Intestinal flora imbalance is closely related to the pathogenesis of rheumatoid arthritis (RA). The existing studies have explored the monomer components such as tripterygium glycosides, total glycosides of Chaenomeles speciosa, and triterpenoid saponins of Clematis, Chinese materia medica such as Tripterygium wilfordii, Caulis Sinomenii, Radix Paeoniae Alba, Fructus Gardeniae, Fructus Chebulae, Radix Ginseng, Radix et Rhizoma Rhei, Rhizoma Atractylodis Macrocephalae, Pterostilbene, and Ginger, as well as the mechanisms of Danggui Sini Decoction, Danggui Niantong Decoction, Duhuo Jisheng Decoction, Yunpi Jiedu Tongluo Qushi Decoction, Qingre Huoxue Decoction, Compound Fengshining, Qingre Yangyin Chushi Decoction, Aconitum Decoction, Zhijing Powder, Jinwu Jiangu Capsule, and Fermented Chinese Medicine Qushi Chubi Decoction in intervening RA by regulating intestinal flora, suggesting that Chinese materia medica can restore intestinal homeostasis, reduce joint inflammation and play a role in the prevention and treatment of RA by regulating immune response, improving intestinal mucosal barrier and regulating intestinal metabolites.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.

OBJECTIVE To analyze the ethanol extracts,total phenols,total flavonoids contents and HPLC fingerprints of typi-cal propolis samples from 6 foreign countries and 5 domestic regions,optimize the extraction process and evaluate the antioxidant activi-ty,so as to provide data support for improving the quality control system of propolis.METHODS The optimization of the propolis ex-traction process utilized flavonoid content as an indicator.Three flavonoid detection methods-namely,the aluminum trichloride meth-od,aluminum nitrate method,and polyamide method-were compared.The content of ethanol extract,total phenol content,and the scavenging ability of DPPH free radicals for each sample were determined.Further analysis was conducted using HPLC fingerprint pro-filing.RESULTS The propolis extract with the highest flavonoid content was obtained using 80%ethanol as the extraction solvent,operating at 50℃,with a stirring time of 3 h,ultrasonic power of 180 W,and ultrasonic time of 15 min.The aluminum trichloride method was proved to be the most effective for determining total flavonoids in propolis.While the ethanol extract,total flavonoids,and total phenols of propolis from Xinjiang,China were relatively low,their antioxidant activity exhibited superiority.HPLC analysis re-vealed,Brazilian red propolis lacked of chrysin,galangin,caffeic acid phenethyl ester and Brazilian green propolis lacked ferulic acid,apigenin,p-coumaric acid,chrysin,and pinocembrin.In contrast,the content of these four compounds in other samples varied,with the antioxidant capacity of the extracts not precisely corresponding to the compound content.CONCLUSION Propolis exhibits a complex chemical composition with significant variations among varieties.Key quality control indexes must be comprehensively consid-ered,encompassing physicochemical characteristics and biological activity.Establishing a multi-angle assessment system with a mate-rial basis-functional linkage is essential.This approach facilitates the realization of high quality and cost-effectiveness,thereby promo-ting the healthy development of the industry.

OBJECTIVE To analyze the ethanol extracts,total phenols,total flavonoids contents and HPLC fingerprints of typi-cal propolis samples from 6 foreign countries and 5 domestic regions,optimize the extraction process and evaluate the antioxidant activi-ty,so as to provide data support for improving the quality control system of propolis.METHODS The optimization of the propolis ex-traction process utilized flavonoid content as an indicator.Three flavonoid detection methods-namely,the aluminum trichloride meth-od,aluminum nitrate method,and polyamide method-were compared.The content of ethanol extract,total phenol content,and the scavenging ability of DPPH free radicals for each sample were determined.Further analysis was conducted using HPLC fingerprint pro-filing.RESULTS The propolis extract with the highest flavonoid content was obtained using 80%ethanol as the extraction solvent,operating at 50℃,with a stirring time of 3 h,ultrasonic power of 180 W,and ultrasonic time of 15 min.The aluminum trichloride method was proved to be the most effective for determining total flavonoids in propolis.While the ethanol extract,total flavonoids,and total phenols of propolis from Xinjiang,China were relatively low,their antioxidant activity exhibited superiority.HPLC analysis re-vealed,Brazilian red propolis lacked of chrysin,galangin,caffeic acid phenethyl ester and Brazilian green propolis lacked ferulic acid,apigenin,p-coumaric acid,chrysin,and pinocembrin.In contrast,the content of these four compounds in other samples varied,with the antioxidant capacity of the extracts not precisely corresponding to the compound content.CONCLUSION Propolis exhibits a complex chemical composition with significant variations among varieties.Key quality control indexes must be comprehensively consid-ered,encompassing physicochemical characteristics and biological activity.Establishing a multi-angle assessment system with a mate-rial basis-functional linkage is essential.This approach facilitates the realization of high quality and cost-effectiveness,thereby promo-ting the healthy development of the industry.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.

