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.

Head irradiation with 10 Gy X-rays was given to adrenalectomized male rats in the present study to observe the changes of serum LH, FSH and testosterone (TS) levels and testcular cAMP content. The results showed that the function of pituitary-gonad axis decreased in the adrenalectomized male rats. The levels of serum LH and FSH were lower, (P0.05). The changes might be related to the interaction of both hypothalamic CRF and GnRH neurons. Both the serum TS level (P

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.

0.05). Serum PRL (P

BACKGROUND: Stem cells, cells with special function in animals and humans, exist in various tissues. Most of stem cells differentiate into special tissue organs and some of them remain in the status of stem cells for tissue repair. Mesenchymal stem cells were transplanted to burn wounds in some researches for inducing the proliferation and activation of skin stem cells so as to cure burn.OBJECTIVE: To observe the effect of stem cell culture medium cultured in vitro instilled locally into the severely traumatic skin in guinea pigs on healing time and healing degree of the wound.DESIGN: Random grouping and blank control trial.SETTING: Department of Toxicology, School of Public Health, Jilin University.MATERIALS: Totally 14 adult healthy guinea pigs of either gender weighing 300 to 350 g were recruited.METHODS: The experiment was conducted in the Laboratory of Toxicology Department, School of Public Health, Jilin University, from March to September 2003. Ten guinea pigs were put to death by bloodletting on the neck. The bone marrow was extracted and cultured in unicellular supematant fluid for use. The 14 guinea pigs were made into models of bilateral severe skin trauma.Ten of the guinea pigs were chosen randomly, stem cell culture was instilled into one side of the animals (stem cell group), while the culture medium was instilled into the other side of the animals (culture medium group). The remaining 4 guinea pigs that received no treatment were blank control group.Three days later, transparent lucite was put on the wound every other day for drawing the shape and observing the wound. After the shape was copied onto the transparent lucite, the wound area was worked out on the rectangular coordinate paper and the speed of wound healing was calculated.MAIN OUTCOME MEASURES: Gross observation was performed on the healing status of the wound and average healing time and speed of the guinea pigs in each group.wound healing status of the guinea pigs in each group: At day 3, the wound in stem cell group was dry without obvious exudation. There was a layer of membrane at the bottom of the wound and it stuck to the pledget closely so that the dressing could not easily be removed. The wound status in the culture medium was practically the same as that of the stem cells, but no membrane-ike material was formed and the dressing was easily removed. Inflammation appeared obviously in blank control group.nificantly less in stem cell group than in culture medium group and blank control group [(12.45±2.18) days vs (26.29±1.38) days and ＞ 30It was obviously faster in stem cell group than in culture medium group and blank control group [(40.42±2.14) mm2 per day vs (15.53±5.22) mm2 per day and(10.27±4.57) mm2 per day,P ＜ 0.05].CONCLUSION: The stem cells of homologous animals were instilled on the skin surface to repair injury wound. Stem cells can grow on the wound and transform into skin cells, which promotes the recovery of wounded skin. Therefore, it is feasible to treat severe skin defect with stem cells.

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: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 detect the inhibiting effects of ionizing radiation combined with inhibitors or inducer of autophagy and apoptosis on MCF7 cell line,and to provide the evidence for human breast cancer therapy radiation.Methods MCF7 cells were exposed to X-rays and randomly divided into 4 groups,including 0 Gy,4 Gy,4 Gy+rapamycin,4 Gy+3-MA,and 4 Gy+z-VAD-fmk groups,including 0 Gy,4 Gy,4 Gy+rapamycin,4 Gy+3-MA,and 4 Gy+z-VAD-fmk groups,respectively.The growth doubling time was calculated by MTT method.The specific protein expressions of LC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents wasLC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents was compared.The percentage of apoptosis of MCF7 cells was measured by flow cytometry (FCM).Resuits The growth doubling time of MCF7 cells in 4 Gy group wag longer than that in O Gy group(t=4.41,P

Objective To observe the effects of 3,4,5-trihydroxybenzoic acid dimmer (TAD) in different doses 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 experiment was divided into 0,3.125,6.250,12.500 and 25.000 ?g TAD groups. Apoptosis was observed with JEM-1200EX transmission electron microscope (TEM).The changes of apoptosis and cell cycle progression were measured with flow cytometry.Results The typical features of apoptosis were found in tumor cells,the nuclei were broken to pieces,mitochondrion cristae were disrupted and vacuoles were showed in nucleus and cytoplasm in 25.000 ?g TAD group observed under TEM.Meantime,the apoptotic percentages of the cells treated with 3.125—25.000 ?g TAD were increased significantly as compared with control group (P

Objective: To investigate the anti-tumor efficiency of B16 melanoma HACs in vivo and in vitro.Methods: Tris-HCI extract and Sephacryl S-200 gel filtration were applied to prepare B16 HACs, and the cytolokicity of specific CTL induced by HACs was tested. Results: The 41, 47 and 53 tube HACs obtained by gel filtration could decrease the tumor incidences, delay the time of tumor development and decrease the mortalitites of mice.Conclusion:60 ~ 97 kD HACs from B16 melanoma cytosol have the activites of inhibiting tumor and could be used in effective anti-tumor therapy.