Comprehensive evaluation of the effectiveness of iodine deficiency disorders prevention and control in Xinjiang Production and Construction Corps from 2014 to 2020 using TOPSIS and RSR methods / 中华地方病学杂志

Objective:To discuss the comprehensive evaluation of the effectiveness of iodine deficiency disorders prevention and control in Xinjiang Production and Construction Corps (Corps for short) using technique for order preference by similarity to an ideal solution (TOPSIS) and rank-sum ratio (RSR) methods, and identify weaknesses in the prevention and control of iodine deficiency disorders in the Corps at present.Methods:The monitoring data on iodine deficiency disorders in the Corps from 2014 to 2020 were collected from the Disease Control and Prevention Center of the Corps. Six indexes were selected, including the consumption rate of qualified iodized salt, the coverage rate of iodized salt, the qualified rate of iodized salt, the appropriate percentage of urinary iodine in children, the goiter rate of children and the appropriate percentage of urinary iodine in pregnant women. The TOPSIS method and RSR method were combined to comprehensively evaluate the prevention and control effect of iodine deficiency disorders in the Corps.Results:The results of TOPSIS method showed that the control effect was from superior to inferior in the order of 2020, 2018, 2016, 2019, 2015, 2017 and 2014. Based on the RSR method, the control effect was divided into three levels: 2018 and 2020 (with an estimated RSR value of ≥0.525) in the first level (good), 2014 (estimated RSR value < 0.007) in the third level (poor), and other years (0.007≤estimated RSR value < 0.525) in the second level (medium). Referring to the monitoring data, the appropriate percentage of urinary iodine in children and pregnant women in the middle years was the weak point. Conclusions:TOPSIS method combined with RSR method can accurately and reasonably evaluate the effectiveness of prevention and control of iodine deficiency disorders in the Corps, the evaluation results are consistent with the actual situation. It is found that the appropriate iodine nutrition levels of children and pregnant women are the weak points in the prevention and control of iodine deficiency disorders in the Corps.

Interpretation of performance verification of clinical microbial culture, identification and antimicrobial susceptibility testing systems / 中华检验医学杂志

The professional standard for the health industry of People′s Republic of China,"WS/T 807-2022 Performance verification of clinical microbial culture, identification and antimicrobial susceptibility testing systems", was issued on November 2, 2022 and implemented on May 1, 2023. This professional standard (voluntary standard) is the basis for the formulation and implementation of the microbiological testing performance verification scheme, providing guidines for quality control procedures in the laboratories. The purpose of this document is to standardize and homogenize the performance verification protocols in the field of clinical microbiological testing. This article explains and analyzes the background, preparation, main contents, implementation difficulties and significance of the standard, so as to help clinical microbiological laboratory personnel fully understand and implement the relevant provisions of the standard, promoting industry standardization and discipline development.

Iodine nutrition level of children aged 8 - 10 years and pregnant women in Southern and Northern Xinjiang of Xinjiang Production and Construction Corps in 2020 / 中华地方病学杂志

