C_(57)BL/G male mice were immunized with SRBC 9 hr after 75 mGy whole body X-irradiation. The hypothalamic M-Enk and L-Enk contents were decreased. Serum TS level kept on fluctuating over the control level. The change of testicular cAMP content was not in the same direction as that of the TS. The change of serum CS level was opposite to that of serum TS, These results suggest that the low dose radiation probably cause the changes of neuroendocrine function, leading to the decrement of hypothalamic EOP contents, the supression of CRF-ACTH-CS axis activity and the enhancement of GnRH-LH-TS axis activity.

The present study has demonstrated a lowered reactivity to Con A stimulation, and also a decreased IL-2 production by splenocytes in adult male rats which were thymectomized within 48 h after birth. Meantime, their body weights, pituitary and testicular weights, serum LH and FSH levels, serum and urine TS contents, and pituitary cAMP contents were all lower than that of the control. The hypothalamic 5-HT metabolism showed that a change of hypothalamic-pituitary-gonad axis might have occured after neonatal thymectomy in male rats.

Objective: To examine the effect of mouthwashing before dental procedure on environmental pollution of microorganism in dental clinic. Methods: Air samples in dental clinic after tooth preparation whether using mouthwashes or not pre operationally were collected and cultured with blood agar plates, the bacteria colonies formed on the plates in different groups were counted as the index for air contamination. Results: Environmental contamination from tooth preparation in dental clinic could be reduced significantly by using mouthwash pre operationally( P 0.05), but the size of the colonies formed on the plates in Kou Jie Su group was smaller than that in drinking water group. Conclusion: Environmental contamination from tooth preparation in dental clinic can be reduced by using mouthwash pre operationally. Combination of the pre operational mouthwashing with vacuum aspirator or ventilation installation may be a better way to control the possible cross infection in dental clinic.

? in the blood. There were three isomeric compounds of DDT in the fat and two in the blood were detectable. Conclusion There was still accumulation of HCH and DDT in human body fat and blood in Xiaogan population although the accumulative levels were significantly lower than that of the allowable residue standard of China.

?-HCH. The average of pp'-DDE in the surface water was the highest, 0.062 ?g/L. In the water in the deep well of 70 meters, organochlorine was still found. Conclusion The residues of organochlorine pesticide in different soil and water of the agricultural products base in Xiaogan have been detected, the contents are under the related national standard limitation, but the potential threat of the accumulation of organic chlorine pesticide should not be underestimated.

Objective To observe the effects of purified product trihydroxybenzoic acid dimmer in different doses from Trapa manshurica Fler on apoptosis and cell cycle progression of liver cancer SMMC-7721 cells in vitro and explore its possible mechanism of inhibiting tumor growth. Methods The changes of apoptosis and cell cycle progression were measured with flow cytometry. Results The apoptotic percentages of the cells treated with the purified products with doses of 3.125, 6.250, 12.500 and 25.000 mg?L~ -1 increased significantly as compared with that in the control (P

Objective:In present study we observed the effect of whole body irradiation (WBI) with 75 mGy X-rays on the immune function of tumor-bearing mice.Methods:Lewis lung carcinoma cells were implanted into the right thigh muscle of C57BL/6J mice.Ten days after tumor implantation,the tumor-bearing mice were administrated with 75 mGy X-rays WBI,then the mice were sacrificed 18 h after irradiation to detect the immune parameters including the spontaneous proliferation of thymocytes,the proliferative response of splenocytes to ConA and LPS,the cytotoxic activities of specific cytotoxic lymphocytes (CTL) and natural killer cells (NK),as well as lymphokine activated killer cells (LAK) in spleen.The methods we used were 3H-TdR incorporation or release assay.Results:The immune parameters of exposed tumor-bearing mice were much higher than those of sham-irradiated tumor-bearing mice (P<0.01).Conclusion:These results suggested that low dose radiation (LDR) could enhance the immune function of tumor-bearing mice,which might be of practical significance in the prevention and therapy of cancer.

