Objective To explore the causal relationship between use of analgesic drugs and incidence of Clostridium difficile enteritis(CDE).Methods Univariate and multivariate Mendelian randomization(MR)methods were employed to investigate the potential causal relationship between use of analgesic drugs and incidence of CDE,using inverse variance weighted as the primary analytical approach.Results Univariate MR analysis indicated that use of nonsteroidal anti-inflammatory drug(NSAID)(OR=2.680,95％CI:1.689-4.252,P＜0.001)and aniline derivatives(OR=2.521,95％CI:1.503-4.229,P＜0.001)increased the risk of CDE,whereas use of opioids(OR=0.955,95％CI:0.818-1.114,P=0.556)and salicylates(OR=1.081,95％CI:0.820-1.425,P=0.579)were not identified as risk factors for CDE.The MR-Steiger test did not suggest the presence of reverse causality between exposure and outcome.After adjustment in the multivariate MR analysis,the use of NSAID was no longer a risk factor for CDE(OR=1.709,95％CI:0.864-3.308,P=0.123),while use of aniline derivatives remained a risk factor(OR=2.147,95％CI:1.239-3.721,P=0.003).Sensitivity analyses showed no evidence of heterogeneity,horizontal pleiotropy,or outliers,and no single nucleotide polymorphisms independently influenced the results.Conclusion The use of opioids does not increase the risk of CDE infection.The causal relationship between NSAID use and CDE remains inconclusive.However,the use of aniline derivatives within the NSAID class is a risk factor for CDE,while use of salicylates is not a risk factor for CDE.

Objective To explore the causal relationship between use of analgesic drugs and incidence of Clostridium difficile enteritis(CDE).Methods Univariate and multivariate Mendelian randomization(MR)methods were employed to investigate the potential causal relationship between use of analgesic drugs and incidence of CDE,using inverse variance weighted as the primary analytical approach.Results Univariate MR analysis indicated that use of nonsteroidal anti-inflammatory drug(NSAID)(OR=2.680,95％CI:1.689-4.252,P＜0.001)and aniline derivatives(OR=2.521,95％CI:1.503-4.229,P＜0.001)increased the risk of CDE,whereas use of opioids(OR=0.955,95％CI:0.818-1.114,P=0.556)and salicylates(OR=1.081,95％CI:0.820-1.425,P=0.579)were not identified as risk factors for CDE.The MR-Steiger test did not suggest the presence of reverse causality between exposure and outcome.After adjustment in the multivariate MR analysis,the use of NSAID was no longer a risk factor for CDE(OR=1.709,95％CI:0.864-3.308,P=0.123),while use of aniline derivatives remained a risk factor(OR=2.147,95％CI:1.239-3.721,P=0.003).Sensitivity analyses showed no evidence of heterogeneity,horizontal pleiotropy,or outliers,and no single nucleotide polymorphisms independently influenced the results.Conclusion The use of opioids does not increase the risk of CDE infection.The causal relationship between NSAID use and CDE remains inconclusive.However,the use of aniline derivatives within the NSAID class is a risk factor for CDE,while use of salicylates is not a risk factor for CDE.

IL-33 is a member of the IL-1 cytokine superfamily.It is a key regulator of pathological inflammation,immune ho-meostasis and fibrosis.IL-33 receptor ST2 is expressed on the surface of all innate immune cells,as well as some subtypes of B and T cells.IL-33 is a dual-function protein.Under normal circumstances,the N-terminal part of IL-33 resides in the nucleus of its ex-pressed cells and is released as a cytokine to exert immunomodulatory properties when cells are damaged or necrotic.Different expres-sion forms of IL-33 are located differently and may play different immunological roles.The immunological effects of IL-33 are highly di-verse.The cytokine IL-33 plays an amplifying and enhancing role in the innate immune response,while the full-length(FL)IL-33 stored in the nucleus inhibits inflammation by binding to NF-κB.IL-33/ST2 signaling plays a key role in both innate and acquired im-mune responses.In innate immunity,IL-33 and group 2 innate lymphocytes(ILC2)provide an important axis for rapid immune re-sponse and tissue homeostasis.In acquired immunity,IL-33 interacts with dendritic cells,Th2 cells,follicular helper T cells(Tfh)and regulatory T cells(Tregs).IL-33/ST2 signaling triggers pro-tumor or anti-tumor immune responses in different cell types in auto-crine and paracrine ways.In addition,the interaction between IL-33 and mitochondrial metabolism is also one of the potential mecha-nisms affecting the immune system.

