Exploring HONO formation and its role in driving secondary pollutants formation during winter in the North China Plain.

Daytime HONO photolysis is an important source of atmospheric hydroxyl radicals (OH). Knowledge of HONO formation chemistry under typical haze conditions, however, is still limited. In the Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain in 2018, we investigated the wintertime HONO formation and its atmospheric implications at a rural site Gucheng. Three different episodes based on atmospheric aerosol loading levels were classified: clean periods (CPs), moderately polluted periods (MPPs) and severely polluted periods (SPPs). Correlation analysis revealed that HONO formation via heterogeneous conversion of NO2 was more efficient on aerosol surfaces than on ground, highlighting the important role of aerosols in promoting HONO formation. Daytime HONO budget analysis indicated a large missing source (with an average production rate of 0.66 ± 0.26, 0.97 ± 0.47 and 1.45 ± 0.55 ppbV/hr for CPs, MPPs and SPPs, respectively), which strongly correlated with photo-enhanced reactions (NO2 heterogeneous reaction and particulate nitrate photolysis). Average OH formation derived from HONO photolysis reached up to (0.92 ± 0.71), (1.75 ± 1.26) and (1.82 ± 1.47) ppbV/hr in CPs, MPPs and SPPs respectively, much higher than that from O3 photolysis (i.e., (0.004 ± 0.004), (0.006 ± 0.007) and (0.0035 ± 0.0034) ppbV/hr). Such high OH production rates could markedly regulate the atmospheric oxidation capacity and hence promote the formation of secondary aerosols and pollutants.

De Novo Protein Design for Novel Folds Using Guided Conditional Wasserstein Generative Adversarial Networks.

Although massive data is quickly accumulating on protein sequence and structure, there is a small and limited number of protein architectural types (or structural folds). This study is addressing the following question: how well could one reveal underlying sequence-structure relationships and design protein sequences for an arbitrary, potentially novel, structural fold? In response to the question, we have developed novel deep generative models, namely, semisupervised gcWGAN (guided, conditional, Wasserstein Generative Adversarial Networks). To overcome training difficulties and improve design qualities, we build our models on conditional Wasserstein GAN (WGAN) that uses Wasserstein distance in the loss function. Our major contributions include (1) constructing a low-dimensional and generalizable representation of the fold space for the conditional input, (2) developing an ultrafast sequence-to-fold predictor (or oracle) and incorporating its feedback into WGAN as a loss to guide model training, and (3) exploiting sequence data with and without paired structures to enable a semisupervised training strategy. Assessed by the oracle over 100 novel folds not in the training set, gcWGAN generates more successful designs and covers 3.5 times more target folds compared to a competing data-driven method (cVAE). Assessed by sequence- and structure-based predictors, gcWGAN designs are physically and biologically sound. Assessed by a structure predictor over representative novel folds, including one not even part of basis folds, gcWGAN designs have comparable or better fold accuracy yet much more sequence diversity and novelty than cVAE. The ultrafast data-driven model is further shown to boost the success of a principle-driven de novo method (RosettaDesign), through generating design seeds and tailoring design space. In conclusion, gcWGAN explores uncharted sequence space to design proteins by learning generalizable principles from current sequence-structure data. Data, source codes, and trained models are available at https://github.com/Shen-Lab/gcWGAN.

Does Distal Clavicle Resection Decrease Pain or Improve Shoulder Function in Patients With Acromioclavicular Joint Arthritis and Rotator Cuff Tears? A Meta-analysis.

