Platelet antibody screening and crossmatch in Chengdu in 2019 / 中国输血杂志

【Objective】 To analyze the status of the platelet antibody screening and crossmatch in Chengdu in 2019, so as to further improve the corresponding detection strategy to improve the clinical transfusion efficacy. 【Methods】 The patients underwent platelet antibody crossmatch in Chengdu Blood Center in 2019 were selected as research objects Platelet antibody screening and crossmatch were performed by solid-phase agglutination technique, and the sample size, the incidence of platelet antibod, age, blood group, seasonal chracteristics, hospital levels, ratio of repeated crossmatch and the transfusion efficacy were analyzed. 【Results】 321 treatment doses of matched platelets after 259 occasions of crossmatch relative to 85 patients were provided. The positive rate of platelet antibody was 87.06%. 64.71% of the patients were over 40 years old, the proportion of ABO group in crossmatch samples was O>A>B>AB, and the crossmatch cases increased each quarter gradually. All samples were provided by tertiary hospitals. 52.94% of the patients needed crossmatch at least twice, and the efficacy rate of matched platelets transfusion was 63.64%. 【Conclusion】 The platelet transfusion efficacy could by improved by platelet antibody screening and crossmatch, so as to avoid the waste of platelets, which deserves active promotion in clinical.

CAS9 is a genome mutator by directly disrupting DNA-PK dependent DNA repair pathway

With its high efficiency for site-specific genome editing and easy manipulation, the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR associated protein 9 (CAS9) system has become the most widely used gene editing technology in biomedical research. In addition, significant progress has been made for the clinical development of CRISPR/CAS9 based gene therapies of human diseases, several of which are entering clinical trials. Here we report that CAS9 protein can function as a genome mutator independent of any exogenous guide RNA (gRNA) in human cells, promoting genomic DNA double-stranded break (DSB) damage and genomic instability. CAS9 interacts with the KU86 subunit of the DNA-dependent protein kinase (DNA-PK) complex and disrupts the interaction between KU86 and its kinase subunit, leading to defective DNA-PK-dependent repair of DNA DSB damage via non-homologous end-joining (NHEJ) pathway. XCAS9 is a CAS9 variant with potentially higher fidelity and broader compatibility, and dCAS9 is a CAS9 variant without nuclease activity. We show that XCAS9 and dCAS9 also interact with KU86 and disrupt DNA DSB repair. Considering the critical roles of DNA-PK in maintaining genomic stability and the pleiotropic impact of DNA DSB damage responses on cellular proliferation and survival, our findings caution the interpretation of data involving CRISPR/CAS9-based gene editing and raise serious safety concerns of CRISPR/CAS9 system in clinical application.

CAS9 is a genome mutator by directly disrupting DNA-PK dependent DNA repair pathway

With its high efficiency for site-specific genome editing and easy manipulation, the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR associated protein 9 (CAS9) system has become the most widely used gene editing technology in biomedical research. In addition, significant progress has been made for the clinical development of CRISPR/CAS9 based gene therapies of human diseases, several of which are entering clinical trials. Here we report that CAS9 protein can function as a genome mutator independent of any exogenous guide RNA (gRNA) in human cells, promoting genomic DNA double-stranded break (DSB) damage and genomic instability. CAS9 interacts with the KU86 subunit of the DNA-dependent protein kinase (DNA-PK) complex and disrupts the interaction between KU86 and its kinase subunit, leading to defective DNA-PK-dependent repair of DNA DSB damage via non-homologous end-joining (NHEJ) pathway. XCAS9 is a CAS9 variant with potentially higher fidelity and broader compatibility, and dCAS9 is a CAS9 variant without nuclease activity. We show that XCAS9 and dCAS9 also interact with KU86 and disrupt DNA DSB repair. Considering the critical roles of DNA-PK in maintaining genomic stability and the pleiotropic impact of DNA DSB damage responses on cellular proliferation and survival, our findings caution the interpretation of data involving CRISPR/CAS9-based gene editing and raise serious safety concerns of CRISPR/CAS9 system in clinical application.