Objective To perform laboratory detection and molecular traceability analysis on a case of imported kala-azar in Shenzhen to determine the infection strain. Methods Bone marrow puncture fluid and blood samples from a case of kala-azar in Shenzhen were collected for laboratory tests. The patient's bone marrow puncture fluid smears were stained with Giemsa and examined under a microscope. Blood samples were examined for antibodies using the rk39 visceral leishmania rapid diagnostic reagent. Whole blood DNA was extracted, and the ITS-1 sequence was amplified by PCR, sequenced and aligned, and a phylogenetic tree was constructed based on the ITS-1 sequence. Results Microscopic examination of the patient's bone marrow smears revealed a large number of Leishmania amastigotes without flagella, confirming the diagnosis of kala-azar. The patient's blood was tested positive with the rk39 rapid diagnostic reagent, and PCR amplification yielded an ITS-1 gene product sequence that matched the expected size. Sequence alignment with the NCBI database showed 100% sequence similarity with the ITS-1 gene sequence of Leishmania infantum, confirming the infecting strain as Leishmania infantum. Phylogenetic tree construction of the amplified ITS-1 sequence revealed clustering into a clade with Leishmania infantum , and close to KC347299, one of the reference sequence selected. Conclusions The case of kala-azar in Shenzhen was caused by Leishmania infantum. Kala-azar still occurs in China, so the diagnostic technology of medical personnel in non-epidemic areas should be strengthened so that they can actively use new diagnostic technologies to assist in diagnosis, thus improving their prevention and control ability of Leishmania parasites.

Abstract: Objective　To analyze and understand the mutations of drug resistance genes in imported Plasmodium falciparum in Shenzhen, aiming to assess the efficacy of antimalarial drugs and guide effective drug use. Methods A total of 85 samples from individuals with imported Plasmodium falciparum confirmed by fluorescence quantitative polymerase chain reaction (PCR) in Shenzhen from 2022 to 2023 were collected and genomic DNA was extracted. Nested PCR was used to amplify resistance genes, including Plasmodium falciparum Kelch 13 (PfK13), multidrug resistance gene 1 (Pfmdr1), chloroquine resistance transporter (Pfcrt), dihydrofolate reductase (Pfdhfr), and dihydropteroate synthase (Pfdhps) genes. Bidirectional sequencing was conducted, and mutations in these resistance genes were analyzed using MEGA11.06 software. Results　The study found one missense mutation (S549P) and four synonymous mutations in PfK13. For Pfmdr1, 62.69% of the samples showed Y184F mutation, and no N86Y mutation was detected. No mutations at positions 72 and 73 were detected in the Pfcrt gene, while mutations at M74I, N75E, and K76T accounted for 17.46%, 15.87%, and 15.87%, respectively. The wild-type of Pfcrt gene is dominant (82.54%, 52), followed by the triple mutant I74E75T76 (15.87%, 10). The most common mutation type for Pfdhfr is I51R59N108 (91.78%, 67), followed by the wild type (2.74%, 2). More than half (60.32%, 38) of the Pfdhps samples were wild-type, with single mutation K540E being the most common mutation type. S436A, G437A, K540E, A581G, A613S, I431V, G556K, and G579E site mutations were detected. Among the Pfdhfr-Pfdhps combination mutations, I51R59N108-E540 was the most frequent combination mutation (11.48%), with 59.02% of samples showing solitary Pfdhfr mutations. Conclusions In this study, PfK13 mutation rates were low, with no reported resistance mutations. The Y184F mutation emerged as the dominant Pfmdr1 mutation, with no detection of N86Y. For Pfcrt, the wild-type was dominant, followed by the I74E75T76 triple mutation variant. Triple mutant I51R59N108 of Pfdhfr was very common, and our study did not find Pfdhfr Pfdhps completely resistant and super resistant mutants, but there were other quintuple and septuple mutant types. In the future, it is crucial to continue to strengthen the monitoring of malaria parasite resistance genes and to further integrate in vivo efficacy monitoring to effectively guide clinical drug use.