Objective:To fully learn about the iodine nutrition level and the status quo of prevention and control of iodine deficiency disorders (IDD) among children aged 8 - 10 years and pregnant women in Southern and Northern Xinjiang of Xinjiang Production and Construction Corps (hereinafter referred to as the Corps), and to provide a basis for consolidating the prevention and control effect of IDD and proposing sustainable prevention and control strategies.Methods:From May to November 2020, IDD monitoring was carried out within the Corps. ⑴Salt iodine monitoring: in 14 divisions of the Corps, 1 regiment was selected in each division from five directions of East, West, South, North and Middle, and 4 companies were selected from each regiment and edible salt samples were collected from the homes of 15 Corps employees to test for salt iodine. ⑵Monitoring of urinary iodine and goiter: in 13 divisions of the Corps, 1 regiment was selected from each division according to five directions of East, West, South, North and Middle, and 40 children aged 8 - 10 years (age balanced, half male and female) from one primary school and 20 pregnant women were selected as the survey subjects. Once random urine sample was collected from children and pregnant women to detect urinary iodine; the thyroid volume of children was measured and the goiter rate was calculated.Results:⑴A total of 4 149 salt samples were tested, the median salt iodine was 27.3 mg/kg, the coverage rate of iodized salt was 99.9% (4 146/4 149), the qualified rate of iodized salt was 98.1% (4 069/4 146), and the consumption rate of qualified iodized salt was 98.1% (4 069/4 149). Among them, 1 197 and 2 952 salt samples were tested in Southern and Northern Xinjiang of the Corps, the median salt iodine was 26.7 and 27.5 mg/kg, respectively; the coverage rate of iodized salt was 99.7% (1 194/1 197) and 100.0% (2 952/2 952), respectively; the qualified rate of iodized salt was 95.0% (1 134/1 194) and 99.4% (2 935/2 952), respectively; the consumption rate of qualified iodized salt was 94.7% (1 134/1 197) and 99.4% (2 935/2 952), respectively; and the differences between regions were statistically significant ( P < 0.05). ⑵A total of 2 602 urine samples of children aged 8 - 10 years were detected, and the median urinary iodine was 186.5 μg/L; the median urinary iodine of children (800 and 1 802) in Southern and Northern Xinjiang of the Corps was 181.9 and 188.5 μg/L, respectively. A total of 1 247 urine samples of pregnant women were detected, and the median urinary iodine was 192.6 μg/L; the median urinary iodine of pregnant women (397 and 850) in Southern and Northern Xinjiang of the Corps was 182.2 and 200.3 μg/L, respectively. ⑶A total of 2 602 children aged 8 - 10 years were examined for thyroid volume, and the goiter rate was 1.2% (31/2 602); the goiter rate of children in Southern and Northern Xinjiang of the Corps was 1.4% (11/800) and 1.1% (20/1 802), respectively. Conclusion:In 2020, the Corps has reached the elimination standard of IDD by divisions, and children aged 8 - 10 years and pregnant women are generally at an appropriate iodine level.

Current status and challenges of pathogen metagenomic high-throughput sequencing testing implemented in a clinical laboratory affiliated to a hospital / 中华检验医学杂志

Pathogen metagenomic next-generation sequencing (mNGS) testing is highly sophisticated. Its requirements for laboratory environment, equipment, and technical capabilities of personnel are very high. How to orderly develop, standardize management, and application of mNGS technology in hospitals is a scientific topic that practitioners must treat with caution. In this article, the establishment mode of the mNGS detection system in clinical laboratories, the analytical and clinical validation of the detection system, the risk management (which from biological factors, detection procedures, and the bioinformatics analysis and information transmission), as well as the requirements for pathogen databases, bioinformatics analysis talents, and diagnostic reports, have been professionally considered and discussed. It is expected to provide scientific advice for the completely implementation of mNGS testing in a clinical laboratory affiliated to a hospital, promoting the standardized application and healthy development of this technology in hospitals.

Laboratory testing for common pathogens of respiratory tract infection in pediatrics / 中华检验医学杂志

Currently, the respiratory tract infection (RTI) is still one of the most common disease that seriously threatens children′s life and health. Timely detection of pathogens in clinical specimens of children with RTI is helpful to accurate diagnosis and reduce the irrational usage of antibiotics. It is also an important strategy to achieve the best clinical management of RTI in children. In recent years, in addition to the traditional staining and microscopy, culture and antigen detection, the polymerase chain reaction, syndromic approach testing and metagenomic next-generation sequencing have also been used for the diagnosis of pathogens in children with RTI, showing a good application prospect. This review aims to systematically summarize the classification of clinical specimens and the detection methods of common pathogens in the diagnosis process of childhood respiratory infections. This not only expands the understanding of pediatric medicine, but also provides more enlightenment for related research work.

Analysis on monitoring results of iodized salt in Xinjiang Production and Construction Corps form 2015 to 2019 / 中华地方病学杂志

Objective:To understand the iodine content of edible salt in residents of Xinjiang Production and Construction Corps (referred to as Corps), and provide scientific evidence for prevention and treatment of iodine deficiency disorders.Methods:According to the requirements of the "National Iodine Deficiency Disorders Surveillance Program" form 2015 to 2019, in accordance with the principle of random sampling, one regiment from each of the five directions of east, west, south, north and center in the Corps was selected, and four companies were selected from each regiment. Edible salt samples from the homes of 15 residents in each company were collected, and salt iodine content was quantitatively tested and the test results were analyzed.Results:From 2015 to 2019, 21 028 household salt samples were collected, qualified iodized salt were 20 204, non-qualified iodized salt were 712, non-iodized salt were 112, iodized salt coverage rate was 99.47% (20 916/21 028), iodized salt qualified rate was 96.60% (20 204/20 916), qualified iodized salt consumption rate was 96.08% (20 204/21 028). The average salt iodine content was (27.72 ± 4.81) mg/kg. From 2015 to 2019, the iodized salt coverage rates in the whole Corps were all > 95%, and the iodized salt qualified rates and the qualified iodized salt consumption rate were all > 90%. Among the 14 divisions of the Corps, iodized salt coverage rates were all > 95%, except for the 12th and 14th divisions, where the iodized salt qualified rates and qualified iodized salt consumption rates were < 90%, all other divisions were > 90%.Conclusions:Iodized salt coverage rate, iodized salt qualified rate and qualified iodized salt consumption rate have all reached the national standard for eliminating iodine deficiency disorders from 2015 to 2019, however, non-iodized salt exists in some areas, and the qualified iodized salt consumption rate is low. We should strengthen monitoring of iodized salt in key areas and promote health education, consolidate and maintain achievements in eliminating iodine deficiency disorders.

