Objective To find out the specific diagnostic antigens in excretory-secretory (ES) products from muscle larvae of Trichinella spiralis. Methods The ES antigens (ESA) of Trichinella spiralis muscle larvae cultured in vitro at 18 h and 30 h were analyzed by SDS-PAGE and Western blotting. Results At different times after cultivation, the protein components of ESA of T. spiralis muscle larvae were similar. SDS-PAGE revealed that the molecular weight(MW) of the major bands of 2 ES antigens were 112, 110, 108, 97, 53, 49, 45, 42, 35, 23 and 16 kDa. Western blotting showed that the protein bands with 102, 97, 95 and 53 kDa in 18 h ESA and the protein bands with 53, 49, 45 and 43 kDa in 30 h ESA cross-reacted with sera from the patients with paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis, respectively. The protein component with 23 kDa in ESA only reacted with sera from the rats and mice infected with T. spiralis and the patients with trichinellosis, but not reacted with sera from animals and patients infected with other parasites, and sera from normal rats, mice and persons. Conclusion The protein component with 23 kDa in T. spiralis ESA is the specific antigen of T. spiralis muscle larvae and it could be applied to the serodiagnosis and seroepidemiological survey of trichinellosis.

Objective To find out the specific antigens for immunodiagnosis of trichinellosis. Methods The soluble antigens of Trichinella spiralis muscle larvae were analyzed by SDS-PAGE and Western blot. Results SDS-PAGE revealed that the soluble antigens of T. spiralis muscle larvae had 29 protein bands with molecular weight (MW) from 112 kDa to 12 kDa, among them the protein bands with MW 65,43,42,31,30,20,17,16 kDa were the major bands. Western blot results showed that the protein bands with 112,110,108, 102,97,95,65,63,58,55,53,49,45,43,42 kDa in T.spiralis muscle larval soluble antigens were cross-reacted with sera from rats and patients with paragonimiasis, sera from patients with clonorchiasis, schistosomiasis, and cys-ticercosis. The protein components with 24 - 20 kDa were only reacted with sera from rats, mice infected with T.spiralis and patients with trichinellosis, and not reacted with sera from animals and patients infected with other parasites,and sera from normal rats, mice and healthy persons. Conclusion The protein components with 24-20 kDa in T.spiralis muscle larval soluble antigens are the specific antigen for T.spiralis muscle larvae, it could be applied to the immunodiagnosis and seroepidemiological investigation on trichinellosis.

In this research a strain of isolated Pseudomonas alcaligenes which causes degradation of dexamethasone was acclimated further and its proteins of every position in the bacterium were separated by the osmotic shock method. The separated intracellular proteins which had the highest enzyme activity were extracted by the salting out with ammonium sulfate and were purified with the cation exchange chromatography and gel chromatography. The purified proteins which was active to cause degradation of dexamethasone had been detected were cut with enzyme and were analyzed with mass spectrometry. The results showed that the degradation rate to dexamethasone by acclimated Pseudomonas alcaligenes were increased from 23.63% to 52.84%. The degrading enzymes were located mainly in the intracellular of the bacteria and its molecular weight was about 41 kD. The specific activity of the purified degrading enzymes were achieved to 1.02 U x mg(-1). Its 5-peptide amino acid sequences were consistent with some sequences of the isovaleryl-CoA dehydrogenase. The protein enzyme may be a new kind degrading enzyme of steroidal compounds. Our experimental results provided new strategies for cleanup of dexamethasone in water environment with microbial bioremediation technique.
Amino Acid Sequence ; Bacterial Proteins ; chemistry ; Chromatography ; Dexamethasone ; chemistry ; Molecular Weight ; Pseudomonas alcaligenes ; enzymology