BACKGROUND: Acromioclavicular joint arthritis is a common, painful, and often missed diagnosis, and it often accompanies other shoulder conditions such as rotator cuff disease. Whether distal clavicle resection is important to perform in patients undergoing surgery for rotator cuff tears and concomitant acromioclavicular joint arthritis is controversial. QUESTIONS/PURPOSES: The purpose of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of distal clavicle resection on (1) outcome scores; (2) shoulder ROM, joint pain or tenderness, and joint instability; and (3) risk of reoperation among patients treated surgically for rotator cuff tears who had concomitant acromioclavicular joint arthritis. METHODS: We systematically searched the PubMed, EMBASE, and Cochrane databases to find RCTs that met our eligibility criteria, which, in summary, (1) compared rotator cuff repair plus distal clavicle resection with isolated rotator cuff repair for patients who sustained a full- or partial-thickness rotator cuff tear and concomitant acromioclavicular joint arthritis; and (2) the followup period was at least 2 years. Two reviewers screened the studies, extracted the data and evaluated the methodological quality, and performed data analysis. Statistical heterogeneity among studies was quantitatively evaluated with the I index. No heterogeneity was detected (I = 0%; p = 0.75) in terms of acromioclavicular joint pain or tenderness, Constant score, forward flexion, external rotation, and risk of reoperation, so fixed-effect models were used in these endpoints. Heterogeneity was moderate for the American Shoulder and Elbow Surgeons (ASES) score (I = 53%; p = 0.12) and low for the visual analog scale (VAS) score (I = 35%; p = 0.22), so random-effect models were used in these endpoints. Subgroup analysis was stratified by the symptom of acromioclavicular joint arthritis. Three RCTs with 208 patients were included. We evaluated the risk of bias using the Cochrane risk-of-bias tool; in aggregate, the three RCTs included showed low to intermediate risk, although not all parameters of the Cochrane tool could be assessed for all studies. RESULTS: There was no difference between the distal clavicle resection plus rotator cuff repair group and the isolated rotator cuff repair group in ASES score (mean difference =1.41; 95% confidence interval [CI], -3.37 to 6.18; p = 0.56) nor in terms of the VAS score and Constant score. Likewise, we found no difference in ROM of the shoulder (forward flexion, internal rotation, and external rotation) or acromioclavicular joint pain or tenderness between the groups (pooled results of acromioclavicular joint pain or tenderness: risk ratio [RR], 1.59; 95% CI, 0.67-3.78; p = 0.30). Acromioclavicular joint instability was only detected in the rotator cuff repair plus distal clavicle resection group. Finally, we found no difference in the proportion of patients undergoing repeat surgery between the study groups (pooled results of risk of reoperation for the rotator cuff repair plus distal clavicle resection and isolated rotator cuff repair: one of 52 versus two of 78; RR, 0.86; 95% CI, 0.11-6.48; p = 0.88). CONCLUSIONS: Distal clavicle resection in patients with rotator cuff tears did not result in better clinical outcome scores or shoulder ROM and was not associated with a lower risk of reoperation. Distal clavicle resection might cause acromioclavicular joint instability in patients with rotator cuff tears and concomitant asymptomatic acromioclavicular joint arthritis. Arthroscopic distal clavicle resection is not recommended in patients with rotator cuff tears and concomitant acromioclavicular joint arthritis. Additional well-designed RCTs with more participants, long-term followup, and data on patient-reported outcomes are needed. LEVEL OF EVIDENCE: Level I, therapeutic study.

Association between interleukin 8 -251 A/T and +781 C/T polymorphisms and osteosarcoma risk in Chinese population: a case-control study.

Interleukin-8 (IL-8) is an angiogenic chemokine that plays a potent role in both development and progression of many human malignancies. However, there are no data about the role of IL-8 polymorphism in development of osteosarcoma. A hospital-based case-control study was conducted among 190 patients with osteosarcoma and 190 healthy controls to investigate the possible association between the IL-8 -251 A/T and +781 C/T polymorphisms, respectively, and the risk of osteosarcoma. Significant differences of genotype distribution were observed between osteosarcoma cases and controls at the IL-8 -251T/A genotypes. Compared with the IL-8 -251T/A homozygote TT, the heterozygous TA genotype was associated with significantly increased risk for osteosarcoma (odds ratio (OR) = 2.16, 95 % confidence interval (CI) = (1.38-4.52), P = 0.021); the AA genotype was associated with increased risk for osteosarcoma (OR = 1.94, 95 % CI = 1.31-3.83, P = 0.018). TA and AA combined variants were associated with increased risk for osteosarcoma compared with the TT genotype (OR = 1.72, 95 % CI = 1.45-4.41, P = 0.023). Moreover, the genotype AA of IL-8 -251T/A carried a higher risk of osteosarcoma metastasis and later Enneking stages, compared with the TT genotype. However, the genotype and allele frequencies of IL-8 +781 C/T polymorphisms in osteosarcoma patients were not significantly different from controls. Our results showed that the IL-8 -251 A/T genotype was associated with increased risk for development and metastasis of osteosarcoma in Chinese Han population.

