach, heart, brain, bone, ovary and uterus. In conclusion, the toxic effect of vincristine in determined organs could be responsible for the alteration of the uptake of the studied radiobiocomplexes

Factors affecting the adhesion of water-stressed Helicobacter pylori to plumbing materials

The most important route(s) of transmission for Helicobacter pylori among the human population has yet to be identified, but water and associated biofilms have been considered as potential environmental reservoirs in several studies. Although molecular techniques have identified H. pylori in water-associated biofilms, there is a lack of studies reporting what factors affect the attachment of the bacterium to plumbing materials. Therefore, the influence of shear stress, temperature, inoculation concentration, and different abiotic substrata on the total counts of attached H. pylori was evaluated using epifluorescence and scanning electron microscopy. Results were statistically significant for adhesion of the bacterium at different shear stress (p < .001), with higher numbers of attached H. pylori being obtained at the lowest flow velocities of the water. By contrast, temperature, inoculation concentration, and different substrata appeared to have no effect on attached bacteria (p > .05). The importance of shear stress in the attachment of the microorganism indicates water storage reservoirs or wells, where low shear forces are usually present, as more probable locations for the subsistence of H. pylori attached to the surfaces and consequently embedded in biofilms. This conclusion supports the findings observed by others where the ingestion of well water was correlated with an increased chance of developing an H. pylori infection