Nanosilica and Polyacrylate/Nanosilica: A Comparative Study of Acute Toxicity.

We compared the acute toxicity of nanosilica and polyacrylate/nanosilica instillation in Wistar rats (n = 60). Exposure to nanosilica and polyacrylate/nanosilica showed a 30% mortality rate. When compared with saline-treated rats, animals in both exposure groups exhibited a significant reduction of PO2 (P < 0.05) at both 24 and 72 hr. after exposure. Both exposure groups exhibited a significant reduction of neutrophils in arterial blood compared to saline controls (P < 0.05) 24 hr. after exposure. The levels of blood ALT and LDH in exposed groups were found to be significantly increased (P < 0.05) 24 hr. following exposure. The exposed groups exhibited various degrees of pleural effusion and pericardial effusion. Our findings indicated respiratory exposure to polyacrylate/nanosilica and nanosilica is likely to cause multiple organ toxicity.

Sodium 3,5,6-trichloropyridin-2-ol poisoning: report of four cases.

Sodium 3,5,6-trichloropyridin-2-ol (STCP) is an important intermediate for synthesizing organophosphate insecticide chlorpyrifos. At present, chlorpyrifos is one of the world's largest species of pesticide products. Many studies have focused on the toxicity of chlorpyrifos, but few reports have looked at the toxicity mechanism of STCP. Even fewer studies have looked at STCP poisoning. With increasing production and usage of STCP, the chances of such poisoning will increase. In this study, we present a report on four workers who helped in the industrial manufacture of STCP and who were affected by exposure to it. We hope that these case studies will provide a foundation for further research into STCP.

[Expression of serum cytokines in patients with pneumoconiosis by antibody chip].

OBJECTIVE: To investigate the changes in expression of serum cytokines in patients with pneumoconiosis using cytokine antibody chips (CACs). METHODS: The CAC technology was applied to measure the serum levels of 60 cytokines in 12 patients with pneumoconiosis and 3 normal controls. RESULTS: In the patients with pneumoconiosis, the highly expressed serum cytokines included interleukin (IL)-1α, IL-1ß, IL-2, ILs 4-16, macrophage colony-stimulating factor, interferon-γ, tumor necrosis factor (TNF)-α, TNF-ß, human bone morphogenetic protein-6, fibroblast growth factor-7, neurotrophin-3, and stem cell factor, and the lowly expressed serum cytokines included recombinant human I-309, monocyte chemoattractant protein (MCP)-1, MCP-2, MCP-3, MCP-4, macrophage inflammatory protein (MIP)-1-δ, and MIP-3-α. CONCLUSION: Patients with pneumoconiosis have changes in the expression of most serum cytokines.

Study on the effect of different oxygen therapies on rats with acute carbon dioxide poisoning.

OBJECTIVE: To study the effect of different oxygen therapies on the rats with carbon dioxide poisoning for screening out the best on-the-spot oxygen-therapy technology for treating acute carbon dioxide poisoning. METHODS: The 60 healthy male Sprague Dawley rats were randomly divided into normal control group (A group), carbon dioxide poisoning group (B group), low-concentration oxygen inhalation treatment group (C group), high-concentration oxygen inhalation treatment group (D group) and hyperbaric oxygen-therapy group (E group). Various kinds of oxygen therapies were given after the contamination. The pH, partial pressure of oxygen (PO(2)) and partial pressure of carbon dioxide (PCO(2)) of arterial blood, serum troponin I (CTNI), creatine kinase (CK), glutamic-oxaloacetic transaminase (AST), γ-glutamyl transpeptidase (GGT), blood urea nitrogen (BUN), potassium (K), sodium (Na) and chlorine (Cl) for the rats of each group were inspected. The lung and the brain tissues were taken for observing the pathological changes. RESULTS: There is no significant difference in pH, PO(2) and PCO(2) among all oxygen-therapy groups (p > 0.05). The levels of CTNI, CK and AST in E group are obviously lower than that in B, C and D groups (p < 0.05). The level of serum K in E group is obviously lower than that in B, C and D groups (p < 0.05). The levels of serum Na and Cl in E group are obviously higher than that in B, C and D groups (p < 0.05). The pathological change of lungs in E group is significantly better than that in C and D groups. CONCLUSIONS: We recommend that the medical units with related conditions can give the hyperbaric oxygen therapy to patients as soon as possible.

[Evaluating the effects of different oxygen therapies on the rats with acute nitrogen asphyxia].