Analysis of the intestinal microbiota in COVID-19 patients and its correlation with the inflammatory factor IL-18 and SARS-CoV-2-specific IgA

The current global COVID-19 pandemic is caused by beta coronavirus Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which already infected over 10 million and caused 500 thousand deaths by June 2020. Overproduction of cytokines triggered by COVID-19 infection, known as "cytokine storm", is a highly risk factor associated with disease severity. However, how COVID-19 infection induce cytokine storm is still largely unknown. Accumulating in vitro and in vivo evidence suggests that gut is also susceptible to COVID19 infection: Human intestinal organoids, an in vitro model which mimic the specific cell type and spatial structure of the intestine, were susceptible to SARS-CoV2 infection; A significant fraction of patients reported gut symptoms; Viral RNA may persist for more than 30 days and infectious virus could be isolated in fecal samples. The gastrointestinal tract is the primary site of interaction between the host immune system with symbiotic and pathogenic microorganisms. The bacteria resident in our gastrointestinal tract, known as gut microbiota, is important to maintain the homeostasis of our immune system. While imbalance of gut microbiota, or dysbiosis, is associated with multiple inflammation diseases5. It's possible that SARS-CoV-2 infection may lead to alternation of gut microbiota thus worsen the host symptom. IL-18 is a proinflammatory cytokine produced multiple enteric cells, including intestinal epithelial cells (IECs), immune cells as well as enteric nervous system, and was shown to increase in the serum of COVID-19 patients. Immunoglobin A (IgA) is mainly produced in the mucosal surfaces, in humans 40-60mg kg-1 day-1 than all other immunoglobulin isotypes combined, and at least 80% of all plasma cells are located in the intestinal lamina propria. Recent study showed that SARS-CoV-2 specific IgA in the serum is positively correlate with the disease severity in COVID-19 patients11. Here we investigated the alterations of microbiota in COVID-19 patients, and its correlation with inflammatory factor IL-18 and SARS-CoV2 specific IgA.

A CRISPR-Cas12a-based specific enhancer for more sensitive detection of SARS-CoV-2 infection

High Ct-values falling in the grey zone are frequently encountered in SARS-CoV-2 detection by real-time reverse transcription PCR (rRT-PCR) and have brought urgent challenges in diagnosis of samples with low viral load. Based on the single-stranded DNA reporter trans-cleavage activity by Cas12a upon target DNA recognition, we create a Specific Enhancer for detection of PCR-amplified Nucleic Acids (SENA) to confirm SARS-CoV-2 detection through specifically targeting its rRT-PCR amplicons. SENA is highly sensitive, with its limit of detection being at least 2 copies/reaction lower than that of the corresponding rRT-PCR, and highly specific, which identifies both false-negative and false-positive cases in clinic applications. SENA provides effective confirmation for nucleic acid amplification-based molecular diagnosis, and may immediately eliminate the uncertainty problems of rRT-PCR in SARS-CoV-2 clinic detection. One Sentence SummaryCRISPR-Cas12a-based COVID-19 diagnosis.

