Objective: To investigate the current status of latent tuberculosis infection (LTBI) among freshmen in junior and senior high schools in Lanzhou, so as to provide scientific basis for improving the tuberculosis prevention and control strategy in schools. Methods: The screening results of 74 516 freshmen in senior and boarding junior high schools in Lanzhou during 2023 and 2024 were collected. The Chi square test and multivariate Logistic regression model were applied to analyze LTBI level, strongly positive risk for tuberculin skin test (TST) and related factors of the freshmen. Results: During 2023 and 2024, the screening rate of tuberculosis among freshmen in senior and boarding junior high schools in Lanzhou was 93.45%, of which the positive rate for TST was 5.71%, the infection rate for LTBI was 3.80%, and the strongly positive rate for TST was 1.24%. There were statistically significant differences in the screening rate of tuberculosis among freshmen in different years, grades, regions, school types and districts ( χ 2=5.34, 2 463.88, 3 516.13, 132.34, 4 436.56, all P <0.05). Multivariate Logistic regression analysis showed that senior high schools ( OR =1.62, 2.18) and urban areas ( OR =2.08, 3.07 ) were all related factors for LTBI and strong positivity for TST among freshmen; schools located in Xigu District, Honggu District, Yongdeng County, Yuzhong County, and Lanzhou New Area ( OR =3.57, 5.67, 9.12, 3.70, 3.64) were related factors of strong positivity for TST among freshmen (all P <0.05). Conclusions The LTBI level among freshmen in senior and boarding junior high schools in Lanzhou is relatively low. Grades and regions are related factors for LTBI and strong positivity for TST.

BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

BACKGROUND:Wogonin is a flavonoid extracted from the root of Scutellaria baicalensis.Previous studies have shown that baicalein has protective effects against cerebral ischemia-reperfusion injury,and can also reduce blood sugar and complications in diabetic mice,but its role and mechanism in diabetic cerebral infarction remain unclear. OBJECTIVE:To explore the effect of wogonin on nerve injury in rats with diabetic cerebral infarction and its mechanism. METHODS:Sprague-Dawley rats were randomly divided into six groups:control group,model group,low-dose wogonin group,medium-dose wogonin group,high-dose wogonin group,and high-dose wogonin+Ras homolog gene family member A(RhoA)activator group.Except for the control group,the other rats were established with diabetes and cerebral ischemia models using intraperitoneal injection of streptozotocin and middle cerebral artery occlusion.Low,medium-and high-dose wogonin groups were intragastrically given 10,20,40 mg/kg wogonin,respectively;high-dose wogonin+RhoA activator group was intragastrically given 40 mg/kg wogonin and intraperitoneally injected 10 mg/kg lysophosphatidic acid;control group and model group were given the same amount of normal saline once a day for 7 consecutive days.Rats in each group were evaluated for neurological deficits and their blood glucose levels were measured after the last dose.TTC staining was applied to detect the volume of cerebral infarction.Hematoxylin-eosin staining was applied to observe pathological changes in brain tissue.ELISA kit was applied to detect tumor necrosis factor-α,interleukin-6,malondialdehyde,and superoxide dismutase levels in brain tissue.Western blot was applied to detect the protein expression of RhoA and Rho-associated protein kinase(ROCK)2 in brain tissue. RESULTS AND CONCLUSION:Compared with the control group,the neuronal structure of rats in the model group was severely damaged,with cell necrosis and degeneration,the neurological deficit score,blood glucose level,and infarct volume were significantly elevated(P<0.05),the levels of tumor necrosis factor-α,interleukin-6,and malondialdehyde,and the protein expression of RhoA and ROCK2 in brain tissue were significantly increased(P<0.05),and the superoxide dismutase level was decreased(P<0.05).Compared with the model group,the low-,medium-,and high-dose wogonin groups showed improved neuronal damage,reduced cell degeneration and necrosis,a significant reduction in neurological deficit score,blood glucose level,infarct volume,and the levels of tumor necrosis factor-α,interleukin-6,and malondialdehyde,and the protein expression of RhoA and ROCK2 in brain tissue,and an increase in the superoxide dismutase level(P<0.05).Compared with the high-dose wogonin group,the high-dose wogonin+RhoA activator group significantly weakened the improvement in the above indexes of rats with diabetic cerebral infarction(P<0.05).To conclude,wogonin can improve the blood glucose level in rats with diabetic cerebral infarction,reduce cerebral infarction and nerve injury,and its mechanism may be related to the inhibition of RhoA/ROCK signaling pathway.

