Aged ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Carcinoma, Signet Ring Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Gastrectomy ; methods ; Histiocytic Sarcoma ; metabolism ; pathology ; surgery ; Humans ; Lymphatic Metastasis ; Male ; Phosphoglucomutase ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; surgery

Objective To observe the learning and memory changes in coal-burning type of fluorosis rats, detect the expressions of neuronal nicotinic acetylcholine receptor(nAChR) at mRNA and protein levels in rat brains and to reveal the mechanism of changed learning and memory ability. Methods Twenty-four healthy SD rats, weighting 100 - 120 g, were randomly divided into three groups(8 in each). Control group was fed with normal diet, and low- and high-dose fluoride groups were fed with corn polluted with high fluoride (fluoride were 11.30,104.20 mg/kg, respectively) during drying processes with local burning-coal from the areas of endemic fluorosis to established rat model of chronic fluorosis. After exposed to fluoride for 6 months, behavioral changes were measured by Morris water maze. Animals were sacrificed, the brain was taken, after homogenizing the fluoride content of brain tissue was determined by fluoride ion selective electrode. The α3, α4 and α7 nAChR subunits at mRNA and protein levels were analyzed by real-time PCR and Western blotting, respectively. Results For rats in low- and high-fluoride groups, the escape latency time[(12.42 ± 8.03),(17.48 ± 8.05)s] was significantly longer than that in the control[(7.04 ± 3.29)s, all P< 0.05]. For rats in high-fluoride group, the numbers of crossing the platforms (1.62 ± 0.87) and the time of staying at the platforms[(16.70 ± 5.02)s] were significantly decreased as compared to that of control[3.53 ± 1.67, (23.33 ± 5.35)s, all P < 0.05]. The fluoride content in rat brain tissue in low- or high-fluoride groups [(1.14 ± 0.04), (1.79 ± 0.04)mg/kg] was significantly higher than that of control [ (0.52 ± 0.05) mg/kg, all P < 0.05]; in addition, the amount of fluoride in brain tissue of high-fluoride group was significantly higher than that of low-fluoride group(P < 0.05). In high-fluoride group, the mRNA expressions of α3, α4 and α7 nAChR subunits in rat brains(1.51 ± 0.20,1.45 ± 0.06,1.63 ± 0.08) were significantly lower as compared to controls (1.79 ± 0.11,1.66 ± 0.14,1.83 ± 0.06, all P< 0.05); whereas there were no significant changes in mRNA levels of these receptor subunits of the rat brains between low-fluoride group(1.65 ± 0.17,1.59 ± 0.09,1.71 ± 0.03) and controls (all P > 0.05). Furthermore, the protein levels of α3, α4 and α7 nAChR subunits in rat brains of highfluoride group(0.58 ± 0.13,0.16 ± 0.03,1.41 ± 0.38) and low-fluoride group(0.56 ± 0.23,0.08 ± 0.02,0.51 ± 0.16) were significantly lower than those of controls( 1.48 ± 0.42,0.57 ± 0.21,2.56 ± 0.26, P<0.05 or < 0.01). Conclusions Decreased ability of learning and memory in coal-burning type of fluorosis rats may be associated with declined expressions of nAChR at proteins and mRNA levels, which might be the main mechanism of the behavior change.

