Zinc oxide nanoparticles trigger dysfunction of mitochondrial respiratory complexes and repair dynamics in human alveolar cells.

Zinc oxide nanoparticles (ZnO NP) are commonly used engineered NPs with extensive usage in consumer products, thus leading to direct exposure to humans. The direct route of exposure is through inhalation. Once inhaled, these particles accumulate in the lungs, increasing the chances of respiratory tract illness through cellular organelle damage. Zinc oxide nanoparticle-treated lung cells are reported to display cytotoxicity, increase DNA damage, and induce oxidative stress. The current study focused on the effects of ZnO NPs on mitochondrial dynamics (fission and fusion) in human lung epithelial cells (A549). The lung cells were exposed to ZnO NPs at 50 and 100 µg/ml concentrations, and their mitochondrial dynamics were assessed to understand the effects of the NPs. Treatment with ZnO NPs reduced the activity of mitochondrial complex I and complex III and altered mitochondrial structural and functional characteristics in a concentration-dependent manner. Zinc oxide nanoparticles exposure showed an increase in small and round-shaped mitochondria. The expression of various fission proteins (Drp1 and Fis1) and fusion proteins (Mfn1, Mfn2, and OPA1) was altered upon exposure to ZnO NPs. Our studies showed dysfunction of the mitochondria induced by ZnO NPs. In fibroblast mitochondrial dynamics, fission symbolizes threshold damage. In this paper, we have shown that the mitochondrial fission phenotype increased upon exposure to ZnO NPs. The paper emphasizes that these particles enter mitochondria, triggering a stress response that results in the removal of mitochondria via fission. It provides relevant data for safety guidelines to ensure the safer use of these particles.

Effects of extremely low-frequency electromagnetic field on different developmental stages of Drosophila melanogaster.

PURPOSE: The model biological organism Drosophila melanogaster has been utilized to assess the effect of extremely low-frequency electromagnetic field (ELF-EMF) on locomotion, longevity, developmental dynamics, cell viability and oxidative stress. MATERIALS AND METHOD: Developmental stages of Drosophila melanogaster (Oregon R strain) individually exposed to ELF-EMF (75 Hz, 550 µT) for 6 h once for acute exposure. For chronic exposure, complete life cycle of fly, that is, egg to adult fly was exposed to ELF-EMF for 6 h daily. The effect of exposure on their crawling and climbing ability, longevity, development dynamics, cellular damage and oxidative stress (generation of reactive oxygen species (ROS)) was evaluated. RESULTS: The crawling ability of larvae was significantly (p < .05) reduced on acute (third stage instar larvae) as well as chronic exposure (F0 and F1 larvae). When locomotion of flies was tested using climbing assay, no alteration was observed in their climbing ability under both acute and chronic exposure; however, when their speed of climbing was compared, a significant decrease in speed of F1 flies was observed (p = .0027) on chronic exposure. The survivability of flies was significantly affected under chronic and acute exposure (at third stage instar larvae). In case of acute exposure of the third stage instar larvae, although all the flies were eclosed by the 17th day, there was a significant decline in the number of flies (p = .007) in comparison to control. While in case of chronic exposure apart from low number of flies eclosed in comparison to control, there was delay in eclosion by one day (p = .0004). Using trypan blue assay, the internal gut damage of third stage instar larvae was observed. Under acute exposure condition at third stage instar larvae, 30% larvae has taken up trypan blue, while only 10% larvae from acute exposure at adult stage. On chronic exposure, 50% larvae of the F1 generation have taken up trypan blue. On evaluation of oxidative stress, there is a significant rise in ROS in case of acute exposure at third stage instar larvae (p = .0004), adult fly stage (p = .0004) and chronic exposure (p = .0001). CONCLUSION: ELF-EMF has maximum effects on acute exposure of third stage instar larvae and chronic exposure (egg to adult fly stage). These results suggest that electromagnetic radiations, though, have become indispensible part of our lives but they plausibly affect our health.

