ObjectiveTo observe the effect of long-term fluoride excess on rat thyroid morphology,thyroid peroxidase(TPO) activity and the expression of TPO protein,and to explore its possible mechanism of action.MethodsForty male SD rats were randomly divided into four groups by weight:control group,low-fluoride group,moderate-fluoride group and high-fluoride group(n =10),and they were fed with ordinary tap water containing fluorine 0.40,15.00,30.00,60.00 mg/L,respectively,and ate ordinary food prepared feed.After fed for 180 days,rats were anesthetized,and thyroid was taken.The morphology of thyroid was observed under light microscope.TPO activity was measured with improved guaiacol method.The expression of TPO protein was evaluated by Western blotting.ResultsThe thyroid histopathology results show:in control group,the thyroid follicular epithelial cells were columnar or cuboidal,with the follicular cavity filled with pink gum; in low-fluoride group,the thyroid follicular epithelial cell presented active hyperplasia; in moderate-fluoride group,the size of follicular increased,and follicular cavity was filled with dark,sticky colloid follicular; follicular increases,follicular cavity filled with dark,sticky colloid follicular; in high-fluoride group,the follicular epithelial cells showed apparent flat shape and excessive concentration of follicular colloid,a small amount of follicular lumen even showed the phenomenon of fusion,forming a giant follicular or cystic cavity.Among the four groups of control group,low-fluoride group,moderate-fluoride group and high-fluoride group,with increased fluoride,TPO activity [ ( 1.572 ± 0.046), ( 1.414 ± 0.086), (1.322 ± 0.049), (0.960 ± 0.083)U/L] decreased,and the differences were statistically significant between the two groups(all P ＜ 0.05).With increased fluoride,the expression of TPO protein (0.335 ± 0.011,0.156 ± 0.027,0.084 ± 0.020,0.045 ± 0.002) decreased,and the differences were statistically significant between the two groups(all P ＜ 0.05).Conclusioons Long-term intake of excessive fluoride can inhibit the thyroid TPO activity and the expressions of TPO as well as thyroid hormone synthesis,and leads to histological changes in rat thyroid.

Objective To study the effect of long-term fluoride excess on the activity of thyroid peroxidase (TPO) and the expression of TPO mRNA in rat thyroid,and explore the underlying mechanism.Methods Forty male SD rats were randomly divided into four groups based on their body mass(n =10 in each group):control group,low-fluoride group,moderate-fluoride group and high-fluoride group,and rats were fed on water containing 0.40(tap water),15.00,30.00 and 60.00 mg/L NaF,respectively,eating ordinary food formulated feed.All rats were sacrificed 180 days afterwards.Serum FT3 and FT4,TPO activity and mRNA expression level were determined by radio-immunoassay,modificd guaiacol method and semi-quantitative RT-PCR,respectively.Results Although serum FT3 levels in low-fluoride [(3.62 ± 0.47)pmol/L],moderate-fluoride [(3.57 ± 0.55)pmoi/L]and high-fluoride [(3.30 ± 0.68)pmol/L]treated groups were decreased compared with the control[(3.64 ± 0.45)pmol/L],the difference was not statistically significant (P ＞ 0.05).Serum T4 levels of the high-fluoride group [(8.64 ± 1.72)pmol/L]were significantly lower compared with other groups[(13.08 ± 1.69),(12.68 ± 1.32),(12.05 ± 1.43)pmol/L,all P ＜ 0.05].TPO activity in control,low-fluoride,moderate-fluoride and high-fluoride-treated groups[(1.572 ± 0.064),(1.414 ± 0.086),(1.322 ± 0.049),(0.960 ± 0.083)U/L]was decreased with the dose of fluoride increasing,the difference was statistically significant between any two groups(all P ＜ 0.05).The TPO activity was negatively correlated with the dose of fluoride(r =-0.955,P ＜ 0.05).With increased fluoride,the expression of TPO mRNA (0.936 ± 0.160,0.368 ± 0.095,0.115 ± 0.018,0.016 ± 0.008) decreased,the difference was statistically significant between any two groups (all P ＜ 0.05).Conclusion Chronic fluoride excess inhibits the activity and the expression of TPO as well as thyroid hormone synthesis.

