Study of the Effect of Hyperbaric Oxygen Therapy on the Viability of Dorsal Cutaneous Flaps in Tobacco-Exposed Rats.

BACKGROUND: Smoking causes a threefold increase in the risk of surgical complications in flaps. Hyperbaric oxygen therapy (HBOT) increases the viability of chronic wounds. However, there are few studies concerning the effects of HBOT on surgical flaps in patients who smoke. This study aimed to analyze the effect of HBOT on the viability of cutaneous flaps in tobacco-exposed rats. METHODS: Twenty Wistar rats were exposed to tobacco smoke for two months. Following this period, all animals underwent a dorsal cutaneous flap (3 × 10 cm) surgery and were divided into two groups: control (n = 10) and HBOT (n = 10). HBOT was performed in seven daily sessions (2 ATA, 90 min). After seven days, the animals were euthanized. The outcomes were total area, viable area, viable area/total area rate, analysis of dermal appendages and angiogenesis (hematoxylin-eosin), and gene expression analysis of iNOS and VEGF-a biomarkers. RESULTS: The HBOT group showed an increase in viable area compared with the control group (84% versus 47%, p = 0.009, respectively). The HBOT group also showed an increase in appendage units (1.69 ± 0.54 versus 1.87 ± 0.58, p = 0.04) and angiogenesis density (1.29 ± 0.45 versus 1.82 ± 0.64, p < 0.001) compared to the control group. There was a difference between the control and HBOT groups in iNOS levels (0.926 ± 1.4 versus 0.04 ± 0.1 p = 0.002, respectively). However, this study did not show a difference between the groups concerning the gene expression of VEGF-a. CONCLUSION: The use of hyperbaric oxygen therapy increased the viability of cutaneous flaps in tobacco-exposed rats and decreased iNOS mRNA levels; however, it did not change VEGF-a levels. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Pollen mother cells of Tradescantia clone 4430 and Tradescantia pallida var. purpurea are equally sensitive to the clastogenic effects of X-rays

The Tradescantia micronucleus test is a sensitive bioassay for mutagenesis that may be employed both under field and laboratory conditions. This test has been standardized mostly on the basis of the results obtained with clone 4430. However, this clone is not well adapted to tropical weather, frequently showing problems with growth and flowering. In addition, it is attacked by parasites and insects, a fact that limits its use in field studies aiming at the biomonitoring of air pollution. In the city of Säo Paulo, Tradescantia pallida (Rose) Hunt. var. purpurea Boom is widely distributed as an ornamental plant in gardens and along roadsides and streets, mostly because of its natural resistance and its easy propagation. In this report, we present dose-response curves indicating that the sensitivity of T. pallida and clone 4430 to X-radiation (1, 10, 25 and 50 cGy) is similar. The results confirm our previous suggestion that T. pallida represents a good alternative for in situ mutagenesis testing in tropical regions, especially biomonitoring studies in which the exposure conditions may not be fully controllable

Pollen mother cells of Tradescantia clone 4430 and Tradescantia pallida var. purpurea are equally sensitive to the clastogenic effects of X-rays.

The Tradescantia micronucleus test is a sensitive bioassay for mutagenesis that may be employed both under field and laboratory conditions. This test has been standardized mostly on the basis of the results obtained with clone 4430. However, this clone is not well adapted to tropical weather, frequently showing problems with growth and flowering. In addition, it is attacked by parasites and insects, a fact that limits its use in field studies aiming at the biomonitoring of air pollution. In the city of São Paulo, Tradescantia pallida (Rose) Hunt. var. purpurea Boom is widely distributed as an ornamental plant in gardens and along roadsides and streets, mostly because of its natural resistance and its easy propagation. In this report, we present dose-response curves indicating that the sensitivity of T. pallida and clone 4430 to X-radiation (1, 10, 25 and 50 cGy) is similar. The results confirm our previous suggestion that T. pallida represents a good alternative for in situ mutagenesis testing in tropical regions, especially biomonitoring studies in which the exposure conditions may not be fully controllable.