To develop a Huntington’s disease(HD) cell model in vitro to screen drugs targeting the aggregation of polyQ,different length of CAG repeat fragments were amplified by random primer PCR, identified by DNA sequencing and were fused to the N-terminus of CAT in the pCAR system respectively which had been constructed and identified before. Recombinant plasmids were transformed into and induced to express in the host E.coli. SDS-PAGE and chloramphenicol resistance test were done to determine the solubility of the polyQ and chloramphenicol resistance levels of the fusions. With different length of CAG repeat fragments cloned and expressed in the CAT-fusion protein reporting system, it is found that when the length of the fragments increased over 40, their encoding polyQ expressed as insoluble protein and chloramphenicol resistance levels are lower, while under 40, the polyQ expressed as soluble ones and chloramphenicol resistance levels are higher. A in vitro HD model that could minimize the pathological process of the HD thus has been developed. With which by measure the recombinant bacteria’s resistance to chloramphenicol, the polyQ’ solubility and folding state in vitro by quality and quantity could be determined. Thus this model can be used to screen drugs or bioactivity materials that can inhibit aggregation of the polyQ, which thereby shedding new light on the prevent, diagnosis and therapy of HD.

Objective To study the dosimetry of different arrangements of 125I seeds in one plane.Methods Nine different in-plane arrangements of 9 125I seeds (2.035 × 107 Bq/seed) were simulated according to distance (cm) along x (horizontal)- and y( longitudinal )-axis using the 3-dimensional treatment planning system (TPS) (3D-TPS): x0.5, y0. 5; x0. 5, y1.0; x0. 5, y1.5; x1.0, y1.0; x1.0, y1.5;x1.5, y1.5; x0. 5, y0. 5 (2)1.0; x0.5, y1.0 (2)0.5; x1.0, y1.0 (2)0.5. The isodose curves of 40,80, 130, 145 and 200 Gy were created and the area, radius and medical cost under the 40, 80, 130, 145and 200 Gy isodose curves were calculated. Results The area, radius and medical cost under the same isodose curves were significantly different with each 125I seed arrangement. The arrangements which had the biggest area under curves of 40, 80, 130, 145 and 200 Gy isodose were x1. 5, y1. 5; x1. 0, y1. 0; x1. 0,y1. 0; x0. 5, y1. 0 and x0. 5, y1. 0, respectively. Conclusion The matched peripheral dose and therapeutic effect were affected significantly by the geometric arrangement of 125I seeds.

This study was purposed to investigate the difference of nucleated cell (NC) count, CD34(+) cell ratio and expansion multiple, cell cycle and colony formation capability in in vitro expanded human umbilical cord blood CD34(+) cells from HOXB4-transfecting directly and HOXB4-transfected human umbilical cord mesenchymal stem cells (HUCMSC) by means of prepared feeder layers of HUCMSC. The HUCMSC were divided into 2 groups:first group, in which HOXB4 gene was transfected into HUCMSC by using lentiviral vecfor, and feeder layers were set up; and second group in which feeder layers for HUCMSC of non-transfected HOXB4 gene were set up. The CD34(+) cells were separated from HUCB by magmatic activated cell sorting(MACS). After culture in medium with cytokines for 2 days, CD34(+) cells were divided into 5 groups, including control group and experimental group. The control groups included CD34(+) cells as group A (blank control group) and GFP-CD34(+) cells as group B (negative control group) and experimental groups included HOXB4-CD34(+) cells as group C, HUCMSC+CD34(+) cells as group D, HOXB4-HUCMSC+ CD34(+) cells as group E and cells in all groups were cultured in vitro. The number of nucleated cells were counted at day 6, 10, 14 of culture and CD34 immunophenotypes, cell cycle and colony forming capability were measured at day 10 of culture in different conditions. The results indicated that HOXB4 gene could be transfected into HUCMSC by lentiviral vector and feeder layers were set up successfully. After culture for 14 days, the nucleated cells in 5 groups could be amplified effectively, and the expansion levels in 5 groups were in order HOXB4-HUCMSC+CD34(+) cell group> HOXB4-CD34(+) cell group>HUCMSC+CD34(+) cell group> control groups (P < 0.05). At day 10 of in vitro expansion the CD34(+) cell percentage decreased significantly in all groups, while the number of CD34(+) cell increased in experiment groups, which were in order HOXB4-CD34(+) cells group> HOXB4-HUCMSC+CD34(+) cell group>HUCMSC+CD34(+) cell group>control groups (P < 0.05). The cell cycle detection showed that the percentage of cells in S+G2/M phase in experiment groups were higher than that in control groups (P < 0.05), and percentage of cells in HOXB4-HUCMSC+CD34(+) cells group was higher (41.57%) than that in HOXB4-CD34(+) cells group(37.87%) and HUCMSC+CD34(+) cell group (28.65%) (P < 0.05). There was no statistical difference in the CFU number between HOXB4-HUCMSC+CD34(+) cell group and HOXB4-CD34(+) cell group, which were both higher than that in HUCMSC+CD34(+) cell group and control groups (P < 0.05).It is concluded that the CD34(+) cells cultured on HOXB4-HUCMSC feeder layers can be amplified significantly and kept the characteristics of stem cells, The feeder lager of HOXB4-HUCMSC is relative safe for amplification of CD34(+) cells in vitro, it possesses the potential useful value.
Antigens, CD34 ; immunology ; Cell Separation ; Cells, Cultured ; Fetal Blood ; cytology ; Homeodomain Proteins ; genetics ; Humans ; Mesenchymal Stromal Cells ; cytology ; immunology ; Transcription Factors ; genetics ; Transfection ; Umbilical Cord ; cytology ; immunology

OBJECTIVEBenzyl butyl phthalate (BBP) is a plasticizer used in food contact materials. Dietary exposure to BBP might lead to reproduction and developmental damages to human. The present paper was aimed to assess the health risk of BBP dietary exposure in Chinese population.

METHODSThe BBP contents were detected in 7409 food samples from 25 food categories by gas chromatography-mass spectrometry operated in selected ion monitoring (SIM) mode. The dietary exposures of BBP in different age and sex groups were estimated by combining the content data with food consumption data derived from 2002 China National Nutrient and Health Survey, and evaluated according to the tolerable daily intake (TDI) of BBP established by European Food safety Agency.

RESULTSIt was found that BBP was undetectable in most samples and the highest level was 1.69 mg/kg detected in a vegetable oil sample. The average dietary exposure of BBP in people aged ⋝2 years was 1.03 μg/kg bw per day and the highest average exposure was found in 2-6 years old children (1.98 μg/kg bw per day). The BBP exposure in 7-12 months old children excessed 10% of tolerable daily intake (TDI) in worst scenario. .

CONCLUSIONThe health risk of BBP dietary exposure in Chinese population is low and, considering BBP alone, there is no safety concern.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; Diet ; Environmental Exposure ; Environmental Pollutants ; analysis ; Female ; Food Contamination ; analysis ; Food Packaging ; Gas Chromatography-Mass Spectrometry ; Humans ; Male ; Middle Aged ; Phthalic Acids ; analysis ; Plasticizers ; analysis ; Young Adult