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are few in bone marrow, and they are easily mingled with other cells, especially red blood cells. Therefore, intervention needs to be depleted in the process of isolation of red blood cells so as to obtain highlypurified BMSCs as many as possible.OBJECTIVE: To isolate and culture BMSCs of rats with red blood cell lysis method, and perform biological identification.DESIGN: Observation and controlled trial.SETTING: Laboratory of Aerospace Cell Molecular Biology, Scientific Research Training Center for Chinese Astronauts.MATERIALS: Fifty 30-day-old male SD rats, weighing about 100 g, of SPF degree, were purchased from Beijing Experimental Animal Center (License No. SCXK (Jing) 2002-0003) and involved in this trial. DAB condensed chromogen (hydrogen dioxide included, Zhongshan Company), rabbit anti-ret polyclonal antibody (Boster Co.,Ltd., Wuhan), fetal calf serum (PAA, Austria) and LG-DMEM medium (Sigma Company, USA) were used in this trial.METHODS: This trial was carried out in the Laboratory of Aerospace Cell Molecular Biology, Scientific Research Training Center for Chinese Astronauts during September 2004 to September 2005. The rats were sacrificed by dislocation to expose bone marrow cavity. Cell suspension was collected. BMSCs were isolated and cultured primarily by whole bonemarrow culture method. ① Red blood cells lysis test: A, B, C and D 4 tubes were chosen and filled with 0.5 mL bonemarrow rinse solution which was filtered and fully beat upon. Then, red blood cell lysis buffer of 2 mL, ammonium chloride of 2 mL, phosphate buffer normal saline of 2 mL and 0.04 volume fraction acetic acid of 0.5 mL were correspondingly added into the 4 tubes. In each tube, absorbance and hemoglobin concentration were measured and cell growth was observed. ② Observation of growth curve, doubling time and surface marker molecule expression of BMSCs: Based on the formula, population doubling time (TD) =t[lg2/(lgNt-lgN0)] (NO and Nt represented the cell number after inoculation and t hours after culture ,respectively), cell population doubling time was calculated and traced and growth curve of the 2nd, 4th and 6th generations of BMSCs were analyzed; The proliferation of BMSCs was measured by methylene blue staining method; Surface marker molecule expression of BMSCs was detected with immunocytochemical staining.MAIN OUTCOME MEASURES: ①Observation of isolation and culture of bone marrowmesenchymal stems of rats. ②Effect of different methods on the lysis of red blood cells and the growth of BMSCs. ③ The growth curve and cell doubling time of the 2nd, 4th and 6th generations of cells. ④Surface marker molecule expression of BMSCs of rats.RESULTS: ① Results of isolation and culture of BMSCs of rats: After 48-hour primary culture, most of the cells had adhered to the wall, and 72 hours later, division growth of the adherent cells presented. Seven to eight days later, cell colonies formed obviously, and then increased quickly, expanded incessantly and fused with each other. On 14 to 16 days, cell clones grew densely. Immediately generative cells presented ball-shape, subsided and adhered the wall verysoon. Some few round cells suspended. Adherent cells distributed evenly and proliferated quickly within 3 to 5 days. Although cell morphology of generative cells did not change after passage, cell proliferation was speeded up obviously and cells covered the bottom of the whole bottom on about 6 days. ② Effect of different methods on red blood cell lysis and the growth of BMSCs: hemoglobin concentration in the red blood cell lysate-treated group, ammonium chloride-treated group and 4％ acetic acid-treated group was significantly higher than that in the phosphate buffer normal saline-treated group, with significant difference (P ＜ 0.01). ③ Observation of growth curve of different generations of BMSCs: The growth curves of the 2nd, 4th and 6th generations of the cells were basically the same: latent period about 1 to 2 days, then logarithmic growth phase, peak on the 5th day and finally plateau phase (about on the 5th to 7th days). The latent period of the 6th generation of BMSCs was not obvious and the population doubling time of BMSCs was about 34 hours. ④ldentification of immunophenotype of different generations of BMSCs: Both CD44 and CD106 staining of each generation of cells were positive, presenting brown granule sediments, and CD34 staining was negative.CONCLUSION: Inoculation of red blood cells lysate-treated bone marrow rinse solution can boost the adherent rate of BMSCs, and does not influence its post-adherent growth, so it is a feasible separation method. Cell surface marker staining confirms that thecells isolated in this study are BMSCs.

OBJECTIVE: To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells. METHODS: The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting. RESULTS: The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein. CONCLUSION The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation/genetics* ; MicroRNAs/metabolism* ; Mitochondria/metabolism* ; Mitochondrial Permeability Transition Pore ; Reactive Oxygen Species ; Stomach Neoplasms/pathology*