Non-clinical reproductive toxicity studies typically employ mammals like rats, rabbits, and cynomolgus monkeys, with animal pregnancy being a key challenge in such testing. This article focuses on the difficulties encountered in the animal pregnancy process and potential countermeasures. Rats can be used for fertility and early embryonic development toxicity studies (Segment Ⅰ), embryo-fetal development toxicity studies (Segment Ⅱ), and perinatal toxicity studies (Segment Ⅲ). The estrous cycle of female rats can be determined by vaginal smear, and mating behavior is confirmed through copulatory plug checks the following day after pairing one female with one male in the same cage. Rabbits are commonly used in embryo-fetal development toxicity studies (Segment Ⅱ). Mating behavior between male rabbits and estrous females is observed to determine the time of conception. However, challenges such as atypical estrus of female rabbits, large variations in estrus between batches, and mating failure often occur in reproductive toxicity testing, which may be addressed through prolonged light exposure, increased protein supplementation, optimized mating strategies, and environmental modifications like female and male rabbits are raised adjacent to each other. Non-human primates (NHPs) are typically employed in perinatal toxicity studies (Segment Ⅲ), where one of the key challenges lies in accurately determining sexual maturity in males - a critical factor for reproductive toxicity testing, which can be assessed through comprehensive evaluation of age, body weight, and testicular volume. Generally, male macaques are considered sexually mature when they meet the following criteria: age >4.5 years, body weight >4.5 kg, single testis volume >10 mL, and combined testicular volume >20 mL. For pregnancy confirmation, ultrasound examination demonstrating visible gestational sacs is required, though this necessitates experienced veterinary clinicians to establish standardized ultrasound examination protocols. In conclusion, reproductive toxicity studies should employ species-appropriate detection methods and evaluation criteria based on anatomical characteristics of the reproductive system to ensure successful mating and proper study execution.

OBJECTIVE To develop a prediction model for durable clinical benefit （DCB） in patients with advanced esophageal squamous cell carcinoma （ESCC） receiving programmed death-1 （PD-1） inhibitor. METHODS The clinical data of patients with advanced ESCC who received PD-1 inhibitor in Jieyang People’s Hospital were retrospectively collected between January 2020 to December 2023. Predictors were screened by least absolute shrinkage and selection operator （Lasso） regression， and a multivariable Logistic regression model was developed to predict DCB. A nomogram was constructed based on the model. Internal validation of the prediction model was performed by using the Bootstrap method， and the model was evaluated by the receiver operating characteristic （ROC） curve， calibration curve， and decision curve analysis. RESULTS A total of 91 patients with advanced ESCC were included. The results of Lasso regression combined with Logistic regression analysis indicated that the baseline lymphocyte monocyte ratio （LMR） [odds ratio （OR）＝1.97， 95% confidence interval （CI）： 1.15-3.36， P＝0.013]， albumin （ALB） content （OR＝1.35， 95%CI： 1.13-1.60， P＜0.001）， body mass index （BMI） category 1 [normal vs. low： OR＝ 0.28， 95%CI （0.09-0.96）， P＝0.042]， BMI category 2 [overweight-obesity vs. low： OR＝0.08， 95%CI （0.01-0.59）， P＝0.013]， and treatment regimen [monotherapy vs. monotherapy combination therapy： OR＝0.07， 95%CI （0.01-0.50）， P＝0.008] were predictive factors for patients with advanced ESCC to achieve DCB when treated with PD-1 inhibitor. A prediction model was constructed based on the above indicators. Internal validation of the model using the Bootstrap method showed an area under the curve of 0.831 （95%CI： 0.746-0.904）， with specificity of 74.4% and sensitivity of 75.0%. The Hosmer-Lemeshow test yielded χ2＝ 9.930， P＝0.270， and the calibration curve slope was close to 1. The decision curve analysis demonstrated that the model exhibited good clinical utility within a threshold range of 0.1 to 1.0. CONCLUSIONS The prediction model based on baseline LMR， ALB content， BMI， and treatment regimen demonstrates robust predictive performance and clinical utility for assessing therapeutic efficacy of PD-1 inhibitor in the treatment of advanced ESCC.

