Objective To explore the mechanism of pulmonary hypoplasia in case of congenital diaphragmatic hernia (CDH), and study the ultramicrostructural features of lung tissue of CDH fetal rat models at different developmental stages. Methods Seven SpragueDawley (SD) pregnant rats were randomly divided into CDH group (n=4) and control group (n=3). For the rats in the CDH group, Nitrofen was used to fill in the stomach once at day 9.5 of pregnancy (125 mg of Nitrofen dissolved in 2 ml of olive oil each), and 3, 10, 17 fetal rats were collected at day 16, 18 and 21 of pregnancy respectively. For the rats in the control group, 2 ml of olive oil was used to fill in the stomach, and 10 fetal rats were collected at day 16, 18, and 21 of pregnancy respectively. The lung tissue sections of the fetal rats collected on day 16 were observed under transmission electron microscope (TEM). For the lung tissue of the fetal rats collected on day 18, hematoxylineosin (HE) staining and TEM observation were performed and the incident of CDH was detected. Besides the procedures carried out for the rats collected on day 18, the ratio of fetal lung to body weight was observed for the lung tissue of the fetal rats collected on day 21. Results (1) The ratio of fetal lung to body weight of fetal rats in the CDH group was significantly lower than that of fetal rats in the control group (0.0238 vs. 0.0430, Plt;0.01). The incidences of CDH in the 18thday and 21stday fetal rats in the CDH group were 90.00% and 82.35%respectively, while no CDH was observed in the corresponding fetal rats in the control group, suggesting pulmonary hypoplasia in the CDH group. (2) The ultramicrostructural observation showed that compared with the control group, pulmonary hypoplasia appeared in 16thday fetal lungs in the CDH group, i.e., broad breathing barrier substrate, little contents, predominant euchromatin and rich ribosomes in the alveolar epithelial cells, and no microvilli in the bronchial lumen. The observation on the 18thday and 21stday samples suggested that, with the progressing of pregnancy, the abovementioned features became more obvious. (3) Typical lamellated body was observed in fetal lung type Ⅱ alveolar epithelial cells from the 21stday fetuses in both the CDH group and the control group, suggesting that some late subcellular structures were normal. Conclusion Lung hypoplasia develops in the early period of fetal rats with CDH rather than in the late period, implying that the treatment of pulmonary hypoplasia of diaphragmatic hernia should be performed in the early stage of lung development.
Objective To study the influence of ischemia-reperfusion on the expression of the hyperpolarization activated cycl icnucleotide gated cation channel 4 (HCN4) and to discuss the mechanism of functional disturbance of sinoatrial node tissue (SANT) after ischemia reperfusion injury (IRI). Methods Eighty five healthy adult rabbits, weighing 2-3 kg, were randomly divided into 3 groups: control group [a suture passed under the root section of right coronary artery (RCA) without l igation, n=5], experimental group A (occluding the root section of RCA for 30 minutes, then loosening the root 2,4, 8 and 16 hours, n=10), experimental group B (occluding the root section of RCA for 1 hour, then loosening the root 2, 4,8 and 16 hours, n=10). At the end of the reperfusion, the SANT was cut off to do histopathological, transmission electronmicroscopical and immunohistochemical examinations and semi-quantitative analysis. Results The result of HE stainingshowed that patho-injure of sinoatrial node cell (SANC) happened in experimental groups A and B after 2 hours of reperfusion, the longer the reperfusion time was, the more serious patho-injure of SANC was after 4 and 8 hours of reperfusion, SANC reached peak of damage after 8 to 16 hours of reperfusion; patho-injure of SANC was more serious in experimental group B than in experimental group A at the same reperfusion time. Immunohistochemical staining showed that the expression of HCN4 located in cellular membrane and cytoplasm in the central area of SANC and gradually decreased from the center to borderl ine. The integral absorbance values of HCN4 expression in the control group (397.40 ± 34.11) was significantly higher than those in the experimental group A (306.20 ± 35.77, 216.60 ± 18.59, 155.40 ± 19.11 and 135.00 ± 12.30) and in the experimental group B (253.70 ± 35.66, 138.70 ± 13.28, 79.10 ± 9.60 and 69.20 ± 8.42) after 2, 4, 8 and 16 hours of reperfusion (P lt; 0.05). With reperfusion time, the expression of HCN4 of SANC decreased, which was lowest after 8 hours of reperfusion; showing significant difference among 2, 4 and 8 hours after reperfusion (P lt; 0.05) and no significant difference between 8 and 16 hours after reperfusion (P gt; 0.05). At the same reperfusion time, the expression of HCN4 was higher in the experimental group A than in the experimental group B. The result of transmission electron microscope showed that ultramicrostructure of SANC was damaged after reperfusion in experimental groups A and B. The longer the reperfusion time was, the more serious ultramicrostructure damage of SANC was, and reached the peak of damage after 8 hours of reperfusion. Ultramicrostructure of SANC was not different between 8 and 16 hours of reperfusion. At the same reperfusion time, the ultramicrostructure damage of SANC was moreserious in experimental group B than in experimental group A. Conclusion IRI is harmful to the morphous and structure ofSANC, and effects the expression of HCN4 of SANC, which is concerned with functional disturbance and arrhythmia.
rough the ultramicroscopic observation on muscle and microcirculation, Group A,where a largeamount of DXM combined with heporin was given svstematically and locally into the femoral artery of the severed limb before replantation, and in Group B only heporin was given, and Group C and D ascontrol.The results showed that if the hormone and heparin were administred in large dosage, it wasadvantageous to reduce the tissues from reperfusion injury during delayed replantation.
