The envelope glycoprotein subunit gp120 and the transmembrane subunit gp41 of human immunodeficiency virus type 1(HIV-1)play important roles in the process of viral entry into target cells, and serve as key targets for developing HIV-1 entry inhibitors. Peptide HIV entry inhibitors, such as T20, are limited in clinical application due to the lack of oral properties. However, because of the possible oral administration and high bioavailability, small molecule compounds become more and more important in the research for HIV entry inhibitors. In this review, we summarize the recent advances in the development of small molecule HIV-1 entry inhibitors, including the NBD and BMS series of small-molecule inhibitors targeting gp120 as well as the NB-206 and ADS-J1 se- ries of small-molecule inhibitors targeting gp41. These small molecule inhibitors are promising compounds with research value, which lay a foundation for the design of more efficient and more reasonable small-molecule HIV-1 entry inhibitors.

Biotoxins widely exist in foods and environments, posing a serious threat to human health. Specific and sensitive detection of biotoxins is the most effective way to prevent unexpected problems caused by biotoxins. In recent years, aptamer-based bio-toxin detections have gradually been prevailing. Aptamers, a new type of recognition molecules with high affinity and specificity, have been used to produce a variety of biosensors. In addition, some aptamers can neutralize the toxicity of biotoxins and inhibit their activities, with the effect to replace the antibody to some extent. This article briefly describes the research advances on biotoxin aptamers and prospects the development and application of aptamers targeting biotoxins in the future.

Objective: To provide data reference for the clinical diagnosis of COVID-19, promote the innovation and improvement of antibody detection technology of COVID-19, and discuss the application of antibody detection of new coronavirus by evaluating the sensitivity, specificity, compliance rate and limit of antibody detection in 10 SARS-CoV-2 antibody detection kits. Methods: According to the instructions of 10 new coronavirus antibody detection kits, the specific IgM and IgG in 74 serum samples were detect- ed, and the limit of detection of each kit was tested with 10 samples diluted by a 2-fold gradient. Results: The coincidence rate of 10 kits(product A-product J)were 89.2%(66/74), 89.2%(66/74), 86.5%(64/74), 95.9%(71/74), 52.7%(39/74), 75.7%(56/74), 86.5%(64/74), 79.7%(59/74), 50.0%(37/74), 20.3%(15/74), respectively. In the detection limit tests for the kits A-J with the 10 of 2x gradient diluted samples, the performance of kit C was the best, with the limit of detection for IgM 0.16AU/ml and the limit of detection for IgG 1.00 AU/ml. Conclusion: There are significant differences in sensitivity, specificity, compliance and limit of detection of 10 new coronavirus antibody testing reagents, and the product of high sensitivity, specificity, and compliance rates should be selected for clinical applications to ensure the accuracy of test results.

Objective: To prepare and characterize the matrine-loaded poloxamer hydrogels and explore their therapeutic effect on chronic eczema in mice. Methods: The matrine hydrogels were prepared with poloxamer 407 and 188 as matrix. The viscoelasticity of the matrine hydrogels was characterized by rheometer. The ear swelling and weight difference were tested, and the levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were detected by ELISA method. The histopathological change of mouse ear tissues was examined via HE-staining, and the immunohistochemical examination was performed to detect the protease-activated re-ceptor-2(PAR-2)expression in mouse ear. These assays were performed to investigate the therapeutic effect of matrine hydrogels on chronic eczema in mice. Results: The matrine hydrogels had good fluidity and spreadability, and rapidly formed a transparent, viscous uniform hydrogel at the skin temperature. Compared with the normal group, the ear weight difference and swelling degree were significantly increased(P<0.05)at the 3, 5 and 10 days after the establishment of the chronic eczema model. Compared with the model group, the ear weight difference and swelling degree were reduced significantly in the martrine hydrogel group(P<0.01), and the serum TNF-α and IL-6 level(P<0.01)and the PAR-2 expression in the chronic eczema tissue(P<0.01, P<0.05)were both significantly decreased in the martrine hydrogel group. Conclusion: Martrine hydrogels could inhibit the inflammatory infiltration of dermal layer and the epidermal layer damage caused by chronic eczema, which are expected to be a good topical gel preparation for treating chronic eczema of skin.

Objective: To investigate the therapeutic effect of glaucocalyxin A(GLA)on airway inflammation in a mouse mod- el of ovalbumin(OVA)-induced asthma and whether the mechanism is associated with the HMGB1/TLR4/NF-κB signaling pathway. Methods: Forty BALB/c mice were divided into 5 groups(8 mice in each group):control group, OVA model group, GLA-L group (10 mg/kg), GLA-H group(40 mg/kg)and dexamethasone group(1 mg/kg). HE and PAS staining were used to observe the inflammatory infiltration and the number of goblet cells in mouse lung tissue;Diff-Quick staining was used to count various cell types in mouse bronchoalveolar lavage fluid(BALF);ELISA was used to detect the content of inflammatory and pro-inflammatory cytokines in mouse BALF;Western blotting(WB)was used to detect the expression of HMGB1, TLR4, MyD88, NF-κB(nuclear)and NF-κB(cytosol)in lung tissue;immunohistochemistry was used to detect the expression level of HMGB1, TLR4 and NF-κB p65 protein in mouse lung tissue. Results: GLA reduced inflammatory cell exudation and goblet cell proliferation in OVA-induced asthmatic model;GLA treatment significantly decreased eosinophils, neutrophils and lymphocytes in BALF of asthmatic mice, and reduced the levels of pro-inflammatory cytokines(P<0.05);WB results showed that GLA inhibited the protein expression of HMGB1, TLR4, MyD88 and NF-κB(nuclear)(P<0.05);immunohistochemistry results showed that GLA reduced the expression of HMGB1, TLR4 and NF-κB p65 protein in lung tissue(P<0.05). Conclusion: GLA could ameliorate the OVA-induced airway inflammation in asthmatic mice, possibly via interfering in the HMGB1/TLR4/NF-κB signaling pathway.