AIM: To investigate the change and the possible role of mitogen-activated protein kinase(MAPK) subfamilies in early recovery process following acute renal ischemia/reperfusion injury. METHODS: Ischemia/reperfusion renal injury model was made by placing an atraumatic vascular clamp in renal pedicel. The morphologic change was observed by transmission electron microscope. The proliferating cell nuclear antigen(PCNA) positive renal cells were detected by immunohistochemistry. Extracellular signal-regulated kinase (ERK) and c-Jun NH 2-terminal kinase(JNK) activity was assayed by specific substrate phosphorylation with immunoprecipitation. RESULTS: After acute ischemia, microvilli in renal tubular cells appeared again after 2h of reperfusion. At the same time, the PCNA-positive cells were initially increased. ERK activity decreased at 45 min of ischemia, and completely recovered at 5 min of reperfusion. JNK activity was not influenced by ischemia, but increased at 5 min of reperfusion, reaching its maximal activity at 20 min of reperfusion, and prolonged within 2h reperfusion. CONCLUSION: After renal ischemia/reperfusion injury, the early recovery of renal tubule damage was related to the changes of MAPKs in which the increase of JNK activity might be more important.

Mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases (ERKs), c-Jun NH2-terminal kinases (JNKs) and p38 MAPK, play an important role in transducting environmental stimuli to the transcriptional machinery in the nucleus in mammalian cells by virtue of their ability to phosphorylate and regulate the activity of various transcription factors. It was recently found that the changes in activity of MAPKs occurred during ischemia/reperfusion, but the biological significance of the changes was still controversial.

Mitogen - activated protein kinases (MAPKs), including extracellular signal - regulated kinases (ERKs), c - Jun NH2 - terminal kinases (JNKs) and p38 MAPK, play an important role in transducting environmental stimuli to the transcriptional machinery in the nucleus in mammalian cells by virtue of their ability to phosphorylate and regulate the activity of various transcription factors. It was recently found that the changes in activity of MAPKs occurred during ischemia/reperfusion, but the biological significance of the changes was still controversial.

Objective To evaluate the role of MCP/DAF expression in the spinal cord in the development of neuropathic pain (NP) induced by chronic constrictive injury (CCI) of the sciatic nerve in rats.Methods Twenty-four Sprague-Dawley rats transfected with MCP/DAF,weighing 200-250 g,were randomly divided into 2 groups (n =12 each) using a random number table:sham operation of transfected rat group (Rsham group) and CCI of transfected rat group (RCCI group).Twenty-four healthy male Sprague-Dawley rats,weighing 200-250 g,were randomly divided into 2 groups (n =12 each) using a random number table:sham operation of normal rat group (Nsham group) and CCI of normal rat group (NCCI group).The right sciatic nerve was exposed and 4 loose ligatures wen placed on the sciatic nerve at 1 mm intervals with 4-0 catgut in RCCI and NCCI groups.The right sciatic nerve was only exposed in Rsham and Nsham groups.Paw withdrawal threshold to yon Frey filament stimulation (PWT) and paw withdrawal latency to nociceptive thermal stimulation (PWL) were measured at 1 day before operation (baseline) and 1,3 and 7 days after operation.The animals were sacrificed after measurement of pain threshold on 7 days after operation and the L4,5 segment of the spinal cord was removed for determination of the expression of OX-42 (by immuno-histochemistry) and MCP mRNA and DAF mRNA (by RT-PCR).Results Compared with Nsham group,the PWT and PWL were significantly decreased on 1,3 and 7 days after operation,the expression of OX-42 was up-regulated,and the expression of MCP mRNA and DAF mRNA was down-regulated in NCCI group (P ＜ 0.05),and no significant changes were found in the PWT and PWL on 1,3 and 7 days after operation and expression of OX-42(P ＞ 0.05),and the expression of MCP mRNA and DAF mRNA was up-regulated in Rsham and RCCI groups (P ＞ 0.05).Compared with NCCI group,the PWT and PWL were significantly increased on 1,3 and 7 days after operation,the expression of OX-42 was down-regulated,and the expression of MCP mRNA and DAF mRNA was up-regulated in RCCI group (P ＜ 0.05).Conclusion Up-regulation of MCP/ DAF expression in the spinal cord can inhibit the development of NP in rats and regulation of activation of microglias in the spinal cord is involved in the mechanism.