Cordyceps sinensis increases hypoxia tolerance by inducing heme oxygenase-1 and metallothionein via Nrf2 activation in human lung epithelial cells.

Cordyceps sinensis, an edible mushroom growing in Himalayan regions, is widely recognized in traditional system of medicine. In the present study, we report the efficacy of Cordyceps sinensis in facilitating tolerance to hypoxia using A549 cell line as a model system. Treatment with aqueous extract of Cordyceps sinensis appreciably attenuated hypoxia induced ROS generation, oxidation of lipids and proteins and maintained antioxidant status similar to that of controls via induction of antioxidant gene HO1 (heme oxygenase-1), MT (metallothionein) and Nrf2 (nuclear factor erythroid-derived 2-like 2). In contrast, lower level of NF κ B (nuclear factor kappaB) and tumor necrosis factor- α observed which might be due to higher levels of HO1, MT and transforming growth factor- ß . Further, increase in HIF1 (hypoxia inducible factor-1) and its regulated genes; erythropoietin, vascular endothelial growth factor, and glucose transporter-1 was observed. Interestingly, Cordyceps sinensis treatment under normoxia did not regulate the expression HIF1, NF κ B and their regulated genes evidencing that Cordyceps sinensis per se did not have an effect on these transcription factors. Overall, Cordyceps sinensis treatment inhibited hypoxia induced oxidative stress by maintaining higher cellular Nrf2, HIF1 and lowering NF κ B levels. These findings provide a basis for possible use of Cordyceps sinensis in tolerating hypoxia.

Systematic review of flexor tendon rehabilitation protocols in zone II of the hand.

BACKGROUND: Restoration of function following flexor tendon repair in zone II represents a difficult clinical problem. Despite many publications on rehabilitation methods, there exists no consensus as to which method is superior. This study was undertaken to determine which flexor tendon rehabilitation protocol provides the best outcome after surgical repair in zone II. METHODS: Electronic databases were searched for articles published between 1970 and 2009. The population included patients aged 5 years and older who sustained a flexor tendon laceration in zone II. The primary outcome was rupture rate. Secondary outcomes were range of motion and quality of life. The following protocols and their variations were considered: passive flexion and active extension protocols (Kleinert type protocols), controlled passive motion protocols (Duran type protocols), combination of the Kleinert and Duran protocols, and early active motion protocols. RESULTS: Seventy-nine articles were identified. Fifteen studies met the inclusion criteria. The mean rate of rupture was lowest in the combined Kleinert and Duran protocols (2.3 percent) and highest in the Kleinert protocols (7.1 percent). No statistically significant differences were found. The combined Kleinert and Duran protocols and the early active motion protocols exhibited the highest proportion of digits with excellent or good results using the Strickland and Buck-Gramcko systems. One study included a quality-of-life assessment-meaningful comparison was not possible. CONCLUSIONS: Both early active motion protocols and combined Kleinert and Duran protocols result in low rates of tendon rupture and acceptable range of motion following flexor tendon repair in zone II. Future studies should include quality-of-life measurements using validated scales.

CASH 2021: commercial access and space habitation.

Issues about commercialization of space have been a growing concern in the past decade for the space community. This paper focuses on the work from a team of 51 students attending the Summer Session Program of the International Space University in Bremen, Germany. CASH 2021 (Commercial Access and Space Habitation) documents a plan that identifies commercial opportunities for space utilization that will extend human presence in space, and will chart the way forward for the next 20 years. The group selected four commercial sectors that show the most promise for the future: tourism, entertainment, space system service, assembly and debris removal, and research and development/production. The content of this document presents the results of their research. Historical activities in each of the commercial sectors are reviewed along with the current market situation. To provide a coherent background for future commercialization possibilities a scenario has been developed. This scenario includes a postulated upon ideal future and includes social, political and economic factors that may affect the space industry over the timeline of the study. The study also presents a roadmap, within the limited optimistic scenario developed, for the successful commercialization of space leading to future human presence in space. A broad range of commercially viable opportunities, not only within the current limits of the International Space Station, but also among the many new developments that are expected by 2021 are discussed.