Argonaute proteins are active throughout the lifetime in a variety of organisms and they bind to small RNAs (sRNAs) to regulate gene expression. The Argonaute proteins of vertebrates can be classified into two clades: the Ago clade and the Piwi clade. Both clades have N, L1, L2, PAZ, MID and PIWI domains. The N domain is involved in the loading of sRNAs. L1 and L2 domains facilitate the linking between domains. The PAZ and MID domains exert functions by anchoring sRNAs. The PIWI domain of some Argonaute proteins has RNase H-like structure and exerts the endonuclease function. Ago proteins regulate gene expression at transcriptional and post-transcriptional levels. Piwi proteins mainly exist in the germ cells, silencing transposons in different ways to keep genome integrality and regulating gene expression. In recent years, great progress has been made in Argonaute proteins in terms of the crystal structures, functions, and expression patterns. By reviewing the relevant studies, we elaborate on the structures, sRNA dependence, gene expression regulation, and biological roles of the Ago and Piwi proteins in vertebrates, aiming to clarify the roles of Argonaute proteins in epigenetic regulation and provide a reference for further research and application of these proteins.
Argonaute Proteins/chemistry* ; Animals ; Vertebrates/metabolism* ; Gene Expression Regulation ; RNA, Small Interfering/metabolism* ; Epigenesis, Genetic ; Humans

【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.

【Objective】 To analyze the hepatitis B virus (HBV) infection data of blood donors from 18 domestic blood stations, so as to investigate the HBV infection situation of blood donors. 【Methods】 The positive rate of HBV and its distribution characteristics of regions, the percentage of HBsAg+ ELISA in first-time vs repeated blood donors, and the percentage of HBsAg-/HBV DNA+ blood donors of 18 domestic blood stations during 2017 to 2020 were collected from the Working Platform for Practice Comparison of Blood Centers, and the HBV infection among blood donors were statistically analyzed. 【Results】 From 2017 to 2020, the positive rate of HBV in blood donors among 18 domestic blood stations was 13.48/10 000-144.02/10 000, with the average HBV positive rate in eastern, central and western region at 26.14/10 000, 51.98/10 000 and 41.00/10 000, respectively. The HBsAg+ rate by ELISA among first-time and repeated blood donors was 14.55/10 000-305.39/10 000 vs 1.04/10 000-87.43/10 000 The HBsAg-/HBV DNA+ yield was 1.80/10 000-35.31/10 000. 【Conclusion】 The distribution of HBV infection in blood donors has regional characteristics, and HBV prevalence was low in repeated blood donors. HBsAg ELISA combined with HBV DNA detection can better ensure blood safety.

Objective:To evaluate the residual risk (RR) of transfusion transmitted HIV (TT-HIV) after the implementation of nucleic acid amplification test (NAT) in blood screening test among blood centers in China.Methods:The data of blood donors and HIV infection markers from 2017 to 2020 were collected from 28 blood centers via the Platform of Comparison of blood establishments Practice in Chinese Mainland. The new infection rate/window period mathematical model was used for two types of blood screening strategies, namely, two rounds ELISA plus individual NAT take turn with pooling NAT (2ELISA+ ID-NAT/MP-NAT) and two ELISA plus one round pooling NAT (2ELISA+ MP-NAT), and the RR of HIV infection was estimated also based on first donors (FDs) and repeated donors (RDs) in different blood donation years. T-test analyses were conducted for comparing TT HIV RR among FDs and RDs in different blood donation years with two blood screening strategies, and the variation trend of RR in HIV test was observed.Results:From 2017 to 2020, the RR of FDs in 2ELISA+ ID-NAT/MP-NAT blood screening strategy was 2.869/10 6 person-year, 3.795/10 6 persons-year, 3.879/10 6 person-year, and 2.890/10 6 person-year respectively. The RR of RDs was 1.797/10 6 person-year, 1.502/10 6 person-year, 1.857/10 6 person-year, and 1.483/10 6 person-year respectively. Significant difference exists between RR of FDs and RDs, with F=9.898 and p<0.05. In 2ELISA+ MP-NAT strategy, the RR of FDs was 3.508/10 6 person-year, 1.868/10 6 person-year, 2.204/10 6 person-year, and 1.765/10 6 person-year respectively. The RR of RDs was 0.948/10 6 person-year, 0.926/10 6 person-year, 0.748/10 6 person-year, and 0.682/10 6 person-year respectively. Statistical difference existed between RR of FDs and RDs, with F=17.126 and P<0.05. There was no significant difference between the RR of FDs in these two strategies with F=3.493 and P>0.05, while there was a difference between the RR of RDs in these two strategies with F=24.516 and P<0.05, and a difference between the RR of total donors (TDs) in these two strategies F=20.216 and P<0.05. Conclusions:The RR of TT HIV significantly decreased after the introduction of NAT into blood test among blood centers in China. There were some differences in the RR of HIV testing among different blood screening strategies. There could be significant differences in the RR of HIV testing among different groups of blood donors. Compared with FDs, RDs is the low risk group for HIV.