Chronic atrophic gastritis （CAG）， a common digestive system disease， has an unclear pathogenesis. Currently， it is mostly believed to be related to Helicobacter pylori （Hp） infection， immune factors， dietary factors， bile reflux， long-term use of antibiotics and anti-inflammatory drugs， and other factors. Ferroptosis is a regulated cell death mechanism that is iron-dependent and characterized by disruption of iron metabolism and accumulation of lipid peroxides. More and more studies have found that ferroptosis is closely related to the onset of CAG. Professor LI Diangui， a master of traditional Chinese medicine， first proposed the turbid toxin theory， which holds that spleen deficiency and turbid toxin is the main pathogenic mechanism of CAG. Abnormal iron metabolism regulation is a prerequisite for the accumulation of turbid toxin in CAG， and ferroptosis is in accordance with the pathogenic mechanism （spleen deficiency and turbid toxin） of CAG. This article explores the pathological mechanism of spleen deficiency and turbid toxin in CAG from the perspectives of iron metabolism， oxidative stress， and lipid peroxidation， providing theoretical support of traditional Chinese medicine for the modern research on CAG. It enriches the modern scientific connotation of the turbid toxicity theory and provides new ideas and breakthrough points for the clinical treatment of CAG.

Chronic atrophic gastritis （CAG）， a common digestive system disease， has an unclear pathogenesis. Currently， it is mostly believed to be related to Helicobacter pylori （Hp） infection， immune factors， dietary factors， bile reflux， long-term use of antibiotics and anti-inflammatory drugs， and other factors. Ferroptosis is a regulated cell death mechanism that is iron-dependent and characterized by disruption of iron metabolism and accumulation of lipid peroxides. More and more studies have found that ferroptosis is closely related to the onset of CAG. Professor LI Diangui， a master of traditional Chinese medicine， first proposed the turbid toxin theory， which holds that spleen deficiency and turbid toxin is the main pathogenic mechanism of CAG. Abnormal iron metabolism regulation is a prerequisite for the accumulation of turbid toxin in CAG， and ferroptosis is in accordance with the pathogenic mechanism （spleen deficiency and turbid toxin） of CAG. This article explores the pathological mechanism of spleen deficiency and turbid toxin in CAG from the perspectives of iron metabolism， oxidative stress， and lipid peroxidation， providing theoretical support of traditional Chinese medicine for the modern research on CAG. It enriches the modern scientific connotation of the turbid toxicity theory and provides new ideas and breakthrough points for the clinical treatment of CAG.