Positron emission tomography (PET) now plays an important role in the research and development (R&D) of central nervous system (CNS) drugs. PET could characterize the biodistribution, pharmacokinetics, and receptor binding of CNS drugs quantitatively. The present review summarized the quantitative methods of PET used in the pharmacokinetics and receptor occupancy analysis of CNS drugs. Moreover, the present review listed various applications of PET supporting R&D of CNS drugs, which could provide a new direction for the R&D of CNS drugs.

Objective lo analyze the difference of peri-coronary tat attenuation index(pr Al)on different grades of hypertension(HT),and to explore the value of pFAI in evaluating the risk of HT patients.Methods Retrospective data on hospitalized patients who underwent coronary computed tomography angiography(CCTA)examination for chest pain were collected.A total of 415 clini-cally confirmed HT patients were selected as observation group(including 132 patients in grade 1 HT group,137 patients in grade 2 HT group,146 patients in grade 3 HT group),and 187 non-hypertension patients during the same period as control group.The differ-ence of fat attenuation index(FAI)in three main coronary arteries[left anterior descending artery(LAD),left circumflex artery(LCX),right coronary artery(RCA)]was compared,and the correlation between pF AI and HT patients was analyzed.Results RCA-FAI(-78.86 HU±7.66 HU)and LAD-FAI(-80.62 HU±7.50 HU)were higher in HT group than those in control group(-84.46 HU± 8.00 HU,-83.43 HU±7.51 HU,P＜0.05).pFAI value was higher in grade 3 HT group than that in grade 1 HT group and grade 2 HT group(P＜0.05),while there were no differences between grade 1 HT group and grade 2 HT group(P＞0.05).After adjusting the influence of traditional risk factors and coronaryartery disease,RCA-FAI had relatively closer relationship with HT grades(r=0.47,P＜0.001).Conclusion LAD-FAI,RCA-FAI in the HT group are higher than those in control group and RCA-FAI has relatively closer relationship with HT grades,suggesting that RCA-FAI may be an imaging indicator to evaluate the pro-gression of HT and predict the risk of HT.

Objective:To analyze the differentially expressed genes (DEGs) in visceral adipose tissue of patients with type 2 diabetes mellitus (T2DM) based on bioinformatics.Methods:The microarray dataset GSE78721 was downloaded from the Gene Expression Omnibus (GEO) database, including visceral fat samples data from 19 T2DM patients and 16 non-diabetic subjects. The analysis of transcriptomic profiling results from tissue samples was conducted, and a comparison between different groups of samples based on gender was performed. The online Xintao Academic Database was utilized for the analysis, employing the "limma" package in R language to filter DEGs. Subsequently, the DEGs were visualized, and Gene Ontology (GO) functional annotation along with Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were carried out and visualized. Based on the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, a protein-protein interaction network (PPI) of DEGs was constructed and key differentially expressed genes were identified and visualized using Cytoscape software.Results:Analysis of visceral adipose tissue gene expression profiles revealed 168 DEGs (|log 2FC|≥1, P<0.05). In females, 42 mRNAs were up-regulated, 3 were down-regulated; in males, 105 were up-regulated, 37 were down-regulated, 19 genes were shared by the two groups. GO analysis linked DEGs to insulin-like growth factor receptor signaling and regulation, nutrient response, and leukocyte migration. KEGG analysis implicated extracellular matrix receptor interactions and leukocyte transendothelial migration. The PPI network unveiled 10 key genes, including COL1A1, COL1A2, TGFB3, PCOLCE, TIMP1, COL6A2, COMP, COL14A1, VCAM1 and THY1. Conclusion:Bioinformatics technology can effectively analyze and screen DEGs in visceral adipose tissue of T2DM patients, providing useful clues for further exploring its molecular mechanism and finding therapeutic targets.

