Sub-chronic Toxicity of Defoamer Used in Seawater Desalination / 生物医学与环境科学（英文）

OBJECTIVE@#To explore the possible long-term health effects of the defoamer used in seawater desalination by sub-chronic toxicity testing.@*METHODS@#Blood analysis, internal organ assessment, and histopathological examination were carried out in rats exposed to low, medium, and high (0.5, 1.0, and 2.0 g/kg BW, respectively) doses of defoamer for 90 days through oral administration.@*RESULTS@#The high dose group showed decreased blood alanine aminotransferase and aspartate aminotransferase (P < 0.05). All doses resulted in a significant increase in albumin and decrease in globulin (P < 0.05). The direct bilirubin and indirect bilirubin were decreased in the medium and high dose groups (P < 0.05). All dose groups showed significant induction of alkaline phosphatase (P < 0.05). Pathological examination revealed a case of liver mononuclear cell infiltration in the medium dose group and three cases of liver congestion, steatosis of hepatic cells around the central vein, and punctate necrosis with multiple focal mononuclear cell infiltration in male rats administered the high dose. The No Observed Adverse Effect Level was 0.5 g/kg BW in rats, with albumin and total bilirubin as health effect indices.@*CONCLUSION@#Long-term defoamer exposure may cause liver injury but has no significant impact on renal function in rats. The effect on blood cells in female rats was more prominent than that in male rats.

Apoptosis of olfactory receptor neurons induced by bulbectomy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study whether apoptosis plays a role in controlling the number of olfactory receptor neurons, so as to reveal the specialty and mystery of neurogenesis.</p><p><b>METHODS</b>Using terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) and transmission electron microscopy to detect apoptosis in olfactory mucosa of normal adult rats and damaged olfactory mucosa of 16, 32, 48 hours and 3, 7, 30 days after bulbectomy.</p><p><b>RESULTS</b>In normal olfactory epithelium, a subpopulation of immature neurons, as well as mature neurons, showed internucleosomal DNA-fragmentation. The number of TUNEL-labeled neurons increased dramatically 32 hours after removal of olfactory bulb. Then it declined quickly and remained at low level. Ultrastructural data of olfactory mucosa showed that the feature of apoptotic neurons was chromatin condensation and cell shrinkage. Besides, some dying cells were characterized by the formation of numerous autophagic vacuoles, and few had some of the features of necrosis but without obvious mitochondrial swelling.</p><p><b>CONCLUSIONS</b>Apoptosis might play a role in turnover of the olfactory epithelium and regeneration in adult rats. There might be other two types of neural death through different mechanism.</p>