Increased long noncoding RNA SNHG20 predicts poor prognosis in colorectal cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been suggested to be involved in the development and progression of malignancies. However, the investigation of small nucleolar RNA host gene 20 (SNHG20) on cancer progression remains unknown. The present study aims to explore the clinical significance of SNHG20 and its potential molecular mechanism in colorectal cancer (CRC). METHODS: Quantitative real-time PCR (qRT-PCR) was used to measure the SNHG20 expression in a total of 107 CRC tissues and CRC cell lines. Loss of function approach was employed to explore the biological roles of SNHG20 in vitro. Its potential molecular mechanism was further verified by western blotting and qRT-PCR. RESULTS: The results suggested that SNHG20 expression was significantly upregulated in CRC tissues compared to corresponding normal tissues from 107 CRC patients. High expression of SNHG20 was remarkably associated with advanced TNM stage in patients with CRC. Multivariate analyses unraveled that SNHG20 expression was an independent prognostic factor for overall survival in CRC patients. Further functional assays revealed that knockdown of SNHG20 suppressed cell proliferation, invasion and migration, and cell cycle progression in CRC cells. Moreover, SNHG20 regulated cell growth through modulation of a series of cell cycle-associated genes. CONCLUSIONS: Our findings suggest that dysregulation of SNHG20 participates in CRC progression and may serve as a potential therapeutic target in CRC patients.

Establishing a reentry procedure for human immunodeficiency virus screening-reactive donors in China.

BACKGROUND: Screening of blood donors for antibody to human immunodeficiency virus Types 1 and 2 (anti-HIV-1/2) and/or HIV nucleic acid test (NAT) is a well-established venue to prevent HIV transfusion-transmitted disease. However, with the current available technologies, HIV testing may result in donor loss due to false-positive results. This study intended to establish a donor reentry procedure for HIV screening-reactive donors in China. STUDY DESIGN AND METHODS: From September 1, 2013, to August 31, 2014, a total of 465 donors from 14 Chinese blood centers were enrolled in this study. Enrollment criteria include all donors who were screened reactive or belonged to the "gray zone" by enzyme-linked immunosorbent assay and/or reactive by NAT when tested at the local blood centers. All donor samples were sent to a central HIV confirmation laboratory where anti-HIV-1/2 and HIV individual-donation NATs were conducted. If the results were reactive for anti-HIV-1/2, then the samples were tested with a recombinant immunoblot assay. RESULTS: Based on the repeat testing at the central HIV confirmation laboratory 8 or 16 weeks after the study, 252 donors of 465 (54.2%) who completed the study could be classified in two categories for HIV status: 45 (18%) true positive and 207 (82%) false positive. A total of 213 of 465 (45.8%) donors were lost on follow-up and, thus, their HIV status cannot be determined with certainty. Based on these data, a donor reentry procedure was proposed. CONCLUSION: Based on our proposed donor reentry procedure for HIV screening-reactive donors, a majority of screening-positive donors (82%, 207/252) can be reentered safely.

Prevalence of Occult Hepatitis C Virus Infection among Blood Donors in Jiangsu, China.

OBJECTIVE: In 2010, only 1 donor blood sample was found to be anti-hepatitis C virus (HCV) negative and HCV RNA positive, as detected by nucleic acid testing. In occult HCV infection (OCI), HCV RNA is found in peripheral blood mononuclear cells (PBMCs). We investigated the prevalence of OCI among blood donors. METHODS: We collected 513 samples from 334 eligible and 179 deferred donors, including 55 anti-HCV-positive, 113 alanine aminotransferase (ALT)-elevated, and 11 hepatitis B virus surface antigen (HBsAg)-positive blood donors. PBMCs were isolated, the 5'-untranslated region of HCV RNA was amplified by reverse transcription nested PCR, and the genotype of the core region was determined. RESULTS: No HCV RNA was detected among the eligible samples. Among the deferred donors, 15 (27.2%) had detectable HCV RNA in 55 anti-HCV PBMC specimens. HCV RNA was detected in 1 (9.1%) HBsAg-positive and 9 (8%) ALT-elevated samples. The prevalence of OCI in the blood donors was 2.2% (10/458). HCV genotypes were determined in 10 subjects, indicating that 2 (20.0%) were subtype 2a, 7 (70.0%) were 1b, and 1 (10%) was 6a. CONCLUSIONS: This study showed that OCI does exist among Chinese blood donors. However, to determine the epidemiology and outcome of this HCV infection, further follow-up with more participants and patients receiving blood components with OCI is needed.

