BACKGROUND:It has been reported that human aerobic endurance, cardiovascular system, blood constituent, immune system, neuroendocrine system, free radical antioxidant system, and acid-base balance system can be influenced under hypoxic conditions. However, very little is known regarding bone metabolism under hypoxic conditions and the underlying mechanisms. OBJECTIVE:To summarize the effects of hypoxic conditions on bone metabolism from the views of hypoxia inducible factors, osteblasts and osteoclasts, and the effects of exercise training under hypoxic conditions on the skeleton, contributing to understanding the theoretical advantages and disadvantages of altitude training. METHODS:A computer-based online search was conducted in CNKI and PubMed databases from January 2000 to September 2015 using the keywords“hypoxia environment, hypoxia inducible factors, bone metabolism, exercise, altitude training”to screen the relevant English and Chinese literatures. A total of 233 literatures were screened and final y 46 eligible literatures were included. RESLUTS AND CONCLUSION:The effects of hypoxic conditions on bone metabolism are complex, which are mainly linked to hypoxia inducible factors, osteblasts and osteoclasts. Hypoxia-inducible factor 1 is considered to influence the skeleton by promoting the bone growth induced by vascular endothelial growth factor and directly affecting the osteblasts and osteoclasts. Additional y, hypoxia-inducible factor 1 has been shown to enhance osteoclast-mediated bone resorption. The balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption is disturbed under hypoxic conditions. We need to pay attention to the training period and intensity at altitude because altitude training may not benefit the bone metabolism.

【Objective】 To apply the spatial distribution analysis based on ArcGIS software, which has been applied widely in other fields, so as to analyze the intended locations for whole blood donation. 【Methods】 After a random stratified sampling was conducted among blood donors in the 17 donation sites during August 1st, 2021- July 30th, 2022, their intended blood donation locations were collected by an e-questionnaire. Addresses of donors′ intended donation locations were derived for GCJ-02 coordinates form and transformed by pandas module of Python to WGS84 coordinates, which further loaded to ArcGIS Arcmap module using Grouping Analysis for 17 median centers. The addresses of 17 blood donation sites in Guangzhou Blood Center were transformed to WGS84 coordinates and loaded to ArcGIS Arcmap module using the same methods for 3 ring buffer analysis. The criterion for judging whether the two were " matched" was whether the intended blood donation sites were covered by or adjacent to the 3 ring buffer zone of the existing blood donation sites. 【Results】 Of the 17 potential sites obtained from the spatial distribution analysis of 40 523 valid addresses of donors, 8 sites were covered or adjacent to the buffer of the existing donation sites, while the other 9 sites were far away from the existing donation sites. 【Conclusion】 By analyzing the spatial distribution of donors′ intended donation addresses, we can find out the service needs of donors for donating blood conveniently, which can provide basis for further blood donation service optimization.

【Objective】 To investigate the CMV-IgG positive yeild among blood donors in Guangzhou and explore the differences in the efficacy of three test reagents, aimed at improving blood safety and service capacity of blood centers. 【Methods】 A total of 630 blood samples from eligible blood donors from July to October 2020 in our center were randomly selected and screened for CMV-IgG by one ELISA reagent.Among them, 180 samples were tested in parallel using three reagents (two ELISA reagents and one ECLIA reagent), and those tested negative were conducted quantitative CMV-DNA detection.The test results of different reagents were compared and analyzed. 【Results】 Out of the 630 samples, a total of 598 positive samples were screened out, including 180 samples yielded by three reagents, 171 and 175 by the two ELISA reagents, respectively, and 175 by ECLIA.The results given by three reagents were consistent (Kappa>0.4), and no significant difference in the positive yeild by three reagents was found.In the 180 samples, 11 were negative, among which 3, 2 and 6 samples were negative by all three reagents, two reagents and one reagent (ELISA), respectively.All the 11 samples were tested negative for CMV-DNA. 【Conclusion】 The yeild of positive CMV-IgG in blood donors was 94.9% (598/630), suggesting a high prevalence of CMV in Guangzhou. CMV serologically negative blood should be considered when providing blood products to immunocompromised patients to improve the safety of recipients.The detection results of ELISA reagents and ECLIA reagent for CMV- IgG are consistent, but ECLIA reagent has better detection efficacy.

【Objective】 To investigate whether the blood donors' coagulation status may lead to apheresis platelet aggregation in vitro. 【Methods】 Thirty blood donors with aggregation in apheresis platelets collected by AMICUS blood cell separator no less than 3 times previously and occurred when the last time of apheresis donation were observed in aggregated group (referred to as the experimental group); Thirty donors without aggregation in apheresis platelets collected by AMICUS blood cell separator no less than 3 times were observed in the control group simultaneously. The basic platelet parameters in the two groups, including Plt, MPV, PDW, Pet, P-LCR were detected by automatic blood cell analyzer (BC-3000Plus), and thromboelastogram indexes including reaction time(R), kinetics time(K), kinetics of clot development(α), maximum amplitude (MA) and coagulation index(CI) were tested by Thrombosis elastography (TEG) before collection. With SPSS24.0 software, t test was used to compare the differences between the two groups. 【Results】 The CI value in experimental group was significantly different from that of the control group (0.48± 1.00 vs -0.99 ±1.96, P< 0.05), and there was no significant difference in all above basic platelet parameters and other TEG parameters (P>0.05 ) . 【Conclusion】 The coagulation status of blood donors may be an independent risk factor for the in vitro aggregation of apheresis platelets.

