Diabetic retinopathy(DR)is a late-stage peripheral micro-neurovascular complication of chronic hyperglycemia, leading to blood-retinal barrier impairment and retinal dysfunction. Recent studies have found that diabetic neuroretinopathy(DN)may be one of the earliest events in diabetic retinal alterations. The main features include defective electroretinographic responses in newly diagnosed patients, early self-activation of microglia and Müller cells, reduced activity of neurotransmitters(e.g., DOPA/GABA), and early mitochondrial dysfunction, such as persistent Drp1-Fis1 fission and mtDNA methylation mismatches. Understanding the molecular basis of DN is essential for elucidating its pathogenesis and developing early treatments. This review summarizes pathological changes and mechanisms of retinal function, glial cells, neurotransmitters, mitochondria, and other factors in early diabetes mellitus, in order to provide a theoretical foundation for investigating early DN mechanisms and developing targeted therapies.

OBJECTIVE To investigate the impact of dapagliflozin on contrast-induced acute kidney injury （CIAKI） and prognosis in patients with diabetes mellitus type 2 （T2DM） and acute coronary syndrome （ACS） who underwent percutaneous coronary intervention （PCI）. METHODS Retrospective selection of data on T2DM patients with ACS who underwent PCI treatment in the Cardiology Department of Tianjin Chest Hospital from January 1st 2021 to December 31st 2022. The patients were divided into dapagliflozin group （96 cases） and control group （148 cases） based on whether they received dapagliflozin or not. Renal function indicators were measured for all enrolled patients before PCI and at 48 h and 1 week after PCI， including blood urea nitrogen （BUN）， serum creatinine （Scr）， estimated glomerular filtration rate （eGFR）， cystatin-C （Cys-C）， kidney injury molecule-1 （KIM-1） and β2-microglobulin （β2-MG）. All patients were followed up for at least 1 year. The incidence of CIAKI and major adverse cardiac event （MACE） during follow-up were recorded for both groups. Logistic regression was used to analyze the impact of dapagliflozin on the occurrence of CIAKI， while the Log-rank test was applied to compare the incidence of MACE between the two groups. Cox regression was employed to analyze the impact of dapagliflozin on prognosis. RESULTS At 48 h and 1 week after PCI， serum levels of Cys-C， KIM-1 and β2-MG were significantly lower in the dapagliflozin group compared to the control group （P＜0.05）. The incidence of CIAKI was lower in the dapagliflozin group compared to the control group （6.25% vs. 14.86%， P＝0.042）. Logistic regression analysis revealed that dapagliflozin was an independent protective factor against CIAKI （OR＝0.280， 95%CI 0.101-0.780，P＝0.015）. During the follow-up period， the incidence of MACE was lower in the dapagliflozin group compared to the control group （7.29% vs. 17.57%， P＝0.049）. Cox regression analysis indicated that dapagliflozin reduced the occurrence of MACE after PCI （HR＝0.374， 95%CI 0.161-0.866， P＝0.022）. CONCLUSIONS With adequate hydration， the use of dapagliflozin does not increase the risk of CIAKI following PCI in T2DM patients with ACS.

Acute lung injury （ALI） is a clinically critical disease with limited treatment options and poor prognosis， with high morbidity and mortality. Pulmonary inflammation caused by trauma， infection， and other factors in vivo and in vitro can damage alveolar epithelial and vascular endothelial barriers， resulting in lung tissue congestion and edema and eventually leading to significant dyspnea and hypoxemia， It can further develop into acute respiratory distress syndrome. Oxidative stress is one of the pathogenesis of ALI. A large number of reactive oxygen species （ROS） can promote the aggregation of inflammatory cells， increase pulmonary capillary permeability， and even directly damage lung tissue. Therefore， regulating oxidative stress becomes one of the effective means to reduce the degree of lung injury. According to the theory of traditional Chinese medicine （TCM）， ALI is divided into the categories of "sudden wheezing" and "dyspnea due to wheezing". TCM treats the causes of dampness， heat， poison， and stasis by syndrome differentiation and treatment， regulates Qi and blood， and balances Yin and Yang to restore the physiological function of the lung. In recent years， a large number of studies have shown that TCM can regulate ROS through multiple targets and mechanisms and play a role in reducing lung inflammation and protecting alveolar epithelial cells and endothelial vessels， in which the nuclear factor E₂ associated factor 2 （Nrf2） antioxidant pathway plays an important role. Based on the generation and clearance of ROS， this article summarized the related mechanisms of TCM monomers， TCM pairs， and TCM compounds in regulating oxidative stress to prevent ALI， so as to provide theoretical reference for the research and development of new TCM for ALI and clinical treatment.