Synthesis and Fungicidal Activity of ß-Carboline Alkaloids and Their Derivatives.

A series of ß-Carboline derivatives were designed, synthesized, and evaluated for their fungicidal activities in this study. Several derivatives electively exhibited fungicidal activities against some fungi. Especially, compound F5 exhibited higher fungicidal activity against Rhizoctonia solani (53.35%) than commercial antiviral agent validamycin (36.4%); compound F16 exhibited high fungicidal activity against Oospora citriaurantii ex Persoon (43.28%). Some of the alkaloids and their derivatives (compounds F4 and F25) exhibited broad-spectrum fungicidal activity. Specifically, compound F4 exhibited excellent high broad-spectrum fungicidal activity in vitro, and the curative and protection activities against P. litchi in vivo reached 92.59% and 59.26%, respectively. The new derivative, F4, with optimized physicochemical properties, obviously exhibited higher activities both in vitro and in vivo; therefore, F4 may be used as a new lead structure for the development of fungicidal drugs.

(60)Co-γ irradiation affects the enzymatic antioxidant system of the citrus red mite Panonychus citri (Acari: Tetranychidae).

Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), phenoloxidase (PO) and acetylocholinesterase (AchE) were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

Study on the Mechanism of Action of the Traditional Chinese Medical Prescription Gushukang in Treating Osteoporosis Based on Network Pharmacology and Experimental Verification.

BACKGROUND: Gushukang (GSK), a traditional Chinese medical prescription, has made a great and extensive contribution to the treatment of different forms of osteoporosis, but polypharmacology studies of its mechanism of action are lacking. This study investigates the pharmacological mechanism of osteoporosis using network pharmacology and molecular docking. Experimental verification was carried out to confirm the efficacy of GSK on RANKLinduced osteoclast differentiation in RAW264.7 cells to verify the network pharmacology studies. METHODS: The effective chemical components and corresponding targets of osteoporosis with oral bioavailability of more than 30% and drug-like properties greater than 0.18 were searched in the TCMSP and TCM-ID databases. DrugBank, GeneCards, OMIM, TTD, and other databases were examined for targets related to osteoporosis. Using Cytoscape software, a network of possible TCM-active ingredient-osteoporosis targets was created. STRING software was used to create the networks of protein-protein interactions. The DAVID program was carried out to conduct GO and KEGG pathway enrichment analyses of the targets. Molecular docking and pattern of action analysis were carried out using software like AutoDock Vina and Discovery Studio Visualizer. The growth media for RAW264.7 cells contained varying doses of GSK serum and 50 ng/mL RANKL. The activity of TRAP was altered. Additionally, genes related to osteoclasts were examined using an RT-PCR assay. RESULTS: Network pharmacological analysis revealed that the primary efficacy targets of osteoporosis were PTGS2, PTGS1, HSP90AA1, NCOA2, ADRB2, ESR1, NCOA1, and AR. The pharmacological targets of osteoporosis may be mediated by substances including quercetin, kaempferol, luteolin, naringenin, icariin, anthocyanin, tanshinone IIA, and cryptotanshinone. GSK markedly inhibited RANKL-induced TRAP activity. qRT-PCR results revealed decreased expression of the PTGS2 and ADRB2 genes upon GSK treatment. CONCLUSION: The findings of network pharmacology, molecular docking, as well as experimental verification provide a new further study for elucidating the pharmacodynamic substance basis and polypharmacology mechanism of GSK in treating osteoporosis.

[Retracted] Tanshinone­IIA attenuates the deleterious effects of oxidative stress in osteoporosis through the NF­κB signaling pathway.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the images shown in Fig. 1E to represent the results from osteoclast differentation experiments were strikingly similar to data appearing in different form in another article written by different authors at different research institutes [Yang Y, Su Y, Wang D, Chen Y, Wu T, Li G, Sun X and Cui L: Tanshinol attenuates the deleterious effects of oxidative stress on osteoblastic differentiation via Wnt/FoxO3a signaling. Oxid Med Cell Longev 6: 351895, 2013]. Owing to the fact that the contentious data in the above article had already been published prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 17: 6969­6976, 2018; DOI: 10.3892/mmr.2018.8741].