Objective To study the effect of Guizhi Fuling Wan(GFW) on tumor apoptosis and apply the experimenting basis of GFW's development and utilization.Methods The S180 mice sarcoma model was used to detect the inhibitory effects of GFW,observe the ultrastructural change by electron microscopy,and the flow cytometer was used for apoptosis determination.The protein expression of P21waf/cip and the mRNA expression of Survivin were evaluated by immunohistochemistry and in situ hybridization.Results For S180 sarcoma,the inhibition ratio of GFW was 38.93%.The apoptosis was 17.79% by the flow cytometer.Some typical apoptotic cells and apoptotic bodies were observed through electron microscope.Chromatin gathered at the side of cell,the nucleus turned into the nucleus band and nucleus projected.Survivin mRNA markedly declined in the GFW group when compared with that in the model group(P

Objective To determine the effect of different doses vitamin D supplementation to the change of bone metabolism in 6 months after Roux-en-Y gastric bypass ( RYGB) .Methods The change of body weight and body mass index ( BMI ) in 36 patients in 6 months after RYGB WAS analyzed.Then,the effect of low-dose (n=11,400 IU/day) and high-dose (n=12,1 600 IU/day) vitamin D to the serum calcium,25-hydroxyvitamin D and bone density were observed ,and 15 patients as control .Results In 6 months after RYGB,the body weight and BMI were decreased ,and the differences were statistical significance (P<0.05).The serum calcium,25-hydroxyvitamin D and bone density were increased in high-dose group,and the differences were statistical significance (P<0.05).Conclusion High-dose (1 600 IU/day) vitamin D supplementation is effective to the bone loss of patients undergoing RYGB .

Objective This paper was performed to investigate the effectiveness of problem-based learning in naval hygiene teaching. Methods Totally 257 clinical medicine undergraduates and general practice undergraduates from Grade 2010 and 2009, Faculty of Naval Medicine, Second Military Medical University attended naval hygiene teaching. PBL and LBL approaches were applied in PBL group (Grade 2010, n=117) and LBL group (Grade 2009, n=140), respectively. The learning outcomes were evaluated by three tests covering PBL evaluation (or usually performance), theoretical examination and experimental practice . Questionnaire was used to investigate the recognition of PBL teaching method and new evaluation system. Data were analyzed by SPSS 16.0 and t test was used to compare the average scores of theory,α=0.05. Results The results showed that the average theory scores of Grade 2010 (78.51±7.57 and 71.68±5.74) were higher than those of Grade 2009 (65.36±6.41 and 59.97±7.08) (P=0.000, P=0.000). The questionnaire surveys indicated that more than 85% students in PBL group considered the PBL teaching method could enhance professional and comprehensive quali-ties, and that 84%students were satisfied with new evaluation system. Conclusions PBL showed better learning results than traditional methods in naval hygiene teaching and could better promoted students' comprehensive ability.

Objective To investigate apoptosis of polymorphonuclear neutrophil and activity of caspase-3 in the peripheral blood and discuss their correlation with development of multiple organ dysfunc- tion syndrome (MODS) after multiple injury. Methods A total of 55 patients with multiple injury were included in the prospective study, and divided into two groups, ie, MODS group (multiple injury patients who developed MODS,) and non-MODS group (multiple injury patients who were free from MODS). The activity of caspase-3 was detected by flow cytometry and the serum levels of IL-6 and IL-10 were detected by ELISA. Then, we evaluated whether the neutrophil apoptesis was correlated with the ser- um levels of IL-6 and IL-10 in patients with MODS. Results Compared with non-MODS group, neu- trophil apoptesis was significantly reduced and activated caspase-3 decreased significantly in MODS group (P <0.05). In MODS group, serum IL-6 was increased significantly while serum IL-10 was decreased significantly compared with non-MODS group. The apoptosis of neutrophil in multiple injury patients with MODS had a negative correlation with IL-6 levels but a positive correlation with IL-10 levels. Conclu- sions The delayed apoptosis of neutrophil due to decreased activated caspase-3 may play partial roles in the development of MODS after multiple injury. IL-6 and IL-10 may contribute to the apoptotic changes.