Objective:To investigate the effect of recombinant plasmid pcEgr-p53 stable transfection in combination with X-ray irradiation on the apoptotic effect and the changes of Bax,Bcl-2 and caspase-3 protein expressions in human A549 tumor cells.Methods:pEgr-hp53 packaged with liposome was stably transfected into A549 cells in vitro.These cells of expressing A549-hp53 and A549-vect were irradiated with 0,0.5,2 and 5 Gy X-rays,respectively,i.e.8 experimental groups.The A549 cells responding to the apoptotic effect and the changes of Bax,Bcl-2 and caspase-3 protein expressions were measured with TUNEL assay and flow cytometry,respectively.Results:The percentage of apoptotic cells in A549-hp53 plus different dose irradiation group were significantly higher than that in 0 Gy group(P

Objective To construct the conditionally replicative adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K carrying early growth response gene-1 (Egr1)promoter and tumor necrosis factor related apoptosis inducing ligand (TRAIL)gene, and to observe the effects of the vector combined with 2 Gy irradiation on the TRAIL expression in MDA-MB-231 cells.Methods Egr-1 promotor sequence was cloned from pMD18 T-Egr1, TRAIL was constructed the downstream of Egr1 promoter, pShuttle-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K (CRAd.pEgr1-TRAIL)was constructed,after the adenovirus vector was packaged successfully,MDA-MB-231 cells were infected with them and irradiated with X-rays.Real time PCR method and ELISA were used to detect the expression levels of TRAIL mRNA and protein, respectively. Six groups in the experiment were set up:control, 2 Gy,CRAd.p,CRAd.pEgr1-TRAIL,CRAd.p + 2 Gy and CRAd.pEgr1-TRAIL + 2 Gy. Results The recombinant adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K was constructed and packaged successfully.The expression level of TRAIL mRNA in MDA-MB-231 cells transfected with the vector of 5 MOI for 24 h following 2.0 Gy X-rays irradiation began to increase and arrived to the top 8 h later in various groups,then declined.The expression level of TRAIL protein in MDA-MB-231 cells began to increase 6 h after irradiation and reached to the peak 24 h later,then declined 48 h later.There were significant differences in the expression levels of TRAIL protein between CRAd.pEgr1-TRAIL + 2.0 Gy and other groups at the same time point (P<0.01). Conclusion The recombinant adenovirus vector is obtained successfully, and the TRAIL mRNA and protein expression levels in MDA-MB-231 cells can be increased significantly by the vector combined with 2.0 Gy X-rays irradiation.

Objective: In the present study we observed the general pattern of the adaptive response of thymocyte apoptosis and cell cycle progression induced by low dose radiation (LDR). Methods: Kunming male mice were irradiated with the inductive dose (D1, 75 mGy) and the challenging dose (D2, 1.5 Gy). The intervals between D1 and D2 were 3, 6, 12, 24 and 60 hours. The changes of thymocyte apoptotic bodies (TAB) and cell cycle progression were measured with flow cytometry with the thymocytes cultured for 4, 20 and 44 hours, respectively, 18 hours after irradiation with D2. Results: When the intervals between D1 and D2 were 3, 6 and 12 hours, the percentages of TAB in the D1 + D2 groups in the thymocytes cultured for 4 and 20 hours were significantly lower than those in the D2 groups (P<0.05) and the percentages of G0/G1 and G2 + M phase cells decreased in varying degrees, while the percentages of S phase cells increased significantly (P<0.05 or P<0.01). Conclusion: The results mentioned above indicate that when the mice were irradiated with 75 mGy (D1, 12.5 mGy/min) 3～12 hours before 1.5 Gy (D2, 0.285 Gy/min) exposure, the adaptive response of apoptosis and cell cycle progression may be induced with the thymocytes cultured for 4 and 20 hours after whole-body irradiation with D2.