Evaluation of enzyme activity predictions for variants of unknown significance in Arylsulfatase A.

Continued advances in variant effect prediction are necessary to demonstrate the ability of machine learning methods to accurately determine the clinical impact of variants of unknown significance (VUS). Towards this goal, the ARSA Critical Assessment of Genome Interpretation (CAGI) challenge was designed to characterize progress by utilizing 219 experimentally assayed missense VUS in the Arylsulfatase A (ARSA) gene to assess the performance of community-submitted predictions of variant functional effects. The challenge involved 15 teams, and evaluated additional predictions from established and recently released models. Notably, a model developed by participants of a genetics and coding bootcamp, trained with standard machine-learning tools in Python, demonstrated superior performance among submissions. Furthermore, the study observed that state-of-the-art deep learning methods provided small but statistically significant improvement in predictive performance compared to less elaborate techniques. These findings underscore the utility of variant effect prediction, and the potential for models trained with modest resources to accurately classify VUS in genetic and clinical research.

A methodological, systematic review of evidence-based independent risk factors for surgical site infections after spinal surgery.

OBJECTIVE: To identify the independent risk factors, based on available evidence in the literature, for patients developing surgical site infections (SSI) after spinal surgery. METHODS: Non-interventional studies evaluating the independent risk factors for patients developing SSI following spinal surgery were searched in Medline, Embase, Sciencedirect and OVID. The quality of the included studies was assessed by a modified quality assessment tool that had been previously designed for observational studies. The effects of studies were combined with the study quality score using a best-evidence synthesis model. RESULTS: Thirty-six observational studies involving 2,439 patients with SSI after spinal surgery were identified. The included studies covered a wide range of indications and surgical procedures. These articles were published between 1998 and 2012. According to the quality assessment criteria for included studies, 15 studies were deemed to be high-quality studies, 5 were moderate-quality studies, and 16 were low-quality studies. A total of 46 independent factors were evaluated for risk of SSI. There was strong evidence for six factors, including obesity/BMI, longer operation times, diabetes, smoking, history of previous SSI and type of surgical procedure. We also identified 8 moderate-evidence, 31 limited-evidence and 1 conflicting-evidence factors. CONCLUSION: Although there is no conclusive evidence for why postoperative SSI occurs, these data provide evidence to guide clinicians in admitting patients who will have spinal operations and to choose an optimal prophylactic strategy. Further research is still required to evaluate the effects of these above risk factors.

CAGI6 ID-Challenge: Assessment of phenotype and variant predictions in 415 children with Neurodevelopmental Disorders (NDDs).

In the context of the Critical Assessment of the Genome Interpretation, 6th edition (CAGI6), the Genetics of Neurodevelopmental Disorders Lab in Padua proposed a new ID-challenge to give the opportunity of developing computational methods for predicting patient's phenotype and the causal variants. Eight research teams and 30 models had access to the phenotype details and real genetic data, based on the sequences of 74 genes (VCF format) in 415 pediatric patients affected by Neurodevelopmental Disorders (NDDs). NDDs are clinically and genetically heterogeneous conditions, with onset in infant age. In this study we evaluate the ability and accuracy of computational methods to predict comorbid phenotypes based on clinical features described in each patient and causal variants. Finally, we asked to develop a method to find new possible genetic causes for patients without a genetic diagnosis. As already done for the CAGI5, seven clinical features (ID, ASD, ataxia, epilepsy, microcephaly, macrocephaly, hypotonia), and variants (causative, putative pathogenic and contributing factors) were provided. Considering the overall clinical manifestation of our cohort, we give out the variant data and phenotypic traits of the 150 patients from CAGI5 ID-Challenge as training and validation for the prediction methods development.

[Study on Reentry Evaluation Mode for Blood Donors Used to be HBV Reactive in Jiangsu Province].

OBJECTIVE: To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy. METHODS: HBsAg+ or HBV DNA+ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb+ / HBcAb+ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg+ and HBV DNA+ blood donors. RESULTS: From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg+ reactive and 70 HBV DNA+ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb+ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA+ donors was 82.86%, which was significantly higher than 47.98% of HBsAg+ donors. CONCLUSION: Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.

[A Sero-epidemiological Study on Transfusion-Transmissible Infectious among Volunteer Blood Donors From 2016 to 2020 in Nanjing].

