Aim To investigate the effects of L-argi-nine on spontaneous contraction of rat colon and the relative mechanisms.Methods An organ bath system was use to measure the spontaneous contraction of both longitudinal smooth muscle strips(LMS)and circular muscle strips(CMS).Whole-cell voltage-clamp tech-niques were applied to observe the alterations in cur-rents of L-type voltage-dependent Ca2+channels(VD-CCs),and voltage-gated K+channel(Kv)in single smooth muscle cells(SMCs)from rat colon.Results L-Arginine(1 mmol·L-1)significantly enhanced the spontaneous contraction of both LMS and CMS.The excitatory response to L-arginine was remarkably attenuated by tetrodotoxin(1 mmol·L-1)and atro-pine(1 mmol·L-1),antagonist of muscarinic ACh receptor(mAChR).However,the inhibitor of nitric oxide(NO)synthesis L-NNA(1 mmol·L-1)failed to block the action of L-Arginine.Furthermore,whole-cell patch-clamp recordings showed that L-arginine ac-tivated VDCCs and inhibited Kv channels on SMCs.Conclusions L-Arginine exerts an excitatory effect on colonic motility in a nitric oxide(NO)-independent manner and the stimulatory action of L-arginine is part-ly mediated by mAChR.In addition,VDCCs and Kv channels are both involved in L-arginine-induced exci-tation.

Aim To study the effect of salidroside combined with rosavin on ischemic stroke in rats.Methods The model of MCAO was established by u-sing thread-embolic method.The rats were divided into the sham group,MCAO group,salidroside combined with rosavin group,positive control group,and the drug was given continuously for seven days.The infarct volume was measured by MRI and neurological deficit score was evaluated by Zea-Longa.The levels of Ne-uN,BDNF,TGF-β1,p-Smad were observed by West-ern blot and immunofluorescence staining.The expres-sions of IL-1β,TNF-α and IL-6 were performed by RT-qPCR/ELISA.The primary cortical neurons were isolated,OGD/R inducted,divided into the normal group,OGD/R group,salidroside combined with rosa-vin group,and TGF-β1 inhibitor+salidroside com-bined with rosavin group,the drug was given for 24 hours,and the expressions of NeuN,BDNF,IL-1β,TNF-α and IL-6 were measured.Results Salidroside combined with rosavin could decrease the infarct vol-ume,improve the neurological function,promote the levels of Neun,BDNF,TGF-β1,p-Smad,and inhibit the expressions of IL-1β,TNF-α and IL-6.Salidroside combined with rosavin could promote NeuN,BDNF,inhibit IL-1β,TNF-α,IL-6 in primary nerve cells in-duced by OGD/R,and these effects were blocked by TGF-β1 inhibitor.Conclusions Salidroside combined with rosavin has neuroprotective effects on MCAO rats,and primary neurons are induced by OGD/R,and these effects are closely related to the TGF-β pathway.

Objective Mobile artificial lumbar complex(MALC)which suitable for reconstruction after subtotal lumbar resection in goats was developed,and to test stability of the complex and postoperative lumbar segmental motor function.Methods Eighteen male boer goats aged from 1 to 2 years old(weighted from 35 to 45 kg)were selected and divided into con-trol group,fusion group and non-fusion group,with 6 goats in each group.According to preoperative CT scans and MRI exami-nations of lumbar,the goat MALC was designed and performed by 3D printed for non-fusion group.Operation was performed on three groups respectively,and only vertebral body and disc were exposed in control group.In fusion group,L4 part of vertebral body and the upper and lower complete disc tissues were removed,and the lumbar spine bone plate fixation was performed with titanium mesh bone grafting.In non-fusion group,vertebral body and disc were removed in the same way,and MALC was im-planted.AP and lateral X-rays of lumbar vertebrae in goat were taken at 6 months after surgery,in order to understand whether the plant was dislocated,displaced and fractured.Biomechanical tests were performed on the specimens by mechanical instru-ment to measure range of motion(ROM)of L2,3,L,4,L4,5intervertebral space and the overall ROM of L2-5 lumbar vertebrae.Results MALC of lumbar vertebra was designed by 3D printing,and its component artificial vertebrae and upper and lower ar-tificial end plates were manufactured.The semi-spherical structure was fabricated by precision lathe using high-crosslinked polyethylene material,and the prosthesis was assembled.Postoperative AP and lateral X-rays of lumbar vertebra at 6 months showed the implant position of implant and MALC were good without displacement and dislocation.In vitro biomechanical test of lumbar vertebrae specimens:(1)There were no statistical significance in ROM of lumbar intervertebral space flexion and extension,lateral flexion and rotation on L.4 and L4,5,between non-fusion group and control group(P＞0.05),while ROM of fu-sion group was significantly reduced compared with the other two groups(P＜0.05).There were no significant difference in ROM of L2.3 intervertebral flexion and extension,lateral flexion and rotation between non-fusion group and control group(P＞0.05),while fusion group was significantly increased compared with the other two groups(P＜0.001).(2)There was no signifi-cant difference in overall lumbar ROM of L2-5(P＞0.05).Conclusion The individual MALC could restore intervertebral height of lumbar vertebra while maintaining the stability of lumbar vertebra and re-establishing motor function of lumbar space.

