Laboratory animals are the "living" tools of medical research. Through animal experiments, people can gain continuous insights into the laws of life, reveal the essence of diseases, develop vaccines and drugs for prevention and treatment, and play an important role in the technological development of fields related to human health. The environmental conditions of laboratory animals have a direct impact on their health, quality, and the results of animal experiments. The higher the degree of environmental control, the more reliable the experimental results are in terms of quality. Therefore, environmental control of laboratory animal facilities is important for ensuring that laboratory animals live under required conditions, which is a key factor for conducting effective animal experiments. This article analyzes the current status of environmental testing of laboratory animal facilities in Sichuan Province, briefly summarizing their number, area, and other basic information, and provides detailed statistics on the ability of institutions to conduct environmental testing for laboratory animal facilities in Sichuan Province. It also summarizes the testing requirements for laboratory animal facility environments based on national standards, regulatory requirements, and the quality control needs of facility users. In the analysis of testing indicators for laboratory animal facilities, based on testing data from 40 laboratory animal facilities in Sichuan Province, it was found that static pressure difference is the indicator most prone to non-compliance, followed by illumination and air exchange rate. Using barrier environments as examples, common problems in the process of environmental testing for laboratory animal facilities are summarized in six aspects: testing personnel, instruments, methods, technical materials, testing environment, and reports, and targeted suggestions are proposed. These suggestions help improve environmental control in laboratory animal facilities, and provide practical reference and guidance for relevant testing institutions, as well as laboratory animal producers and users in the industry.

Background The benchmark dose (BMD) method calculates the dose associated with a specific change in response based on a specific dose-response relationship. Compared with the traditional no observed adverse effect level (NOAEL) method, the BMD method has many advantages, and the 95% lower confidence limit of benchmark dose lower limit (BMDL) is recommended to replace NOAEL in deriving biological exposure limits. No authority has yet published any health-based guideline for rare earth elements. Objective To evaluate genotoxicity threshold induced by acute exposure to neodymium nitrate in mice using BMD modeling through micronucleus test and comet assay. Methods SPF grade mice (n=90) were randomly divided into nine groups, including seven neodymium nitrate exposure groups, one control group (distilled water), and one positive control group (200 mg·kg⁻¹ ethyl methanesulfonate), 10 mice in each group, half male and half female. The seven dose groups were fed by gavage with different concentrations of neodymium nitrate solution (male: 14, 27, 39, 55, 77, 109, and 219 mg·kg⁻¹; female: 24, 49, 69, 97, 138, 195, and 389 mg·kg⁻¹) twice at an interval of 21 h. Three hours after the last exposure, the animals were neutralized by cervical dislocation. The bone marrow of mice femur was taken to calculate the micronucleus rate of bone marrow cells, and the liver and stomach were taken for comet test. Results The best fitting models for the increase of polychromatophil micronucleus rate in bone marrow of female and male mice induced by neodymium nitrate were the exponential 4 model and the hill model, respectively. The BMD and the BMDL of female mice were calculated to be 31.37 mg·kg⁻¹ and 21.90 mg·kg⁻¹, and those of male mice were calculated to be 58.62 mg·kg⁻¹ and 54.31 mg·kg⁻¹, respectively. The best fitting models for DNA damage induced by neodymium nitrate in female and male mouse hepatocytes were the exponential 5 model and the exponential 4 model, respectively, and the calculated BMD and BMDL were 27.15 mg·kg⁻¹ and 11.99 mg·kg⁻¹ for female mice, and 16.28 mg·kg⁻¹ and 10.47 mg·kg⁻¹ for male mice, respectively. The hill model was the best fitting model for DNA damage of gastric adenocytes in both female and male mice, and the calculated BMD and BMDL were 36.73 mg·kg⁻¹ and 19.92 mg·kg⁻¹ for female mice, and 24.74 mg·kg⁻¹ and 14.08 mg·kg⁻¹ for male mice, respectively. Conclusion Taken the micronucleus rate of bone marrow cells, DNA damage of liver cells and gastric gland cells as the end points of genotoxicity, the BMDL of neodymium nitrate is 10.47 mg·kg⁻¹, which can be used as the threshold of genotoxic effects induced by acute exposure to neodymium nitrate in mice.