OBJECTIVE: To investigate the status of transfusion-transmissible infection (TTI) among voluntary blood donors in Nanjing in recent five years, in order to provide data support for the recruitment of blood donors and formulation and updating of blood screening strategies. METHODS: HIV/HBV/HCV/TP serological markers were detected by ELISA in 487 120 blood donors in Nanjing from 2016 to 2020. Confirmatory assay was applied in anti-HIV positive samples by Nanjing Municipal Center for Disease Control and Prevention. The prevalence of TTI was calculated and the trend of disease was analyzed under different demographic groups. RESULTS: The total positive rate of TTI in blood donors was 0.49% (2 411/487 120), in which the overall seroprevalence rate of HBsAg, anti-HCV, anti-HIV and anti-TP was 0.23%, 0.09%, 0.01% and 0.16%, respectively. The overall prevalence of HIV and TP remained relatively steady (P>0.05), whereas HBV and HCV decreased year by year (P<0.05). The prevalence of TTI was higher among people with lower education level, high age group and first-time blood donation. CONCLUSION: The prevalence of TTI among voluntary blood donors in Nanjing is at a low level from 2016 to 2020, but the risk still exists. The recruitment of regular donors and the improvement of blood screening technology can effectively reduce the risk of TTI.

[Prevalence of Human T-Cell Lymphotropic Virus Type 1 and 2 among Blood Donors in Jiangsu from 2016 to 2019].

OBJECTIVE: To investigate the prevalence of human T-cell lymphotropic virus (HTLV) type-I/II infection among voluntary blood donors in Jiangsu (Nanjing, Suzhou, Xuzhou). METHODS: From 2016 to 2019, 408 262 samples of voluntary blood donors from four blood stations in Jiangsu Province (Jiangsu Province Blood Center, Nanjing Red Cross Blood Center, Suzhou Central Blood Station, and Xuzhou Central Blood Station) were screened for HTLV-I/II antibody by ELISA. The positive samples were sent to National Center for Clinical Laboratories for confirmation by RT-PCR and Western blot. RESULTS: The positive rate of HTLV-I/II screened by ELISA was 0.20‰ (82/408 262), and three HTLV-I positive samples were confirmed. The prevalence of HTLV-1 infection was 0.74 per 100 000 (3/408 262). All three donors were female repeated blood donors of childbearing ages. CONCLUSION: Jiangsu is a low prevalence area of HTLV, and a reasonable blood screening strategy for HTLV can further reduce the risk of transfusion-transmitted virus infection.

[Analysis of Reasons Causing False Positive of HBsAg Single-ELISA-Reactive in Blood Donors].

OBJECTIVE: To explore the reasons causing the false positive of HBsAg single-ELISA-reactive in blood donors of Jiangsu province so as to provide reference data for the return of blood donors. METHODS: Serological test: HBsAg ELISA parallel detection was performed on 319 444 samples of blood donors from 2014 to 2017; the ECLIA was employed to confirm the single-ELISA-reactive (S/CO≥0.5) samples, the nucleic acid test was used to detect the HBV DNA on the all single-ELISA-reactive samples in 6/8 people mixed/single. Reagent evaluation: the Receiver-Operating-Characteristic curve (ROCC) was drawn by the ECLIA/NAT results as the gold standard, and the diagnostic performance of reagents A and B under different cut-off was evaluated. RESULTS: A total of 227 (0.71‰) single-ELISA-reactive samples were detected among 319 444 blood donors, including 39 cases (17.2%) of positive HBsAg and 12 cases (5.3%) of positive HBV DNA; Under the maximum YI, the COI (1.0) employed by the manufacturer recommendation has a better diagnostic value than laboratory COI (0.5), and the capability of reagent A was better than that of reagent B (AUC: 0.661 vs 0.632; Youden: 0.329 vs 0.297), but the specificity of both reagents was restricted (＜60%). Under the maximum YI, the best cut-off value of reagents A and B were 2.4 and 1.4 COI, respectively. Compared with the cut-off value of manufacturer, the sensitivity of reagents A decreased by 33% and the false positive rate decreased by 60% while the sensitivity of reagent B increased by 140% and the false positive rate increased by 36%, respectively. CONCLUSION: The false positive of HBsAg single-ELISA-reactive in blood donors is caused by the limited specificity of ELISA reagent and the setting of COI values. According to ROCC maximum YI method, the COI can be set as 2.4 COI and (0.5-1.4) COI for reagent A and B to reduce false positive rate.

