Postnatal development of rat retina:a continuous observation and comparison between the organotypic retinal explant model and in vivo development

The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.

Effects and interaction of temperature and relative humidity on the trend of influenza prevalence:A multi-central study based on 30 provinces in China's Mainland from 2013 to 2018

Background:Evidence is inefficient about how meteorological factors influence the trends of influenza transmission in different regions of China.Methods:We estimated the time-varying reproduction number(Rt)of influenza and explored the impact of temperature and relative humidity on Rt using generalized additive quasi-Poisson regression models combined with the distribution lag non-linear model(DLNM).The effect of temperature and humidity interaction on Rt of influenza was explored.The multiple random-meta analysis was used to evaluate region-specific association.The excess risk(ER)index was defined to investigate the correlation between Rt and each meteorological factor with the modification of seasonal and regional characteristics.Results:Low temperature and low relative humidity contributed to influenza epidemics on the national level,while shapes of merged cumulative effect plots were different across regions.Compared to that of median temperature,the merged RR(95%CI)of low tem-perature in northern and southern regions were 1.40(1.24,1.45)and 1.20(1.14,1.27),respectively,while those of high temperature were 1.10(1.03,1.17)and 1.00(0.95,1.04),respectively.There were negative interactions between temperature and relative humidity on national(SI=0.59,95%CI:0.57e0.61),southern(SI=0.49,95%CI:0.17e0.80),and northern regions(SI=0.59,95%CI:0.56,0.62).In general,with the increase of the change of the two meteorological factors,the ER of Rt also gradually increased.Conclusions:Temperature and relative humidity have an effect on the influenza epidemics in China,and there is an interaction between the two meteorological factors,but the effect of each factor is heterogeneous among regions.Meteorological factors may be considered to predict the trend of influenza epidemic.