ObjectiveThis study explores the methods of lung tissue extraction and fixation required for pathological studies of fetal rats, based on the unique physiological structure of fetal rat lung tissue and existing lung tissue fixation techniques for adult rats. MethodsSix pregnant adult SD rats at 20.5 days of gestation were subjected to cesarean section to obtain fetal rats. Four healthy fetal rats with similar body weight, vital signs, and respiratory status were selected from each pregnant rat, and they were randomly divided into the following groups using a random number table: direct lung infiltration group, lung infiltration group after intratracheal infusion, whole-body infiltration group of fetal rats, and whole-body infiltration group after intratracheal infusion of fetal rats. To systematically compare and analyze the anatomical morphology under different fixation methods, lung tissues from four groups of fetal rats were harvested, perfused, and fixed, and the gross morphology of lung tissues in each group was observed. Paraffin sections were prepared and stained with Hematoxylin-Eosin (H&E). The histological morphology of the whole lung, alveoli, and bronchi was further examined under optical microscopy. ResultsIn the direct lung infiltration group, the hilar structures were unclear, lung lobation was indistinct, the shape was irregular, lung cavities were small, and alveoli and bronchi were shrunken. In the lung infiltration group after intratracheal infusion, the hilar structures were clear, lobation was pronounced, the shape was regular, lung cavities were large, and alveoli and bronchi were full. Both the whole-body infiltration group and whole-body infiltration group after intratracheal infusion of fetal rats exhibited visible lungs, hearts, skins, and other organs. The lung tissues of both groups showed obvious lobulation, irregular shape, and damage at the margins of lung lobes. In the whole-body infiltration group, the thoracic cavities of the fetus were flattened, lung cavities were small, and alveoli and bronchi were shrunken. In the whole-body infiltration group after intratracheal infusion of fetal rats, the fetal thoracic cavities were full, lung cavities were large, and alveoli and bronchi were relatively full. ConclusionThe lung infiltration after intratracheal infusion method for fetal rat lung tissue fixation outperforms direct lung infiltration, whole-body infiltration of fetal rats, and whole-body infiltration after intratracheal infusion of fetal rats in terms of preservation of the lung tissue's original morphology, paraffin sectioning, staining, and pathological observation and analysis. The embedding, sectioning, and staining processes are also simple and save consumables. Therefore, intratracheal infusion followed by lung infiltration method is recommended for fixation in histopathological observation of fetal rat lung tissue.

Objective To investigate and compare the effects of electroacupuncture and dexamethasone on lung function and histomorphology and behavior in the offspring of perinatal nicotine exposure(PNE)rats.Methods Twenty-four pregnant Sprague-Dawley rats were randomly divided into control,model,electroacupuncture shallow needling,and dexamethasone groups using the random number table method(n=6 rats per group).A pulmonary dysplasia model in offspring rats with PNE was prepared by cervicodorsal subcutaneous injection with nicotine,and successful establishment of the model was confirmed by demonstrating statistically significant differences in growth parameters,lung function,and lung morphology compared to the control group.From the sixth day of maternal conception,the control group received cervicodorsal subcutaneous injection with 0.9%sodium chloride solution(1 mg/kg once per day),and the remaining groups were similarly injected with nicotine(1 mg/kg once per day).Concurrent with the nicotine injections,the electroacupuncture shallow needling group received electroacupuncture interventions at the"Zusanli"(ST 36)acupoint on both sides once a day for 20 min.In contrast,the offspring rats in the dexamethasone group received intraperitoneal dexamethasone injections from postnatal day 8(1.5 mg/kg once per day for 3 days),with a later dose of 0.75 mg/kg once per day for 4 days.Following successful model establishment,four offspring per rat were retained in each group using the random number table method.Until the 21st day after the birth of the offspring,using the random number table method,one offspring randomly selected from the four retained offspring per rat in each group was assigned to growth parameter assessment including body weight,lung weight,and lung index;simultaneously,one offspring was randomly selected for pulmonary function which was detected by a small animal pulmonary function machine,with the parameters of forced vital capacity(FVC),functional residual capacity(FRC),dynamic lung compliance(Cdyn),peak expiratory flow(PEF),peak inspiratory flow(PIF),and airway resistance(RL);concurrently,one offspring was randomly selected for hematoxylin and eosin staining to observe the histomorphology of the lung tissue,alveolar numbers,and mean alveolar septal thickness;additionally,one offspring was randomly selected for Morris water maze testing to evaluate the effects of the two intervention methods on learning and memory capabilities in offspring rats with PNE.Results Compared with the control group,the body weight,lung weight,lung index,FVC,PEF,FRC,Cdyn,alveolar number,platform crossing times,target quadrant time percentage,and target quadrant path percentage in the Morris water maze experiment were significantly decreased in the offspring rats of the model group(P<0.01).In contrast,PIF,RL,average thickness of alveolar septa,and latency of the Morris water maze experiment were significantly increased in the offspring rats of the model group(P<0.01).Compared with the model group,both electroacupuncture shallow needling group and dexamethasone group exhibited significant increases in body weight,lung weight,lung index,FVC,PEF,FRC,Cdyn,and alveolar numbers(P<0.05,P<0.01),along with significant decreases in PIF,RL values,and mean alveolar septal thickness(P<0.01).However,in the Morris water maze experiment,compared with the model group,the electroacupuncture shallow needling group demonstrated significantly more platform crossing times and a higher target quadrant time percentage and target quadrant path percentage(P<0.01),coupled with reduced latency period(P<0.01),whereas the dexamethasone group showed no significant differences compared to the model group.Compared to the electroacupuncture shallow needling group,the dexamethasone group showed significantly less platform crossing times and a lower target quadrant time percentage and target quadrant path percentage,coupled with increased latency period(P<0.01).Conclusion Both electroacupuncture and dexamethasone demonstrated protective effects on lung development in PNE offspring rats by ameliorating lung histomorphology and pulmonary function.However,offspring receiving late,small-dose,short-course dexamethasone exhibited inferior learning and memory capabilities,whereas the electroacupuncture group showed significantly superior cognitive performance compared to the dexamethasone group.