The purpose of this study was to investigate the regulatory effects of biofilm associated non-coding small RNA(sRNA)00085 on the survival and environmental fitness of Listeria monocytogenes.Homologous recombination technology was used to construct a deletion mutant strain(△sRNA 00085)and a complementary strain(C △sRNA 00085)of the sRNA00085 target gene.The differences in biological characteristics were compared among the standard strain,△sRNA 00085,and C△sRNA 00085.The deletion of sRNA00085 led to a significant decrease in biofilm formation capacity and sensitivity to several antibiotics,including penicillin,piperacillin,doxycycline,tetracycline,vancomycin,and cotrimoxazole.However,only the minimum inhibitory concentration(MIC)of tetracycline exhibited a significant decrease in △sRNA00085.Meanwhile,the decreased biofilm formation and antibiotic resistance of the sRNA00085 mutant were restored in the C△sRNA00085 strain.Furthermore,we investigated the transcription levels of tetracycline resistance-related genes in L.monocytogenes.Down-regu-lated transcription of the tetS gene but no significant difference in transcription of the tetA gene were observed in △sRNA 00085 compared with the standard strain and C△sRNA00085.Moreover,the elimination of sRNA00085 did not affect bacterial growth ability or sensitivity to disinfectants.These findings highlight that sRNA00085 plays an important role in the environ-mental adaptability of L.monocytogenes by affecting bacterial biofilm formation and resistance.

Objective:To investigate possible mechanism on protien LMP1 expressed by EBV inducing plasmablast differentiation of DLBCL cell via the mTORC1 pathway.Methods:The expression levels of LMP1 protein,CD38 and the phosphorylation levels of p70S6K in EBV+and EBV-DLBCL cell lines were detected by Western blot.Cell lines overexpressing LMP1 gene stablely were constructed and LMP1 gene was silenced by RNAi.The expression of LMP1 gene was verified by RT-qPCR.The expression levels of LMP1 and CD38 and the phosphorylation levels of p70S6K in each group were detected by Western blot.Results:Compared with EBV-DLBCL cells,the expression of LMP1 was detected on EBV+DLBCL cells(P=0.0008),EBV+DLBCL cells had higher phosphorylation levels of p70S6K(P=0.0072)and expression levels of CD38(P=0.0091).Compared with vector group,the cells of LMP1OE group had higher expression levels of LMP1 and CD38(P=0.0353;P＜0.0001),meanwhile molecular p70S6K was phosphorylated much more(P=0.0065);expression of LMP1 mRNA was verified(P＜0.0001).Compared with si-NC group,expression level of LMP1 protein(P=0.0129)was not detected and phosphorylated p70S6K disappeared of LMP1KO group(P=0.0228);meanwhile,expression of CD38 decreased,although there was no significant difference(P=0.2377).Conclusion:LMP1 promotes DLBCL cells plasmablast differentiation via activating mTORC1 signal pathway.

Objective:To observe the clinical efficacy and safety of hypomethylating agent therapy in chronic myelomonocytic leukemia(CMML).Methods:From February 2014 to June 2021,the clinical data,efficacy,survival time and safety of CMML patients diagnosed in the Second Hospital of Hebei Medical University and treated with hypomethylating agent therapy were retrospectively analyzed.Results:A total of 25 CMML patients received hypomethylating agent therapy,including 18 cases treated with decitabine(DEC)and 7 cases treated with azacytidine(AZA)as the basic treatment.Among them,20 patients responded,and 7 patients got complete remission(CR).All patients with CR were treated with DEC as the basic treatment.Five cases of CR occurred in the first 4 courses of treatment.After a median follow-up of 16.4(9.4-20.5)months,4 patients with CR progressed to acute myeloid leukemia(AML).The median overall survival(OS)time of 25 CMML patients was 17.4 months(95％CI:12.437-22.363).According to MD Anderson prognostic scoring system(MDAPS),CMML-specific prognostic scoring system(CPSS),CPSS molecular(CPSS-mol),Mayo molecular model(MMM),risk stratification of patients was performed,and the difference only between different risk stratification of MDAPS and survival time was statistically significant.Common adverse reactions of hypomethylating agent therapy in CMML patients included infection,gastrointestinal reaction,hematological toxicity,skin allergy and liver function damage.All patients'symptoms were improved after corresponding treatment.Conclusion:Hypomethylating agent therapy is effective and safe for CMML patients.CR mostly occurs in the first 4 courses of treatment,and hypomethylating agent therapy combined with low-dose chemotherapy can be used for patients who do not respond.Hypomethylating agent therapy can delay the disease,but can't prevent progression.