Objective To investigate the expression and distribution of the downstream substrate of extracellular regulated protein kinase(ERK1/2) pathway, ternary complex factor phospho-Elk-1, in rat brains with chronic fluorosis, and reveal the mechanism of the impaired learning and memory ability caused by chronic fluorosis. Methods Seventy-two SD rats, weighing 100 - 120 g, were randomly divided into 3 groups, 24 in each group (half male and half female). The rats in control group were fed with tap water (fluoride < 0.5 mg/L); low- and high-dose fluoride groups were fed with tap water with different concentrations of NaF(5.0,50.0 mg/L F-, respectively). After 6 months, body weight was weighed, dental fluorosis was determined by observation and urinary fluoride and bone fluoride were detected by fluorine ion-selective electrode; the learning ability of rats was measured by navigation test of Morris water maze, and memory ability by spatial probe test in Morris water maze; the expression and distribution of phospho-Elk-1 in different brain regions were detected by immunohistochemistry method. Results In low- and high-fluoride groups, the body weight of rat[(449.2 ± 77.1), (312.8 ± 89.7)g] was significantly decreased than that of control [(635.5 ± 76.2 )g, all P< 0.05], the varying degrees of dental fluorosis were observed(x2 = 7.83, P<0.05), urinary fluoride[(2.56 ±0.91),(5.73 ±3.14)mg/L] and bone fluoride[(709.2 ± 37.4) ,(1306.3 ± 102.4) mg/kg] were significantly higher than those in controls[(0.92 ± 0.30)mg/L,(348.5 ± 89.2)mg/kg, all P< 0.05]. The escape latency of low- and high-fluoride groups[ (7.4 ± 4.1), (12.2 ± 5.7)s] was longer than that of control [(4.8 ± 2.7 )s, all P < 0.05] and the escape latency in high-fluoride group was significantly longer than that in other groups (all P < 0.05); in spatial probe test, the time of first crossing platform was longer in rats with fluorosis [(4.18 ± 1.10),(5.89 ± 0.56)s] as compared to control[(1.17 ± 0.75)s, all P< 0.05]. Expressions of phospho-Elk-1 in the hippocampus CA1(167.4 ± 8.3,163.2 ± 9.4), CA2(175.7 ± 5.0,183.3 ± 4.2), CA3(165.2 ± 11.6,162.9 ± 4.4), CA4(168.7± 6.9,169.5 ±5.3), fascia dentate (185.2 ±4.0,193.1 ±6.1) and caudate putamen( 181.4 ± 3.8, 179.8 ± 5.5) in low- and high-fluoride groups were higher than those of controls(142.4 ± 8.1,144.9 ± 8.4,143.6 ± 5.8, 116.8 ± 9.1,140.2 ± 7.8,163.1 ± 13.1, all P< 0.05). Conclusion Chronic fluorosis can cause increased expression of phospho-Elk-1 in the hippocampus and caudate putamen region of rat brains, which might be related to the mechanisms of decreased learning and memory ability of rats overexposed to fluoride.

Objective To investigate the changes of reactive oxygen species(ROS) level and mitochondria fission-fusion-balance in cortical neurons of rats with chronic fluorosis and reveal the correlation between these two factors. Methods One hundred and twenty rats were randomly divided into 3 groups(control group, low-dose fluorosis group, high-dose fluorosis group) and 40 rats were in each group according to body weight and the experiments were carried out for 3 months or 6 months. The rats were fed with different concentrations of fluoride (NaF) to establish fluorosis models. Controls were fed with tap water( < 0.5 mg/L), experimental animals in low- or high-dose group were fed with water containing NaF 10.0,50.0 mg/L, respectively. The level of ROS and the morphology in mitochondria fission-fusion balance in neurons of the cortex of rat brains prepared with cortical frozen sections were detected with ROS fluorescent probe and MitoTracker RED probe, respectively. Results Significant differences of the level of ROS and the numbers of abnormal mitochondria in morphology in the cortical neurons were found between 3 groups at the experiment period of 3 month and 6 month(F= 3.07,3.06,3.05,3.07, all P < 0.05). As compared with control group(10.43 ± 5.98,4.12 ± 3.86) at the experiment period of 3 month, the level of ROS and the numbers of abnormal mitochondria in morphology in the cortical neurons were obviously increased in high-dose fluorosis group(25.48 ± 6.09,20.47 ± 6.09, all P < 0.05), whereas no significant changes were found in low-dose fluorosis group(11.67 ± 3.49,6.68 ± 3.48, all P> 0.05). Furthermore, the increases in both ROS level and abnormal numbers of mitochondria were significant observed in the cortical neurons of low-dose fluorosis group (63.02 ± 8.15, 49.33 ± 8.61) and high-dose fluorosis group(65.60 ± 7.40,53.10 ± 6.95) as compared with the control group (25.26 ± 6.41,20.26 ± 6.41) at the experimental period of 6 month (all P < 0.05). The abnormal numbers of mitochondria correlated with ROS level(r = 0.93,0.81, all P < 0.05). Conclusions Taking excessive amount of fluoride results in high level of oxidative stress and impaired the balance of mitochondrial fission-fusion,which is dependent on the feeding times and doses of fluoride. The mechanism of the mitochondrial abnormalities might be associated with the high level of oxidative stress induced by chronic fluorosis.