Analysis of the impact of postpartum fatigue on the onset of lactation / 中华护理杂志

Objective To explore the impact of postpartum fatigue on the onset of lactation.Methods Totally 553 mother-infant dyads were enrolled from three hospitals in Nantong City using sampling method of probability proportional to size.The timing of the onset of lactation,delayed onset of lactation and maternal postpartum fatigue were measured during the period of hospitalization.Postpartum fatigue was measured by Fatigue Scale-14.The timing of onset of lactation was determined by matemal perception of breast fullness.One-way analysis of variance was used to compare the difference of onset of lactation in four groups with varied fatigue scores.Impact of the maternal fatigue on the onset of lactation was analyzed by multiple linear regression.Results Mothers' fatigue score was related to the onset of lactation(r-0.15,P＜0.001).Mothers with postpartum fatigue scores ranging from 9 to 14 had delayed onset of lactation compared with those with fatigue score ranging from 0 to 3 and from 4 to 5,and the differences were significant (P=0.004),and the rate of delayed onset of lactation was increased (P=0.020).Postpartum fatigue was an independent risk factor,after controlling mode of delivery,mode of anesthesia,duration of infant sucking,maternal pain,and infant sucking gesture(t=3.26,P=0.001).Conclusion Postpartum fatigue is one of reasons leading to delayed onset of lactation.Health care providers and family members should pay more attention to postpartum fatigue and take effective measures to promote a successful onset of lactation and breastfeeding.

Homology of methicillin-resistant Stphylococcusaureus isolated from neo-nates,health care workers,and environment / 中国感染控制杂志

Objective To investigate the homology of methicillin-resistant Stphylococcusaureus(MRSA)from the neonatal intensive care unit(NICU)of a children's hospital,and evaluate routes and preventive strategies of MRSA healthcare-associated infection(HAI). Methods MRSA strains from neonates and environment of NICU between October and December 2014 were collected,and strains were identified by VITEK-2 microbial analysis system and cefoxitin Kirby-Bauer method,homology of MRSA was analyzed by pulsed-field gel electrophoresis (PFGE ). Results A total of 6 MRSA strains were isolated from NICU between October and December 2014,3 of which (bed-58,70,and 100)were detected MRSA from specimens,MRSA were isolated from neonatal incubator and nurse (nasal swabs and hands)who cared for neonate at bed 58. 5 of 6 MRSA strains were homology,antimicrobial susceptibility testing result showed that No. 1-5 strains were resistant to clindamycin and amoxicillin/clavulanic acid,No. 6 strain was slightly different from No. 1-5 strains,No. 6 strain was susceptible to both clindamycin and amoxicillin/clavulanic acid. PFGE results showed that No. 1-5 strains were of the same type,No. 6 strain was a different type. Conclusion The main route of this MRSA transmission is contact transmission,especially through the hands of health care workers,identification and analysis of epidemic strains by PFGE technique is an effective measures to prevent HAI outbreak and perform epidemiological study.

Genetic approach to track neural cell fate decisions using human embryonic stem cells

With their capability to undergo unlimited self-renewal and to differentiate into all cell types in the body, human embryonic stem cells (hESCs) hold great promise in human cell therapy. However, there are limited tools for easily identifying and isolating live hESC-derived cells. To track hESC-derived neural progenitor cells (NPCs), we applied homologous recombination to knock-in the mCherry gene into the Nestin locus of hESCs. This facilitated the genetic labeling of Nestin positive neural progenitor cells with mCherry. Our reporter system enables the visualization of neural induction from hESCs both in vitro (embryoid bodies) and in vivo (teratomas). This system also permits the identification of different neural subpopulations based on the intensity of our fluorescent reporter. In this context, a high level of mCherry expression showed enrichment for neural progenitors, while lower mCherry corresponded with more committed neural states. Combination of mCherry high expression with cell surface antigen staining enabled further enrichment of hESC-derived NPCs. These mCherry(+) NPCs could be expanded in culture and their differentiation resulted in a down-regulation of mCherry consistent with the loss of Nestin expression. Therefore, we have developed a fluorescent reporter system that can be used to trace neural differentiation events of hESCs.

Functional analysis of the acetylation of human p53 in DNA damage responses

As a critical tumor suppressor, p53 is inactivated in human cancer cells by somatic gene mutation or disruption of pathways required for its activation. Therefore, it is critical to elucidate the mechanism underlying p53 activation after genotoxic and cellular stresses. Accumulating evidence has indicated the importance of posttranslational modifications such as acetylation in regulating p53 stability and activity. However, the physiological roles of the eight identified acetylation events in regulating p53 responses remain to be fully understood. By employing homologous recombination, we introduced various combinations of missense mutations (lysine to arginine) into eight acetylation sites of the endogenous p53 gene in human embryonic stem cells (hESCs). By determining the p53 responses to DNA damage in the p53 knock-in mutant hESCs and their derivatives, we demonstrate physiological importance of the acetylation events within the core domain (K120 and K164) and at the C-terminus (K370/372/373/381/382/386) in regulating human p53 responses to DNA damage.