Objective:To analyze the detection strategy and basic detection situation of markers of infectious diseases transmitted by transfusion in blood testing laboratories of blood stations in China.Methods:Based on the data of practice comparison working party of Blood Stations in Mainland of China from 2017 to 2021, the data on the testing strategies and the basic detection information of the markers for the transmission of infectious diseases through transfusion in the member laboratories of the practice comparison working party of Blood Stations in Mainland of China from 2017 to 2021 were collected, and the situation of the selection for testing markers, testing strategy and the testing method and other relevant aspects were sorted out and analyzed by charts.Results:The selection of the testing markers was consistent, but HTLV testing item was added in some member laboratories. The detection strategy of using two ELISA reagents and one nucleic acid testing (NAT) reagent simultaneously was adopted in 47 member blood stations; 3) NAT method was dominated by mini pool-NAT in member laboratories. The number of members adopting mini-pools of 8 (MP8)-NAT decreased from 17 in 2017 to 14 in 2021, while the number of members adopting mini-pools of 6 (MP6)-NAT increased from 13 in 2017 to 22 in 2021; Roche NAT system accounted for the largest proportion.Conclusions:In order to ensure blood safety and avoid missing detection, the blood stations still adopt the detection strategy of using two ELISA reagents and one nucleic acid testing (NAT) reagent simultaneously; Meanwhile, in order to increase the NAT positive rate, the proportion of mini pool-NAT mainly decreased year by year despite its dominating role, while the proportion of individual donation-NAT increased year by year; NAT method is transiting from mini-pools of 8 (MP8) to mini-pools of 6 (MP6); The proportion of imported NAT system used in NAT laboratory is relatively large.

【Objective】 To study the annual financial expenditure in blood stations with different scales, and to establish the regression equation between blood collection units and total expenditure. 【Methods】 The annual total expenditure, the per capita cost of serving population, as well as the collection units of whole blood and apheresis platelet of 24 blood stations were collected. The financial expenditure required for collecting 10 000U blood was calculated.The statistical analysis was carried out with SPSS statistical software. 【Results】 From 2017 to 2020, the total annual financial expenditure of 24 blood stations showed an upward trend. The total expenditure among blood stations was different. The per capita cost of servicing population in the areas where the 24 blood stations were located had been increasing year by year. The 24 blood stations were divided into two grades according to the blood collection volume as 50 000 U, and the relationship equation between the blood collection volume and the annual total expenditure had been established. After testing, each equation was effective(P<0.05); There was no difference in the financial expenditure required for collecting 10 000U blood among blood stations with different scales. 【Conclusion】 From 2017 to 2020, the blood stations with an annual collection volume more than 50 000 U demonstrated a higher financial expenditure and the per capita cost of serving population than those <50 000 U. The blood collection volume of blood stations is significantly correlated with the annual total expenditure and the per capita cost of serving population.

Acute liver failure is a serious and complex liver disease with a high short-term mortality rate. Its pathogenesis remains unknown and there is still a lack of effective drugs. Animal models play an important role in further revealing the pathogenesis of acute liver failure and the therapeutic mechanism of drugs, and the selection of experimental animals and preparation methods is the key to the effective implementation of research. This article summarizes the commonly used and new animal models of acute liver failure in recent years and the corresponding preparation methods and divides the animal models of acute liver failure into following four categories: chemical drug model, surgical model, infection model, and other models. Meanwhile, the above models are evaluated based on Terblanche and Hickman evaluation criteria for liver failure models, hoping to provide a reference for model selection and evaluation in basic research on this disease.