TROP-2, a tumor-associated antigen, has been implicated in the progression of various epithelial tumors. Due to its favorable expression profile, TROP-2 has emerged as a promising target for antibody-drug conjugates (ADCs) based anti-tumor therapies. Although ADCs have shown efficacy in cancer treatment, their application in solid tumors is hindered by their high molecular weight, poor tumor penetration, and release of cytotoxic molecules. Therefore, a recombinant immunotoxin was developed based on a shark-derived variable domain of immunoglobulin new antigen receptor (VNAR) antibody. VNARs are only one-tenth the size of IgG antibodies and possess remarkable tissue penetration capabilities and high stability. In this study, a shark VNAR phage display library was created, leading to the identification of shark VNAR-5G8 that targets TROP-2. VNAR-5G8 exhibited a high affinity and cellular internalization ability towards cells expressing high levels of TROP-2. Epitope analysis revealed that VNAR-5G8 recognizes a hidden epitope consisting of CRD and TY-1 on TROP-2. Subsequently, VNAR-5G8 was fused with a truncated form of Pseudomonas exotoxin (PE38) to create the recombinant immunotoxin (5G8-PE38), which exhibited significant anti-tumor activity in vitro and in vivo. Overall, this study highlights the promise of 5G8-PE38 as a valuable candidate for cancer therapy.

The eutR gene deletion mutant of Salmonella enteritidis was successfully constructed by homologous recombination.Through the study of its biochemical characteristics,motility,resist-ance to stress in vitro and survival ability in RAW 264.7 cells,it was found that the biochemical characteristics and motility of the eutR gene deletion mutant of Salmonella enteritidis had no sig-nificant change compared with the wild type of Salmonella enteritidis.The ability of eutR gene de-letion strain of Salmonella enteritidis to resist acid,alkali and oxidation was significantly reduced,while the ability to resist heat was not significantly changed;the survival ability of eutR gene dele-tion strain in RAW 264.7 cells was significantly reduced compared with the wild type.In order to further analyze the effect of eutR gene on the expression of virulence factors of Salmonella enterit-idis,the relative expression levels of invH,ssav,ssrA,xthA,orf245,sodC,lrp,mrr1 and hflk virulence genes of the deletion strain and the wild strain were detected by SYBR Green PCR.It was found that the expression of the virulence factors mentioned above in the eutR gene deletion strain of Salmonella enteritidis was significantly down-regulated compared with that in the wild-type strain.The LD50 of the eutR gene-deleted strain of Salmonella enteritidis was determined by ani-mal experiments,and the results showed that the LD50 of the eutR gene-deleted strain was higher than that of the wild-type strain,indicating that the eutR gene could affect the virulence of Salmonella.This study clarified the effect of eutR gene on the survival ability,some biological characteristics and virulence of Salmonella enteritidis in macrophages,and provided a new gene knockout target for the development of attenuated Salmonella enteritidis genetic engineering vac-cine.

Background With the rapid industrialization, cadmium has become a primary heavy metal pollutant in cultivated land soil in China, which seriously affects human health. Previous studies have found that cadmium exposure associates with cognitive dysfunction in individuals, but there is a lack of research on the mechanism of cadmium exposure associated cognitive impairment in offspring in early life which is more vulnerable to various toxins and crucial for development of the neuro. Objective To explore the potential mechanism of brain-derived neurotrophic factor/tyrosine kinase receptor B (BDNF-TrkB) signaling pathway in cognitive dysfunction in mice after cadmium exposure in early-life. Methods Twelve 8-week-old C57BL/6 pregnant mice were randomly divided into 2 groups, namely control group and cadmium exposure group, with 6 mice in each group. The exposure period was from pregnancy day 4.5 to lactation day 21 (E4.5-P21), during which distilled water or cadmium chloride solution (2.5 mg·kg⁻¹·d⁻¹) was given. After lactation, the offspring of the control group and the cadmium exposure group were given distilled water until 8 weeks of age. Then the toxicity effects of cadmium exposure on mice were evaluated by body weight and selected biochemical indicators. The cadmium content in brain was detected and the learning and memory ability was tested by Y maze and Morris water maze to evaluate cognitive function of offspring mice. Histopathological changes of the hippocampus were observed after Nissl staining and Golgi staining. The mRNA and protein expression levels of the BDNF-TrkB pathway and synapse were detected by real-time quantitative PCR (qPCR) and Western blot. Results Compared with the control group, no significant change was found in body weight, liver or kidney function in the cadmium exposure group (P> 0.05). However, compared with the control group, the cadmium content in brain was increased in the cadmium exposure group (P<0.001). The behavioral changes associated with cognitive dysfunction were positive in the cadmium exposure group (all P<0.05). The histopathological observation after Nissl staining showed abnormal tissue structure, decreased number of neurons and increased karyopyknosis in the cadmium exposure group (P<0.01).The spine density of Golgi staining was decreased in the cadmium exposure group (P<0.001). The BDNF-TrkB pathway-related mRNA and the synapse-related mRNA in the hippocampus were reduced in the cadmium exposure group (all P<0.05). The expression levels of BDNF-TrkB pathway-related proteins and synapse-related proteins in the hippocampus were also reduced in the cadmium exposure group (P<0.05). Conclusion Early-life cadmium exposure may induce synaptic dysplasia and lead to cognitive dysfunction by down-regulating the BDNF-TrkB signaling pathway in mice.