ObjectiveTo analyze the effect of mitochondrial ultrastructural changes caused by morphine toxicity on abnormal discharge of cat cerebral cortex, and to explore the possible mechanism of brain function damage caused by morphine dependence.MethodsTwelve domestic cats were divided into control group (3 cats) and morphine exposed group (9 cats) according to the method of random number table. After the model was successfully established by the method of dose increasing, the changes of mitochondrial ultrastructure of cortical neurons were observed under the electron microscope.ResultsElectroencephalogram (EEG) monitoring in morphine exposed group showed that the cortical EEG was widely abnormal, physiological waves were reduced, and abnormal discharges were frequent. And the electron microscopy showed that the number, morphology, internal membrane structure and the inclusion body in the matrix of neurons changed in various aspects. The EEG and electron microscopy of the control group were normal.ConclusionMorphine can damage neurons in the cerebral cortex and lead to abnormal discharge, which is closely related to the ultrastructural changes of neuron mitochondria. The toxicity of morphine mitochondria can be the initial mechanism of energy metabolism dysfunction of brain cells and eventually lead to the disorder of brain electrophysiological function.
ObjectiveTo observe the effectiveness and safety of pars plana vitrectomy (PPV) combined with inner limiting membrane (ILM) removal and 41G microneedle subretinal injection of balanced salt solution (BSS) in the treatment of refractory macular hole. MethodsA prospective clinical study. From January to June 2023, 20 cases (20 eyes) of refractory macular hole patients diagnosed through examination at The Affiliated Eye Hospital of Nanchang University were included in the study. The basal diameter of the affected eye's basal diameter (BD) was ＞1 000 μm. Macular hole index (MHI) was ＜0.5. The affected eye received treatment with 23G PPV combined with ILM removal and 41G microneedle subretinal injection of BSS. Best corrected visual acuity (BCVA), microperimetry, and optical coherence tomography angiography (OCTA) were performed before and 1, 2, 3, and 6 months after surgery for the affected eye. BCVA examination was performed using standard logarithmic visual acuity chart, and convert it to logarithmic minimum resolution angle (logMAR) visual acuity for statistical purposes. MP-3 microperimetry was used for micro view examination, record the mean sensitivity (MS) of the retinal within a 12° range of the fovea. OCTA was used to measure the area of the avascular zone of the macula (FAZ), perimeter of the FAZ (PERIM), retinal vascular length density (VLD), and vascular perfusion density (VPD). The changes in BCVA, MS, FAZ area, PERIM, VLD, VPD before and after surgery were compared and analyzed. After the same time, the closure of macular hole and the occurrence of complications after surgery were observed. Single factor analysis of variance was used to compare the observation indicators at different times before and after surgery. The correlation between various observation indicators and preoperative minimum diameter (MD), BD, and hiatus height at 6 months after surgery were analyzed using Pearson correlation analysis. ResultsAmong the 20 cases with 20 eyes, there were 2 males with 2 eyes and 18 females with 18 eyes. Age was (61.45±8.56) years old. The logMAR BCVA, MS, FAZ area, PERIM, VLD, and VPD of the affected eye were 1.46±0.21, (16.20±5.81) dB、(0.40±0.17) mm2, (2.89±0.99) mm, (6.23±3.59) mm−1, (0.17±0.10)%, respectively. Six months after surgery, out of 20 eyes, macular hole closure and incomplete closure were 18 (90.0%, 18 /20) and 2 (10.0%, 2 /20) eyes, respectively. The logMAR BCVA, MS, FAZ area, PERIM, VLD, and VPD were 0.80±0.20, (22.20±4.60) dB, (0.18±0.10) mm2, (1.83±0.80) mm, (9.54±2.88) mm−1, (0.31±0.14)%. Compared with before surgery, the differences were statistically significant (P＜0.05). The correlation analysis results showed a positive correlation (P＜0.05) between preoperative BD and postoperative 6-month PERIM and VPD. There was a negative correlation between preoperative MD and postoperative VLD at 6 months (P＜0.05). There was a negative correlation between preoperative MHI and logMAR BCVA and VPD at 6 months after surgery (P＜0.05). No complications such as elevated or decreased intraocular pressure, damage to retinal pigment epithelium, retinal hemorrhage, endophthalmitis, or retinal detachment occurred after surgery in all affected eyes. ConclusionMinimally invasive PPV combined with ILM removal and 41G microneedle subretinal injection of BSS can effectively improve the closure rate of refractory macular hole patients in the short term, improve vision, and have good safety.