Analysis of the changes and characteristics of pediatric outpatient visits in a general hospital in Beijing before and after the COVID-19 pandemic / 北京大学学报(医学版)

OBJECTIVE@#To analyze the changes and characteristics of pediatric outpatient visits in a general hospital before and after the coronavirus disease (COVID-19) epidemic.@*METHODS@#Based on the registration data of pediatric outpatient visits in the information system (HIS)of Beijing Tsinghua Changgung Hospital, from January 1 2018 to December 31 2020, aged 0 to 16 years, we analyzed the changes of outpatient visits before and after the epidemic, focusing on respiratory infection including influenza. The relationship between the outpatient visits and age and quarterly distribution were also studied.@*RESULTS@#(1) Respiratory infection accounted for the majority of outpatient visits in 2018 and 2019 (60.6% and 60.5%, respectively). Non-respiratory infection accounted for the main proportion of outpatient visits in 2020, while respiratory infection accounted for only 47.4%. Annual respiratory infection visits, respiratory infectious diseases visits especially influenza visits all decreased significantly in 2020 compared with that in 2018 and 2019 (P < 0.05). (2)Respiratory infection visits were highest in the infant group, lowest in the school age group (P < 0.05) and highest in the fourth quarter each year. It decreased significantly in the second quarter of 2020 with statistical significance when compared with the other quarters of 2020(P < 0.05). (3)Influenza accounted for the highest proportion of respiratory infectious diseases visits in each year. It was highest in first quarter, which was significantly different from the other quarters of the year (P < 0.05). There were different distributions of influenza visits throughout 2018 and 2019, while it was only distributed in the first quarter and 99% in January in 2020.@*CONCLUSION@#The respiratory infection and influenza visits have decreased significantly in our pediatric outpatient department after the COVID-19 epidemic, which is considered closely related to the lifestyle and personal protection after the epidemic. It is recommended that health education on respiratory infection and influenza prevention should be strengthened, especially in winter and spring, to promote the development of good respiratory and hand hygiene habits.

The three-dimensional structure and the relationship between external and internal vascularizations in the brain of rat embryos / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>There have been no detailed reports of the three-dimensional structure and the relationship between the external and internal vascularizations observed successively for a long duration in the rat fetus, although many authors have studied the vascular morphology of the developing brain. This study examined the three-dimensional structure of both the external and internal vascularizations of the prenatal rat telencephalon from embryonic days 12 (E12) to 20 (E20).</p><p><b>METHOD</b>A microvascular casting method for scanning electron microscopy (SEM) was used in this study, along with vascular staining using gold-gelatin solution-autometallography (GGS-AMG) after intravascular injection of colloidal gold, as well as hematoxylin-eosin (HE) staining for paraffin embedded specimens.</p><p><b>RESULTS</b>In GGS-AMG stains, E16 fetuses had a few short perforating cortical blood vessels (SPCVs); E17 fetuses had long perforating cortico-medullary vessels (LPCVs). Older fetuses had specific patterns of vascular networks in the cortex and the deeper subcortical part of the telencephalon. In the cortex, fine longitudinal blood vessels were connected by transverse channels. The deep telencephalon had fine blood vessels running in all directions. Using SEM, the external vascularization was already visible in E12 fetuses as arborizations of arterial branches, forming a mesh of fine vascular networks covering the telencephalon. A coralliform fine venous plexus was observed in the external vascularization of E16 fetuses. There were ring-like anastomoses and bud-like protrusions in the network of small blood vessels, most likely the angiogenesis of fetal vessels. From E12 to E16, an immature and incomplete internal vascularization began to appear. There were short blood vessels with ballooned terminals branching from the external vascularization. They penetrated the brain tissue to form networks in the superficial layer, comparable to SPCVs. In E17 to E20 fetuses, tortuous venous branches, straight arterial blood vessels, and a fine network of small blood vessels formed the external vascularization. There were fewer arterial than venous branches connecting to the fine networks of small blood vessels. LPCVs were noted at E17, at the time the white matter emerged. They branched from the external vascularization, and perpendicularly penetrated the brain surface, traversing the cortical plate, and entering into the deep brain. At E17, arterial and venous blood vessels could be clearly distinguished in the external vascularization. At E20, the cortex and white matter contained specific arrangements of networks of fine blood vessels, as seen by GGS-AMG staining.</p><p><b>CONCLUSION</b>These findings show that the development of both the external and internal vascularization follows the development of the telencephalon. In particular, the emergence of the cortical plate and white matter on E16 and E17 influence the development of both the internal and the external vascularization. The laminal arrangement of blood vessels was not observed corresponding to the respective laminal neuronal layers.</p>