The authors helpfully discuss the design idea,experimental module design,examination methods,and experiment textbook construction in experimental teaching of microbiology,and conduct further researches on the basic skill training,verifying experiment,integrative experiment,and investigative experiment in the course. This study aims to enhance effects of the experimental teaching,to cultivate high potential talents who can master essential knowledge and skills,and creatively carry out scientific research.

Objective To observe the expression of mitochondrial fission protein locus Fis1 and ultrastructural changes in the renal cells of rats with chronic fluorosis,and to reveal the mechanism in mitochondrial damage of the renal cells.Methods Sixty SD rats were randomly divided into 3 groups according to sex and body mass(20 in each group):control group,lower fluoride group and higher fluoride group.All the rats were fed with different doses of sodium fluoride in drinking water(0,10 and 50 mg/L,respectively).Six-month later,the expression of Fisl in renal cells was determined by real-time fluorenscence quantitative PCR and immunohistochemistry technology,the mitochondrial morphology of renal cells was observed under transmission electron microscopy (TEM).Results As compared with the control group(28.70 ± 12.41),Fis1 mRNA levels(91.48 + 34.83 and 582.09 ± 184.69) in renal cells of the lower fluoride and the higher fluoride groups were increased(all P ＜ 0.05).As compared with the control group(10.49 ± 7.66),Fisl protein levels(16.33 ± 10.26 and 21.50 ± 5.24) in renal cells of the lower fluoride and the higher fluoride groups showed a trend of increasing,the higher fluoride group was higher than that of the control group(P ＜ 0.05).By TEM,mitochondrial crest in renal cells of the lower fluoride and the higher fluoride groups was vague or disappeared,mitochondrial division section appeared.Conclusions Fluoride is a kind of toxicant that can cause damage to mitochondrion of renal cells,induce the expression of Fis1 in transcriptional and protein level,and lead to the obstacles of mitochondrial fusion-fission and ultrastructural abnormality of mitochondrion,which may play an important role in mechanism of mitochondrial damage in the renal cells of rats with chronic fluorosis.

Background and purpose: With the development of the means of preoperative diagnosis and treatment of breast cancer, ifne needle puncture no longer seems to be popular with the clinical use. The safety and effectiveness of fine needle aspiration as preoperative diagnosis of breast cancer are controversial. This study was aimed to investigate the application of fine needle aspiration (FNA) of breast cancer and association between FNA and recurrence and metastasis for 30 years in our hospital. Methods:A total number of 1 260 patients with breast cancer treated in Peking Union Medical College Hospital from 1975 to 2006 were reviewed in two groups for clinical characters, recurrence, and survival rate. The two groups were FNA and non-FNA. Results:The positive rate of FNA was 61.4%and the highest rate was inⅣstage (100%). StageⅡandⅢwere the major ones in FNA group (45.2%). The local recurrence (7.0%vs 6.4%), recurrence and metastasis (13.2%vs 14.0%), 5-year (82.0%vs 81.0%) and 10-year disease free survival rates (51.0%vs 64.0%) have no signiifcant difference between FNA and non-FNA groups. Conclusion:FNA is still one of the most important methods for preoperative investigation of breast cancer. Background and purpose: With the development of the means of preoperative diagnosis and treatment of breast cancer, ifne needle puncture no longer seems to be popular with the clinical use. The safety and effectiveness of fine needle aspiration as preoperative diagnosis of breast cancer are controversial. This study was aimed to investigate the application of fine needle aspiration (FNA) of breast cancer and association between FNA and recurrence and metastasis for 30 years in our hospital. Methods:A total number of 1 260 patients with breast cancer treated in Peking Union Medical College Hospital from 1975 to 2006 were reviewed in two groups for clinical characters, recurrence, and survival rate. The two groups were FNA and non-FNA. Results:The positive rate of FNA was 61.4%and the highest rate was inⅣstage (100%). StageⅡandⅢwere the major ones in FNA group (45.2%). The local recurrence (7.0%vs 6.4%), recurrence and metastasis (13.2%vs 14.0%), 5-year (82.0%vs 81.0%) and 10-year disease free survival rates (51.0%vs 64.0%) have no signiifcant difference between FNA and non-FNA groups. Conclusion:FNA is still one of the most important methods for preoperative investigation of breast cancer.