ObjectiveTo investigate a suspected outbreak of healthcare-associated infection with carbapenem-resistant Klebsiella pneumoniae (CRKP) in a geriatric emergency ward, and to provide references for the prevention and control of multidrug-resistant bacteria in a hospital in Shanghai. MethodsOn-site epidemiological investigation, combined with environmental hygiene monitoring and pulsed field gel electrophoresis (PFGE) molecular typing method, were adopted to investigate a suspected outbreak of CRKP infection in the geriatric emergency ward of a hospital from October to November 2022, aiming at finding out factors caused the outbreak before taking corresponding control measures. ResultsA total of 3 cases of healthcare-associated CRKP infection were identified, of which 2 cases were homologous to a previous case of community-associated CRKP infection. What’s more, the 2 cases lived in the same ward with the latter and with adjacent beds, but the third case was non-homologous to the community-associated infection case. A total of 46 samples were collected from the environmental surfaces and the hands of healthcare workers, of which 7 samples tested positive for CRKP and were identical to the strains from the 2 healthcare-associated infection cases and the 1 community-associated infection case, originating from the bedrails, bedside tables, surface of non-invasive ventilator, bed curtains and panels of monitoring equipment, with a detection rate of 15.22%. But none of the 11 samples from the hands of healthcare workers tested positive for CRKP. The outbreak was effectively controlled after taking specific prevention and control measures such as strengthening personnel management, intensifying environmental cleaning and disinfection and strictly enforcing hand hygiene among healthcare workers. Subsequently, no similar new cases were reported during the 14-day follow-up period. ConclusionIncomplete environmental cleaning and disinfection, as well as inadequate enforcement of hand hygiene among heatheare workers may have contributed to the suspected outbreak of CRKP in the geriatric emergency ward. Early warning and timely investigation of suspected outbreaks of multidrug-resistant bacteria are crucial for preventing and controlling such outbreaks in hospitals.

To clarify the current situation of ketosis in dairy cattle on large-scale pastures in China and provide new insights,a questionnaire survey was conducted to analyze the incidence,preven-tion,treatment methods,and associated costs of ketosis in 79 large-scale pastures.The results showed that the average incidence of ketosis in dairy cows was 3.97％,with a cure rate of 92.40％.The order of importance of methods for preventing and controlling ketosis was as follows:feed for-mulation optimization＞blood ketone monitoring＞negative energy balance monitoring＞feed in-take monitoring＞milk yield monitoring.The most important treatment methods are intravenous glucose＞propylene glycol butyl phosphate＞vitamins＞choline.The most important diagnostic methods are blood ketone testing＞milk ketone testing＞negative energy balance testing＞clinical symptoms＞blood glucose testing.Economic analysis revealed that treatment costs were lower on larger farms and higher milk yields farms.Continuous optimization of feeding management,preven-tion,and control measures should be implemented on large-scale farms in China to reduce the oc-currence of ketosis in dairy cows.Additionally,more effective diagnostic and treatment methods should be employed to improve the cure rate and overall farm income.

Objective To clone the glycosyltransferase gene UGT708Z1 in Anemarrhena asphodeloides and perform its bioinformatics analysis,prokaryotic expression analysis and functional characterization.Methods A candidate glycosyltransferase gene UGT708Z1 was mined and screened out from Anemarrhena asphodeloides based on the transcriptome data.According to its full-length open reading frame,the specific primers with homologous arms were designed.Subsequently,the UGT708Z1 gene was cloned by PCR.The prokaryotic expression recombinant vector pET-32a(+)-UGT708Z1 was constructed through homologous recombination technology,and the soluble target protein was obtained by prokaryotic expression and purified protein technology.Finally,the function of UGT708Z1 was identified through enzymatic reaction in vitro.Results Sequence analysis showed that the open reading frame of UGT708Z1 was 1377 bp,encoding 458 amino acids.The result of prokaryotic expression showed that UGT708Z1 successfully expressed the soluble target protein,and the purified recombinant protein was 70.86 kDa.The results of enzymatic reaction in vitro showed that UGT708Z1 had flavonoid 7-OH glycosylation activity and could catalyze icaritin to produce icariside I.In addition,UGT708Z1 also possessed the activities of catalyzing the 7-O-glycosylation of quercetin and apigenin.Conclusion In this study,a flavonol glycosyltransferase UGT708Z1 was successfully cloned and identified from Anemarrhena asphodeloides,which would lay a foundation for further analysis of flavonol glycosides biosynthesis.

