1.Properties of ACh-sensitive BK channels in mice type Ⅱ vestibular hair cells and its modulation by calcium
Changkai GUO ; Song ZHANG ; Weijia KONG ; Qingsong YU ; Qingtian LI
Chinese Journal of Pathophysiology 2000;0(10):-
AIM: To explore the properties of the acetylcholine(ACh)-sensitive potassium channel in type Ⅱ vestibular hair cells(VHCs Ⅱ) in mice saccular macula and the modulation effect of calcium ions.METHODS: Under the whole-cell patch mode,the pharmacology properties of ACh-sensitive potassium channel and the modulation of calcium ions on ACh-sensitive potassium channel were investigated.RESULTS: Following extracellular perfusion of ACh,VHCs Ⅱ displayed a slow and sustained outward current,which was sensitive to tetraethylammonium(TEA,5 mmol/L) and charybdotoxin(CTX,100 nmol/L),but not sensitive to 4-aminopyride(4-AP,15 ?mol/L).ACh-sensitive potassium current was inhibited by intracellular application of ethylene glycol-bis(B-aminoethylether)-N,N,N',N'-tetraacetic-acid(EGTA,5 mmol/L) and extracellular perfusion of Cd2+ and Ni2+,respectively.Intracellular application of heparin(8 g/L) failed to inhibit ACh-sensitive potassium current.CONCLUSION: Extracellular application of ACh activates the big conductance,calcium-dependent potassium current(BK) in VHCs Ⅱ of mice,which is potently modulated by extracellular Ca2+ ions.However,intracellular IP3-dependent Ca2+ ions release mechanism is not involved in the activation of the ACh-sensitive BK channel.
2.MODULATORY EFFECT OF CAFFEINE ON GABA-ACTIVATED CURRENT FROM ACUTELY ISOLATED RAT DORSAL ROOT GANGLION NEURONS
Shao LI ; Changkai SUN ; Jian ZHANG ; Aiping LI ; Hua PIAO ; Zhiwang LI
Chinese Journal of Neuroanatomy 2007;23(3):251-255
Whole-cell patch clamp technique was performed on acutely isolated rat dorsal root ganglion (DRG) neurons to investigate the modulatory effect of caffeine on γ-aminobutyric acid (GABA)-activated currents (IGABA). The results showed that the majority of the neurons examined (97.4%, 113/116) were sensitive to GABA. 1-1000 μmol/L GABA activated a concentration-dependent inward current which manifested obvious desensitization. After the neurons were treated with caffeine (0.01-100 μmol/L) prior to the application of GABA (100 μmol/L) for 30 s, GABA-activated membrane currents were obviously inhibited. Caffeine shifted the GABA dose-response curve downward and decreased the maximum response to 57% without changing Kd value. These results indicate that the inhibitory effect is non-competitive. Theophylline showed a similar and stronger inhibitory effect on IGABA. The pretreatment with caffeine (10 μmol/L) inhibited IGABA, which was potentized by diazepam (1 μmol/L). Intracellular application of H-8 almost completely abolished the inhibitory effect of caffeine on IGABA. The present results suggest that caffeine may be able to antagonize the effect of presynaptic inhibition of GABA in primary afferent.
3.Investigation on degeneration of outer hair cells in guinea pig.
Xixun KANG ; Weijia KONG ; Wanrong LI ; Xiaorong ZENG ; Song ZHNAG ; Changkai GUO ; Xiang HUANG
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2008;22(23):1087-1089
OBJECTIVE:
To investigate the degeneration mechanics of outer hair cells in guinea pig.
METHOD:
The mechanics of outer hair cells isolated by enzyme were observed under inverted microscope for 6-8 h continuously.
RESULT:
Over half of living outer hair cells could keep good conditions in 6 hours. During the degeneration there was always a longitudinal fold line from tip to base. Presence or absence of calcium, as well as lossing of stereociliary bundle, couldn't change the conditions of out hair cells.
CONCLUSION
Neither calcium nor stereociliary bundle is the decisive cause in keeping outer hair cells alive, and its degeneration may be basically related with something surrounding the cell.