Objective To investigate and compare the effects of electroacupuncture and dexamethasone on lung function and histomorphology and behavior in the offspring of perinatal nicotine exposure(PNE)rats.Methods Twenty-four pregnant Sprague-Dawley rats were randomly divided into control,model,electroacupuncture shallow needling,and dexamethasone groups using the random number table method(n=6 rats per group).A pulmonary dysplasia model in offspring rats with PNE was prepared by cervicodorsal subcutaneous injection with nicotine,and successful establishment of the model was confirmed by demonstrating statistically significant differences in growth parameters,lung function,and lung morphology compared to the control group.From the sixth day of maternal conception,the control group received cervicodorsal subcutaneous injection with 0.9%sodium chloride solution(1 mg/kg once per day),and the remaining groups were similarly injected with nicotine(1 mg/kg once per day).Concurrent with the nicotine injections,the electroacupuncture shallow needling group received electroacupuncture interventions at the"Zusanli"(ST 36)acupoint on both sides once a day for 20 min.In contrast,the offspring rats in the dexamethasone group received intraperitoneal dexamethasone injections from postnatal day 8(1.5 mg/kg once per day for 3 days),with a later dose of 0.75 mg/kg once per day for 4 days.Following successful model establishment,four offspring per rat were retained in each group using the random number table method.Until the 21st day after the birth of the offspring,using the random number table method,one offspring randomly selected from the four retained offspring per rat in each group was assigned to growth parameter assessment including body weight,lung weight,and lung index;simultaneously,one offspring was randomly selected for pulmonary function which was detected by a small animal pulmonary function machine,with the parameters of forced vital capacity(FVC),functional residual capacity(FRC),dynamic lung compliance(Cdyn),peak expiratory flow(PEF),peak inspiratory flow(PIF),and airway resistance(RL);concurrently,one offspring was randomly selected for hematoxylin and eosin staining to observe the histomorphology of the lung tissue,alveolar numbers,and mean alveolar septal thickness;additionally,one offspring was randomly selected for Morris water maze testing to evaluate the effects of the two intervention methods on learning and memory capabilities in offspring rats with PNE.Results Compared with the control group,the body weight,lung weight,lung index,FVC,PEF,FRC,Cdyn,alveolar number,platform crossing times,target quadrant time percentage,and target quadrant path percentage in the Morris water maze experiment were significantly decreased in the offspring rats of the model group(P<0.01).In contrast,PIF,RL,average thickness of alveolar septa,and latency of the Morris water maze experiment were significantly increased in the offspring rats of the model group(P<0.01).Compared with the model group,both electroacupuncture shallow needling group and dexamethasone group exhibited significant increases in body weight,lung weight,lung index,FVC,PEF,FRC,Cdyn,and alveolar numbers(P<0.05,P<0.01),along with significant decreases in PIF,RL values,and mean alveolar septal thickness(P<0.01).However,in the Morris water maze experiment,compared with the model group,the electroacupuncture shallow needling group demonstrated significantly more platform crossing times and a higher target quadrant time percentage and target quadrant path percentage(P<0.01),coupled with reduced latency period(P<0.01),whereas the dexamethasone group showed no significant differences compared to the model group.Compared to the electroacupuncture shallow needling group,the dexamethasone group showed significantly less platform crossing times and a lower target quadrant time percentage and target quadrant path percentage,coupled with increased latency period(P<0.01).Conclusion Both electroacupuncture and dexamethasone demonstrated protective effects on lung development in PNE offspring rats by ameliorating lung histomorphology and pulmonary function.However,offspring receiving late,small-dose,short-course dexamethasone exhibited inferior learning and memory capabilities,whereas the electroacupuncture group showed significantly superior cognitive performance compared to the dexamethasone group.

Objective: To investigate the influence of hepatitis B virus X gene (HBx) on apoptosis of hepatic cells mediated by Fas in HePG2 cells. Methods: HBx eukaryotic vector pcDNA3.1(+)-X was transfected into HEPG2 cells with lipofectamine, and the null vector pcDNA3.1(+) and untransfected HEPG2 were used as normal controls. The cells were collected 72 h after transfection, and the expression of HBx mRNA and protein was determined using RT-PCR and Western blot, respectively. The mRNA expression of apoptosis-related genes Bcl-2 and Bax mRNA was also determined using RT-PCR. Cytotoxicity and apoptosis were evaluated using CCK-8 and flow cytometry, respectively, after HepG2-HBx and HepG2-3.1 cells were treated with stimulatory monoclonal antibody anti-Fas CH11. The t test was used for pairwise comparison. Results: The cell line HepG2-HBx was successfully established, as confirmed by RT-PCR and Western blot, and RT-PCR results showed that HepG2-HBx cells had significantly higher expression of Bcl-2 mRNA than HepG2-3.1 and HepG2 cells (P < 0.05), but had significantly lower expression of Bax mRNA than HepG2-3.1 and HepG2 cells (P < 0.05); CCK-8 and flow cytometry showed that anti-Fas CH11 had a lower cytotoxicity to HepG2-HBx cells and allowed for a lower apoptosis rate of HepG2-HBx cells compared with HepG2-3.1 and HepG2 cells. Conclusions HBx can inhibit apoptosis of hepatic cells mediated by the Fas pathway.