Multidrug resistance(MDR) is the leading cause of treatment failure in cancer therapy. Overexpression of the ATP-binding cassette (ABC) transporter family increases the cellular efflux, decreases the effectiveness of chemotherapeutic agents,and results in MDR. In particular,overexpression of P-glycoprotein and its encoding genes(mdr1) is the major mechanism. It is feasible for overcoming MDR by studying the factors affecting mdr1 gene expression so as to block the expression of mdr1. Pregnane X receptor(PXR) can regulate the expression of MDR proteins, suggesting that it be possible to overcome drug resistance by regulating PXR. In this paper,the relation between PXR and MDR and recent development of PXR antagonists to pharmacologically modulate PXR are reviewed. The review proposes that selectively preventing the elevation of MDR levels by regulating PXR rather than non-selectively inhibiting the MDR activity by using MDR inhibitors can be a less toxic approach to overcome drug resistance during cancer therapy.

OBJECTIVE: To explore the clinical application value of using needle electrode in transurethral plasmakinetic resection of bladder tumor around ureteral orifice. METHODS: Retrospective analysis was performed on the clinical data of 16 cases who had bladder tumors around ureteral orifice and underwent transurethral resection using plasmakinetic needle electrode in Department of Urology, Peking University International Hospital from June 2015 to December 2019. There were nine cases with the tumor of one to two centimeters from the ureteral orifice. The rest of the seven cases had tumor that was within one centimeter from the ureteral orifice, including two cases whose ureteral orifice was invaded by the tumor. All the patients studied were diagnosed before surgery and contraindications were excluded. The plasmakinetic needle electrode was used to treat the tumor with en bloc resection, and all the excised tissue was sent for pathological examination. Intravesical chemotherapy and postoperative follow-ups were performed. Statistical analysis was performed on the operation time, the incidence of obturator nerve reflex, the peri-operative bleeding, the parameters of indwelling ureteral catheter or double-J stent, the incidence of postoperative hydronephrosis, the clinical stage of tumor, and the recurrence rate. RESULTS: The operation was successfully completed for all the sixteen cases. The operation time was 16 to 57 minutes, with an average of (32.6±11.8) minutes. No obvious obturator nerve reflex and perioperative bleeding occurred in all the patients. Ureteral catheters were indwelled prior to the operation of tumor resection in seven cases. Four of the seven cases had the ureteral catheters remained while the rest three were replaced by double-J stent after surgery. Postoperative pathological analysis showed that all the tumors were urothelial carcinoma, including 9 cases of low grade and 7 cases of high grade. Pathological staging: 10 cases were in Ta stage, 5 cases in T1 stage, and 1 case in T2a stage. All tumor bases and lateral margins were negative. All the patients received 3-56 months, with an average of (26.0±18.1) months of follow-up. There was no case of upper urinary tract hydronephrosis or tumor recurrence. CONCLUSION The transurethral plasmakinetic resection of bladder tumor using needle electrode can realize en bloc tumor resection without obturator nerve reflex and reduce the risk of ureteral orifice injury. It is a safe and effective surgical method for treating bladder tumors around the ureteral orifice.
Carcinoma, Transitional Cell ; Electrodes ; Humans ; Neoplasm Recurrence, Local ; Retrospective Studies ; Urinary Bladder Neoplasms/surgery*

Humans ; Neck ; Solitary Fibrous Tumors

Mind map is an effective and intuitive knowledge organization and presentation tool which can help computer teaching commendably. We can use Mind Map to design and organize the whole teaching process, including preparing, designing, guiding, analyzing and reviewing. This way can turns tedious logic of computer teaching into imagery thinking and helps medical students improv-ing their learning effect of computer courses.

OBJECTIVE: To investigate berberine's potential to enhance the sensitivity of doxorubicin-resistant human leukemia cell lines (K562/DOX) to doxorubicin in vitro. METHODS: MTT assay was performed to determine the effect of berberine on the sensitivity of K562/DOX cells to doxorubicin. Doxorubicin accumulation assay was performed by Arrary Scan VTI HCS600 High-Contents. The effect of berberine on doxorubicin-induced cell apoptosis was tested by PI/Hoechst 33342 assay. The efflux activity of P-gp was investigated by measuring the accumulation of the rhodamine 123 after treatment with berberine. RESULTS: μmol · L-1 of berberine, as a wild dose, reduced IC50 of doxorubicin to K562/DOX cells by 1.5 times. 1 μmol · L-1 of berberine showed the enhancement effect on doxorubicin-induced apoptosis. The increase of doxorubicin and rhodamine 123 accumulation was observed in K562/ DOX cells treated with 1 μmol · L-1 of berberine which indicated the inhibition of the activity of P-gp. CONCLUSION: Berberine is shown to effectively enhance chemosensitivity of K562/DOX cells to Dox by inhibiting the efflux activity of P-gp.

Two parental strains BY-14 and BY-6,with high leavening ability in lean and sweet dough respectively,were selected.Through spore production and separation,two haploids with opposition types were selected for cross-breeding.At last one hybridization strain was obtained,with good fermentation ability as BY-14 in lean dough and better than BY-6 by 25%in sweet dough.