Effects of recombinate mouse granulocyte-macrophage-colony-stimulating factor along with marrow-derived mesenchymal stem cells on lung injury induced by hyperoxia exposure in newborn rats / 中华急诊医学杂志

Objective To investigate the effects of recombinate mouse granulocyte-macrophage-colony-stimulating factor(GM-CSF) alone with mesenchymal stem cells(MSCs) on injured lung of rots after exposure to hyperoxia. Method Mouse MSCs were separated, cultured, amplificated, identified and labeled with 4', 6-diamidino-2-phenylindole(DAPI). Thirty-two 3-day-old Sprague Dawley(SD) rats from four litters were randomly divided(random number) into four groups, namely hypemxia exposured + GM-CSF + MSCs group(group A), hyperoxia exposured + GM-CSF group( group B), hyperoxia exposured + MSCs group( group C) and hypemxia exposured group(group D). All rats were placed in a closed Plexiglas chamber with a minimal flow in and out, providing six to seven exchanges of the chamber volume per hour and maintaining O_2 levels above 95%. Seven days lair,all of them were taken out of the chamber. Rats in group A were treated with 5 x 10~4 MSCs intraperitoneally alone with 9 μg/kg GM-CSF subcutaneously, rats in group B received 9 μg/kg GM-CSF subcutaneously, rats of group C were treated with 5 x 10~4 MSCs intraperitonealiy and rats of group D were administrated with phosphatebuffered solution(PBS). Three days latter, all animals were sacrificed by an injection of 120 mg/kg sodium pentobarbital, perfused with cold 0.9% NaCl, and the left lungs were removed. The upper lobe of them were grinded to make tissue homogenates used for ELASA, and the lower lobes of them were made into frozen sections for fluorescence microscope. The right lungs were fixed in situ for 2 hours by intratracheal instillation of 10% neutral formalin and then were still fixed for additional 24 hours. Sagittal sections of paraffin-embedded middle lobe and upper lobe of left hmg tissue were used for Immunohistochemistry and histological study respectively, Immunohistochemistry was used to detect the expression of telomerase reverse transcrip tase(TERT) grade. Results Among 4groups, there were significantly differences in radical alveolar counts(RAC), TNF-α and IL-β1 in tissue homogenates( P < 0. 01 ). Compared with group D, increase in RAC and the decrease in both TNF-α and IL-β1 were found in other groups, and furthermore there were obvious differences in those changes between group A and group B as well as between group A and group C. There were significant differences in TERT(P<0.01) among four groups. The TERT grade in group A and group B were increased more markedly. DAPI-positive cells were found in group A and group C with significantly differences(6.23 ± 1.88, 5.10 ± 0.91, t = 1.53, P<0.05).Conclusions The protective effects of GM-CSF/MSCs on injuried lungs of new born rats after exposure to hyperoxia may be associated with the increase in the proliferation of stem cells improving the local micro-environment of lung tissue. This protective effects against lung injury induced by hyperoxia exposure may be attributed to the synergism between GM-CSF and MSCs.

Analysis of the relationship between blood donor testing results and crowd structure / 中国输血杂志

Objective To form the basis of establishing a strategy for safe blood donor recruitment and to identify and subdivide the structures of donors.Methods Demographic data of blood donors, and blood testing results of HBsAg, anti-HCV, anti-HIV, and syphilis, from Nov. 2004 to Jun. 2005, were collected and analyzed.Results Among the 45270 voluntary blood donors, the total positive test rate were 3.11%, which was related to age, level of education and occupation of blood donors. About 76.7% of donors were young people, aged from 18 to 30. As the age increased, female donors were less than male ones. Among all the donors, 81.6% received higher education, which had lower positive test rate than those with lower level of education. Among the 45270 donors, farmers had the highest positive test rate; workers and service people came the second; students and medical staff had the lowest. As to donors with incomplete record, the positive test rate was higher than those with complete record.Conclusion During blood donor recruitment, quality control is important. People younger than 30, with student or higher education background, are relatively safe to recruit.

Analysis of the factors affecting voluntary blood donation, an investigation among blood donors in Chengdu / 中国输血杂志

Objective To find out factors influencing voluntary blood donation activities and establish the most appropriate method for recruiting blood donors. Methods Questionnaire investigation of donors and data analysis by SPSS+ software. Results In Chengdu city, 2385 residents' knowledge on nonrenumerated blood donation was as follows: among the 2385 residents, the percentage of people who knew the government policies of blood donation was high (87.5%), but the percentage having common knowledge of blood donation was only 29.4%, of risk behavior was 32.5%. Among the 1349 participants who had donated blood, the percentages having common knowledge of blood donation and risk behavior were 33.4% and 38.1% respectively, compared to the 1036 participants who never donated (24.2% and 25.1%, respectively)(P