Aging is the process spontaneously occurred in living organisms. Cardiac fibrosis is a pathophysiological process of cardiac aging. Mangiferin is a wellknown C-glucoside xanthone in mango leaves with lots of beneficial properties. In this study, rat model of cardiac fibrosis was induced by injected with 150 mg/kg/d Dgalactose for 8 weeks. The age-related cardiac decline was estimated by detecting the relative weight of heart, the serum levels of cardiac injury indicators and the expression of hypertrophic biomakers. Cardiac oxidative stress and local inflammation were measured by detecting the levels of malondialdehyde, enzymatic antioxidant status and proinflammatory cytokines. Cardiac fibrosis was evaluated by observing collagen deposition via masson and sirius red staining, as well as by examining the expression of extracellular matrix proteins via Western blot analysis. The cardiac activity of profibrotic TGF-β1/p38/MK2 signaling pathway was assessed by measuring the expression of TGF-β1 and the phosphorylation levels of p38 and MK2. It was observed that mangiferin ameliorated D-galactose-induced cardiac aging, attenuated cardiac oxidative stress, inflammation and fibrosis, as well as inhibited the activation of TGF-β1/p38/MK2 signaling pathway. These results showed that mangiferin could ameliorate cardiac fibrosis in D-galactose-induced aging rats possibly via inhibiting TGF-β/p38/MK2 signaling pathway.

Aging is the process spontaneously occurred in living organisms. Cardiac fibrosis is a pathophysiological process of cardiac aging. Mangiferin is a wellknown C-glucoside xanthone in mango leaves with lots of beneficial properties. In this study, rat model of cardiac fibrosis was induced by injected with 150 mg/kg/d Dgalactose for 8 weeks. The age-related cardiac decline was estimated by detecting the relative weight of heart, the serum levels of cardiac injury indicators and the expression of hypertrophic biomakers. Cardiac oxidative stress and local inflammation were measured by detecting the levels of malondialdehyde, enzymatic antioxidant status and proinflammatory cytokines. Cardiac fibrosis was evaluated by observing collagen deposition via masson and sirius red staining, as well as by examining the expression of extracellular matrix proteins via Western blot analysis. The cardiac activity of profibrotic TGF-β1/p38/MK2 signaling pathway was assessed by measuring the expression of TGF-β1 and the phosphorylation levels of p38 and MK2. It was observed that mangiferin ameliorated D-galactose-induced cardiac aging, attenuated cardiac oxidative stress, inflammation and fibrosis, as well as inhibited the activation of TGF-β1/p38/MK2 signaling pathway. These results showed that mangiferin could ameliorate cardiac fibrosis in D-galactose-induced aging rats possibly via inhibiting TGF-β/p38/MK2 signaling pathway.

Objectives:This study aimed to evaluate the effect of the strategies on COVID-19 outbreak control in Shenzhen, and to clarify the feasibility of these strategies in metropolitans that have high population density and strong mobility.Methods:The epidemic feature of COVID-19 was described by different phases and was used to observe the effectiveness of intervention. Hierarchical spot map was drawn to clarify the distribution and transmission risk of infection sources at different time points. The Susceptible-Exposed-Infectious-Asymptomatic-Recovered model was established to estimate case numbers without intervention and compare with the actual number of cases to determine the effect of intervention. The positive rate of the nucleic acid test was used to reflect the risk of human exposure. A survey on COVID-19 related knowledge, attitude and behaviors were used to estimate the abilities of personal protection and emergency response.Results:The epidemic of COVID-19 in Shenzhen experienced the rising, plateau and decline stage. The case number increased rapidly at the beginning, with short duration of peak period. Although the epidemic curve showed human-to-human transmission, the "trailing" was not obvious. From the spot map, during the intervention period, the source of infection was widely distributed. More cases and higher transmission risk were observed in areas with higher population density. After the effective intervention measures, both infection sources and the risk of transmission decreased. After compared with the estimated case numbers without intervention, actual number proved the COVID-19 control strategies were effective. The positive rate of nucleic acid test for high risk populations decreased and no new cases reported since February 16. Shenzhen citizens had high knowledge, attitude and behavior level, and high protection ability and emergency response.Conclusions:Although the response initiated by the health administration department played a key role at the early stage of the epidemic, it was not enough to contain the outbreak of COVID-19. The first-level emergency response initiated by provincial and municipal government was effective and ensured the start of work resumption after the Spring Festival. Metropolitans like Shenzhen can also achieve the goals of strategies and measures for containment and mitigation of COVID-19.