Objective:To investigate the feasibility of using spectral CT chest enhancement venous phase images to obtain virtual non-contrast (VNC) images and virtual arterial phase images to achieve one phase scan instead of three phase scans.Methods:Imaging data of 100 patients who underwent spectral CT chest plain and dual-phase enhancement scans at the First Affiliated Hospital of Kunming Medical University from January to May 2022 were analyzed retrospectively. The venous phase images of all patients were post-processed to obtain virtual non contrast (VNC) and 40 keV virtual mono-energy images (VMI) for simulated arterial phase images (Vart). Image quality and lesion detection were compared between true non-contrast (TNC) and VNC images, and conventional arterial phase (CIart) and Vart images by paired t-test, Wilcoxon test and McNemar test. Objective evaluation indexes of image quality included thoracic aorta, all levels of pulmonary artery, T4 vertebral bone cancellous, chest wall fat CT value, background noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR); the subjective score of image quality was assessed by double-blind method on a 5-point scale; the assessment of lesion detection included the detection rate of calcified foci and pulmonary nodules size, density, volume, percentage of solid components and imaging characteristics. Results:Except for chest wall fat and T4 vertebral bone cancellous, the differences in CT values between VNC and TNC images were not statistically significant ( P>0.05); Except for right upper pulmonary artery and right lower pulmonary artery, the differences in background noise values and SNR between TNC images and VNC images were statistically significant ( P<0.05). Compared with CIart images, the CT values of chest wall fat were lower in Vart images ( P<0.05), and the CT values of the remaining sites were significantly higher ( P<0.05); the background noise values of all sites on Vart images were smaller than those on CIart images, and the SNR and CNR values were higher than those on CIart images ( P<0.05).The differences of subjective scores of images quality were not statistically significant between TNC and VNC images, between CIar and Vart images ( P>0.05). Taking TNC as the standard, the overall detection rate of VNC for calcification was 88.53% (301/340). Except for the short diameter of partially solid nodules, the differences of qualitative and quantitative assessment indexes of lung nodules between TNC and VNC images were not statistically significant ( P>0.05). Conclusions:Spectral CT chest venous phase 40 keV VMI can simulate arterial phase images in the diagnosis of vascular lesions, and venous phase VNC basically meets the standard of conventional plain scan, so it is feasible to replace plain scan, arterial phase and venous phase images in a certain range.

Objective To explore the efficacy and safety of traditional Chinese medicine(TCM) combined with chemotherapy in the prevention and treatment of postoperative recurrence and metastasis of locally advanced gastric cancer (LAGC) by meta-analysis. Moreover, we evaluated the efficacy of TCM on the quality of life, immune indexes, and toxic and side effects during adjuvant chemotherapy. Methods The CNKI, Wanfang, PubMed, and other databases were searched by computer. Randomized controlled trials (RCTs) were searched. After literature screening and data extraction, Review Manager 5.3 software provided by Cochrane was used for meta-analysis. Results A total of 18 RCTs were included. Compared with chemotherapy alone, TCM combined with chemotherapy could improve the KPS score and CD3⁺ and CD4⁺/CD8⁺ index levels. The incidence rates of postoperative leucopenia, hemoglobin reduction, thrombocytopenia, nausea and vomiting, diarrhea, and neurotoxicity were reduced. In terms of postoperative QLQ-C30 score, abnormal liver function, and abnormal renal function, the incidence of TCM combined chemotherapy was similar to that of chemotherapy alone, with no statistical difference. Compared with chemotherapy alone, TCM combined chemotherapy could reduce the 1-, 2-, 3-, and 5-year cumulative recurrence and metastasis rates and prolong the disease-free survival time. Conclusion Compared with chemotherapy alone in adjuvant chemotherapy, TCM combined chemotherapy could improve the immune level and KPS score of LACC patients after surgery, reduce the incidence of adverse reactions, as well as reduce the recurrence and metastasis rate of LAGC after surgery and DFS could be improved.