OBJECTIVE: To Evaluate the effects of different oxygen therapies on the rats with acute nitrogen asphyxia and to study the best oxygen therapic protocol for patients with acute nitrogen asphyxia on the spot. METHODS: Sixty healthy male Wistar rats were divided into 5 groups: control, exposure to nitrogen, 33% oxygen treatment, 50% oxygen treatment and hyperbaric oxygen treatment groups. The behavioral performance, arterial oxygen pressure (PO2), carbon dioxide partial pressure (PCO2) and oxygen saturation (SPO2), biochemical changes in liver and kidney function and myocardial enzymes in 5 groups were measured. RESULTS: The rats exposed to nitrogen firstly were excited then inactive symptoms, but consciousness was recovered after oxygen therapy. The PO2 and SPO2 in nitrogen exposure group were (79.67 +/- 9.12) and (94.92 +/- 2.78) mm Hg, respectively, which were significantly lower than those in control group (P<0.01). The PO2 and SPO2 of 3 oxygen treatment groups were (94.75 +/- 7.24), (94.92 +/- 8.98), (104.58 +/- 7.12)mm Hg and (97.17 +/- 0.83), (96.92 +/- 1.16), (97.42 +/- 0.67)mm Hg, respectively, which were significantly higher than those in nitrogen exposure group (P<0.05). The PO2 in hyperbaric oxygen treatment group was significantly higher than those in other 2 oxygen treatment groups (P<0.05). The SPO2 in hyperbaric oxygen treatment group was (51.42 +/- 6.60) mm Hg which was significantly higher than that [(44.58 +/- 3.42)mm Hg] in 50% oxygen treatment groups (P< 0.05). AST [(270.50 +/- 49.05 )U/L], ALT [(122.67 +/- 55.44 )U/L], BUN [(7.31 +/- 0.93 )mmol/L], Cr[(28.32 +/- 4.35) micromol/L], CK [(1808.42 +/- 582.05)U/L] and CtnI [(22.52 +/- 14.29 )ng/ml] in nitrogen exposure group were significantly higher than those in control group (P<0.05). AST [(165.25 +/- 30.87) U/L], HBDH [(350.83 +/- 103.00)U/L] and CtnI [(11.23 +/- 5.38) ng/ml] in hyperbaric oxygen treatment group were significantly lower than those in other 2 oxygen treatment groups (P<0.05). CONCLUSION: Timely and effective oxygen therapy can significantly increase arterial pressure of oxygen and oxygen saturation in the rats with acute nitrogen asphyxia, and can improve liver function and cardiac damage. The hyperbaric oxygen chamber can significantly increase the therapeutic effects on rats with acute nitrogen asphyxiation.

[Evaluation of different oxygen therapies on therapeutic effects in rats with acute carbon dioxide poisoning].

OBJECTIVE: To study therapeutic effects by using different oxygen therapies in rats with acute carbon dioxide poisoning, to select the best oxygen therapy technology for patients with acute carbon dioxide poisoning on the spot. METHODS: Sixty healthy male Sprague-Dawley rats were randomized into normal control group, carbon dioxide exposure group, hyperbaric oxygen treatment group (pressure 2 ATA, FiO(2)100%), high concentration of atmospheric oxygen treatment group (FiO(2)50%), low concentration of atmospheric oxygen treatment group (FiO(2)33%). After treated with different oxygen in rats with acute carbon dioxide poisoning, arterial pH, PO2 and PCO2 of rats were detected, in addition observe pathological changes of lung tissue and brain tissue. RESULTS: The arterial pH (7.31 ± 0.06) and PO2 [(68.50 ± 15.02) mm Hg] of carbon dioxide exposure group were lower than those of control group [pH (7.42 ± 0.02) and PO2 (92.83 ± 8.27) mm Hg], PCO2 [(71.66 ± 12.10) mm Hg] was higher than that of control group [(48.25 ± 2.59) mm Hg] (P < 0.05); the arterial pH (hyperbaric oxygen treatment group 7.37 ± 0.02, high concentration of atmospheric oxygen treatment group 7.39 ± 0.03, low concentration of atmospheric oxygen treatment group 7.38 ± 0.02) and PO2 of oxygen treatment groups [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (82.25 ± 12.98), (84.75 ± 11.24), (83.75 ± 16.77) mm Hg, respectively] were higher than that of carbon dioxide exposure group, PCO2 [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (52.25 ± 4.95), (51.75 ± 4.82), (52.66 ± 5.61) mm Hg, respectively] was lower than that of carbon dioxide exposure group (P < 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 between oxygen treatment groups and control group (P > 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 among oxygen treatment groups (P > 0.05). There was large area of bleeding of lungs in rats with carbon dioxide poisoning, the bleeding of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment was better than the rats with carbon dioxide poisoning, there was no abnormal appearance of lungs in rats with hyperbaric oxygen treatment. The light microscope observation showed that there were diffuse bleeding and exudation of lungs in rats with carbon dioxide poisoning, the bleeding and exudation of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment were better than the rats with carbon dioxide poisoning, there were only minor bleeding and exudation of lungs in rats with hyperbaric oxygen treatment. There was no difference of brain in anatomy and microscopy among all groups, there were no significant bleeding, edema, cell degeneration and necrosis. CONCLUSIONS: Lung pathology in acute carbon dioxide poisoning rats with hyperbaric oxygen treatment is better than the rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment, there is no significant difference of effect between high concentration of atmospheric oxygen treatment group and low concentration of atmospheric oxygen treatment group, however, the results of blood gas analysis and lung pathology than the exposure group improved, so qualified medical unit for hyperbaric oxygen therapy as soon as possible, hyperbaric oxygen treatment facilities in the absence of circumstances, the emergency treatment of early oxygen is also a good measure.