AIM:To study the relationship between ocular parameters and lens thickness(LT)in myopic patients with different anterior chamber depth(ACD).METHODS:Cross-sectional study. A total of 118 myopic subjects(236 eyes)underwent posterior chamber phakic implantable collamer lens(Phakic-ICL)implantation in the refractive department of our hospital from May 2022 to May 2024 were selected. Ocular parameters examined before surgery included uncorrected visual acuity(UCVA), subjective refraction, best corrected visual acuity(BCVA), contactless intraocular pressure(IOP), ACD, white-to-white(WTW), horizontal sulcus-to-sulcus(STSH), vertical sulcus-to-sulcus(STSV), and LT. ACD without corneal thickness was measured by Pentacam, and subjects were divided into three groups: shallow anterior chamber group(2.8 mm≤ACD≤3.2 mm), middle anterior chamber group(3.2 mm3.4 mm). The differences in WTW, STSH, STSV, and LT among groups were compared, and the correlation between the above parameters under different ACD groups was analyzed, as well as the multiple linear regression analysis was used to research LT with the above ocular parameters.RESULTS:There was no statistically significant difference in LT between the middle ACD group and the deep ACD group(P=1.00), while there were statistically significant differences in LT between shallow and middle ACD groups(P<0.0167); there were statistical significant differences in WTW, STSH and STSV among different ACD groups(F=226.36, 15.58, 11.92, all P<0.01), but the differences were varied after pairwise comparison. There was a weak negative correlation between LT and ACD only in the shallow ACD group and overall data of patients(r=-0.231, P<0.05; r=-0.222, P<0.01). There was no correlation in LT and ocular parameters between the middle ACD group and deep ACD group(all P>0.05); moderate correlations were discovered among WTW, STSH and STSV in different ACD groups and overall data(all P<0.01); in the overall data of patients, ACD had weak to low correlations with WTW, STSH, STSV and LT(all P<0.01). Through multiple linear regression analysis, it was found that only the shallow ACD group and the overall data had statistically significant independent variables that were linearly correlated with LT, and their equations were as follows: LTS=5.492-0.167×WTW+0.267×STSV-0.448×ACD; LTT=3.884-0.303×ACD, the corrected R2 of equations showed low values, revealed 0.141 and 0.056, respectively.CONCLUSION:Among different ACD groups, there was no correlation or linear relationship between LT and WTW, STSH and STSV; in the shallow ACD group and the overall data, LT had a weak negative correlation with ACD, and its corrected R2 was low. Therefore, there is no linear relationship between LT and ocular diameter parameters under different ACD.