Animals
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Calcium
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Cells, Cultured
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Cochlea
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cytology
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pathology
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Culture Media
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Guinea Pigs
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Hair Cells, Auditory
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cytology
4.Application of practical network teaching in clinical blood transfusion teaching and training
Lele HAN ; Di LI ; Changkai ZHANG ; Changfeng SHAO
Chinese Journal of Medical Education Research 2023;22(6):886-888
In order to explore the platform role and practicability of network teaching in the teaching and training of clinical blood transfusion. By building an "Internet+APP" teaching and training management platform, this research develops personalized teaching and training courses and assessment plans for different groups such as interns, trainees and on-the-job staff in the blood transfusion department, so as to achieve time-saving and high-efficient training results. The results showed that the interns' assessment scores were all up to standard, with more than 90 points accounting for 66% and 80-90 points accounting for 34%. The assessment scores of the trainees and on-the-job personnel were above 90 points, which showed that they had significant improvement of their professional level. The teaching resources of this teaching mode are stable, centered on the trainees, free from traditional time and space constraints, high-efficient, time-saving, and easy to accept.
5.Sleep deprivation disrupts the lacrimal system and induces dry eye disease
Sanming LI ; Ke NING ; Jing ZHOU ; Yuli GUO ; Houjian ZHANG ; Yu ZHU ; Liying ZHANG ; Changkai JIA ; Yongxiong CHEN ; Peter SOL REINACH ; Zuguo LIU ; Wei LI
Experimental & Molecular Medicine 2018;50(3):e451-
Sleep deficiency is a common public health problem associated with many diseases, such as obesity and cardiovascular disease. In this study, we established a sleep deprivation (SD) mouse model using a ‘stick over water’ method and observed the effect of sleep deficiency on ocular surface health. We found that SD decreased aqueous tear secretion; increased corneal epithelial cell defects, corneal sensitivity, and apoptosis; and induced squamous metaplasia of the corneal epithelium. These pathological changes mimic the typical features of dry eye. However, there was no obvious corneal inflammation and conjunctival goblet cell change after SD for 10 days. Meanwhile, lacrimal gland hypertrophy along with abnormal lipid metabolites, secretory proteins and free amino-acid profiles became apparent as the SD duration increased. Furthermore, the ocular surface changes induced by SD for 10 days were largely reversed after 14 days of rest. We conclude that SD compromises lacrimal system function and induces dry eye. These findings will benefit the clinical diagnosis and treatment of sleep-disorder-related ocular surface diseases.
6.A new method for constructing engineered corneal epithelium based on embryonic stem cells
Yangluowa QU ; Shangkun OU ; Tingting LIU ; Liying ZHANG ; Dulei ZOU ; Juan LI ; Hui HE ; Changkai JIA ; Chengyou ZUO ; Minjie ZHANG ; Xin HE ; Zuguo LIU ; Wei LI
Chinese Journal of Experimental Ophthalmology 2018;36(11):826-833
Objective To construct engineered corneal epithelium from embryonic stem cells (ESCs) using Rock inhibitor combined with hypoxia-normoxia culture condition. Methods Human ESC line H1 was induced to differentiate into epithelial-like cells by addition of retinoic acid (RA) and bone morphogenetic protein 4(BMP4) in the differentiation medium under the adherent culture condition. The ESCs derived epithelial-like cells were expanded in the mixed medium of SHEM and KSFM with the mixture ratio of 1 : 2 with or without Rock inhibitor Y27632. The H1 derived epithelial-like cells were seeded on the denuded ammonic membrane to construct engineered corneal epithelium under hypoxia,normoxia and hypoxia-normoxia culture conditions,respectively. The inducted effect of ESCs into epithelial-like cells,the expansion ability of the epithelial-like cells and the characteristics of the constructed engineered corneal epithelium were evaluated by morphological observation, real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR) and immunofluorescence technology. Results Compared with the control group,the relative expressions of ESCs marker Oct4 mRNA, Notch signaling