Objective To exploring the correlation between serum miR-195 and metabolic associated fatty liver disease(MAFLD)in type 2 diabetes mellitus(T2DM)patients.Methods A total of 79 patients with T2DM who were treated in the Endocrinology Department of Gansu Provincial People's Hospital were enrolled in this study from October 2022 to August 2023.They were divided into simple T2DM(n=37)and MAFLD group(MAFLD,n=42)according to whether they were complicated with MAFLD.Meanwhile,34 healthy individuals who underwent physical examinations were selected as the normal control(NC)group.Results Compared with the NC group,FPG,HbA1c and HOMA-IR increased,while HDL-C decreased in T2DM and MAFLD group(P<0.05).The TG and hs-CRP levels were higher in MAFLD group than in NC and T2DM group(P<0.05).The serum miR-195 expression decreased sequentially(P<0.05),while FAS increased sequentially in NC,T2DM,and MAFLD group(P<0.05).Spearman correlation analysis showed that miR-195 was negatively correlated with FPG,HOMA-IR,hs-CRP,and FAS(P<0.05).Multiple linear regression analysis showed that HOMA-IR and FAS were the influencing factors for serum miR-195.Conclusions Down-regulation of serum miR-195 expression in patients with T2DM combined with MAFLD may be by glucose and lipid metabolism,IR and inflammatory response.

Objective: The therapeutic benefits of exosomes obtained from mesenchymal stem cells (MSCs) in acute spinal cord injury (SCI) have been demonstrated in recent years, but the precise mechanisms remain unknown. In this study, the efficacy and mechanisms of MSC-derived exosomes (MSC-Exo) in acute SCI were investigated. Methods: By utilizing a BV2 ferroptosis cellular model and an SCI rat model, we investigated the effects of MSC-Exo on iron death related indicators and NF-E2 related factor 2 (Nrf2)/GTP cyclolase I (GCH1)/5,6,7,8-tetrahydrobiopterin (BH4) signaling axis, as well as their therapeutic effects on SCI rats. Results: The results revealed that MSC-Exo effectively inhibited the production of ferrous iron, lipid peroxidation products malonaldehyde and reactive oxygen species, and ferroptosis-promoting factor prostaglandin-endoperoxide synthase 2. Concurrently, they upregulated ferroptosis suppressors FTH-1 (ferritin heavy chain 1), SLC7A11 (solute carrier family 7 member 11), FSP1 (ferroptosis suppressor protein 1), and GPX4 (glutathione peroxidase 4), contributing to enhanced neurological recovery in SCI rats. Further analysis showed the Nrf2/GTP/BH4 signaling pathway’s critical role in suppressing ferroptosis. Additionally, MSC-Exo was found to inhibit lipopolysaccharide-induced ferroptosis in BV2 cells and SCI rats by activating the Nrf2/GCH1/BH4 axis. Conclusion In summary, the study demonstrates that MSC-Exo mitigates microglial cell ferroptosis via the Nrf2/GCH1/BH4 axis, showing potential for preserving and restoring neurological function post-SCI.