【Objective】 To explore the effectiveness of using donor plasma reinfusion to flush the leukoreduction system (LRS) chamber during the final reinfusion phase with the Trima Accel automated blood collection system in preventing the reduction of CD4+ and CD8+ T lymphocytes. 【Methods】 A longitudinal and cross-sectional study was designed. CD4+ count<200 cells/μL and CD8+ count<125 cells/μL were considered as the criteria for deficiency. Eighteen first-time platelet donors were followed up. The lymphocyte count was measured at 0, 3-6 and 7-14 times of blood donation in the last 300 days. 170 healthy blood donors who have not donated blood were selected as the control group. According to the cut-off point(October 2021), 88 blood donors who mainly used automatic blood collection system to donate platelet apheresis in the last 365 days(median blood donation times ≥17.5)were divided into three groups(A, B and C)and blood samples were obtained. The time for Groups A, B and C started donating platelet apheresis were as follows: Group A: before October 2019, Group B: from October 2019 to September 2021, Group C: after October 2021. Blood samples were analyzed to obtain blood counts including CD4 + and CD8 + T lymphocytes. Blood samples were analyzed to obtain blood cell counts including CD4+ and CD8+ T lymphocytes. Through a comparative analysis, this study aimed to determine if there are any statistical differences in the detection indices between the follow-up groups with varying frequencies of blood donation, the control group, and groups A, B, and C. This approach was employed to infer the efficacy of donor plasma reinfusion in flushing the leukoreduction system (LRS) chamber for preventing the decline of CD4+ and CD8+ T lymphocytes. 【Results】 Eighteen first-time blood donors who were converted to regular platelet apheresis donors did not show a decrease of CD4 + and CD8 + T lymphocytes in the 5 th and 11 th blood donation (median number of blood donation), and there was no significant difference between the above indexes and those in the 0 th blood donation. Among the previous frequent blood donors, the CD4+ and CD8+ T lymphocyte counts in Group B and Group C are both higher than the standard value, showing no statistical difference from the control group. Among regular blood donors, the CD4+ and CD8+ T lymphocyte counts in groups B and C were higher than the criteria values, and had no statistical difference compared to the control group.The CD4+ T lymphocyte count in Group A was normal, with only one donor in Group A having a CD8+ T lymphocyte count below 125 cells/μL. This donor has donated 281 times of platelet apheresis, and the group he belongs to has started blood donation 2-21 years(median of 5 years) before the adjustment of reinfusion mode. The CD4+ and CD8+ T lymphocyte counts in Group A showed significant differences compared to the control group, with median counts (Group A/Control Group) of 359/521 and 257/372, respectively, P<0.001. In Group A, 0%(0/35) had a CD4+ count below 200 cells/μL, and 2.85%(1/35) of donors had a CD8+ count below 125 cells/μL, which was far lower than the proportion of CD4+ and CD8+ T cell deficiency found in regular apheresis donors by John M. Gansner and Mahboubeh Rahmani. The study showed that the adjustment of the plasma reinfusion mode did not further reduce the T lymphocyte counts in blood donors, but instead further restored the T lymphocyte counts in regular blood donors. This indicated that after the adjustment of plasma reinfusion mode, blood donors might not have lost CD4+ and CD8+ T lymphocytes during blood donation, or only lost a small amount, and can recover even if they donate platelet apheresis frequently. 【Conclusion】 Trima Accel automated blood collection system has a good effect on preventing CD4 + and CD8 + T lymphocytes from being reduced by flushing the LRS chamber with donor plasma.

【Objective】 To explore effective ways to mobilize more blood donors to become voluntary donors of hematopoietic stem cells (HSCs), so as to increase the HSCs supply in China. 【Methods】 Two scales(the information scale and the control scale) with the same items were designed and both included questions concerning the knowledge of HSCs donation and the level of demand. The information scale indicated the correct answer to these questions, while the control scale did not. A total of 3 000 blood donors in Guangzhou were randomly assigned into the intervention group (n=1 500, filled in the information scale) and the control group (n=1 500, filled in the control scale). 【Results】 Blood donors who filled in the informational scale expressed a higher intention to become HSCs volunteers (MInformation =4.32, SD=0.87; MControl=4.02, SD=0.93, t(529)=3.87, P<0.001). Altruism and perceived need (the degree of HSCs demands) were the moderators of grouping and intention, that is, the information scale made blood donors, with stronger altruism and higher perceived need, more willing to become stem cell volunteers. Perceived risk (the negative impact of HSCs donation on health) was a partial mediator of grouping and intention. The information scale reduced blood donors' anxiety about the risk of HSCs donation, and promoted their intention to become HSCs volunteers. 【Conclusion】 This study proved that the informational scale can effectively mobilize blood donors to become HSCs volunteers.