pathway related factors Notch1 and Jagged1 mRNA,and Wnt signaling pathways related factors c-myc and Cyclin D1 mRNA were significantly reduced, and the relative expressions of cutaneous ectoderm markers p63 and K18 mRNA were significantly increased at day 8 after induction in the induced group,with significant differences between them (t =14.63,20.15,93.50,11.60, 19.30,18.44,22.63;all at P<0.05). Compared with the without Y27632 group,the relative expressions of p63 and K14 mRNA,Notch signal pathway receptor Notch1 and Jagged1 mRNA were significantly increased,and Wnt signaling pathways downstream targeted gene c-myc and CylinD1 mRNA were significantly decreased at day 8 after induction in the Y27632 group,with significant differences between them (t =20.29,59.22,2.90,39.59,5.32,10.14;all at P<0.05),and the relative expression of K18 mRNA in the two groups was not significantly changed(t=1.38,P>0.05). The ESCs derived epithelium and constructed under hypoxia-normoxia culture condition showed more obvious stratification and tighter cell arrangement in comparison with those cells cultured in consistent hypoxia culture condition or normoxia culture condition. Epithelial markers Pan-CK and K18 as well as epithelial progenitor cell markers p63 and K14 expressed in the whole cell layers of the ESCs derived epithelium constructed under hypoxia-normoxia culture condition. Conclusions The addition of Y27632 enhances the proliferation ability of H1 derived epithelial cells and actives Notch signaling pathway and inhibits Wnt signaling pathway. The culture and construction in the expansion medium with Y27632 under the hypoxia-normoxia culture condition can promote the stratification of H1 derived engineered corneal epithelium.
7.Treatment for abdominal infection caused by metallo- β-lactamase-producing Klebsiella pneumoniae in an infant after liver transplantation :a case report and literature review
Donghua LIU ; Yanlei GUO ; Haijun QU ; Changkai ZHOU ; Xianghua QUAN ; Mengna CUI ; Jing LI
China Pharmacy 2022;33(11):1397-1402
OBJECTIVE To investigate the treatment plan for az treonam-resistant metallo- β-lactamase(MBL)-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients. METHODS The clinical data of aztreonam-resistant MBL-producing Klebsiella pneumoniae caused intra-abdominal infection of an infant after liver transplantation were retrospectively analyzed. Abdominal infection occurred after operation. The pathogenic bacterium was MBL-producing K. pneumoniae . The drug sensitivity results showed that the infant was resistant to aztreonam. Based on the results of sensitivity test ,polymyxin B combined with tigecycline were selected as initial regimen. The treatment effect was poor ,with recurrent disease and shock spots. The clinical pharmacist assisted the clinician to formulate treatment regimen of ceftazidime avibactam 0.5 g,q8 h combined with aztreonam 0.18 g,q6 h. Relevant domestic and foreign literature were reviewed ,and the treatment plan of MBL-producing Enterobacteriaceae infection after solid organ transplantation was summarized. RESULTS & CONCLUSIONS The infant was finally cured and discharged with ceftazidime avibatan combined and aztreonam. Several foreign literature reported that ceftazidime avibactam combined with aztreonam could effectively treat the infection caused by aztreonam-resistant MBL-producing Enterobacteriaceae infection in patients with organ transplantation. It is expected to be an effective treatment for aztreonam-resistant MBL-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients.
8. Human body networks mechanisms of melatonin and its clinical applications
Rong LIU ; Shui GUAN ; Bingcan LIAO ; Sha LI ; Kai LIANG ; Changkai SUN ; Mingkun SHAO ; Hui MA ; Pin SUN ; Tao CONG
Chinese Journal of Clinical Pharmacology and Therapeutics 2022;27(9):1031-1040
Melatonin is mainly an endogenous indoleamine hormone with many physiological functions. Melatonin not only plays an important role in the treatment of sleep disorders, but also plays an important role in the treatment of nervous system diseases, cancer, cardiovascular diseases, and bone diseases. In this paper, the human Melatonin is mainly an endogenous indoleamine hormone with many physiological functions. Melatonin not only plays an important role in the treatment of sleep disorders, but also plays an important role in the treatment of nervous system diseases, cancer, cardiovascular diseases, and bone diseases. In this paper, the human body networks mechanisms and the clinical applications of melatonin were summarized to provide reference for exploring the focus and direction of further clinical application research.