COVID-19 diagnosis and study of serum SARS-CoV-2 specific IgA, IgM and IgG by a quantitative and sensitive immunoassay

BackgroundThe pandemic of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is causing great loss. Detecting viral RNAs is standard approach for SARS-CoV-2 diagnosis with variable success. Currently, studies describing the serological diagnostic methods are emerging, while most of them just involve the detection of SARS-CoV-2-specific IgM and IgG by ELISA or "flow immunoassay" with limited accuracy. MethodsDiagnostic approach depends on chemiluminescence immunoanalysis (CLIA) for detecting IgA, IgM and IgG specific to SARS-CoV-2 nucleocapsid protein (NP) and receptor-binding domain (RBD) was developed. The approach was tested with 216 sera from 87 COVID-19 patients and 483 sera from SARS-CoV-2 negative individuals. The diagnostic accuracy was evaluated by receiver operating characteristic (ROC) analysis. Concentration kinetics of RBD-specific serum antibodies were characterized. The relationship of serum RBD-specific antibodies and disease severity was analyzed. ResultsThe diagnostic accuracy based on RBD outperformed those based on NP. Adding IgA to a conventional serological test containing IgM and IgG improves sensitivity of SARS-CoV-2 diagnosis at early stage. CLIA for detecting RBD-specific IgA, IgM and IgG showed diagnostic sensitivities of 98.6%, 96.8% and 96.8%, and specificities of 98.1%, 92.3% and 99.8%, respectively. Median concentration of IgA and IgM peaked during 16-20 days after illness onset at 8.84 g/mL and 7.25 g/mL, respectively, while IgG peaked during 21-25 days after illness onset at 16.47 g/mL. Furthermore, the serum IgA level positively correlates with COVID-19 severity. ConclusionCLIA for detecting SARS-CoV-2 RBD-specific IgA, IgM and IgG in blood provides additional values for diagnosing and monitoring of COVID-19. SummaryChemiluminescence immunoanalysis of SARS-CoV-2 RBD-specific serum IgA as well as IgM and IgG improves accuracy of COVID-19 diagnosis. Concentration kinetics of serum RBD-specific IgA, IgM and IgG are revealed. Serum IgA levels positively correlate with COVID-19 severity.

Tocilizumab treatment in severe COVID-19 patients attenuates the inflammatory storm incited by monocyte centric immune interactions revealed by single-cell analysis

ABSTRACTDespite the current devastation of the COVID-19 pandemic, several recent studies have suggested that the immunosuppressive drug Tocilizumab can powerfully treating inflammatory responses that occur in this disease. Here, by employing single-cell analysis of the immune cell composition of severe-stage COVID-19 patients and these same patients in post Tocilizumab-treatment remission, we have identified a monocyte subpopulation specific to severe disease that contributes to inflammatory storms in COVID-19 patients. Although Tocilizumab treatment attenuated the strong inflammatory immune response, we found that immune cells including plasma B cells and CD8+ T cells still exhibited an intense humoral and cell-mediated anti-virus immune response in COVID-19 patients after Tocilizumab treatment. Thus, in addition to providing a rich, very high-resolution data resource about the immune cell distribution at multiple stages of the COVID-19 disease, our work both helps explain Tocilizumab’s powerful therapeutic effects and defines a large number of potential new drug targets related to inflammatory storms.Competing Interest StatementJingwen Fang is the executive officer of HanGen BiotechView Full Text

Optimization of Microbiological Laboratory Detection Strategy for Patients in A Designated Hospital Treating Novel Coronavirus Pneumonia in Anhui Province

Novel coronavirus pneumonia (NCP) is an emerging, highly contagious community acquired pneumonia (CAP) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Highly efficient and accurate microbiological laboratory assay is essential to confirm the SARS-CoV-2 infection, rule out other pathogens that can cause CAP, and monitor secondary infections. Here, we enrolled and provide microbiological analysis for 129 suspected and 52 transferred confirmed NCP patients hospitalized in the First Affiliated Hospital of University of Science and Technology of China (USTC) from Jan 21 to Feb 29, 2020. By analyzing the dual swab samples (sputum and pharyngeal) from 129 suspected patients with realtime RT-PCR, we confirmed 33 SARS-CoV-2 infections, with two co-infection cases with adenovirus or rhinovirus. We also used multiplex PCR to detect 13 common respiratory tract pathogens in 96 non-NCP patients, and found that 30 patients (31.25%) were infected with at least one respiratory tract pathogen that may cause CAP. Further, we performed bacterial and fungal cultures as well as fungal serologic tests and found that there is no secondary bacterial/fungal infections in confirmed NCP patients. Our studies suggest that, during the epidemic of NCP in Anhui province, there was a certain proportion of infection and co-infection of other common pathogens of CAP, and the secondary bacterial and fungal infection is not detectable in NCP patients. In comparison with SARS-CoV-2 detection alone, this optimized strategy combining multiple pathogen detection for identification of NCP and other CAP patients as well as cultures and serologic tests for confirmed patients increases the diagnosis efficiency and facilitates the personalized medication.