Natamycin is a safe and efficient antimycotics which is widely used in food and medicine industry. The polyene macrolide compound, produced by several bacterial species of the genus Streptomyces, is synthesized by type Ⅰ polyketide synthases using acetyl-CoA, malonyl-CoA, and methylmalonyl-CoA as substrates. In this study, four pathways potentially responsible for the supply of the three precursors were evaluated to identify the effective precursor supply pathway which can support the overproduction of natamycin in Streptomyces gilvosporeus, a natamycin-producing wild-type strain. The results showed that over-expressing acetyl-CoA synthetase and methylmalonyl-CoA mutase increased the yield of natamycin by 44.19% and 20.51%, respectively, compared with the wild type strain under shake flask fermentation. Moreover, the yield of natamycin was increased by 66.29% compared with the wild-type strain by co-overexpression of acetyl-CoA synthetase and methylmalonyl-CoA mutase. The above findings will facilitate natamycin strain improvement as well as development of strains for producing other polyketide compounds.
Natamycin/metabolism* ; Methylmalonyl-CoA Mutase/metabolism* ; Acetyl Coenzyme A/metabolism* ; Streptomyces/genetics* ; Polyketide Synthases/metabolism*

Objective:To investigate the clinical manifestations of acquired immunodeficiency syndrome(AIDS) patients with initial-stage cytomegalovirus (CMV) retinitis (CMVR).Methods:Retrospective case series study. From July 2017 to November 2019, 21 patients with 22 eyes of AIDS combined with CMVR in the initial stage of AIDS and CMVR diagnosed in the eye examination in the study. Among them, there were 19 males with 19 eyes and 2 females with 3 eyes; the average age was 34.3±9.6 years. The average CD4 + T lymphocyte count of patients was 26.1±23.2/μl. Routine fundus screening revealed 17 cases, and the contralateral eye disease was found in 4 cases. There were 13 cases of CMVR in both eyes (61.9%, 13/21). Among them, both eyes were in the initial stage of CMVR, and the contralateral eyes were in the early stage of CMVR in 12 cases. The contralateral eye included 2 cases of human immunodeficiency virus-related retinal microangiopathy, 1 case of optic disc edema, and 5 cases of no obvious abnormality on fundus examination. All patients underwent slit lamp microscopy and ultra-wide-angle fundus photography examination. At the same time, 18 eyes underwent optical coherence tomography (OCT). Blood CMV-DNA detection was performed in 17 cases within 1 week before the first diagnosis; aqueous CMV-DNA detection was performed in 7 eyes within 1 week after the first diagnosis. Within 1 week after the fundus examination, 8 eyes of 8 cases and 8 eyes of 7 cases were received and not received systemic anti-CMV treatment; the treatment status was unknown in 6 cases and 6 eyes. After treatment, 18 eyes of 17 cases were followed up. The follow-up time was 0.5-28 months. Results:There were no obvious abnormalities in the anterior segment examination of all the affected eyes; the vitreous body was transparent. The fundus lesions were less than 1 optic disc diameter (DD), and they were white granular, clustered, with blurred edges. Among them, there were granular satellite lesions around the lesion in 18 eyes (81.8%, 18/22). The lesions were located in 19 eyes (86.4%, 19/22) in zone 2, 1 eye in zone 1 and 2 (4.5%, 1/22), and 2 eyes in zone 3 (9.1%, 2/22). In 18 eyes that underwent OCT examination, 12 eyes failed to obtain image data because the lesion was not in the conventional scanning range; the other 6 eyes showed the inner or full retina thickened or atrophy depression, structural destruction, accompanied by local vitreous punctate strong reflection. Among the 17 patients who underwent blood CMV-DNA testing, 1 (5.9%, 1/17) and 16 (94.1%, 16/17) cases were CMV-DNA negative and positive, respectively. The 7 eyes that underwent the CMV-DNA test of aqueous humor were all negative. Among the 18 eyes who were followed up, the lesions did not expand, and gradually subsided and absorbed in 4 eyes (22.2%, 4/18); the varying degrees of lesion enlargement in 14 eyes (77.8%, 14/18).Conclusion:The patients with AIDS and CMVR at the initial stage have no obvious ocular symptoms; the fundus shows white granular lesions less than 1 DD with blurred edges.

