Objective: To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods: Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200 -220 g) matched female rats were control group (Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results: Compared with control group, the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P<0.05). The spontaneous cell activity and discharge of RN neurons (spikes/ s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P<0.01). Conclusion: The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN.

Objective:To investigate if the combined use of CDAⅡ and sodium butyrate can induce demethylation and re-expression of retinoic acid receptor?2(RAR?2)gene in cultured human breast cancer cells MCF7.To explore if the two drugs can inhibit cell growth and induce cell apoptosis synergetically.Methods:MCF7 cell line was treated with CDAⅡ,sodium butyrate,combination of the two drugs respectively.Methylation was assessed by methylation-specific polymerase chain reaction(MSP)for RAR?2 gene.Gene expression was evaluated by reverse transcription polymerase chain reaction(RT-PCR).Apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL)and Hoechst33342/propidiumiodide(PI)staining.Cell growth inhibition was measured by MTT assay.Results:Neither CDAⅡ nor sodium butyrate induced demethylation and re-expression of RAR?2 gene,Combination of the two drugs partially demethylated gene promoter accompanied by re-expression of RAR?2.The apoptotic cells in the double-drug group were obvious following Hoechst33342/PI staining.The percentage of apoptotic cells in the double-drug group was significantly higher than that of the two single-drug group(39.5% vs 5.2%,8.1%)(P

Objective To explore the efficacy of calmodulin antagonist berbamine(BBM)on multidrug resistance(MDR)reversal and its mechanism. Methods Human breast cancer cell line MCF7 and its adriamycin-resistant counterpart MCF7/ADR were used in the study.The cells were cultured with ADR and different concentration of BBM. MTT assay was used to analyze the effect of BBM on cell growth inhibition.According to the MTT assay,the 50% inhibitory concentration(IC 50 ),the multiples of drug resistance and increased sensitivity of ADR were calculated.The concentration of intracellular ADR and expression level of P-glycoprotein(P-gp)were detected by flowcytometry(FCM).The mRNA expression level of mdr1 gene was detected by semi-quantitative reverse transcriptase polymerase chain reaction(RT-PCR)with ?-actin as internal reference. Results The IC 50 of ADR in MCF7 and MCF7/ADR cells were(0.98?0.06)?mol/L and(101.20?5.72)?mol/L,respectively.The resistant multiple of MCF/ADR cells to ADR was 103 folds higher than that of MCF7 cells.BBM increased the chemo-sensitivity of ADR in MCF7/ADR cells with dose-dependent relationship,i.e.when 5*!?mol/L ,10*!?mol/L and 20*!?mol/L BBM was added into the culture the chemo-sensitivity of ADR was increased to 2.76,5.88,and 28.26 folds(P

Objective To observe the changes of diameter of intrafusal fibers and capsule at equatorial region of rat soleus muscle spindle caused by hindlimb-unloading.Method Tail-suspended female rats were used as the model of hindlimb-unloading,all rats were randomly divided into 4 groups according to body weight.The four groups were exposed to tail-suspension for: 7 d,14 d,28 d and 0 d,respectively.The diameter of intrafusal fibers and capsule of single muscle spindle was measured and analyzed.Result The diameter of intrafual fibers,including nuclear-bag fibers and nuclear-chain fibers, were reduced slightly in both 7 d group and 28 d group and obviously reduced in 14 d group.The capsule diameter at equatorial region was obviously reduced in 7 d group.Conclusion Hindlimb-unloading can obviously reduce the diameters of intrafusal fibers and capsule at equatorial region of rat soleus muscle spindle.

Objective To observe the substance P(SP) and calcitonin gene-related peptide(CGRP) expressions in the temporomandibular joints(TM J) of the rats undergone emotional stress and explore the relationship between emotional stress and temporomandibular joint disorder(TMD). Methods Ninety SD rats were averagely randomly divided into emotional stress ( ES ) group( n = 30 ), electric foot-shocked (FS) group ( n = 30 ) and control (CON) group( n = 30). The emotional stress was induced by communication box. The TMJ tissues in ES and CON groups were removed after 1, 3 and 5 weeks of emotional stress for scanning electron microscope ( SEM ) test and immunohistochemistry test. The SP and CGRP expressions were examined with SABC immunohistochemistry and then analyzed by image analysis system. Results The expressions of SP and CGRP had significant difference after 1 ,3 and 5 weeks emotional stress ( SP: 124.5 ± 16.9,185.6 ± 1.8 and 193.5 ± 3.5, respectively; CGRP: 185.9 ±5.3, 112.5 ±5.2 and 174.3 ±5.3 ,respectively) (P＜0. 05 ). The SEM results showed that there was a series of structural change on the condylar surface after emotional stress. Conclusion The SP and CGRP energy nerve fibers take part in the TMJ pathological process undergone emotional stress.

Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200-220g) matched female rats were control group(Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results Compared with control group ,the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P＜0.05). The spontaneous cell activity and discharge of RN neurons (spikes/s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P＜0.01). Conclusion The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN.

Objective To investigate changes induced by hindlimb unloading in morphology of nerve endings in soleus muscle spindles.Method Hindlimb unloading model was simulated by tail suspension in female rats.Fast silver-staining was used to observe morphology of nerve endings of single muscle spindle in 7 d,14 d,21 d and 28 d tail-suspended and control rats.Result Nerve endings of muscle spindles in control rats were intact and clear,and there was no obvious abnormality in single soleus muscle spindle of 7 d tail-suspended rats.Slight fragmentation of nerve endings was observed in Equatorial Region of soleus muscle spindle in 14 d tail-suspended rats,while reduction in density and disruption of nerve endings were observed in soleus muscle spindle in 21 d tail-suspended rats.Serious degeneration and distortion of nerve endings were found in soleus muscle spindle in 28 d tail-suspended rats.Conclusion Hindlimb-unloading can induce time-related changes in morphology of nerve endings of muscle spindle in rats soleus muscle.

Objective: To investigate hyperthermia enhanced expression of heat shock protein70 (HSP70) in breast cancer drug sensitive cell line MCF7 and multi-drug resistant (MDR) cell line MCF7/ADR, so as to increase cytotoxic activity of immunologic effector cells against the target cells, and to provide an experimental basis for cell immunotherapy based on hyperthermia. Methods: The immunological effector cells were induced and expanded by cytokines. Breast cancer cell lines MCF7 and MCF7/ADR were treated at 42 ℃ for an hour. Then after being incubated for additional 4 hours, 24 hours and 48 hours, the cells were digested. Flow cytometry (FCM) was used to detect the expression of HSP70 on the target cells. MTT assay was employed to evaluate cell proliferation and the cytotoxic activity of immunologic effector cells against target cells. Results: The expressions of HSP70 in both the target cells had significant difference. The expression of HSP70 in MCF7/ADR cells was higher than in MCF7 cells before hyperthermia. After hyperthermia the expression of HSP70 increased by 6 folds in MCF7/ADR cells, and 22 folds in MCF7 cells and was higher than in MCF7/ADR cells at hour 4. The proliferation inhibition fraction of hyperthermia against MCF7 was significantly lower than that of MCF7/ADR. The cytotoxic activity of immunologic effector cells against MCF7 cells was lower than against MCF7/ADR cells before hyperthermia. After hyperthermia the cytotoxic activity of immunologic effector cells against MCF7 cells rose by 86.23%, and was higher than against MCF7/ADR cells (rose by 30.32%). Conclusion: The expression of HSP70 in breast cancer drug sensitive cell line MCF7 and MDR cell line MCF7/ADR were enhanced significantly by hyperthermia. Cytotoxic activity of immunologic effector cells against both the target cells were increased by hyperthermia. The differential expressions of HSP70 in breast cancer drug sensitive cell line MCF7 and MDR cell line MCF7/ADR affect the cytotoxic activity of immunologic effector cells.

Objective To study counteracting effects of high frequency vibration on simulated weightlessness-induced atrophy of soleus muscles in rats. Methods Female Sprague-Dawley (SD) rats were assigned randomly to one of the three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus high frequency vibration (SUS+HFV). Soleus muscles were examined 7 days later. Sections were treated with adenosinetriphosphatase (ATPase) stain. The cross-sectional areas (CSA) of fibers, the relative proportion of types I and II were measured using Leica image analysis system. Results Compared with those of CON, the wet weight /body of soleus and the cross-sectional areas (CSA) of type I/II fibers in SUS were significantly reduced. The relative proportion of type I fibers in SUS was reduced and type II fibers increased. In SUS+HFV group, the wet weight/body of soleus and the cross-sectional areas (CSA) of type I/II fibers recovered completely. The relative proportion of type I/II fibers recovered completely. Conclusion The present study demonstrates that HFV is effective in counteracting the muscle atrophy induced by simulated weightlessness.

The severity of disease can be used to evaluate the current situation of patients as well as to predict the diseases outcome.In the meantime, the severity among different diseases has been more and more applied in the evaluation of the patients at hospital level.This study collected and summarized different types of international disea-ses grouping tools'characteristics and applications based on the severity of disease, and their suitability and practical values in hospital performance evaluation were compared and analyzed.