Clinical and Laboratory Profiles of 75 Hospitalized Patients with Novel Coronavirus Disease 2019 in Hefei, China

The outbreak of the novel coronavirus disease 2019 (COVID-19) infection began in December 2019 in Wuhan, and rapidly spread to many provinces in China. The number of cases has increased markedly in Anhui, but information on the clinical characteristics of patients is limited. We reported 75 patients with COVID-19 in the First Affiliated Hospital of USTC from Jan 21 to Feb 16, 2020, Hefei, Anhui Province, China. COVID-19 infection was confirmed by real-time RT-PCR of respiratory nasopharyngeal swab samples. Epidemiological, clinical and laboratory data were collected and analyzed. Of the 75 patients with COVID-19, 61 (81.33%) had a direct or indirect exposure history to Wuhan. Common symptoms at onset included fever (66 [88.0%] of 75 patients) and dry cough (62 [82.67%]). Of the patients without fever, cough could be the only or primary symptom. The most prominent laboratory abnormalities were lymphopenia, decreased percentage of lymphocytes (LYM%), decreased CD4+ and CD8+ T cell counts, elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH). Patients with elevated interleukin 6 (IL-6) showed significant decreases in the LYM%, CD4+ and CD8+ T cell counts. Besides, the percentage of neutrophils, CRP, LDH and Procalcitonin levels increased significantly. We concluded that COVID-19 could cause different degrees of hematological abnormalities and damage of internal organs. Hematological profiles including LYM, LDH, CRP and IL-6 could be indicators of diseases severity and evaluation of treatment effectiveness. Antiviral treatment requires a comprehensive and supportive approach. Further targeted therapy should be determined based on individual clinical manifestations and laboratory indicators.

Role of spinal peroxisome proliferation-activated receptor-γ in protection D1-induced reduction of neuropathic pain in rats / 中华麻醉学杂志

Objective:To evaluate the role of spinal peroxisome proliferation-activated receptor-γ (PPAR-γ) in protectin D1 (PD1)-induced reduction of neuropathic pain (NP) in rats.Methods:Forty-eight clean-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 4 groups ( n=12 each) by a random number table method: sham operation group (Sham group), NP group, NP plus PD1 group (NP+ PD group), and NP plus PD1 plus GW9662 group (NP+ PD+ GW group). Neuropathic pain was induced by spared nerve injury in anesthetized rats.In NP+ PD and NP+ PD+ GW groups, PD1 900 ng (diluted to 20 μl in dimethyl sulfoxide [DMSO]) was intrathecally injected once a day for 8 consecutive days starting from 30 min before establishing the model.In NP+ PD+ GW group, the PPAR-γ antagonist GW9662 200 ng (diluted to 20 μl in DMSO) was intrathecally injected once a day for 8 consecutive days starting from 45 min before establishing the model.The equal volume of DMSO was intrathecally injected in Sham group.The mechanical paw withdrawal threshold (PWT) was measured before establishing the model and at 1, 3, 5, 7, 10 and 14 days after establishing the model.Six rats in each group were sacrificed on day 14 after establishing the model, and their lumbar enlargements were removed for determination of the expression of PPAR-γ, TNF-α and IL-6 by Weston blot.Six rats in each group were sacrificed on day 14 after establishing the model, L 4, 5 segments of the spinal cord were removed, and the co-expression of PPAR-γ with neuron-specific nucleoprotein (NeuN), glial fibrillary acidic protein (GFAP) or serum calcium binding adapter molecule 1 (Iba-1) was determined by immunofluorescence staining. Results:Compared with group Sham, PWT was significantly decreased at each time point after establishing the model, the expression of PPAR-γ was down-regulated, and the expression of TNF-α and IL-6 was up-regulated in the other three groups ( P<0.05). Compared with group NP, PWT was significantly increased at 7-14 days after establishing the model, the expression of PPAR-γ was up-regulated, and the expression of TNF-α and IL-6 was down-regulated in group NP+ PD, and no significant change was found in the parameters mentioned above in group NP+ PD+ GW ( P>0.05). Compared with group NP+ PD, PWT was significantly decreased at 7-14 days after establishing the model, the expression of PPAR-γ was down-regulated, and the expression of TNF-α and IL-6 was up-regulated in group NP+ PD+ GW ( P<0.05). The results of immunofluorescence staining of the spinal cord showed that PPAR-γ was co-expressed with NeuN and GFAP. Conclusion:The mechanism by which PD1 mitigates NP is related to promoting the activation of PPAR-γ in spinal cord neurons and astrocytes and inhibiting inflammatory responses in rats.

