This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

Targeted covalent inhibitors,primarily targeting cysteine residues,have attracted great attention as potential drug candidates due to good potency and prolonged duration of action.However,their dis-covery is challenging.In this research,a database-assisted liquid chromatography-tandem mass spec-trometry(LC-MS/MS)strategy was developed to quickly discover potential cysteine-targeting compounds.First,compounds with potential reactive groups were selected and incubated with N-acetyl-cysteine in microsomes.And the precursor ions of possible cysteine-adducts were predicted based on covalent binding mechanisms to establish in-house database.Second,substrate-independent product ions produced from N-acetyl-cysteine moiety were selected.Third,multiple reaction monitoring scan was conducted to achieve sensitive screening for cysteine-targeting compounds.This strategy showed broad applicability,and covalent compounds with diverse structures were screened out,offering structural resources for covalent inhibitors development.Moreover,the screened compounds,norket-amine and hydroxynorketamine,could modify synaptic transmission-related proteins in vivo,indicating their potential as covalent inhibitors.This experimental-based screening strategy provides a quick and reliable guidance for the design and discovery of covalent inhibitors.

Targeted covalent inhibitors, primarily targeting cysteine residues, have attracted great attention as potential drug candidates due to good potency and prolonged duration of action. However, their discovery is challenging. In this research, a database-assisted liquid chromatography-tandem mass spectrometry (LC-MS/MS) strategy was developed to quickly discover potential cysteine-targeting compounds. First, compounds with potential reactive groups were selected and incubated with N-acetyl-cysteine in microsomes. And the precursor ions of possible cysteine-adducts were predicted based on covalent binding mechanisms to establish in-house database. Second, substrate-independent product ions produced from N-acetyl-cysteine moiety were selected. Third, multiple reaction monitoring scan was conducted to achieve sensitive screening for cysteine-targeting compounds. This strategy showed broad applicability, and covalent compounds with diverse structures were screened out, offering structural resources for covalent inhibitors development. Moreover, the screened compounds, norketamine and hydroxynorketamine, could modify synaptic transmission-related proteins in vivo, indicating their potential as covalent inhibitors. This experimental-based screening strategy provides a quick and reliable guidance for the design and discovery of covalent inhibitors.

The toad, known for its various medicinal properties including parotid gland secretion (toad venom), dried skin, and gallbladder (toad bile), holds considerable medicinal applications as a valuable traditional Chinese animal medicine. Currently, in-depth attentions have been paid to the chemical composition and pharmacological properties of toad venom and skin; however, a lesser number of detailed analyses were concentrated on the toad bile. This review provides an overview of the chemical constituents in the bile of the Bufo genus, with a special focus on the cholestane and bufadienolides, and highlights the progress in their biosynthetic pathway and pharmacological activities. The analysis uncovers a distinct category of unsaturated Δ²² or Δ²³-C₂₇/C₂₈ bile acids in the toad gallbladder, potentially acting as key intermediaries in forming C-17 α-pyrone of bufadienolides. Furthermore, the high presence of 3α-OH configured bufadienolides in toad bile, in contrast to the common 3β-OH configured found in toad venom or skin, indicates a possible link between their minimal toxicity and the toad's self-defensive or physiological control. This review provides scientific basis for the development and utilization of toad bile resources, and provides useful reference for the discovery of lead compounds, analysis of the biosynthetic pathway of bufadienolides, and research on toad physiology.

Objective:To investigate the efficacy and side effects of concurrent chemoradiotherapy with or without nimotuzumab in the treatment of locally advanced nasopharyngeal carcinoma after neoadjuvant chemotherapy.Methods:In the prospective study, 100 patients with stage Ⅲ-Ⅳa locally advanced nasopharyngeal carcinoma (except T 3N 0M 0 stage) who met the inclusion criteria were randomly divided into the experimental and control groups using the random number table method. Patients in both groups were treated with neoadjuvant chemotherapy using TPF (paclitaxel liposome, cisplatin, and 5-fluorouracil) regimen for 2 cycles. At 2 weeks after chemotherapy, concurrent chemoradiotherapy plus nimotuzumab targeted therapy was given in the experimental group, and concurrent chemoradiotherapy was delivered in the control group. The main observation index was the distant metastasis-free survival (DMFS) rate. Log-rank test and multivariate Cox regression analysis were used. Results:The objective remission rate and complete remission rate in the experimental and control groups were 100% vs. 98% ( P=1.000) and 92.0% vs. 80% ( P=0.084). The 3-year DMFS in the experimental and control groups were 91.4 % vs. 76.1 % ( P=0.043). The 3-year progression-free survival (PFS), locoregional recurrence-free survival (LRFS) and overall survival (OS) in two groups were 87.3 % vs. 74.1 % ( P=0.097), 94.5 % vs. 85.6 % ( P=0.227) and 90.5% vs. 85.2% ( P=0.444). Subgroup analysis showed that patients with age<60 years ( HR=0.34, 95% CI=0.12-0.94, P=0.037), neutrophil-to-lymphocyte ratio (NLR)≤4 ( HR=0.34, 95% CI=0.13-0.89, P=0.028) received concurrent chemoradiotherapy plus nimotuzumab obtained better PFS. Multivariate analysis showed that NLR was an independent risk factor for disease progression ( HR=5.94, 95% CI=1.18-29.81, P=0.030) and distant metastasis ( HR=13.76, 95% CI=1.52-124.36, P=0.020). Conclusions:Compared with concurrent chemoradiotherapy alone, concurrent chemoradiotherapy combined with nimotuzumab after neoadjuvant chemotherapy can significantly increase DMFS rate for patients with locally advanced nasopharyngeal carcinoma. The incidence of side effects is similar in two groups. Concurrent chemoradiotherapy plus nimotuzumab after neoadjuvant chemotherapy may be a preferred treatment strategy for locally advanced nasopharyngeal carcinoma.