OBJECTIVE To establish a method for determining the contents of clopidogrel （CLP）， clopidogrel carboxylate （CLP-C）， clopidogrel acyl-β-D-glucuronide （CLP-G） and contents of clopidogrel active metabolite （CAM） in rat plasma， and to investigate their in vivo pharmacokinetic characteristics. METHODS The Shisedo CAPCELL ADME column was used with a mobile phase consisting of water and acetonitrile （both containing 0.1% formic acid） in a gradient elution. The flow rate was 0.4 mL/min， and the column temperature was maintained at 20 ℃. The injection volume was 2 μL. The analysis was performed in positive ion mode using electrospray ionization with multiple reaction monitoring. The ion pairs for quantitative analysis were m/z 322.1→211.9 （for CLP）， m/z 308.1→197.9 （for CLP-C）， m/z 322.1→154.8 （for CLP-G）， m/z 504.1→154.9 [for racemic CAM derivative （CAMD）]. Six rats were administered a single intragastric dose of CLP （10 mg/kg）. Blood samples were collected before medication and at 0.08， 0.33， 0.66， 1， 2， 4， 6， 10， 23 and 35 hours after medication. The established method was used to detect the serum contents of various components in rats. Pharmacokinetic parameters were then calculated using WinNonlin 6.1 software. RESULTS The linear ranges for CLP， CLP-C and CAMD were 0.08-20.00， 205.00-8 000.00， and 0.04-25.00 ng/mL， respectively （r≥0.990）. The relative standard deviations for both intra-day and inter-day precision tests were all less than 15%， and the relative errors for accuracy ranged from －11.68% to 14.40%. The coefficients of variation for the matrix factors were all less than 15%， meeting the requirements for bioanalytical method validation. The results of the pharmacokinetic study revealed that， following a single intagastric administration of CLP in rats， the exposure to the parent CLP in plasma was extremely low. Both the area under the drug concentration-time curve （AUC0-35 h） and the peak concentration of the parent CLP were lower than those of its metabolites. The AUC0-35 h of the active metabolite CAM was approximately 43 times that of CLP， though it had a shorter half-life （2.53 h）. The inactive metabolite CLP-C exhibited the highest exposure level， but it reached its peak concentration the latest and was eliminated slowly. The AUC0-35 h of CLP-G was about four times that of CAM， and its half-life was similar to that of CLP-C. CONCLUSIONS This study successfully established an liquid chromatography-tandem mass spectrometry method for the determination of CLP and its three metabolites， and revealed their pharmacokinetic characteristics in rats. Specifically， the parent drug CLP was rapidly eliminated， while the inactive metabolites CLP-C and CLP-G exhibited long half-lives， and active metabolite CAM displayed a transient exposure pattern.

ObjectiveTo clarify the repair effect of Mume Fructus on the intestinal mucosal epithelial barrier in the mouse model of inflammatory bowel disease （IBD） and explore the repair mechanism. MethodsThirty-six male C57BL/6 mice were randomly assigned into six groups： normal， model， low-， medium-， and high-dose （200， 400， and 800 mg·kg^-1） Mume Fructus， and sulfasalazine （300 mg·kg^-1）. Except the normal group， the rest groups had free access to 2% dextran sulfate sodium （DSS） solution for seven days to establish the IBD model， followed by a seven-day drug intervention. The body weight change and disease activity index （DAI） were recorded. After the last administration， spleen and colon tissue samples were collected to analyze the differences in colon length and spleen index. Hematoxylin-eosin staining was used to observe the morphology of the colon tissue. The level of diamine oxidase （DAO） in the serum was measured by the DAO assay kit. Immunohistochemistry was employed to determine the expression of tight junction proteins such as Claudin-1， Occludin， and zonula occludens-1 （ZO-1） in the colon tissue. Real-time PCR was performed to measure the mRNA levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） in the colon tissue. Finally， Western blot was employed to determine the protein levels of mitogen-activated protein kinase kinase （MEK）， extracellular signal-regulated kinase （ERK）， phosphorylated （p）-MEK， and phosphorylated ERK in the colon tissue. ResultsCompared with the normal group， the model group exhibited decreases in body weight and colon length （P<0.01）， increases in DAI， spleen index， and serum DAO level （P<0.01）， damaged colonic epithelium and goblet cells， and obvious infiltration of inflammatory cells. In addition， the model group exhibited higher positive expression of Claudin-1， Occludin， and ZO-1 （P<0.01）， higher mRNA levels of TNF-α and IL-1β （P<0.01）， and higher protein levels of p-MEK and p-ERK （P<0.05， P<0.01） than the normal group. However， sulfasalazine and three doses of Mume Fructus markedly decreased the body weight and DAI （P<0.05）， recovered the colon length and spleen index， alleviated colon tissue damage， lowered the level of DAO in the serum （P<0.01）， and down-regulated the mRNA levels of TNF-α and IL-1β （P<0.01） and the protein levels of p-MEK and p-ERK （P<0.05）. Sulfasalazine and low- and medium-dose Mume Fructus increased the positive expression of Occludin， Claudin-1， and ZO-1 （P<0.05， P<0.01）. Furthermore， high-dose Mume Fructus elevated the protein expression of Occludin （P<0.05）. ConclusionMume Fructus can restore the expression of intestinal epithelial tight junction proteins by inhibiting the phosphorylation of proteins in the MEK/ERK signaling pathway and down-regulating the levels of TNF-α and IL-1β， thus repairing the intestinal mucosal barrier in the mouse model of IBD.