【Objective】 To explore the correlation between serological screening of human T-lymphotropic virus antibodies (anti HTLV) and Western blot(WB) confirmatory tests among blood donors, so as to explore the infection status of HTLV Ⅰ/Ⅱ in Guangzhou. 【Methods】 The anti HTLV Ⅰ/Ⅱ enzyme-linked immunosorbent assay(ELISA) kit was used to screen voluntary blood donors from Guangzhou Blood Center from July 2016 to August 2022. WB was used to confirm 395 reactive blood samples by ELISA. The correlation between the S/CO values of anti HTLV Ⅰ/Ⅱ ELISA reagents and the confirmatory test was analyzed using ROC curves. 【Results】 The results showed that 25 out of 395 initially screened reactive blood donor samples were confirmed as HTLV positive by WB, while 16 were uncertain. ROC curve analysis showed a correlation between the S/CO values by ELISA and the confirmatory test results: the S/CO value at the highest Youden index was 3.789, which was the optimal threshold. The S/CO value had a certain correlation with the predicted positive rate of confirmatory results (P<0.05): the larger the S/CO value, the higher the predicted positive value. The overall prevalence of HTLV in Guangzhou is relatively low. 【Conclusion】 The prevalence of HTLV among blood donors in Guangzhou is low.Since the false positive rate of HTLV Ⅰ/Ⅱ antibody by ELISA serological screening is high, the confirmatory testing is particularly important.

Due to pediatric patients,there are the absence of clinical cases and the conflict between physicians and patients during teaching. Formative assessment(FA)is a teaching method to provide feedback and correctives at each stage in the teaching-learning process,which has been applied in clinical training for medical students and resident standardizing training recent years. Standardized patient(SP)is a simulated teaching tool,and when SPs are introduced in formative assessment by applied to history taking,patient education and counseling and communication skills. The combination not only solves the scarcity of clinical cases,but avoids doctor-patient contradiction. Therefore,SPs provide a broader application prospect for formative assessment. In fact,the combination offers new ideas for pediatric teaching.

【Objective】 To further determine the relationship between blood donor role cognition and blood donation behavior, then prepare of blood donor role identity scale(BDRIS). 【Methods】 The preparation of the scale was divided into five stages. It includes literature retrieval, expert interview, construction of the basic framework of the scale, scale test and statistical index test. The study focused on items selection, dimensions identification, measurement reliability, content and structural validity. 【Results】 The blood donor role identity scale consisted of 35 items. Exploratory factor analysis divided the items into six common factors, including role identity, role expectation, current situation of blood collection and supply, role conflict, external reward and blood donation experience. The α of scale was 0.840. 【Conclusion】 The reliability and validity of the scale meet the basic measurement requirements, and the framework of the blood donor role scale is basically formed. It can be used as one of the means to explore the ways and mechanisms of the role identity of blood donors in blood donation behavior.

ObjectiveFocused on the laboratory animal domestication and breeding of domestic cats, to explore the feeding management methods and breeding techniques of experimental cats. MethodsSeven Chinese garden cats from three litters were introduced from the rural suburbs of Guangzhou, and a breeding seed colony was established. The cats were domesticated in captivity, bred, closed breeding and transmission according to the feeding and management methods of laboratory animal. The population reproduction, the number of pregnancies per year, the litter season, the birth and weaning quality of the cats, and the survival rate of weaning were statistically collected. ResultsThe young breeding cats were able to adapt to the cage feeding management. In the transmission breeding and the expanded breeding colony, the number of female cats pregnant with one, two or three litters a year accounted for 63.2%, 26.3% and 10.5%, respectively. The proportions of litters born from the 1st to the 4th quarters were 20.7%, 20.7%, 27.6%, and 31.0%. A total of 29 pregnancies and 101 kittens were got from 19 female cats, with an average of (3.5±1.33) kittens per litter. The birth weights of female and male cats were (89.31±13.69) g and (93.47±15.12) g, respectively. Sixty-seven kittens survived from weaning. The average survival rate was 60.86%, and the weaning weights of female and male cats were (361.62±82.77) g and (376.0±91.71) g, respectively. ConclusionDomestic Chinese garden cats can adapt to laboratory animal feeding and breeding rules, and have strong fertility. They can normally pregnant and breeding throughout the year. The kittens grow to 5-6 months of age can meet the weight requirements for the examination of pharmaceutical hypotensive substances, and can be used as experimental cats for pharmaceutical examination with clear origin.