Objective The pathophysiological process of acute high-altitude hypoxia-induced lung injury affects protein expression levels,which are mainly evaluated by Western blot.No systematic study has investigated changes in internal control proteins as calibration loading amounts.Methods Lung injury at an altitude of 6000 m was induced in a low-pressure,low-oxygen chamber for 8,24,and 72 h using C57BL/6J mice.Establishment of the model was confirmed by hematoxylin and eosin staining.Expression levels of various internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor 5(EIF5),β-actin,and glyceraldehyde 3-phosphate dehydrogenase(GAPDH)were detected by Western blot,and total protein expression was detected by Coomassie blue staining.Furthermore,the lung injury model in vitro was establised by using,Bronchial epithelial cell(BZAS-2B)andhunman umbilical vein endothelial cells(HUVECS)confirmed by TUNEL staining.Expression levels of internal control proteins were detected by Western blot,and total protein expression was detected by Coomassie Blue staining.Results Acute 8,24,and 72 h hypoxic models were successfully established in lung tissue,demonstrating consistent total protein expression and stable levels of the internal reference proteins vinculin,α-tubulin,EIF5,andβ-actin.GAPDH expression was elevated in the HH8 h,HH24 h,and HH72 h groups compared with the normoxia(Nor)group,but only the increase at HH72 h groups was significant.Similarly,8,24,and 48 h hypoxic models were successfully established in BEAS-2B cells and HUVECs,with consistent total protein expression.In BEAS-2B cells,expression levels of the internal reference proteins β-actin and GAPDH were consistent with the normoxic control(NC)group,while vinculin,α-tubulin,and EIF5 expression levels were significantly reduced under hypoxic conditions for up to 24 h.In HUVECs,vinculin and α-tubulin expression levels were also consistent with the NC group,while EIF5,β-actin,and GAPDH expression levels were significantly reduced at 8 h and increased at 48 h.Conclusions Acute hypoxia induces lung tissue injury,and protein expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,and β-actin are stable,making them suitable internal references for Western blot.Additionally,Western blot detected differential expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,β-actin,and GAPDH in BEAS-2B cells and HUVECs,as the most important in vitro lung tissue models of hypoxia-induced injury.

Objective To investigate the risk factors and clinical significance of layered plaques that were detected by optical coherence tomography(OCT)in patients with angiographically intermediate coronary lesions,and relationship with prognosis.Methods This was a signal-center retrospective study focusing on patients whom underwent coronary angiography and OCT.The layered plaque group and non-layered plaque group were divided according to the presence or absence of stratified plaque.Clinical data,laboratory indicators,angiography,and OCT results were collected and compared between the two groups.Using logistic regression to analyze the relationship between stratified plaques and clinical features;Cox regression analysis was used to investigate the influencing factors of cardiovascular adverse events in patients with critical coronary artery disease.Results A total of 172 patients were enrolled,including 96 patients in non-layered plaque group and 76 patients in layered plaque group.Male(OR 2.415,95％CI 1.162-5.020,P=0.018),diabetes(OR 2.505,95％CI 1.137-5.525,P=0.023)and history of hyperlipidemia(OR 3.590,95％CI 1.478-6.333,P=0.003)were independent risk factors for stratified plaque.In OCT analysis,the proportion of thin-cap fibroatheroma(TCFA)plaque,macrophage infiltration,microvascularization,thrombosis,plaque rupture,and intimal dissection,as well as lipid plaque length,lipid plaque arc,and lipid plaque index were higher in the layered plaque group.After adjusting for other risk factors,macrophage infiltration is independently associated with stratified plaques(OR 2.106,95％CI 1.019-4.353,P=0.044).Kaplan-Meier survival analysis showed that the target lesion revascularization rate in the layered plaque group was higher than that in the non-layered plaque group(Log-rank P=0.030).Cox regression analysis shows that it has both stratified plaque and thin fibrous membrane plaque characteristics was an independent predictor of cardiovascular adverse events(HR 5.165,95％CI 1.696-15.727,P=0.004).Conclusions In patients with angiographically intermediate coronary lesions,OCT detection of stratified lesions is often accompanied by other unstable plaque features,indicating an increased risk of adverse cardiovascular events.Simultaneously possessing features of stratified plaques and TCFA is an independent predictor of adverse cardiovascular events in patients with critical coronary artery disease.