Objective: To explore the differences in drug resistance and genotypes of Mycobacterium tuberculosis(MTB) strains isolated from Xining city and agricultural and pastoral areas of Qinghai province, China, so as to provide reference for prevention and clinic treatment of tuberculosis in Qinghai province. Methods: The drug resistance of isolated 249 strains of MTB was tested by proportional method, the regional distribution characteristics and the relationship between drug resistance and spoligotyping geno-type were analyzed by statistical methods. Results: The total first-line drug resistance rate of 249 strains of MTB was 56.6%, and the total drug resistance rate in agricultural and pastoral areas(74.6%)was higher than that(50.0%)in Xining city(P<0.05). The multidrug resistance rate in agricultural and pastoral areas(49.3%)was higher than that(25.3%)in Xining(P<0.05). It was found that ofloxacin had the highest drug resistance rate both in Xining and rural areas. The dominant strain was Beijing genotype both in Xining city as well as the agricultural and pastoral areas. The multidrug resistance rate of Beijing genotype strains in Xining(21.2%)was lower than that of non-Beijing genotype strains(36.0%). The resistance rates of Beijing genotype strains to isoniazid(INH)and ethambutol (EMB)in rural area were higher than those of non-Beijing genotype strains(65.4%:33.3% and 63.4%:33.3%, respectively, both P< 0.05). Conclusion: The Beijing genotype MTB is the main epidemic strain in both Xining and agricultural or pastoral areas, and drug resistance of MTB is severe in rural areas.

Objective: To screen human single chain antibodies against human C3d from phage-displayed single-chain variable fragment(scFv)library, and analyze their binding activities. Methods: The phage display library was exposed to 3-round selections in immunotubes coated with recombinant C3d at a decreasing concentration range and progressively stringent washing conditions. The positive clones were identified by ELISA, followed with sequencing to determine the specific genes which were then cloned intoex-pression vectors. The single chain antibodies were expressed in the FreeStyleTM 293-F system and harvested by affinity purification. The binding activities with recombinant C3d were determined by using Bio-Layer Interferometry technology. Results: These experiments resulted in three novel single chain antibodies(that is, A1, A3 and B6)against C3d with high affinity ranging from 22.7 to 171 pmol/ L. Conclusion: The high affinity human single chain antibodies against human C3d were obtained.

Objective: The reverse engineering technology was used to analyze the prescription and process of Good Sense Stay Awake®, the reference listed drug of caffeine tablets, in order to provide guidance for the development of generic caffeine tablets. Methods: Firstly, the prescription information of the reference listed drug was obtained by literature research. Then, quantitative analysis of the composition of the prescription was achieved by the high-performance liquid chromatography with a crystal refractive index detection and the gravimetric analysis method;the particle size of raw and auxiliary materials was analyzed by Raman imaging technology;the crystal habit and crystal form of active pharmaceutical ingredient(API)were characterized by the optical microscope and X-ray powder diffraction technology, respectively;the preparation process of reference listed drug was determined by disintegration method;and finally, the package material was identified by the morpholine reagent. Moreover, three batches of samples were pre-pared according to the determined prescription and process, and the quality was compared with the reference listed drug. Results: By the reverse engineering analysis of the reference listed drug, the prescription composition of the reference listed drug was determined to be composed of glucose, microcrystalline cellulose, pregelatinized starch, maltodextrin, magnesium stearate, colloidal silica and yellow lake, in which the glucose content was 32% and the microcrystalline cellulose content was <23%. The API crystal form of the reference listed drug was consistent with that of the self-made preparation. The average particle size of caffeine, microcrystalline cellulose, glucose, maltodextrin and pregelatinized starch was approximately 206, 112, 172 and 61 μm, respectively. The tablet preparation process was the direct compression method, and the packaging material was polyvinyl chloride aluminum foil. The quality of the three batches of home-made preparations was the same as that of the reference listed drug. Conclusion: Caffeine tablets with the same quality as Good Sense Stay Awake® were successfully prepared by reverse engineering of the reference listed drug, which provides a reference for the application of reverse engineering in the generic drug development and consistency evaluation.

P53 gene is one of the most widely studied genes in cancer. As a tumor suppressor gene, wild-type P53 can effectively inhibit the occurrence and development of tumors, but P53 mutations are found in about 50% of cancer patients[1]. In recent years, the mechanism of oncogenesis caused by the imbalance of P53 signaling pathway has become a focus of academic research. With the development of biotechnology, long non-coding RNA(lncRNA)has become a new hotspot in the research field. A large number of researches have shown that the interaction between some lncRNA and P53 can affect relevant signaling pathways in tumor development, such as P21(long intergenic noncoding RNA-P21, linc RNAP21)and loc285194, resulting in abnormal cell proliferation. This paper reviews the latest research progress in lncRNA which is closely related to P53 in the process of cancer occurrence, so as to provide a reference for further understanding of the mechanism of cancer.

Many diseases such as tumor, ischemia and inflammation produce acidic extracellular microenvironment at the lesion site. This extracellular microenvironment also provides a new opportunity for the diagnosis and treatment of these diseases. Acidresponding peptides (pH low insertion peptides, pHLIP) can spontaneously fold into transmembrane helices under acidic microenvironment and insert across cell membranes, providing new opportunities for targeting these acidic tissues. At present, pHLIP has attracted more and more attention in the diagnosis and treatment of diseases. This article summarizes the advances in the pHLIP research from the aspects of the discovery and development, action mechanism and application of pHLIP.