BACKGROUND: The method of culture purified sinoatrial node cell is important in investigating its ultrastructural characteristics and autorhythmic mechanisms.However,the corresponding method has not been standardized.OBJECTIVE: To summarize the localization,cultivation and purification of sinoatrial nodes isolated from newborn rabbits,and to study the morphological characters of primary cultured pacemaker cells.METHODS: Hearts of the newborn rabbits(within 24 hours)were embedded in paraffin for hematoxylin-eosin staining,The location of sinoatrial nodes was observed under an optical microscope,the morphology of sinoatrial nodes cells were observed by light microscope and electron microscope.RESULTS AND CONCLUSION: Sinoatrial nodes localized in the anterior wall of the superior vena cava and the posterior laterial wall of right atrium.There was about 0.32 mm between its lowest point and sulcus terminalis.Three distinct types of cells were observed among the cultured cells of sinoatrial nodes: spindle,spider and polygon.The spindle cells occupied the greatest proportion of the cultured cells(59.6±7.3)%.The spontaneous contraction frequency of spindle cells was the highest among the constracting cells(145±9)times per minute.The ultrastructure observation showed that myofibrils and other organelles in spindle cells were sparse and significantly decreased in number compared with triangle cells.There was no significant difference between triangle cells isolated from sinoatrial nodes and from atrial muscle.Sinoatrial nodes could be harvested along the anterior root of the superior vena cava down to the posterolateral sulcus.Among the cultured cells from neonatal rabbit sinoatrial nodes,the spindle cells with small body and fast pulse frequency are pacemaker cells.

Objective:To observe and analyze the clinical features and prognosis of proliferative diabetic retinopathy (PDR) with chronic myeloid leukemia.Methods:A retrospective case series study. From May 2011 to December 2020, 5 patients (10 eyes) were included in this study in Eye-ENT Hospital of Fudan University. Basic information about the patient's age, gender, diabetes history and CML history were collected. The endocrine and hematological indexes of all patients were evaluated. All the patients were undertaken visual acuity, intraocular pressure, slit lamp and fundus examination and other examinations to observe the eye conditions. Ophthalmic treatments included panretinal laser photocoagulation, intravitreal injection of anti-vascular endothelial growth factor, vitrectomy. During the follow up period from 5 months to 6 years, prognosis was observed at each office visit. During the follow up period, patients' vision, intraocular pressure, anterior segment and retinal status were observed.Results:There were 4 males and a female in 5 patients. The ages were from 27 to 49 years, with the mean age of 39 years. All patients were bilateral. All patients suffered type 2 diabetes for 3 months to 13 years. Four of them were diagnosed as chronic myeloid leukemia before visiting to ophthalmologists, while the other visited to ophthalmology first due to poor vision. The initial visual acuity ranged from light perception to 0.4 and 6 eyes were less than 0.1. In addition to the typical manifestations of diabetic retinopathy, such as venous tortuous dilation, exudation, microaneurysm and neovascularization, patients also presented with Roth spot as leukemic fundus manifestations. All eyes developed to PDR stage. Abnormal thickening of the neovascular membranes may occur in the lower part of the retina, with secondary traction retinal detachment. All the eyes were treated with pan retinal photocoagulation and 9 eyes underwent pars plana vitrectomy. After treatment, retina of 8 eyes kept flat. The best corrected visual acuity ranged from no light perception to 1.0, and only 4 eyes reached more than 0.2. Unfortunately, one eye lost vision because of secondary neovascular glaucoma.Conclusions:PDR patients with CMLof fundus not only have venous tortuous dilation, exudation, microaneurysm and neovascularization, also present with Roth spot as leukemic fundus manifestations. Diabetic retinopathy combined with CML could progress rapidly, and its aggravating complications such as hyperplastic membrane, vitreous hemorrhage and traction retinal detachment may result in poor visual prognosis. Early screening and treatment can help improve the prognosis of patients.