Background To study the pathogenesis and management of diabetic retinopathy (DR) has an important clinical significance.With the development of biomedical photonics in recent years,photobiomodulation therapy has been paid more and more attention.However,the sudy on biological regulation of light to DR is rarely reported.Objective This study was to explore the photobiomodulating effects on the apoptosis of retinal neuronal cells induced by high glucose environment and tried to offer a basis for the management of DR.Methods The retinal neurons were isolated from Wistar rats using immunomagnetic beads and primarily cultured in Neurobasal,and the cells were identified by Nissl staining.The cells were divided into normal control group,high-glucose group and high-glucose+LED group.The glucose at the concentration of 25 mmol/L was added into medium for 48 hours in the high-glucose group,and the cells induced by high-glucose were irradiated in incubator by LED for consecutive 300 seconds per time in a 12-hour interval with the wavelength of 620 nm,maximal power of 1 W,central light radiation exposure of 6.67 mW/cm2 and spot diameter of 2.0 cm.The apoptosis rate of the cells was assayed by flow cytometry;the intracellular Ca2+ content was determined by laser scanning confocal microscope;the relative expression level of phosphorylated serine-threonine kinase (p-AKT) protein in the cells was detected by Western blot.Results The cells grew well 2-3 days after cultured with the polygon and oval shape,and nucleolus were visible.More neuronal processes were obtained in 5-7 days after culture.Nissl staining showed the blue violet color in cytoplasma of neurons.The proportion of neurons and glial cells was 91％.The apoptosis rates of the cells were (7.634±3.176)％,(33.642 ±9.315)％ and (23.914±6.375)％ in the normal control group,high-glucose group and high-glucose+LED group,respectively,and the apoptosis rates of high-glucose group and high-glucose + LED group were significantly higher than that in the normal control group,while the apoptosis rate in the high-glucose+LED group was lower than that in the high-glucose group (all at P＜0.01).The fluorescence of Ca2+ in the cytoplasma was strong in the highglucose group and weak in the normal control group.The fluorescence pixel values in the high-glucose group and highglucose+LED group were significantly higher than that in the normal control group,and that in the high-glucose+LED group was reduced in comparison with high-glucose group (all at P＜0.05).The expressing band of p-AKT protein was strong in the normal control group and weak in the high-glucose group.The relative expressing levels were 10.34± 3.18,2.16±0.46 and 7.15 ±1.72 in the normal control group,high-glucose group and high-glucose+LED group,and relative expression level of high-glucose+LED group was significatly lower than that in the high-glucose group (P＜ 0.05).Conclusions High-glucose environment inhibits PI3K/AKT pathway and calcium homeostasis of retinal neurons,which results in cell apoptosis.Low intensity of LED light irradiation activates the anti-apoptotic PI3K/AKT pathway and therefore reduces apoptosis induced by high glucose.

Objective To explore the genotype of patients with glucose-6-phosphate dehydrogenas(G6PD)deficiency in Dong-guan and provide the basis for the clinical diagnosis and prevention.Methods The clinical data of patients who took G6PD activity screening in the hospital were collected from January 2011 to December 2013,the G6PD/6PGD ratios were recorded.469 patients with positive G6PD/6PGD ratio were randomly enrolled in the study,whose mutations were detected by reverse dot blot(RDB)as-say.Results During this period,we measured G6PD activity of 16 464 cases by G6PD/6PGD ratios,there were 672 positive cases, the positive rate was 4.08%.Randomly selected 469 positive samples,detected their genotye by RDB assay.We detected 173 cases of G1376T,141 cases of G1388A,82 cases of A95G,60 cases of G871A,23 cases of G392T,14 cases of C1024T.In addition to that, we also found some rare mutations,such as 6 cases of C1004T,2 cases of T517C,1 cases of C1360T.65 cases of C1311T gene poly-morphism and 96 cases of dual gene mutations were detected.Conclusion The incidence of G6PD deficiency is high and the gene mutation types in Dongguan are both representative for Chinese population and with local heterogeneity.The study on gene muta-tions of G6PD deficiency is benefit for diagnosis and prevention.

Objective To explore the image quality of 3.0 T Magnetic Resonance foot and ankle array coil on Achilles tendon ab-normalities for the clinical application.Methods 26 patients (with Achilles tendon symptoms)and 5 volunteers underwent MR exam-ination.The scanning sequences were used:T1 WI、PDWI、T2 WI-FS and STIR.Image diagnoses and clinical data of all patients were obtained and analyzed.Subjective scores on image quality were used.Degrees of comfort in coil were evaluated.Results 10 patients had Achilles tendon inj ury,6 patients with Achilles tendonitis,3 patients with part Achilles tendon rupture,1 patient with tendon xanthoma,and 6 patients were normal.Image scores in patients with T1 WI、PDWI and T2 WI-FS sequences were higher,the anatom-ic structures,lesions of whole Achilles tendon were clear.On the contrary,the lower scores were in STIR sequences.In the heel, images were distorted,the level of organization was disappeared and signal intensity was increased.The volunteers felt a slight dis-comfort at the coil entrance and support point of the heel.Conclusion Patients using 3.0T foot and ankle array coil for the Achilles tendon scanning could get high image quality and degrees of comfort.