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Objective To investigate the influence of internal and external sphincter loss synergy on stress distributions and urine flow rates of lower urinary tract organs and tissues. Methods Based on collodion slice, the geometric model of the lower urinary tract was reconstructed, and finite element model of the lower urinary tract with muscle active force was established. Through fluid structure coupling simulation, the changes of tissue stress and urine flow rate were simulated under four conditions: normal contraction of internal and external sphincter, total loss of muscle active force and single loss of muscle active force for internal and external sphincters at the end of urination. Results The urethral stress changes in normal contraction of internal and external sphincter muscles were the same as the clinically measured urethral pressure changes. Compared with normal contraction, when the internal sphincter lost its muscle active force alone, stress of the internal sphincter and the urethra of the prostate was reduced by 33.6% and 13.8%, and flow rate of urine in this position was also reduced. When the external sphincter lost its muscle active force alone, the urethral stress of the external sphincter and external urethra was reduced by 59.5% and 24.03%, respectively. When the internal and external sphincter lost muscle active force, stress of the internal sphincter, the prostate, the external sphincter and the external urethra were reduced by 38.77%, 18.6%, 63.58%, 29.74%, respectively, and flow velocity in the corresponding position was also reduced. Conclusions Internal and external sphincter loss synergy resulted in the difference of tissue stress and urine flow rate. The results can provide the theoretical basis for surgical treatment of urinary incontinence caused by sphincter.
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Males typically have high rates of morbidity of primary bladder neck obstruction, while the existing urodynamic examination is invasive and more likely to cause false diagnosis. To build a non-invasive biomechanical detecting system for the male lower urinary tract, a finite element model for male lower urinary tract based on the collodion slice images of normal male lower urinary tract was constructed, and the fluid-structure interaction of the lower urinary tract was simulated based on the real urination environment. The finite element model of the lower urinary tract was validated by comparing the clinical experiment data with the simulation result. The stress, flow rate and deformation of the lower urinary tract were analyzed, and the results showed that the Von Mises stress and the wall shear stress at the membrane sphincter in the normal male lower urinary tract model reached a peak, and there was nearly 1 s delay than in the bladder pressure, which helped to validate the model. This paper lays a foundation for further research on the urodynamic response mechanism of the bladder pressure and flow rate of the lower urinary tract obstruction model, which can provide a theoretical basis for the research of non-invasive biomechanical detecting system.
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AIM: The pathogenesis of interstitial lung disease is still uncertain. This study observed the effect of interferon-gamma (IFN-?) in combination with methylprednisolone (M-pred) on the proliferation of human embryonic lung fibroblast (HELF) to identify whether it can be used as an effective treatment of interstitial lung disease in clinic. METHODS: The experiment was performed at the Research Laboratory of Cytobiology, Hebei Medical University from July 2005 to May 2006. ①The eighth passage HELFs were cultured in vitro. According to the common dose range for human of IFN-? and M-pred, cells were divided into control group, M-pred (15 mg/L) group, IFN-? (250, 500, 750, 1 000, 1 250 U/mL) groups and combination group (IFN-? and M-pred). ②HELFs were incubated with IFN-? alone or combined with M-pred for 48 hours before they were harvested. ③MTT assay was used to measure the inhibition rate of M-pred combined with different concentrations of IFN-? on HELF. Flow cytometry was used to observe cell cycle distribution and the proliferation index of HELF. The expression of proliferating cell nuclear antigen (PCNA) was detected by immunocytochemistry. RESULTS: ①Both alone and combination usage of IFN-? and M-pred could inhibit HELF proliferation (P 0.85). ② IFN-? mainly acted on G1 and G2M periods, while M-pred on S period. The proliferation index decreased in combination group (P
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Objective To investigate the mechanism of cisplatin enhanceing the effect of tineposide killing small cell lung cancer cell line by combination of the two drug.Methods The microculture tetrazolium(MTT) assay was used to determine the inhibition rates of CDDP combined with VM-26.Acridine orange/ethidium bromide(AO/EB) fluorescent staining was used to show the cell vitality rates,DNA disruption ladder were applied to reveal cell apoptosis.The mRNA and protein level of topoisomerase Ⅱ(Topo Ⅱ) and transcript factor SP1 were measured by semi-quantitative RT-PCR and western blot.Results There is synergistic effect between the two drug.The cell vitality rates were decreased in combination group than that of CDDP or VM-26 used alone.the combination treatment group resulted in more serious DNA strand breakage.The expression of Topo Ⅱ?,? and SP1 mRNA and protein both increased in CDDP treatment group,while the Topo Ⅱ?,? expression decreased and(the SP1 expression) has no obviously change in VM-26 treatment group.In combination group,Topo Ⅱ? expressionwere decreased comparing with CDDP used alone,SP1 expression increased comparing with VM-26 used alone,but has no obviously change as comparing with CDDP used alone.Conclusion CDDP could enhance Topo Ⅱ expression through up-regulating SP1 expression,which offer more target for Topo Ⅱ inhibitor VM-26 to act on killing small cell lung cancer cell.
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Objective To investigate the effect of methylprednisolone on the expression of glial fibrillary acidic protein (GFAP) and proliferating cell nuclear antigen (PCNA) in M?ller cells of rats' retinae injured by laser. Methods Forty SD rats were randomly divided into two groups and inflicted with laser photocoagulation.The rats in treatment group were given methylprednisolone by intraperitoneal injection with a dose of 30 mg/kg for 3 days.At the 3rd,7th,14th,and 28th day after photocoagulation respectively, the eyes were enucleated,fixed and cut into sections.Immunohistochemical examination was used to detect the expression of PCNA and GFAP. Results After photocoagulation the M?ller cells expressed PCNA both in the treatment and control group,and the expression of PCNA decreased sharply after 3 days. The expression of PCNA in treatment group was less than that in control group. After photocoagulation the M?ller cells also expressed GFAP and the expression of GFAP lasted for at least 28 days ,and the expression of GFAP expression in the treatment group was less than that in the control group. Conclusion Methylprednisolone can reduce the expression of GFAP and PCNA in M?ller cells of rats' retinae injured by laser.
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AIM:To look for a better method to deal with interstitial lung disease,interferon-gamma(IFN-?)combined with methylprednisolone(M-pred)to influence human embryonic lung fibroblast on proliferation,collagen synthesis and the expression of transforming growth factor-?1(TGF-?1)protein and mRNA were investigated.METHODS:Exponentially growing cells were preincubated for 48 h before harvested.The microculture tetrazolium(MTT)assay was used to measure the inhibition ratios of M-pred combined with different concentrations of IFN-?.The expression of proliferation cell nuclear antigen(PCNA)was detected by immunocytochemical analysis.Hydroxyproline kit was adopted to detect collagen synthesis.The expressions of TGF-?1 mRNA and protein were detected respectively by RT-PCR and Western blotting.RESULTS:Methylprednisolone,IFN-? as well as the combination of methylprednisolone and IFN-? inhibited the proliferation of HELF and the expression of PCNA in comparison with control group(P