BACKGROUND:In recent years,some scholars in the field of tendon bone injury have attached stromal cell-derived factor 1 to tissue engineering scaffolds to promote tendon bone healing,and achieved good results.However,whether stromal cell-derived factor 1 promotes tendon bone healing mechanisms and participates in the repair of natural healing has not yet been defined. OBJECTIVE:To study the expression of stroma-cell derived factor 1 during tendon bone healing after rupture of the whole supraspinatus muscle of the rabbit rotator cuff and its migration effect and optimal in vitro migration promoting concentration on stem cells during tendon bone injury. METHODS:Totally 18 adult New Zealand rabbits were randomly selected to establish rotator cuff injury models,and an additional 3 rabbits were selected as blank controls.At 3,5,7,14,21,and 28 days after modeling,three rabbits were executed separately and the rabbits in the blank group were sacrificed.The tissues of tendon bone junction were taken and stored in a-80℃refrigerator.The expression of stromal cell-derived factor 1 was detected by ELISA at each time point after injury.Mesenchymal stem cells were isolated from the bone marrow of young rabbit femur,cultured,and identified.Transwell assay was performed to verify the migration-promoting effect of stromal cell-derived factor 1 on stem cells and the optimal migration-promoting concentration in vitro.The stem cells cultured to P3 were co-cultured with BrdU and injected into the rabbit ear marginal vein,and immunohistochemical staining was used to verify whether the stem cells migrated to the injury site. RESULTS AND CONCLUSION:(1)Stromal cell-derived factor 1 gene expression was bimodal during rotator cuff tendon bone healing.Stromal cell-derived factor 1 gene expression increased significantly at 3 days post-injury(P<0.01)and then decreased,reaching a minimum at 5 days post-injury.It increased again and reached a peak 14 days after injury(P<0.01)and then decreased.(2)Cell immunohistochemical staining displayed that stem cells labeled with BrdU did migrate to the injury site.(3)The results of the transwell experiment exhibited that 60-80 ng/mL stromal cell-derived factor 1 had the best effect on promoting migration of stem cells,while a concentration of 200 ng/mL inhibited migration.(4)Stromal cell-derived factor 1 is involved in the healing of rotator cuff tendon bone during the inflammatory response phase and the proliferation phase.The mechanism of action may be to promote the migration of stem cells to the injury and their differentiation into various types of cells to promote repair.In addition,the pro-migration effect of stromal cell-derived factor 1 exists at a range of concentrations,beyond which it may act as an inhibitor.

This study aimed to investigate the effect of iron overload on the transplant outcomes of pediatric patients with severe aplastic anemia (SAA) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). A retrospective analysis was conducted on the clinical data of 74 children with SAA who received allo-HSCT at the Hematology Department of Wuhan Children’s Hospital between January 2018 and August 2022. Children with iron overload (serum ferritin >1 000 μg/L) before transplantation had a longer disease course, received more red blood cell transfusions, and had a higher number of CD34 + cells infused. Moreover, iron overload significantly delayed the reconstitution of regulatory T cells after transplantation, increasing the incidence of hemorrhagic cystitis and grade Ⅲ-Ⅳ acute graft-versus-host disease after transplantation. However, iron overload did not significantly affect the overall survival and failure-free survival rates of the children.

Objective:To evaluate the safety and efficiency of China-made Toumai Robot-assisted laparoscopic radical prosta-tectomy(LRP).Methods:This study included 40 cases of PCa treated from January 2023 to May 2023 by robot-assisted LRP with preservation of the bladder neck and maximal functional urethral length,15 cases with the assistance of Toumai Robot(the TMR group)and the other 25 with the assistance of da Vinci Robot as controls(the DVR group).We recorded the docking time,laparo-scopic surgery time,vesico-urethral anastomosis time,intraoperative blood loss and postoperative urinary continence,and compared them between the two groups.Results:Operations were successfully completed in all the cases.No statistically significant differ-ences were observed between the TMR and DVR groups in the docking time(6 min vs 5 min,P＞0.05)or intraoperative blood loss(200 ml vs 150 ml,P＞0.05).The TMR group,compared with the DVR group,showed a significantly longer median laparoscopic surgery time(146 min vs 130 min,P＜0.05)and median vesico-urethral anastomosis time(19 min vs 16 min,P＜0.05).There were no statistically significant differences between the TMR and DVR groups in the rates of urinary continence recovery immediately af-ter surgery(60.0％[9/15]vs 64.0％[16/25],P＞0.05)or at 1 month(80.0％[12/15])vs(76.0％[19/25],P＞0.05),3 months(93.3％[14/15])vs(92.0％[23/25],P＞0.05)and 6 months postoperatively(100％[15/15])vs(96％[24/25],P＞0.05).Conclusion:China-made Toumai? Robot surgical system is safe and reliable for laparoscopic radical prosta-tectomy,with satisfactory postoperative recovery of urinary continence.