BACKGROUND:Although incidents of organophosphate-induced delayed neurotoxicity have been documented for over a century, the molecular mechanisms underlying the axonopathy remain poorly understood.
OBJECTIVE:To discuss the effects of tri-ortho-cresyl phosphate (TOCP) on homeostasis of the glutamate-glutamine cycle and the expression of key enzymes in the brains of hens.
METHODS:Twenty-four adult hens were randomly divided into three groups (n=8). TOCP group was treated with TOCP by gavage at a single dosage of 1 000 mg/kg, and control group was given an equivalent volume vehicle by gavage, while hens in the phenylmethylsulfonyl fluoride (PMSF)+TOCP group were subcutaneously injected with 40 mg/kg PMSF fol owed by 1 000 mg/kg TOCP 24 hours later. The hens were kil ed on days 5 and 21 post-dosing. The brains were taken out quickly and preserved in a-80℃deep freezer. ELISA was used to determination the content of glutamine synthetase and glutaminase and the activity of glutamine synthetase. Corresponding kits were used to measure the level of glutamate and glutamine. Fluo3-AM was used to measure cytosolic calcium concentration. RESULTS AND CONCLUSION:The activity and content of glutamine synthetase and the concentration of glutamine were down-regulated, while the concentrations of the intracellular Ca2+and glutamate were up-regulated in the early stage after TOCP administration. It is also suggested that the downregulated expression of glutamine synthetase may be associated with organophosphate-induced delayed neurotoxicity through the disruption of homeostasis of the glutamate-glutamine cycle and cytosolic calcium concentration.

BACKGROUND:Although incidents of organophosphorus poisoning-induced delayed neuropathy (OPIDN) have been documented for over a century, the molecular mechanisms underlying the axonopathy remain poorly understood. Therefore, OPIDN treatment has been increasingly concerned. OBJECTIVE:To construct the OPIDN hen model induced by triorthocresyl phosphate (TOCP) and to explore the effect of phenylmethylsulfonyl fluoride (PMSF) intervention. METHODS:Adult hens were randomly divided into four groups: two TOCP groups, a PMSF group and a control group. TOCP groups were treated with TOCP by gavage at a single dosage of 1 000 mg/kg and 750 mg/kg respectively; control group was given an equivalent volume of saline by gavage while hens in the PMSF group were subcutaneously injected with 40 mg/kg PMSF 24 hours after 1 000 mg/kg TOCP injection. OPIDN neurological signs were assessed by a six-point graded scale. The changes of the hen weight were recorded. The hens were kiled on day 5 and 21 post-dosing. The samples were cut into 50 nm thick sections and examined by transmission electron microscopy. RESULTS AND CONCLUSION:OPIDN neurological signs such as abnormal gaits progressed in severity with time (P < 0.05), and the hen weight was significantly decreased in TOCP groups (P < 0.05). However, no clinical signs of delayed neurotoxicity were observed in hens of the PMSF group and the control group during the experiment period. The mild mitochondrial sweling and the fragmentation of microfilament and microtubule arrangement in axons were observed on day 5 post-dosing, leaving the other organeles remained unchanged. On day 21, neuronal degeneration was apparent, including sweling of endoplasmic reticulum, abnormal change of mitochondria, and disordered arrangement of cytoskeleton. The optimal dose of TOCP was 1 000 mg/kg. Experimental findings indicate that, OPIDN hen model induced by TOCP and PMSF intervention hen model were successfuly constructed. PMSF intervention significantly improved the pathologic changes and clinical symptoms of OPIDN induced by TOCP in hens.

Objective To understand the pollution status of indoor volatile organic compounds(VOCs) and to provide evidence for preventing the adverse effects of them on resident health.Methods According to the different times of the house decoration, 53 residents were randomly selected from a district of Dalian.Air was sampled in the bedrooms, the kitchens and the outdoors for 24 h by sampling tubes which were activated by activated carbon and the concentrations of VOCs were analyzed by GC-MS/ SIM.Results The concentrations of VOCs indoor were higher at the half year after decoration.The concentrations of methyl isobuthyl ketone, butyl acetate, 1, 2-dichloroethane, 1, 1, 1-trichlo-roethane, tetrachlorocarbon, hexane and buthanol were 0.60, 9.15, 3.10, 1.00, 1.67, 1.90 and 14.50 ?g/m3 in the bedrooms;they were 0.60, 8.10, 3.95, 1.74, 0.85, 1.87 and 12.45 ?g/m3 in the kitchens.The concentrations of VOCs indoor were still higher than those of outside atmosphere(P

BACKGROUND:Bone marrow mesenchymal stem cel s from chickens are important cel models for embryonic developmental biology, immunology and oncology research. However, it is difficult to keep bone marrow mesenchymal stem cel s with good undifferentiated potential in a large-scale expansion system.
OBJECTIVE:To establish a culture system in vitro with laminin coating to expand bone marrow mesenchymal stem cel s from chickens.
METHODS:Isolated bone marrow mesenchymal stem cel s from chickens were seeded in laminin-coated plates and traditional two-dimensional plates, respectively. After expansion in vitro, the morphological characteristics, expression of surface markers, expansion characteristics and adipogenic differentiation of bone marrow mesenchymal stem cel s in both conditions were analyzed and compared.
RESULTS AND CONCLUSION:There were no statistical differences in the morphological characteristics and expression of surface markers of bone marrow mesenchymal stem cel s expanded by laminin-coated plates and traditional two-dimensional plates. But, the expansion characteristics and adipogenic differentiation of bone marrow mesenchymal stem cel s cultured in laminin-coated plates were better than those in traditional two-dimensional plates. Laminin culture system could quickly amplify out of a large number of chicken bone marrow mesenchymal stem cel s with better proliferation ability and undifferentiated performance. Al above results indicated that a more efficient expansion system with laminin coating is established.

BACKGROUND:Bone marrow mesenchymal stem cells are rare in vivo. It is important to purify, proliferate and differentiate bone marrow mesenchymal stem cells in vitro for further research. OBJECTIVE:To evaluate the biological characteristics, phenotype and multiple differentiation potential cultivation of bone marrow mesenchymal stem cells that are isolated, cultured and purified using the whole bone marrow adherence method. METHODS:Bone marrow mesenchymal stem cells were isolated, purified and cultured by the whole bone marrow adherence method. Morphological observation and flow cytometry determination of cellsurface markers were performed. Osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells was induced. RESULTS AND CONCLUSION:We successful y purified and proliferated bone marrow mesenchymal stem cells with high cellviability and differentiation ability. Fibroblast-like cells were harvested, expressing CD29 and CD90, but not CD45. Fol owing osteogenic and adipogenic induction, cells were positive for oil red O staining and alizarin red staining. The whole bone marrow adherence method is easy to operate, has little impact on cellviability, and can be used to harvest high-purification bone marrow mesenchymal stem cells with high cellviability and differentiation ability.