Objective:To explore the accuracy of artificial intelligence (AI) system based on deep learning in evaluating bone age of children with abnormal growth and development.Methods:The positive X-ray films of the left wrist of children with abnormal growth and development who were treated at the Affiliated Hospital of Guizhou Medical University from January 2020 to December 2021 were collected retrospectively. A total of 717 children were collected, including 266 males and 451 females, aged 2-18 (11±3) years. Based on Tanner Whitehouse 3 (TW 3)-RUS (radius, ulna, short bone) and TW3-Carpal (carpal bone) method, bone age was measured by 3 senior radiologists, and the mean value was taken as reference standard. The bone ages were independently evaluated by the AI system (Dr.Wise bone age prediction software) and two junior radiologists (physicians 1 and 2). The accuracy within 0.5 year, the accuracy within 1 year, the mean absolute error (MAE) and the root mean square error (RMSE) between the evaluation results and the reference standard were analyzed. Paired sample t-test was used to compare MAE between AI system and junior physicians. Intraclass correlation coefficient (ICC) was used to evaluate the consistency between AI system, junior physician and reference standard. The Bland-Altman diagram was drawn and the 95% consistency limit was calculated between AI system and reference standard. Results:For TW3-RUS bone age, compared with the reference standard, the accuracy within 0.5 year of AI system, physician 1 and physician 2 was 75.3% (540/717), 62.1% (445/717) and 66.2% (475/717), respectively. The accuracy within 1 year was 96.9% (695/717), 86.3% (619/717) and 89.1% (639/717), respectively. MAE was 0.360, 0.565 and 0.496 years, and RMSE was 0.469, 0.634 and 0.572 years, respectively. For TW3-Carpal bone age, compared with the reference standard, the accuracy within 0.5 year of AI system, physician 1 and physician 2 was 80.9% (580/717), 65.1% (467/717) and 71.7% (514/717), respectively. The accuracy within 1 year was 96.0% (688/717), 87.3% (626/717) and 90.4% (648/717), respectively. MAE was 0.330, 0.527 and 0.455 years, and RMSE was 0.458, 0.612, 0.538 years, respectively. Based on TW3-RUS and TW3-Carpal bone age, the MAE of AI system were lower than those of physician 1 and physician 2, and the differences were statistically significant ( P all<0.001). The evaluation results of AI, physician 1 and physician 2 were in good agreement with the reference standard (ICC all>0.950). The Bland-Altman analysis showed that the 95% agreement limits of AI system for assessing TW3-RUS and TW3-Carpal bone age were -0.75-1.02 years and-0.86-0.91 years, respectively. Conclusion:The accuracy of AI system in evaluating the bone age of children with abnormal growth and development is close to that of senior doctors, better than that of junior doctors, and in good agreement with senior doctors.

Objective:To investigate macular microvascular abnormalities in eyes with subfoveal fibrotic nodules secondary to Coats' disease.Methods:A cross-sectional study. From January 1, 2018 to July 30, 2021, 45 eyes of 45 patients diagnosed with Coats' disease with or without subfoveal fibrotic nodules in Eye and ENT Hospital, Shanghai Medical College of Fudan University were included in this study. There were 40 eyes in 40 males and 5 eyes in 5 females. All were under 21 years old. According to the presence or absence of subfoveal fiber nodules, the patients were divided into fibrotic group (26 cases, 26 eyes) and non-fibrotic group (19 cases, 19 eyes). Optical coherence tomography angiography was used to scan 3 mm×3 mm or 6 mm×6 mm macular area of both eyes. The software of the device automatically processed the images. The presence of FAZ edge anastomotic vascular arch ring breakage and abnormal microvascular branch (AMB) in the foveal avascular zone (FAZ) were observed.Results:In 26 eyes of fibrosis group, AMB originating from the parafoveal retinal capillary network was observed, which grew into and destroyed the integrity of the vascular arch ring at the edge of FAZ. AMB was crisscrossing and winding, and its curvature expands. B-scan images showed the blood flow signal in the subfoveal fiber nodule, and the blood flow signal traversed between the inner retina and the fiber nodule in 23 eyes (88.46%, 23/26). In the non-fibrosis group, all the vascular abnormalities were characterized by capillary dilation and defect, and no breakage of FAZ anastomotic vascular arch ring or AMB was observed.Conclusions:In Coats' disease with subfoveal fiber nodules, staggered and dilated AMBs emerge from the parafoveal vascular network, grow into and destroy the integrity of the vascular arch ring at the edge of FAZ, and grow down longitudinally into the fiber nodules.