Background The respiratory toxicity of inhaled polyhexamethylene guanidine (PHMG) has been extensively studied since the humidifier disinfectant incident. However, the impacts of inhalation of PHMG on the immune system are not comprehensively studied yet. Objective To explore the effects of inhalation of PHMG disinfectant aerosol on major immune organs and immune cells in mice. Methods Thirty male C57BL/6J mice (6-8 weeks old) were randomly divided into three groups: control, low-dose (0.1 mg·m⁻³ PHMG), and high-dose (1.0 mg·m⁻³ PHMG), with ten mice in each group. The mice were administered by oral-nasal inhalation of PHMG aerosol for 4 h per day, 5 d per week for 4 weeks consecutively. After designed treatment, venous blood was collected from the inner canthus of the eyes of mice and peripheral hematological indicators were measured with a blood analyzer. Then the mice were sacrificed by cervical dislocation and the lung, thymus, spleen, and femur were isolated. Lung, thymus, and spleen were weighed and organ coefficients were calculated, and single cell suspensions of thymus, spleen, and bone marrow were prepared to analyze lymphocytes phenotypes and proportions by flow cytometry. Results The body weight of mice in the high-dose group was lower than that of mice in the control group (P<0.01) from the 7th day of inhalation, and decreased by 15.74% compared with that of mice in the control group at the end of inhalation (P<0.01). The lung coefficients of both the low-dose and high-dose groups were higher than that of the control group (P<0.01), the thymus coefficient of mice in the high-dose group was lower than that of the control group (P<0.05), but the spleen coefficient did not change significantly (P>0.05). Leukocyte count [(1.49±0.22)×10⁹·L⁻¹], lymphocyte count [(0.96±0.36)×10⁹·L⁻¹] and its proportion [(63.13±14.96)%] in the peripheral blood of mice in the high-dose group were lower than those in the control group [(2.69±0.25)×10⁹·L⁻¹, (2.33±0.28)×10⁹·L⁻¹, and (86.23±3.40)%, respectively] (P<0.01), whereas red blood cell count [(12.32±0.46)×10¹²·L⁻¹], hemoglobin count [(175.25±4.65) g·L⁻¹], and hematocrit [(53.55±0.70)%] in the peripheral blood of mice in the high-dose group were higher than those in the control group [(11.11±0.37)×10¹²·L⁻¹, (160.67±4.04) g·L⁻¹, and (45.10±9.75)%, respectively] (P<0.05). Compared with the control group, the proportion of CD4+ CD8+ double-positive T cells decreased (P<0.05), the proportions of CD4+ T cells and CD8+ T cells increased (P<0.05), and the amounts of CD8+, CD4+ CD8+, CD4+, and CD4- CD8- cells decreased (P<0.05) in the thymus of mice of the high-dose group, the proportion of CD4+ T cells in the spleen of the high-dose group increased (P<0.05), the proportions and amounts of T cells, CD4+ T cells, and CD8+ T cells in the bone marrow of the high-dose group increased (P<0.05). Conclusion Inhalation of PHMG may cause thymic atrophy, disrupt T-lymphocyte development, and lead to an imbalance in the number of immune cells in the bone marrow, peripheral blood, and spleen, suggesting that inhalation of PHMG induces immune dysfunction.