ObjectiveIn nature, objects cast shadows due to illumination, forming the basis for stereoscopic perception. Birds need to adapt to changes in lighting (meaning they can recognize stereoscopic shapes even when shadows look different) to accurately perceive different three-dimensional forms. However, how neurons in the key visual brain area in birds handle these lighting changes remains largely unreported. In this study, pigeons (Columba livia) were used as subjects to investigate how neurons in pigeon’s ventrolateral mesopallium (MVL) represent stereoscopic shapes consistently, regardless of changes in lighting. MethodsVisual cognitive training combined with neuronal recording was employed. Pigeons were first trained to discriminate different stereoscopic shapes (concave/convex). We then tested whether and how light luminance angle and surface appearance of the stereoscopic shapes affect their recognition accuracy, and further verify whether the results rely on specify luminance color. Simultaneously, neuronal firing activity of neurons was recorded with multiple electrode array implanted from the MVL during the presentation of difference shapes. The response was finally analyzed how selectively they responded to different stereoscopic shapes and whether their selectivity was affected by the changes of luminance condition (like lighting angle) or surface look. Support vector machine (SVM) models were trained on neuronal population responses recorded under one condition (light luminance angle of 45°) and used to decode responses under other conditions (light luminance angle of 135°, 225°, 315°) to verify the invariance of responses to different luminance conditions. ResultsBehavioral results from 6 pigeons consistently showed that the pigeons could reliably identify the core 3D shape (over 80% accuracy), and this ability wasn’t affected by changes in light angle or surface appearance. Statistical analysis of 88 recorded neurons from 6 pigeons revealed that 83% (73/88) showed strong selectivity for specific 3D shapes (selectivity index>0.3), and responses to convex shapes were consistently stronger than to concave shapes. These shape-selective responses remained stable across changes in light angle and surface appearance. Neural patterns were consistent under both blue and orange lighting. The decoding accuracy achieves above 70%, suggesting stable responses under different conditions (e.g., different lighting angles or surface appearance). ConclusionNeurons in the pigeon MVL maintain a consistent neural encoding pattern for different stereoscopic shapes, unaffected by illumination or surface appearance. This ensures stable object recognition by pigeons in changing visual environments. Our findings provide new physiological evidence for understanding how birds achieve stable perception (“invariant neural representations”) while coping with variations in the visual field.

Objective To evaluate the bioequivalence of metronidazole tablet and reference formulation in Chinese healthy subjects.Methods A single-dose,two-cycle,randomized,open,self-crossover trial was designed with 48 healthy subjects randomly assigned to fasting or postprandial group.For each group,a single oral dose of metronidazole tablet(200 mg)or a reference preparation(200 mg)per cycle were enrolled.The concentration of metronidazole in plasma was measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS).The non-compartmental model was applied to calculate the pharmacokinetic parameters for bioequivalence analysis via SAS 9.3 software.Results The main pharmacokinetic parameters of test and reference metronidazole tablets in the fasting group were as follows,the Cmax were(4 855.00±1 383.97)and(4 799.13±1 195.32)ng·h·mL-1;the AUC0-t were(54 834.68±12 697.88)and(55 931.35±11 935.28)ng·h·mL-1;the AUC0-∞ were(56 778.09±13 937.76)and(57 922.83±13 260.54)ng·h·mL-1;the Tmax were respectively 1.17 and 1.00 h;t1/2 were(8.99±1.76)and(9.11±1.73)h,respectively.The ratio of the geometric mean and its 90％confidence intervals(CI)of Cmax,AUC0-t and AUC0-∞ were all within the equivalent interval of 80.00％-125.00％.As for postprandial conditions,the main pharmacokinetic parameters of test and reference metronidazole tablets were as follows,the Cmax were(4 057.08±655.08)and(4 044.17±773.98)ng·h·mL-1;the AUC0-t were(55 956.42±12 228.12)and(55 121.04±11 784.55)ng·h·mL-1;the AUC0-∞ were(58 212.83±13 820.00)and(57 350.38±13 229.46)ng·h·mL-1;the Tmax were 2.50 and 2.25 h;the t1/2 were(9.37±1.68)and(9.37±1.79)h,respectively.The ratio of the geometric mean and 90％CI of Cmax,AUC0-t and AUC0-∞ were all within the equivalent interval of 80.00％-125.00％.Conclusion The two preparations were bioequivalent to Chinese healthy adult volunteers under both fasting and fed conditions.