Objective:To observe the ultra-wide-angle fundus imaging characteristics of acquired immunodeficiency syndrome (AIDS) combined with cytomegalovirus retinitis (CMVR).Methods:This study was a retrospective study. From July 2017 to November 2019, 124 eyes of 86 patients diagnosed with AIDS and CMVR at the Department of Ophthalmology, Beijing You'an Hospital, Capital Medical University, were included in the study. Among them, 80 patients were males (93.0%) and 6 patients were females (7.0%) with 17-58 years old. The average age was (36.86±8.82) years old. There were 48 cases (55.8%) in one eye and 38 cases (44.2%) in both eyes. All the affected eyes underwent indirect ophthalmoscope fundus examination and Aalborg ultra-wide-angle fundus photography examination. According to the characteristics of CMVR in ultra-wide-angle fundus images, it can be divided into classic type, granular type, frost-like dendritic vasculitis and optic neuroretinitis. We observed and analyzed the type of fundus of the affected eye. According to the position of the vortex vein in the fundus image and record of the lesion as the posterior pole or peripheral part, the scope of the lesion was divided into ≤1 quadrant, >1 quadrant and ≤2 quadrants (1-2 quadrants), >2 quadrants and ≤3 quadrants (2-3 quadrants), >3 and ≤4 quadrants (3-4 quadrants). The upper and lower vascular arches or disc edges of the macula were used as boundaries to record whether the macular area or optic disc was involved. At the same time, we recorded whether the vitreous body had obvious turbidity. The comparison of CD4 + T lymphocyte count between patients of different types was performed by one-way analysis of variance, and the comparison of the positive rate of blood CMV-DNA was performed by the χ2 test; pairwise comparisons between groups were performed by the least significant difference method. Results:Among the 124 eyes, CMVR was classified into 35 eyes (28.2%) with classic type, 68 eyes with granular type (54.8%), 3 eyes with frost-like dendritic vasculitis (2.4%), and 18 eyes with optic neuroretinitis (14.5%). The lesion involved 83 eyes (66.9%) at both the posterior pole and the periphery, 22 eyes (17.7%) confined to the posterior pole, and 19 eyes (15.3%) confined to the periphery; the extent of the lesion was ≤1 quadrant in 76 eyes (61.3%), 23 eyes (18.5%) in 1-2 quadrants, 7 eyes (5.6%) in 2-3 quadrants, and 18 eyes (14.5%) in 3-4 quadrants. 54 eyes (43.5%) showed lesions involving the macular area; 52 eyes (41.9%) had lesions involving the optic disc; 33 eyes (26.6%) showed obvious vitreous inflammatory opacities. Among 86 patients, the average number of CD4 + T lymphocytes in 82 patients was 1 to 168 cells/μl, with an average of 33.60±40.02 cells/μl; the remaining 4 patients (4.7%) were unknown. There was no statistically significant difference in the positive rate of CD4 + T lymphocyte count and blood CMV-DNA load between patients in different subtypes groups ( F=0.863, 0.926; P=0.462, 0.431). Conclusion:The ultra-wide-angle fundus images of AIDS combined with CMVR have certain characteristics, which can manifest as classic, granular, frost-like dendritic vasculitis and optic neuroretinitis.