Objective To investigate the expression of c-Jun-N-terminal kinase(JNK) in rat brains with chronic fluorosis and try to reveal the molecular mechanism for the neural impairment induced by the disease.Methods The rats were randomly divided into 3 groups, normal control group(drinking water containing less than 0.5 mg/L of sodium fluoride, NaF), lower fluoride exposed group(drinking water containing 5 mg/L NaF) and higher fluoride exposed group(drinking water containing 50 mg/L NaF), 24 in every group. The rats were examined at the sixth month after feeding. The concentration of fluorine in urine and blood was detected by F-ion selective electrode. The expression of JNK in brains was investigated by using Western blotting and immunohitochemistry staining, and analyze the correlation between activating of JNK and the concentration of fluorine in blood. Results The increased concentration of fluorine in urine(control: 0.92 ± 0.30, lower fluoride exposed group: 2.56 ± 0.91,higher fluoride exposed group: 5.73 ± 3.14, P ＜ 0.05) were observed when 6 months after the beginning of the experiment, and the amount of fluorine in blood was also higher in rats with fluorosis(control: 0.12 ± 0.07, lower fluoride exposed group: 0.36 ± 0.14, higher fluoride exposed group: 0.50 ± 0.18, P ＜ 0.05). The expression of phospho-JNK at protein levels were higher in the brains of rats with fluorosis than that of controls (control: 1.00 ± 0.37, lower fluoride exposed group: 1.20 ± 0.28, higher fluoride exposed group: 1.74 ± 0.69, P ＜ 0.05), whereas no change of total-JNK was found(F = 0.046, P ＞ 0.05). Furthermore, the expression of phospho-JNK in the parietal cortex(119.3 ± 14.1), occipital cortex(112.7 ± 5.4), hippocampus CA3(100.6 ± 8.9), dorsal thalamus (117.8 ± 10.4) and olivary nucleus( 112.6 ± 5.9) of rats in higher fluoride exposed group were higher than that in control( 104.1 ± 8.9,106.6 ± 9.6,106.6 ± 9.7,108.9 ± 6.4,100.3 ± 8.4, all P ＜ 0.05) and lower fluoride exposed group(96.7 ± 17.1,102.5 ± 8.3,106.4 ± 6.5,110.2 ± 9.3,102.4 ± 4.7,102.5 ± 9.8, all P＜ 0.05). The positive stained neurons of total-JNK also distributed in the same brain regions of rats, but no difference was detected between the rats with fluorosis and controls(all P ＞ 0.05). The increased level of phospho-JNK was positively correlated with the fluoride contents in blood of the rats with fluorosis (r = 0.677). Conclusions The expression of phospho-JNK in brains of rats with fluorosis was significantly increased with a correlation to fluoride content in blood, which might be connected to the mechanism of neural impairment induced by chronic fluorosis.