【Objective】 To investigate the inhibitory effect of BFD-6b on colorectal cancer cell growth and its preliminary mechanism. 【Methods】 The inhibitory effect of BFD-6b on the growth of various tumor cells （SW480， MCF-7， T47D， SMMC-7721， BEL-7402， 97H， SK-HEP-1， H460， H1299， A549， MS751， and HELA） was investigated by MTT assay； the effect of BFD-6b on apoptosis and cell cycle was detected by flow cytometry； the effect of BFD-6b on the expressions of cell cycle-related proteins and apoptosis-related proteins was examined by Western blotting. 【Results】 BFD-6b inhibited the proliferation of different cancer cells such as SW480， MCF-7， H460， H1299， A549， and HELA. Among all of them， SW480 cells were most sensitive to BFD-6b， and the IC50 value was 7.09 μmol/L. Furthermore， BFD-6b could inhibit the growth of another three colorectal cell （SW620， Lovo， and HCT116 cells）； the IC50 values were 7.23， 8.08 and 8.96 μmol/L， respectively. BFD-6b could downregulate the amount of cyclinD1， cyclinE， and cell cycle-dependent kinase CDC2， thereby arresting the cell cycle at G1 phase. Also， BFD-6b downregulated the expressions of anti-apoptotic proteins Mcl-1 and Bcl-2， and upregulated the expressions of pro-apoptotic proteins BAK and BAX， thus inducing apoptosis of SW480 cells. 【Conclusion】 BFD-6b arrests SW480 cells at G1 phase by downregulating the expressions of cyclinD1， cyclinE and CDC2， and induces SW480 cell apoptosis by downregulating the expressions of Mcl-1 and Bcl-2 and upregulating the expressions of BAK and BAX， thereby inhibiting the proliferation of colorectal cancer SW480 cells.

Objective:To explore the attitudes of Chinese medical students toward the elderly and their willingness to practice in geriatrics, and to investigate the influence of geriatrics education on their attitudes.Methods:Medical students studying diagnostics in four medical universities were enrolled in a cross-sectional survey and, for the intervention study, graduate trainees from non-geriatrics specialties taking a geriatrics course were interviewed before and after the course.An electronic questionnaire was used to collect general information, the experience of interacting with the elderly, attitudes towards the elderly and the willingness to develop careers in geriatric medicine.Changes in attitudes towards the elderly and their willingness to practice in geriatrics before and after the 40-hour geriatric medicine course were compared.Results:A total of 648 medical students completed the cross-sectional survey, with the highest score in compassion for the elderly(3.54±0.54)and the lowest score for medical services for elderly patients(3.36±0.78). Only 2.2%(14/648)of the students showed strong interest in geriatric medicine.The results of the intervention from 42 graduate trainees showed that the average scores of revised Geriatric Attitude Scale(r-GAS)were 3.80±0.43 and 3.92±0.40 before and after the course, respectively, and the difference was statistically significant( t=2.148, P=0.038). At the end of the course, 7 trainees(16.7%, 7/42)showed great interest in geriatrics, significantly different from 2 trainees(4.8%, 2/42)before the course( χ2=8.211, P=0.025). Conclusions:Chinese medical students show a serious lack of interest in geriatrics, and geriatrics education can improve their attitudes towards the elderly and their willingness to work in geriatrics.With the rapid population aging in China, it is urgent to strengthen the education of geriatric medicine.