Separation and Purification of Alhagi sparsifolia n -butanol Extract Monomeric Compounds and Study on Their Effects on Human Cervical Cancer HeLa Cells / 中国药房

OBJECTIVE： To separate and purify Alhagi sparsifolia n-butanol extract monomeric compounds， and to investigate its effects on the proliferation and metastasis of human cervical cancer HeLa cells. METHODS： The n-butanol extract was separated and purified by silica gel column， Sephadex LH-20 gel column and prep-HPLC. The structures of compounds were analyzed and identified according to physicochemical properties and spectrum （mass spectrum， hydrogen spectrum， carbon spectrum） data. Using human cervical cancer HeLa cells as objects， 5-FU as positive control， MTT assay was used to detect the inhibitory rate of HeLa cells pretreated with different doses of compounds （6.25， 12.5， 25， 50， 100， 200 μg/mL）； IC50 was calculated to screen active monomers. Scratch test was used to investigate the effects of above active monomers （all 50 μg/mL） on the migration ability of HeLa cells. Kim’s formula was used to evaluate the effects of 5-FU separately combined with above active monomers [（3.125+6.25），（6.25+12.5），（12.5+25），（25+50）μg/mL]. RESULTS： Six compounds were isolated from the n-butanol extract part of A. sparsifolia and identified as butin （Ⅰ）， 3′，4′，7-trihydroxyisoflavone （Ⅱ）， p-methoxyphenylacetic acid （Ⅲ）， 4-hydroxyacetophenone （Ⅳ）， aurantiamide acetate （Ⅴ）， protocatechualdehydea （Ⅵ）. Compared with blank control group， 5-FU and each compound （5-FU：6.25-200 μg/mL， compound Ⅰ： 12.5-200 μg/mL； compound Ⅱ： 25， 50， 200  μg/mL； compound Ⅲ： 6.25， 100， 200 μg/mL； compound Ⅳ： 50， 100， 200 μg/mL； compound Ⅴ： 12.5， 25， 200 μg/mL； compound Ⅵ： 6.25-200 μg/mL） could significantly increase the cell inhibition rate. IC50 of compound Ⅰ， Ⅴ， Ⅵ were decreased significantly （P＜0.05 or P＜0.01）， and those of compound Ⅰ and Ⅵ were lower relatively. The migration distance of cells in 5-FU and compound Ⅰ and Ⅵgroups were decreased significantly， compared with blank control group （P＜0.05 or P＜0.01）. 5-FU separately combined with compound Ⅰ and Ⅵ showed additive and enhanced inhibitory effects on the proliferation of HeLa cells （synergistic index＞0.9）. CONCLUSIONS： Compounds Ⅰ-Ⅵ are isolated from Alhagi for the first time. Butin and protocatechualdehydea are active monomers of its n-butanol extract part. Above two monomers can inhibit the proliferation and migration of human cervical cancer Hela cells， with strong inhibitory effect in vitro， and stronger inhibitory effect combined with 5-FU than any compound alone.

Enhance the affinity of nanobodies to CD47 antigen by fusion expression of COMP48 self-folding peptide / 国际生物医学工程杂志

Objective To modify CD47 nanobody with the self-folding peptide human cartilage oligomeric matrix protein (COMP48) so as to enhance its affinity to CD47 antigen. Methods The fusion sequences of COMP48 and CD47 nanobody (VHHB1) were designed and synthesized, and the recombinant plasmid pET22b-VHHB1-COMP48 was constructed and transformed into E. coli BL21 (DE3) to induce expression of the fusion protein. The binding specificity and affinity of the fusion protein and the antigen CD47 were detected by Western Blot, indirect enzyme-linked immunosorbent assay (ELISA) and non-competitive ELISA. Results The recombinant VHHB1-COMP48 was expressed in BL21(DE3) by inducing with 1 mmol/L IPTG and purified at 90％homogenous in IMAC. Western Blot results showed that the recombinant protein VHHB1-COMP48 specifically binds to antigen CD47 but not to unrelated protein. The indirect ELISA and non-competitive ELISA results showed that the affinity of the conjugated recombinant protein VHHB1-COMP48 was enhanced compared to that of the non-conjugated nanobody, and the difference was statistically significant ( P<0 . 01 ) . Through non-competitive ELISA , the constants of affinity and dissociation constants were 6.97 ×107 L/mol and 1.434 ×10-8 mol/L, respectively. Conclusions The affinity of the nanobody for the antigen can be improved by conjugating a human cartilage matrix protein (COMP48) after the nanobody.