9.Effect of different liver biopsy needle track management on Yttrium-90 selective internal radiation therapy on liver cancer
Zhenyuan XU ; Xue LIU ; Shuqun SHEN ; Zhijia XU ; Changkai LI ; Yefa YANG
Chinese Journal of Clinical Medicine 2025;32(2):288-294
Objective To explore the effect of different needle track management on Yttrium-90 microsphere selective internal radiation therapy (90Y-SIRT) on liver cancer after liver biopsy. Methods A retrospective analysis was conducted on the clinical data of 21 patients with liver cancer who underwent Technetium-99m-macroaggregated albumin (99mTc-MAA) evaluation and 90Y-SIRT after liver biopsy from June 2023 to December 2024. The methods of needle track management, hepatic arteriovenous shunting, and lung shunt fraction (LSF) were recorded. The occurrence of hepatic arteriovenous fistula (HAVF), as well as the corresponding countermeasures were analyzed. Results Among the 21 liver cancer patients, 7 cases (medical glue group) underwent embolization of the needle tract with medical glue (N-butyl 2-cyanoacrylate [NBCA]) immediately after biopsy, and no significant HAVF was observed during the 99mTc-MAA tests; 14 cases (non-medical glue group) were treated with delayed needle extraction or gelatin sponge particle blocking after biopsy, among which 7 cases developed significant HAVF, and the fistulas were treated with NBCA. The LSF of the medical glue group was significantly lower than that of the non-medical glue group ([7.06±2.33] % vs [12.43±7.73] %, P=0.037). All 21 patients successfully completed 90Y-SIRT. Conclusions Liver biopsy may affect 90Y-SIRT by causing iatrogenic HAVF. Immediate NBCA-embolization of the needle tract after biopsy or timely NBCA-embolization of fistulas during 99mTc-MAA tests may reduce the impact.
10.Discovery of novel exceptionally potent and orally active c-MET PROTACs for the treatment of tumors with MET alterations.
Pengyun LI ; Changkai JIA ; Zhiya FAN ; Xiaotong HU ; Wenjuan ZHANG ; Ke LIU ; Shiyang SUN ; Haoxin GUO ; Ning YANG ; Maoxiang ZHU ; Xiaomei ZHUANG ; Junhai XIAO ; Zhibing ZHENG ; Song LI
Acta Pharmaceutica Sinica B 2023;13(6):2715-2735
Various c-mesenchymal-to-epithelial transition (c-MET) inhibitors are effective in the treatment of non-small cell lung cancer; however, the inevitable drug resistance remains a challenge, limiting their clinical efficacy. Therefore, novel strategies targeting c-MET are urgently required. Herein, through rational structure optimization, we obtained novel exceptionally potent and orally active c-MET proteolysis targeting chimeras (PROTACs) namely D10 and D15 based on thalidomide and tepotinib. D10 and D15 inhibited cell growth with low nanomolar IC50 values and achieved picomolar DC50 values and >99% of maximum degradation (Dmax) in EBC-1 and Hs746T cells. Mechanistically, D10 and D15 dramatically induced cell apoptosis, G1 cell cycle arrest and inhibited cell migration and invasion. Notably, intraperitoneal administration of D10 and D15 significantly inhibited tumor growth in the EBC-1 xenograft model and oral administration of D15 induced approximately complete tumor suppression in the Hs746T xenograft model with well-tolerated dose-schedules. Furthermore, D10 and D15 exerted significant anti-tumor effect in cells with c-METY1230H and c-METD1228N mutations, which are resistant to tepotinib in clinic. These findings demonstrated that D10 and D15 could serve as candidates for the treatment of tumors with MET alterations.