Manganese superoxide dismutase catalyzes the dismutation of two molecules of superoxide radicals to one molecule of oxygen and one molecule of hydrogen peroxide. The oxidation of superoxide anion to oxygen by Mn³⁺SOD proceeds at a rate close to diffusion. The reduction of superoxide anion to hydrogen peroxide by Mn²⁺SOD can be progressed parallelly in either a fast or a slow cycle pathway. In the slow cycle pathway, Mn²⁺SOD forms a product inhibitory complex with superoxide anion, which is protonated and then slowly releases hydrogen peroxide out. In the fast cycle pathway, superoxide anion is directly converted into product hydrogen peroxide by Mn²⁺SOD, which facilitates the revival and turnover of the enzyme. We proposed for the first time that temperature is a key factor that regulates MnSOD into the slow- or fast-cycle catalytic pathway. Normally, the Mn²⁺ rest in the pent-coordinated state with four amino acid residues (His26, His74, His163 and Asp159) and one water (WAT1) in the active center of MnSOD. The sixth coordinate position on Mn (orange arrow) is open for water (WAT2, green) or O₂^• to coordinate. With the cold contraction in the active site as temperature decreases, WAT2 is closer to Mn, which may spatially interfere with the entrance of O₂^• into the inner sphere, and avoid O₂^•/Mn²⁺ coordination to reduce product inhibition. Low temperature compels the reaction into the faster outer sphere pathway, resulting in a higher gating ratio for the fast-cycle pathway. As the temperature increases in the physiological temperature range, the slow cycle becomes the mainstream of the whole catalytic reaction, so the increasing temperature in the physiological range inhibits the activity of the enzyme. The biphasic enzymatic kinetic properties of manganese superoxide dismutase can be rationalized by a temperature-dependent coordination model of the conserved active center of the enzyme. When the temperature decreases, a water molecule (or OH^-) is close to or even coordinates Mn, which can interfere with the formation of product inhibition. So, the enzymatic reaction occurs mainly in the fast cycle pathway at a lower temperature. Finally, we describe the several chemical modifications of the enzyme, indicating that manganese superoxide dismutase can be rapidly regulated in many patterns (allosteric regulation and chemical modification). These regulatory modulations can rapidly and directly change the activation of the enzyme, and then regulate the balance and fluxes of superoxide anion and hydrogen peroxide in cells. We try to provide a new theory to reveal the physiological role of manganese superoxide dismutase and reactive oxygen species.

Objective:To study the clinical safety and validity of retrograde new endoscopic field of vision in miniature pigs.Methods:6 live miniature pigs were selected as study subjects,En-doscopic Retrograde New View(ERNV)was selected.The performance,image quality and intraoper-ative and postoperative complications were evaluated.To evaluate whether all the experimental ani-mals could complete the relevant endoscopy.Verify ERNV's operating performance,including whether the duodenoscope can enter the biliary tract smoothly,and made sure whether the injection,suction,and instrument channels were unobstructed.Choledochoscope image clarity,color resolu-tion,image deformation and distortion,accurate evaluation of lumen conditions and clear observation of mucosal surface conditions were analyzed.Whether there were operant injuries such as bleeding and perforation,as well as adverse events such as respiratory depression and cardiac arrest.The sur-vival status and adverse reactions of all pigs were observed.Results:The choledochoscope was successfully inserted into the bile duct of 6 miniature pigs.The product had good operation perfor-mance and could enter the bile duct through the duodenoscope smoothly.The injection,suction and instrument channels were relatively smooth.In addition,the endoscopic images are clear,with better color resolution,and without image deformation and distortion,which can realize accurate evaluation of the conditions in the lumen and observe the mucosal surface conditions more clearly.No bile duct stenosis or dilatation occurred in all miniature pigs,and the bile duct mucosa was smooth,without hyperemia and edema,and no abnormal thickening or bending of mucous vessels.During the exami-nation,there were no operational injuries such as bleeding and perforation,and no adverse events such as respiratory depression and cardiac arrest occurred.The vital signs of all miniature pigs tended to be stable after operation,and the survival state was good,and there were no complications such as cholangitis,bleeding and perforation.Conclusion:ERNV has good clinical safety and efficacy,ex-cellent operation performance and excellent image quality,and is worthy of clinical application.