AIM:To explore the fundus vascular characteristics of healthy individuals based on deep learning techniques, with a view to discovering the range of normal values of the fundus arteries and veins, as well as the relationship between physiological factors, such as gender, age, body mass index(BMI), blood pressure, and fundus vasculature characteristics.METHODS:Fundus images of healthy people were taken from a professional fundus camera, and the subject's blood pressure and laboratory test was collected. Additionally, the fundus arteries and veins were segmented by the improved U-Net model, and the color, morphology and Haralick texture features of the vessels were extracted from computer vision technology.RESULTS:A total of 4 487 cases fundus images were taken and 326 cases with healthy and clear fundus images were screened, including 200 males and 126 females. There were differences in the morphology, color, and textural characteristics of the left and right eyes, as well as of the fundus arterioles and veins, with a mean vessel width(width)of 1.146 in the arteries and 1.430 in the veins, and an arteriovenous ratio about 4:5. Fundus artery and vein characteristics in healthy individuals of different ages(21-30, 31-40, 41-50): compared with the healthy population aged 21-30 and 31-40 years, arterial and venous inverse difference moment(idm), f12 and venous angular second moment(asm)values increased, and arterial and venous contrast(con), entropy(ent), difference entropy(den), and venous sum entropy(sen)values decreased in 41-50 years. Compared with the 21-30 years age group, arterial f12 values increased and venous con values decreased in 31-40 years(all P<0.05). Fundus vascular characteristics of healthy individuals of different sexes: compared with male, fundus arterial and venous sum average(sav), sum variance(sva)values, arterial curved values, and venous b mean, bsd, variance(var), sen, ent values increased in female, while venous area value of female decreased(all P<0.05). There were no statistically significant differences in fundus arteriosus and venous features in healthy subjects with different levels of BMI(all P>0.05). Fundus characteristics of healthy people with different degrees of blood pressure: there were statistically significant differences in fundus arteriosus area, width, and venous con, idm, dva, and den values between the normal blood pressure and high blood pressure groups(all P<0.05).CONCLUSION: The characteristics of the left and right eyes as well as the fundus arteries and veins differ in healthy individuals and correlate with physiological factors such as gender, age and blood pressure, which have the value of a potential microcirculation marker.

Objective:To delineate the clinical characteristics and outcomes associated with severe cardiac toxicity during the preconditioning phase of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with aplastic anemia (AA).Methods:This retrospective case series study included 31 patients with severe AA who underwent allo-HSCT and were diagnosed with severe cardiac toxicity at the Hematology Department of Peking University People′s Hospital from August 2012 to June 2022. The clinical manifestations of severe cardiac toxicity observed during the preconditioning process were assessed. Patient survival was assessed using the Kaplan-Meier method.Results:In this cohort of 31 patients, the median follow-up period was 9 days (range: 4-365 days). Severe cardiac toxicity manifested within 6 days after the initial cyclophosphamide (Cy) administration. Twenty patients died within 30 days of initiating Cy preconditioning, of which 16 patients died due to severe cardiac toxicity within 25 days. Patients whose cardiac function improved within 30 days post-preconditioning showed a median survival duration of 222 days ( n=11). Troponin I (TNI) levels in patients who died within 30 days of initiating Cy preconditioning began increasing on day 5 post-Cy, peaking sharply by day 9 after a notable rise on day 8. B-type natriuretic peptide (BNP) levels in patients who died within 30 days of initiating Cy preconditioning started to rise from day 1, stabilized between days 2 and 5, and then doubled daily from days 6 to 8, remaining elevated thereafter. Notably, the initial increases in BNP and TNI correlated with electrocardiogram (ECG) signs of low voltage and T-wave inversion in 83.87% of cases ( n=26). Most patients ( n=28, 90.32%) were administered corticosteroid therapy. In those with restored cardiac function, the ejection fraction returned to >50% within 30 days of initiating Cy preconditioning. Conclusions:Patients with severe cardiac toxicity during the preconditioning phase of allo-HSCT typically exhibit early, sustained, and marked elevations in myocardial damage markers, including BNP and TNI, accompanied by ECG abnormalities following Cy administration, with BNP often increasing first. These indicators are associated with rapid disease progression and high mortality. Prompt initiation of treatment upon clinical diagnosis is critical for improving survival outcomes.