Analysis of iodine nutritional status among children and pregnant women before and after adjusting iodine content in iodine salt in Xinjiang Production and Construction Corps / 中华地方病学杂志

Objective To analyze the impact of reduction of iodine content in iodine salt on iodine nutrition level among children and pregnant women in Xinjiang Production and Construction Corps (hereinafter referred to as the Corps).Methods In 2011 (before adjusting),the population proportional probability sampling (PPS) method was used to select 30 round fields in the Corps,one primary school was selected in each round field,and 40 children aged 8-10 years old (half males and half females) were taken from each primary school,to collect salt samples from their homes,salt iodine level was determined and thyroid examination was performed;among those 40 children,12 children (half males and half females) were selected,and urine samples were collected to test urine iodine level;at the same time,10 pregnant women were selected from the school location,and their urine samples were collected to test urine iodine level.In 2015 (after adjusting),in 14 divisions of the Corps,one round field was selected in each division from each of five directions of east,west,south,north and middle.Four company teams were selected in each round field,and 15 salt samples of households were collected in each company team,salt iodine was detected.One team primary school was selected in each round field,40 children aged 8-10 years old (half males and half females) were taken from each primary school,urine samples were collected to detect urine iodine level,and thyroid examination was performed;20 pregnant women were taken from each round field,and urine samples were collected to detect urine iodine level.A comparative analysis of iodine nutritional status in children and pregnant women in 2011 and 2015 was conducted.Goiter was examined by B-ultrasonography;salt iodine was detected by direct titration;urine iodine was detected by arsenic cerium catalytic spectrophotometry (WS/T 107-2006).Results A total of 1 195 and 4 215 salt samples were collected in 2011 and 2015,the medians of salt iodine were 32.3 and 28.2 mg/kg,respectively;the goiter rates of children were 3.4％ (42/1 220) and 1.0％ (26/2 552),respectively,both were below national standards (5.0％);the medians of urine iodine of children were 235.3 and 217.9 μg/L,respectively,both were more than the appropriate level;the medians of urine iodine of pregnant women were 183.0 and 157.7 μg/L,respectively,both were at appropriate level.Conclusion The reduction of salt iodization has no significant effect on iodine nutritional status in children and pregnant women,the iodine nutrition levels of children and pregnant women are good.

Construction and quality analysis of phage display library for random mutagenesis of camel nanobody / 国际生物医学工程杂志

Objective To construct phage display antibody library of artificial mutation to compare with the sequence of the natural phage display antibody library. To scientifically evaluate the quality of the artificial mutation of phage display library, and provide some references for the further transformation of the nanobody. Methods Using random mutation method, NNY fixed-point santuration mutation was performed on combine the follicle-stimulating hormone receptor (FSHR) of human nanobody. The mutant DNA sequence was connected to the vector pMECS to construct the phage display library of VHH06-CDR3 random mutation. By sequencing and analysis of DNA sequences, the diversity of the library and the amino acid distribution of CDR3 were compared between mutation library and the immune library of FSHR. The degree of enrichment of cloning was determined by six rounds of affinity screening. Results According to the NNY mutation rule ,the CDR3 regions with 16 amino acids by random mutations was synthesized and the VHH-CDR3 random mutant phage display library was constructed . The phage display library of VHH06-CDR3 random mutant size was 7.36×108 cfu/ml. Polyclonal and monoclonal phage ELISA showed that after six rounds of screening, the output phage and the combination of FSHR showed obvious enrichment, but there was no clone combined with FSHR. Conclusions Although the VHH06-CDR3 mutant phage display library has sequence diversity, it is not conducive to obtaining target antibodies in affinity screening due to the lack of functional diversity of CDR3.