Objective To investigate the expression of extraeellular signal-regulated protein kinase (ERK1/2)pathway in rat brains with fluorosis and the effects of fluoride on learning and memory of the rats,and to reveal the mechanisms of damaged nervous system resulted from the toxicity of the ion.Methods Seventy-two SD rats were divided into 3 groups and 24 rats were in each group.Three groups were fed respectively with different concentrations of fluoride(NaF)for 6 months to establish rat models with fluorosis.Controls were fed with tap water (NaF＜0.5 mg/L):lower and higher concentration group were fed with water containing NaF(5,50 ms/L).Animals are sacrificed after 6 months of treatment with fluoride and the dissected brains were kept for analysis.The protein levels of ERK1/2 in rat brains were detected by Western-blotting and the mRNA level by RT-PCR. The spatial learning and memorizing ability was measured by Morris water maze test. Results The ERK1/2 protein in control group,lower and higher concentration group was 0.944±0.10,1.253±0.02,1.953±0.07,the differece being statistieally sighificant between any two groups (P ＜ 0.05). The phospho-ERKl/2 protein in control group,lower and higher concentration group was 0.73±0.08,0.77±0.07,1.28±0.11,the differece being statistieally sighificant between any two groups(P ＜ 0.05);the activation rate of phospho-ERK1/2 in lower and higher concentration group [(68.4± 3.8)%,(64.1±3.2)%] was decreased compared to control group[ (82.3±10.7)%],the differece being significant(P ＜ 0.05). In the navigation trial,longer escape latencies of lower concentration group on the second, the third,the fifth and the sixth day were observed[ (46.0±8.0),(24.0±2.7),(8.9±5.3),(7.4±4.1 )s] compared to the control[ (39.3±6.9),(19.1±9.1 ),(8.3±3.4),(4.8±2.7)s],the differece being significant (P ＜ 0.05 or ＜ 0.01 );the similar results were also observed in the higher concentration group[ (36.9±16.8),(37.7±12.9), (19.7±7.6),(12.2±5.7 )s],and the escape latencies of the higher concentration group on the third,the fifth and the sixth day were longer than that in lower concentration group. In the probe test,the rats took more time to reach the first cross in lower and higher concentration group[(1.17±0.75),(4.18±1.10)s] than control group[ (5.89± 0.56 ) s ],the differece being significant (P ＜ 0.05 or ＜ 0.01 ) ;stayed shorter [ ( 17.05±4.25 ),(18.20±4.57 ) s ] than control [(25.37±5.65 )s ] in platform area (P ＜ 0.01 );the activation rates of ERK1/2 were directly correlated with the time taken to reach the first cross platform located in the probe test(r = 0.364,P ＜ 0.05) and the activation rates were also directly correlated with the escape latencies on the sixth day(r = 0.497,P ＜ 0.05). Conclusion Long-term exposure of excessive fluoride induces the change of expression and activating rate of the ERK1/2 in rat brains,leading to the decreased capacity of learning and memory.

Objective The aim of the study was to investigate the expression of P-glycoprotein (P-gp)and nuclear factor κB (NF-κB) in the cerebral cortex of rat with chronic fluorosis,and to reveal the mechanisms of damaged nervous system resulted from the toxicity of fluoride.Methods Sixty SD rats were randomly divided into three groups.The rats in each group were given drinking water containing different levels of fluoride:control group less than 0.5 mg/L,small amount of fluoride exposure group 10.0 mg/L and large amount of fluoride exposure group 50.0 mg/L.The animals were examined at the sixth month after initiating the experiment.Protein levels of P-gp and NF-κB in brain tissues were detected by immunocytochemistry and Western blotting,and the P-gp protein and mRNA level by quantitative real time PCR method.Results As compared to the control group(28.21 ±6.13),the numbers of positive staining cells by P-gp antibody in the cortex of rat brains were significantly increased in both the small and the large amount of fluoride exposure groups[(48.46 ± 8.00),(53.72 ± 9.15),respectively,all P ＜ 0.05] ; the protein levels in the control group(100.00 ± 3.86)％ detected by Western blotting were significantly increased in the cortex of rat brains treated with fluoride in both the small and the large amount of fluoride exposure groups[(189.47 ± 3.14)％,(191.36 ± 11.09)％,respectively,all P ＜ 0.05].The significantly increased expression of NF-κB at the protein level was observed in the cortex of rat brains of the small and the large amount of fluoride exposure groups[(365.97 ± 6.04)％ and (417.15 ± 10.89)％,respectively] as compared with the control group[(100.00 ± 10.07)％,all P ＜ 0.05].The mRMA level of P-gp in the cortex of rat brains of the small and the large amount of fluoride exposure groups(2396 ± 427,3479 ± 371,respectively) were higher than that of the control group(260 ± 106,all P ＜ 0.05).Conclusion The increased expressions of P-gp and NF-κB in the cortex of rat brains are induced by chronic fluorosis,which might be connected with the mechanism of brain damages.