Objective:To investigate the impact of donor human leukocyte antigen (HLA) -Bw4 expression on natural killer (NK) cell reconstitution and transplant outcomes in recipients undergoing haploidentical hematopoietic stem cell transplantation (HSCT) from maternal or related donors without ex vivo T-cell depletion.Methods:This study prospectively enrolled 32 patients who received T-replete haploidentical HSCT from maternal or collateral donors (cohort 1) to evaluate the facilitating effect of donor HLA-Bw4 expression on NK cell reconstitution. Furthermore, a retrospective analysis was conducted on 278 patients who underwent T-replete haploidentical HSCT from maternal or collateral donors (cohort 2) to analyze the impact of donor HLA-Bw4 expression on HSCT outcomes. Thus, a comparison was made between the effects of donor HLA-Bw4 expression on HSCT outcomes in patients receiving or not receiving post-transplant cyclophosphamide (PT-Cy) conditioning.Results:Donors expressing HLA-Bw4 alleles facilitated NK cell reconstitution and functional recovery, which remained unaffected by PT-Cy. Donors with HLA-Bw4 expression were associated with reduced transplant-related mortality (TRM), particularly mortality related to infections. The use of PT-Cy did not impact the ability of donor HLA-Bw4 to decrease TRM.Conclusion:In haploidentical HSCT from maternal or related donors without ex vivo T-cell depletion, the presence of donor HLA-Bw4 expression promotes rapid NK cell reconstitution and functional recovery and is significantly associated with lower TRM, especially infection-related mortality. These findings underscore the clinical significance of donor HLA-Bw4 expression in patients who underwent HSCT. Hence, the consideration of donor HLA-Bw4 in recipient selection and HSCT strategies holds important clinical implications.

Objective:To evaluate the safety of patients with hepatic adenoma undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) .Methods:A retrospective analysis of the clinical characteristics and prognosis of eight patients with hepatic adenoma who underwent allo-HSCT in the Hematology Department of Peking University People’s Hospital from January 2010 to March 2024 was conducted.Results:Of the eight patients who underwent allo-HSCT with hepatic adenoma, one patient was considered MDS-h transfusion-dependent and seven had aplastic anemia. The median age of the patients was 23 years (13-48 years). The median time from the diagnosis of AA or MDS to transplantation was 14 years (6-24 years), whereas the median time from taking androgens to diagnosing hepatic adenoma was 9 years (5-13 years). Six cases underwent haplo-HSCT, one case underwent matched unrelated donor HSCT, and one case underwent matched related donor HSCT. All patients achieved neutrophil engraftment at a median time of 11.5 days (11-20 days) and PLT engraftment within 60 days at a median of 19 days (10-37 days) after haplo-HSCT. Moreover, seven patients developed CMV anemia after transplantation, three patients had hemorrhagic cystitis, and two patients developed acute GVHD. During and after transplantation, eight patients did not show severe liver function damage or rupture of hepatic adenoma. In relation to imaging size, four patients showed varying degrees of reduction in hepatic adenoma size after transplantation, whereas four patients did not show significant changes in hepatic adenoma size after transplantation. The median follow-up time was 540.5 (30-2 989) days. Of the eight patients, six survived and two died. Furthermore, no direct correlation was observed between death and hepatic adenoma.Conclusion:Patients with hepatic adenomas undergoing allo-HSCT are not contraindications for transplantation, which will not increase transplant-related mortality.

Objective To evaluate the efficacy and safety of a domestic arterial thrombus aspiration catheter in treating acute arterial ischemic events in the experimental dogs,and to compare this catheter with Penumbra suction catheter.Methods Acute ischemic embolism model was established in the external carotid and renal arteries of experimental dogs,and the experimental dogs were randomly assigned to the study group and control group.The embolized blood vessels were treated with thrombectomy.Results A total of 12 experimental dogs were enrolled in this study,with 6 dogs in each group.All of the 12 experimental dogs were successfully modeled.In the study group and the control group,the cumulative success rates of thrombectomy were 92.9％and 66.7％respectively(P＞0.05),the incidences of intraoperative vascular dissection were 0％and 8.3％respectively(P＞0.05),and the incidences of vasospasm were 35.7％and 0.75％respectively(P＞0.05).Conclusion In treating thrombus-embolized blood vessels with mechanical thrombectomy in experimental dogs,no statistically significant differences in the efficacy and safety exist between using domestic arterial thrombus aspiration catheter and using Penumbra suction catheter.(J Intervent Radiol,2023,32:1207-1210)

