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BACKGROUND:Pathogenesis of Parkinson’s disease is not completely understood, and there is yet no effective therapy that can prevent the neurodegenerative process of the disease fundamentaly. OBJECTIVE:To explore the effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on lactacystin-induced Parkinson’s disease dopaminergic PC12 cel apoptosis and its molecular mechanism. METHODS: Under induction by nerve growth factors, PC12 cels differentiated into dopaminergic neurons, and then were treated with different concentrations of lactacystin for different time. When the cel survival rate was about 50%,the concentration and action time oflactacystin were selected to establish cel models of Parkinson’s disease. In the study, there were control group, lactacystin group, PACAP1-27 group (intervention group 1) and PACAP1-27+PACAP6-27 co-intervention group (intervention group 2). Changes of cel morphology were observed under inverted microscope; cel viability was detected with MTT method; the expression of endoplasmic reticulum stress specific protein caspase-12 was detected by western blot. Then the action of PACAP1-27 and PACAP6-27 to the cytoxicity of lactacystin was observed. RESULTS AND CONCLUSION: With different concentrations and action time of lactacystin, the viability of PC12 cels presented a concentration- and time-dependent decline. When the lactacystin at 20μmol/L acted for 24 hours, the cel viability was declined by about 50%. Under same conditions of lactacystin concentration and action time (20 μmol/L, 24 hours), the cels in the lactacystin group appeared to have damaged changes, declined cel viability, and increased caspase-12 activity in comparison with the control group (P< 0.01). Compared with the lactacystin group, the cel damage was relieved and cel viability was increased significantly in the intervention group 1 as wel as the expression of caspase-12 was decreased (P < 0.01). Experimental findings in the intervention group 2 were similar to those in the lactacystin group. These results suggest that lactacystin, an ubiquitin proteasome inhibitor, can lead to cel damage; PACAP1-27 plays a protective role by regulating the above-mentioned signal pathway. As one PACAP1-27 receptor antagonist, PACAP6-27 can attenuate this effect of PACAP1-27.
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Objective To analyze the resistance of Stenotrophomonas maltophilia to commonly used antibacterial drugs,and to investigate the existence status of 3 kinds of integron(Ⅰ,Ⅱand Ⅲ)and the carrying drug resistance gene cassettes so as to offer help for better preventing and controlling the infectious diseases caused by stenotrophomonas maltophilia in local place.Methods 51 strains of Stenotrophomonas maltophilia from clinical samples were collected and the minimum inhibitory concentration(MIC)of 17 kinds of antibacterial drugs to stenotrophomonas maltophilia was measured by the broth microdilution antifungal susceptibility test(Mi-AFST).3 kinds of integron(Ⅰ,Ⅱand Ⅲ)were amplified by PCR with primers designed according to registrated DNA se-quence in GenBank.The variable region products in the positive integron strains were amplified and performed the sequencing analy-sis.The homological comparison in the Genebank database was performed on the sequencing results for finding out what gene was included in variable domain of those integrons.Results (1)Among 51 strains of stenotrophomonas maltophilia,41 srains (80.39%) were collected from sputum samples,and the infected crowd was dominated by individuals aged over 60 years,38 strains accounted for 74.5%.In the department distribution,20 strains(39.22%)were collected from ICU,13 strains (25.49%)from the respiratory department and 6 strains(11 .76%)from the veteran cardres wards,which accounted for the larger proportion.(2)The drug suscep-tibility test demonstrated that stenotrophomonas maltophilia strains had the higher resistance to most of commonly used antibacteri-al drugs,some strains even showed the multi-drug resistance to over 9 kinds of antibacterial drugs.(3)The PCR gene amplification results showed that 7 strains (13.7%)were positive integronⅠ,while no strains containing integron Ⅱ or ⅢI were detected;the resistance genes carried in the variable region of integron I included the 5 kinds of aacA4,aadA1,catB8,dfrA17 and aphA15.Conclu-sion Stenotrophomonas maltophilias has relatively high resistance to majority of commonly used antibacterial drugs in clinic,and some strains show the muti-drug resitance.IntegronⅠis one of important factors for the multi-drug resistance of Stenotrophomonas maltophilias.
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Objective To report a family with lipoid proteinosis (LP) from Shandong province and to analyze mutations in the extracellular matrix protein 1 (ECM1) gene in this family.Methods Eight members in a threegeneration family with LP were clinically investigated,and two patients were identified to suffer from LP,including the proband (Ⅲ 1) and her mother (Ⅱ 2).Both of the patients presented with papules on the palpebral margin,short and thick lingual frenum,and hoarseness.Indirect laryngoscopy showed infiltrating and thickening of the vocal cord.Pathological examination of lesions on the palpebral margin and laryngeal mucosa revealed deposits of hyaline-like material in the dermis,which was strongly positive for periodic acid-Schiff (PAS) staining and resistant to diastase digestion.The pathological diagnosis was LP.Blood samples were collected from all the family members and 100 ethnically matched,unrelated and unaffected Chinese human controls followed by DNA extraction.PCR and sequencing were performed to detect the ECM1 gene,and nested PCR followed by agarose gel electrophoresis to analyze mutations in the coding region of the ECM1 gene.Results Both of the two patients were compound heterozygotes.Three missense mutations,incluing p.P169T,p.A44T and p.R392W,were found in the ECM1 gene of the affected mother,with p.P169T in one allele and p.A44T as well as p.R392W in the other.The girl patient inheried the missence mutation p.P169T from her mother and a synonymous mutation c.879G ＞ A from her father (Ⅱ 1).Nested PCR showed that the c.978G ＞ A mutation generated a splice-acceptor site AG,which leaded to a splicing defect.Conclusion A novel synonymous splice-acceptor site mutation c.879G ＞ A in the ECM1 gene is identified in the family with LP.
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Objective To study and to optimize culture conditions of islet-like cells induced in vitro from fetus bone marrow(BM) mesenchymal stem cells(MSCs).Methods BM was obtained from miscarried human fetus.The MSCs between three to eight passages were used to differentiate into islet-like clusters-through three stages of culture supplemented with 2mercaptoethanol,epidermal growth factor(EGF),basic fibroblast growth factor(bFGF),B_(27) and nicotinamide.Results The 2nd stage cells expressed nestin and/or panceatic and duod-enal homeobox 1(PDX-1),and the 3rd stage cells formed islet-like clusters expressing insulin and glucagon together with positive dithizone staining.Specific insulin secretion could be detected(81.3?23.6?u /ml) from differentiated MSCs which have the capacity to respond to different glucose concentrations.Conclusion Fetal bone marrow MSCs can be differentiated into pancreatic islet-like clusters,and 20mmol/L nicotinamide could be the optimal concentration in culture.