Objective To investigate the effects of sulforaphane (SFN) on proliferation and invasion of human small cell lung cancer NCI-H446 and the activity of matrix metalloproteinase (MMP) -9.Methods NCI-H446 cells were cultured with 0,25,50,100 μmol/L SFN for 24 ～ 72 h,then MTT assay was employed to detect cell proliferation.Chamber invasion assay was used to study the cell invasion,and gelatin zymography assay was implied in MMP-9 enzyme activity.Results After treatment of 25,50,100μmol/L SFN,the growth of NCI-H446 cells were inhibited.When cells were incubated with 25,50,100μmol/L of SFN for 72h,the inhibition ratio was ( 11.1 ± 2.26 ) ％,( 25.2 ± 3.24 ) ％ and ( 44.6 ±4.2) ％,respectively,the difference was statistically significant compared with the solvent control group ( t =10.685,8.417,5.264,P ＜0.05 ).Chamber invasion assay showed that NCI-H446 cell invasion could be reduced.25,50,100 μmol/L of SFN could decrease the trans-membrane cells to (48.6 ± 1.84)％,(35.4 ± 2.22) ％ and (27.8 ± 1.36) ％,and it was statistically significant compared with the solvent control group ( t =6.341,5.562,4.925,P ＜0.05 ),respectively.In addition,MMP-9 activity was significantly inhibited by SFN.25,50,100 μmol/L of SFN could decrease the gray value of MMP-9 to 764 ±18.4,685 ± 14.74 and 638 ± 21.54 ( control group 822 ± 12.53,t =4.971,7.582,11.235,respectively,P ＜0.05).Conclusions SFN can inhibit NCI-H446 cells growth,invasion and the activity ofMMP-9.

Objective To study the distribution of intestinal autofluorescent microorganisms in the rat intestine at different developmental stages. Methods The distribution of intestinal autofluorescent microorganisms in rat intestine at va-rious developmental stages was tested and evaluated using a small animals living imaging system. First, standard E. coli strain was tested by fluorescence detection in vitro. Then, the distribution of E. coli under the same test conditions was tested. The intestinal autofluorescent bacteria distribution was detected in the SD rats at 3 days,14 days and 60 days of age. After expanding the range of excitation wavelength fluorescence detection,removing the background of fluorescence feed and feces and other foreign autofluorescent substances. Results E. coli can be excited in the range of 485 -535 nm wave?length and to emit fluorescence. E. coli mainly existed in the stomach and only a few E. coli were found in the ileum of 3?days old SD rat. . In the 14?days old rats, E. coli mainly existed in the stomach and cecum, and only a few E. coli were found in the ileum. In the 60-days old SD rats, E. coli mainly existed in the ileum, and only a few E. coli were found in the colon, cecum and jejunum. After the expansion of the excitation light wavelength range of fluorescence detection, E. co?li were observed mainly in the ileum, and only a few E. coli were found in the stomach in 3?days old SD rat. E. coli mainly existed in the stomach, then the cecum and only a few E. coli were found in the ileum and jejunum in 14-days old SD rats. E. coli could be found in the whole intestinal system but mainly in the ileum and cecumin of the 60-days old rats. Conclu?sions Examining the intestinal autofluorescent microbes with the small animal in vivo imaging system can be helpful and make guidance to study the distribution of intestinal microbes in the host at different developmental stages, and to provide a basis for studying the relationship of intestinal microbes with its host and the gastrointestinal drug administration.

Objective To explore the mechanism of neuropmtective effects of puerarin for the treatment of acute spinal ischenia-reperfusion injury in a rat model.Methods Acute spinal ischemia-reperfusion injury was induced via aortic occlusion in 28 male Sprague-Dawley rats.The animals were randomly divided into four groups,as follows:group negative contrast (NC sham operation),group positive control group (IR+ S ischemia/reperfusion + saline),group puerarin (IR+P ischemia/reperfusion + puerarin),group mscovitine (IR+R ischemia/reperfusion + roscovitine).The motor function,spinal infarction volume,apoptosis indices,and CDK5 and P25 activities were examined.Results Spinal ischemia-reperfusion caused the injury of the spines and was associated with motor deficit,elevation of CDK5 and P25 activities,and increase in the spinal apoptosis and spinal infarction volume.Puerarin improved motor function and decreased apoptosis,spinal infarction volume,and CDK5 and P25 activities.Conclusion The findings of the present study indicated that puerarin treatment-mediated reduction of spinal injury was associated with the inhibition of CDK5 and P25,and that the inhibition was one among the neuroprotective mechanisms of puerarin against acute ischemia/reperfusioninduced spinal injury in rats.

Epilepsy is one of the most common chronic diseases of the central nervous system,many epilepsy patients need lifelong medication.Epidemiological studies have shown that 3‰-5‰ neonates born by women suffering from epilepsy.Treatment become more challenging because not only the patients themselves but also the breastfed in fants should be taken into consideration.This paper reviewed how to choose lactation antiepileptic drug.In short,choosing drugs which transport less to milk and have less side effects to infants,using the lowest effective dose and avoiding combination if possible can ensure the safety of breastfeeding.