Preparation and identification of the nano antibodies of anti-programmed death receptor-1 / 国际生物医学工程杂志

Objective To prepare camelid-derived nano antibodies with high affinity binding to programmed death receptor-1 (PD-1) antigen,and to provide experimental basis for subsequent functional studies.Methods The PD-1-Fc recombinant protein expressed in eukaryotic expression was used to immunize Xinjiang Bactrian camel 6 times.The peripheral blood was collected and the lymphocytes were isolated.Nested PCR amplification was performed to obtain the genes in variable region of camelid heavy chain antibody (VHH),and to construct a phage display library.The phage display library was screened by solid phase enzyme-linked immunosorbent assay (ELISA).The PD-1 antigen,which was sequentially reduced in mass concentration (5.00、2.50、1.00 μg/ml),was coated in an ELISA plate,and the phage display library was subjected to 3 rounds of affinity selection.Individual clones that bind to PD-1 were further screened by soluble monoclonal ELISA.According to the results of DNA sequencing,three VHH monoclonals with multiple repeats were selected and ligated into pET22b vector,and transformed into E.coli BL21 (DE3) competent cells,and then induced by isopropyl-β3-D-thiogalactoside.The recombinant VHH antibody protein was purified by nickel column affinity chromatography,and its binding activity and affinity to PD-1 antigen were detected by Western Blot and ELISA.Results After immunization of Bactrian camel 6 times with recombinant protein PD-1-Fc,high titer specific antibody was stimulated,and the immune serum titer reached 1∶32 000.A VHH phage display library with a reservoir size of 2.6×108 cfu/ml was constructed from the immunized camel lymphocytes.After 3 rounds of affinity selection,46 VHH monoclonals with absorbance (A600) values above 0.6 were obtained by soluble monoclonal ELISA.Among them,three clones of VHH-B7,VHH-H5 and VHH-H12 had higher repeats,indicating that significant enrichment was obtained.The results of Western Blot and ELISA showed that the purified B7,H5 and H12 nanobodies had good binding activity to PD-1 antigen and had high affinity.Their affinity constants were 1.19×1011 and 1.63×1011,1.59×1011 L/mol,respectively.Conclusion The anti-PD-1 camelid-derived nanobodies were obtained by affinity selection of VHH phage display library,which can bind to the PD-1 antigen with high affinity.This study can provide an experimental basis for subsequent functional studies.

Current situation of iodine deficiency disorders in Xinjiang Production and Construction Corps in 2015 / 中华地方病学杂志

Objective To understand the current situation of iodine deficiency disorders of Xinjiang Production and Construction Corps,in order to provide evidence for establishing prevention and control strategies.Methods According to their sub-area positions of east,west,south,north and center,5 units were extracted in each division via the random sampling method,4 companies were sampled in each chosen unit,15 households were selected in each chosen company to detect salt iodine content in 2015;and 1 elementary school was sampled in each chosen unit,40 students aged 8-10 were selected to collect their urine samples in each school to test urinary iodine and determine the goiter.Twenty pregnant women were randomly selected in each unit to test urinary iodine.Salt iodine was tested using direct titration,urinary iodine was determined using arsenic osmium catalytic spectrophotometry,thyroid was examinated using B-ultrasound.Results Totally 3 915 edible salt samples were monitored.The mean of salt iodine was (27.8 ± 5.5) mg/kg,with 99.1％ (3 880/3 915) iodized salt coverage rate,93.2％ (3 617/3 880) iodized salt qualified rate and 92.4％ (3 617/3 915) qualified iodized salt consumption rate.The goiter rate was 1.0％ (26/2 552) and the median of urinary iodine was 217.9 μg/L of 2 552 children aged 8-10,urinary iodine of southern region and northern region was 212.1 and 222.1 μg/L,respectively.The median of urinary iodine of 1 233 pregnant women was 157.7 μg/L.Conclusion The iodine nutrition level of key groups have already reached the national standard for eliminating iodine deficiency disorders,we should pay more attention to lower level urinary iodine of pregnant women.

Complete Mitochondrial Genome of the Chagas Disease Vector, Triatoma rubrofasciata

Triatoma rubrofasciata is a wide-spread vector of Chagas disease in Americas. In this study, we completed the mitochondrial genome sequencing of T. rubrofasciata. The total length of T. rubrofasciata mitochondrial genome was 17,150 bp with the base composition of 40.4% A, 11.6% G, 29.4% T and 18.6% C. It included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. We constructed a phylogenetic tree on the 13 protein-coding genes of T. rubrofasciata and other 13 closely related species to show their phylogenic relationship. The determination of T. rubrofasciata mitogenome would play an important role in understanding the genetic diversity and evolution of triatomine bugs.