Objective:To investigate the effect of selenium on cyclophosphamide(CTX)-induced spermatogenic impairment(SI)in mice and its underlying mechanism.Methods:We equally randomized 36 male KM mice into 3 SI model and 3 control groups,the first 3 treated by intraperitoneal injection of CTX at 100 mg/kg(the SI model control group),CTX plus SI model control group,selenium deficient model group(-Se SI),selenium supplemented model group(+Se SI),while latter 3 by intraperitoneal injection of normal saline(the normal control),selenium deficiency control group(-Se control),selenium addition control group(+Se control),respectively,all once a week for 6 successive weeks.Then we observed the histopathological changes in the testes of all the mice by HE staining,obtained the sperm count in the epididymides,determined the expressions of glutathione peroxidase 4(GPx4)and SLC7A11 proteins by Western blot and ferroptosis-related genes by RT-qPCR,and examined the changes in the expres-sions of ferroptosis-related proteins and genes in the GC2-spd cells treated with ferroptosis inhibitors and inducers in combination with different concentrations of inorganic sodium selenite(SeS)and organic selenomethionine(SeM).Results:Compared with the nor-mal controls,the SI model mice showed significantly decreased testicular and prostatic organ coefficients,reduced spermatogenic lay-ers,increased voids,decreased serum ferritin concentration(P<0.05),and elevated transferrin concentration(P<0.05).The or-gan coefficients were significantly higher in the+Se SI and+Se control than in the-Se SI and-Se control groups(P<0.05,P<0.01),with evident pathological improvement of the testis tissue in the+Se controls.The expressions of the GPx4 and solute carrier family 7 members 11(SLC7A11)genes in the testis were dramatically down-regulated in the SI model controls(P<0.01),but up-reg-ulated in the+Se SI and+Se control compared with those in the-Se SI and-Se control group(P<0.01 and P<0.05),but there were no statistically significant differences between their protein expressions.The results of in vitro GC2 spd cell experiments indicated that the GPx4 gene and GPx4 protein levels in the-Se group were significantly lower than those in the normal control group(P<0.05),while the SLC7A11 gene level decreased(P<0.01).Different doses of SeS and SeM significantly increased the GPx4 protein expression compared to the average Se group.Low doses of SeM promoted a significant increase in GPx4 gene levels,while high doses of SeS increased the expression levels of SLC7A11 gene and SLC7A11 protein(P<0.05,P<0.01).The Se group showed a signifi-cant decrease in the levels of acsl4 and ptgs2 genes compared to the normal control group.SeM promoted the expression of acsl4,while SeS promoted the expression of ptgs2 and fth1(P<0.01,P<0.05).The intervention results of GC2 spd showed that the Erastin group had a decrease in ptgs2 compared to the normal control group,while the SeS+Erastin and SeM+Erastin groups had an increase in ptgs2 gene expression compared to the Erastin group.However,the ptgs2 expression of Fer-1 was lower than that of the normal con-trol group,and the ptgs2 gene level of SeS+Fer-1 and SeM+Fer-1 groups was lower than that of Fer-1 group(P<0.05);The gene quantity of GPx4 in the SeM+Erastin and SeM+Fer-1 groups increased compared to the Erastin and Fer-1 groups(P<0.01,P<0.05);SeM+Erastin and SeS+Erastin showed a decrease in SLC7A11 compared to the Erastin group,as well as SeM+Fer-1 and SeS+Fer-1 groups compared to the Fer-1 group,accompanied by an increase in acsl4 and fth1(P<0.01).Conclusion:Selenium deficiency causes the reduction of the SLC7A11 and GPx4 gene levels,disorder of ferroptosis-related genes and down-regulation of the GPx4 protein expression in the mouse testis and spermatocytes.Selenium can promote the expression of GPx4,up-regulate the level of SLC7A11,and improve spermatogenesis in the testis of the mouse with SI.There are differences between organic SeM and inorganic SeS in regulating the ferroptosis pathway-related genes.

AIM To optimize the extraction process for uracil,hypoxanthine,xanthine,uridine,thymine,inosine,guanosine and 2'-deoxyguanosine from Pheretima guillelmi(Michaelsen),and to determine their contents.METHODS With solid-liquid ratio,ultrasonic time and ultrasonic temperature as influencing factors,contents of hypoxanthine and total nucleosides as evaluation indices,the extraction process was optimized by orthogonal test.HPLC was adopted in the content determination of varioud nucleosides,the analysis was performed on a 30℃thermostatic Agilent C18 column(4.6 mm×250 mm,5 μm),with the mobile phase comprising of methanol-water flowing at 1 mL/min in a gradient elution manner,and the detection wavelength was set at 260 nm.RESULTS The optimal conditions were determined to be 1∶250 for solid-liquid ratio,60 min for ultrasonic time,and 60℃for ultrasonic temperature.Eight nucleosides showed good linear relationships within their own ranges(R2＞0.999 0),whose average recoveries were 99.11%-103.27%with the RSDs of 0.85%-2.89%.CONCLUSION This stable and reliable method can be used for the extraction and content determination of nucleosides from P.guillelmi.