[Evaluation of the Cutoff of Anti-HCV Antibody Enzyme-Linked Immunosorbent Assay in 7 Blood Station Laboratories].

OBJECTIVE: To evaluate the necessity and suitability of the anti-HCV ELISA teot gray zone setted up by 7 blood station laboratories. METHODS: 7 blood station laboratories were coded as 1, 2, 3, 4, 5, 6 and 7 respectively; 8 kinds of ELISA reagents were coded as A, B, C, D, E, F, G and H respectively. 1 or 2 of 8 ELISA reagents produced by different manufactories were used to detect the anti-HCV in specimens of same group by 7 blood station laboratories; the Westen blot was used to detect the specimens with difference of detected results so as to difine the serological status of specimens. The true positive rate of specimens detected by laboratories and gray zone-comfirined positive rate of specimens were accounted so as to analyze the necessity of setting up the gray zone for anti-HCV ELISA test of 7 blood station laboratories; the optimal cut-off value for anti-HCV ELISA test was determined in 7 blood station laborafories by ROC curve and the changes of sensitivity and specificity of 3 different cut-off value(laboratory work cut-off value, manifactory-recommended cun-off value and optimal cut-off value) were compared so as to analyze the suitability of gray zone for anti-HCV ELISA test in 7 blood station laboratories. RESULTS: The true positive rate detected by 7 blood station laboratories, out of which coded 1 laboratory used 2 kinds of coded A, B reagents was 95.40%(1A), 99.23% (1B), 94.25% (2C), 96.17% (3D), 98.08% (4E), 96.93% (5F), 97.32%(6G) and 93.10%(7H). Except for 2C(94.25%) and 7H(93.10%), the true positive rate detected by laboratoies which not sutted up gray zone, the gray zone-con-firmed positive rate in 6 blood station laboratories setted up gray zone: was 0.00%, 0.00%, 21.43%, 0.00%, 0.00%, 0.00% and 38.89%. The comparison of 3 different cut-off valuces by ROC curve showed that the anti-HCV cut-off values in 5 laboratories(1B, 2C, 4E, 5F and 6G) were as follows: optimal cut-off value＞manufactory recommeded cut-off value＞laboratory work cut-off value, thus use of manufactory-recommeded cut-off value abreadly has reached the high sensitivity requinements for laboratory screening; however, the optimal cut-off value in laboratories 1A, 3B and 7H, thas the appropriate gray zone should be used. In 6 laboratories setting up gray zone, the gensitivity in 3D, 7H laboratories only a little improved (1.60% and 2.70% raspectively) in Eamparison between laboratory work cut-off value and manufactorg-recommeded cut-off value; moreover, the sensitivity in other laboratories not is changed, but the specificity decreased (0.20%-0.50%). CONCLUSION: In addition to setting up the appropriate gray zone in laboratories 1A, 3D and 5H, the gray zone in other laboratories may be cancelled. Even in the same laboratory, the setting up the gray zone also should be scientifically assessed, the same scale cannot be blindly used, thus appropniate strategies should be established.

A unique group of inactive serine protease homologues from snake venom.

A number of inactive serine protease homologues (SPHs), which have poorly understood functions, have been identified in invertebrates and vertebrates. Recently, several SPH transcripts have been reported from snake venom glands, which provide potential new tools for the study of the functions of SPHs. Herein we report for the first time a snake venom serine protease homologue (svSPH) protein, designated as TjsvSPH, isolated from the venom of Trimeresurus jerdonii. Despite its high sequence similarity to snake venom serine proteases (SVSPs), TjsvSPH is devoid of arginine esterase and proteolytic activity. This is probably due to the replacement of Arg-43 by His-43 in the catalytic triad. TjsvSPH did not influence the coagulation time of human plasma, induce human platelet aggregation, inhibit adenosine diphosphate/thrombin-induced human platelet aggregation or increase capillary permeability. Phylogenetic analysis showed that svSPHs were separated from SVSPs and formed an independent group. Structural analysis revealed that the structures of svSPHs are quite different from those of SPHs previously reported. These results indicate that snake venoms contain a unique group of svSPH proteins.