Objective:To investigate the safety and efficacy of haplo-identical hematopoietic stem cell transplantation (haplo-HSCT) conditioning with the same dosage form of antithymoglobulin (ATG) in patients with severe aplastic anemia (SAA) failure to ATG.Methods:This was a retrospective cohort study. A total of 65 patients with SAA who failed ATG treatment and received haplo-HSCT conditioning with the same dosage of ATG at the Institute of Hematology, Peking University People′s Hospital between July 2008 and October 2020 were included as the ATG treatment failure group. An additional 65 SAA patients who applied ATG for the first time during haplo-HSCT were randomly selected by stratified sampling as the first-line haplo-HSCT group. Baseline clinical data and follow-up data of the two groups were collected. Conditioning-related toxicity within 10 days after ATG application and long-term prognosis were analyzed. The Kaplan-Meier was used to calculate the overall survival rate, and the Log-rank test was applied to compare the rates of the two groups.Results:In the ATG treatment failure group, there were 36 males and 29 females, and the age at the time of transplantation [ M ( Q1, Q3)] was 16 (8, 25) years. In the first-line haplo-HSCT group, there were 35 males and 30 females, with a median age of 17 (7, 26) years. Within 10 days of ATG application, the incidence of noninfectious fever, noninfectious diarrhea, and liver injury in the ATG treatment failure group was 78% (51 cases), 45% (29 cases), and 28% (18 cases), respectively, and in the first-line haplo-HSCT group was 74% (48 cases), 54% (35 cases), and 25% (16 cases), respectively; the difference between the two groups was not statistically significant for any of these three parameters (all P>0.05). For graft-versus-host disease (GVHD), there was no significant difference between the ATG treatment failure group and the first-line haplo-HSCT group in the development of 100 day Ⅱ to Ⅳ acute GVHD (29.51%±0.35% vs. 25.42%±0.33%), Ⅲ to Ⅳ acute GVHD (6.56%±0.10% vs. 6.78%±0.11%), and 3-year chronic GVHD (26.73%±0.36% vs. 21.15%±0.30%) (all P>0.05). Three-year overall survival (79.6%±5.1% vs. 84.6%±4.5%) and 3-year failure-free survival (79.6%±5.1% vs. 81.5%±4.8%) were also comparable between these two groups (both P>0.05). Conclusions:Compared with no exposure to ATG before HSCT, similar early adverse effects and comparable survival outcomes were achieved in patients with SAA who failed previous ATG treatment and received haplo-HSCT conditioning with the same dosage form of ATG. This might indicate that previous failure of ATG treatment does not significantly impact the efficacy and safety of salvaging haplo-HSCT in patients with SAA.

Objective:To compare the clinical features, laboratory test results and imaging findings between cases of Mycoplasma pneumoniae ( Mp) infection complicated by coagulation dysfunction and isolated Mp infection, and analyze the predictive value of related indicators for Mp infection with coagulation dysfunction. Methods:A total of 65 cases of Mp infection complicated by coagulation dysfunction (case group) and 92 cases of isolated Mp infection (control group) treated in the Children′s Hospital Affiliated to Capital Institute of Pediatrics in 2021 were enrolled. Clinical data of the two groups were compared, and receiver operating characteristic (ROC) curves were drawn to analyze the predictive value of differential indicators to the case group. Results:There were no significant differences in the general clinical features or imaging findings between the case group and the control group. The levels of fibrinogen (FIB), D-Dimer, fibrinogen degradation product (FDP), IgE, lactic dehydrogenase (LDH), alanine transaminase (ALT), aspartate aminotransferase (AST), adenosine deaminase (ADA) and C-reactive protein (CRP), activated partial thromboplastin time (APTT), thrombin time (TT), blood platelet count (PLT), neutrophil count, length of hospital stay, peak body temperature, and duration of cough and fever in the case group were higher than those in the control group, and the differences were statistically significant ( P<0.05). The areas under ROC curves of LDH, CRP, peak body temperature, ADA, ALT, neutrophil count, AST and IgE for predicting Mp infection complicated by coagulation dysfunction were 0.855, 0.810, 0.730, 0.716, 0.692, 0.648, 0.631 and 0.603, respectively. The area under ROC curve of LDH, CRP and peak body temperature used in combination was 0.901. Conclusions:LDH, CRP, peak body temperature, ADA, ALT, neutrophil count, AST and IgE had predictive value for Mp infection complicated by coagulation dysfunction, among which LDH, CRP and peak body temperature had higher predictive value. LDH, CRP and peak body temperature used in combination had the highest diagnostic value (AUC=0.901).