The regulation of astroglia on synaptic plasticity in the CA1 region of rat hippocampus was examined. Rats were divided into three groups: the newly born (< 24 h), the juvenile (28-30 days) and the adult groups (90 - 100 days), with each group having 20 animals. The CA1 region of rat hippocampus was immunohistochemically and electron-microscopically examined, respectively, for the growth of astroglia and the ultrastructure of synapses. The high performance liquid chromatography was employed to determine the cholesterol content of rat hippocampus. In the newly-born rats, a large number of neurons were noted in the hippocampal CA1 region of the newly-born rats, and few astroglia and no synaptic structure were observed. In the juvenile group, a few astroglias and some immature synapses were found, which were less than those in adult rats (P < 0.01). The cholesterol content was 2.92 +/- 0.03 mg/g, 11.20 +/- 3.41 mg/g and 12.91 +/- 1.25 mg/g for newly born, the juvenile and the adult groups, respectively, with the differences among them being statistically significant (P < 0.01). Our study suggests that the astrocytes may play an important role in the synaptic formation and functional maturity of hippocampal neurons, which may be related to the secretion of cholesterol from astrocytes.
Age Factors ; Animals, Newborn ; Astrocytes/cytology ; Astrocytes/metabolism ; Astrocytes/*physiology ; CA1 Region, Hippocampal/*physiology ; CA1 Region, Hippocampal/*ultrastructure ; Cell Communication/physiology ; Cholesterol/metabolism ; Neuronal Plasticity/*physiology ; Random Allocation ; Rats, Wistar ; Synapses/*physiology ; Synapses/ultrastructure

The regulation of astroglia on synaptic plasticity in the CA1 region of rat hippocampus was examined. Rats were divided into three groups: the newly born (＜24 h), the juvenile (28-30days) and the adult groups (90-100 days), with each group having 20 animals. The CA1 region of rat hippocampus was immunohistochemically and electron-microscopically examined, respectively,for the growth of astroglia and the ultrastructure of synapses. The high performance liquid chromatography was employed to determine the cholesterol content of rat hippocampus. In the newly-born rats, a large number of neurons were noted in the hippocampal CA1 region of the newly-born rats,and few astroglia and no synaptic structure were observed. In the juvenile group, a few astroglias and some immature synapses were found, which were less than those in adult rats (P＜0.01). The cholesterol content was 2.92±0.03 mg/g, 11.20± 3.41 mg/g and 12.91 ± 1.25 mg/g for newly born, the juvenile and the adult groups, respectively, with the differences among them being statistically significant (P＜0.01). Our study suggests that the astrocytes may play an important role in the synaptic formation and functional maturity of hippocampal neurons, which may be related to the secretion of cholesterol from astrocytes.

Objective To analyze the infection status and epidemic characteristics of Vibrio parahaemolyticus diarrhea cases in Shanghai in recent years， and to explore its influencing factors and provide a basis for the prevention and control of Vibrio parahaemolyticus infection. Methods Food-borne disease surveillance data in Shanghai from 2017 to 2018 was collected， and the infection status and epidemic characteristics of Vibrio parahaemolyticus were analyzed. χ ² test and multivariate unconditional logistic regression were used to analyze the factors of Vibrio parahaemolyticus infection. Results Among the food-borne surveillance cases in Shanghai from 2017 to 2018， the positive detection rate of Vibrio parahaemolyticus reached 5.1%， and the positive cases were concentrated in July， August， and September. Those working in the catering industry， migrant workers and workers， and the young and middle-aged people （19‒59 years old） have a high incidence. The results of multivariate analysis showed that dining in Qingpu， Songjiang or Minhang District， occupations of migrant workers and workers， age over 19 years old， the third quarter of a year， and the consumption of aquatic animals and related foods are risk factors for Vibrio parahaemolyticus infection. Conclusion The infection of Vibrio parahaemolyticus in Shanghai is still one of the food-borne diseases that warrant our attention. Strengthening food safety management and supervision， and promoting publicity and education for key populations are important for reducing the risk of infection by this pathogen. At the same time， long-term monitoring of infectious diarrhea cases in this city is necessary to dynamically understand the infection and epidemic characteristics of Vibrio parahaemolyticus ， and adjust the annual prevention and control measures in time.

ObjectiveTo analyze the epidemiological features of foodborne disease outbreaks in Shanghai and to find the risk factors. MethodsWe collected the data of foodborne disease outbreaks occurred in Shanghai between 2010 and 2020， analyzed the characteristics of outbreaks， including time and geographic distribution， pathogenic factors and possible reasons caused outbreaks. ResultsBetween 2010 and 2020， there were 108 foodborne disease outbreaks with 1 736 cases， 45 inpatient cases and 1 death. May to September was the epidemic period， with about 64.81% of the outbreak occurrence. 39.81% outbreaks occurred in Pudong， Songjiang and Chongming Districts. Most outbreaks occurred in small restaurants （25%） and most foodborne cases were in staff canteen outbreaks （27.53%）. The main possible reasons caused outbreaks were improper food storage （19.44%）， cross-contamination （14.81%） and improper cooking （12.04%）. The major pathogenic factor was biological， caused 75.92% outbreaks and 77.59% cases. Methanol poisoning caused 1 death. The main contaminated food caused outbreaks was meat （17.59%）， multiple food （12.04%） and aquatic products （11.11%）. ConclusionThe foodborne disease outbreaks in Shanghai caused inpatient cases and death. We should pay more attention to foodborne disease outbreaks and we can control the risk factors by strengthening supervision and carrying out health education to reduce foodborne disease outbreaks.

ObjectiveTo learn the epidemiological features of foodborne diseases， and to provide scientific basis for disease control. MethodsThe monitoring data of foodborne diseases in Minhang from 2016 to 2020 were analyzed. Stool or swab specimens were collected to detect salmonella， Vibrio parahaemolyticus， Escherichia coli， Shigella， Campylobacter jejuni and norovirus. ResultsThe information of15 951 foodborne disease cases and 11 176 samples were collected， with the positive rate of 12.03%.The cases with diarrhea accounted for 99.90% of the total. The cases with fever accounted for 14.70% of the total. The cases with water stool accounted for 89.70% of the total. May to October were the epidemic periods of foodborne diseases in Minhang（79.78%）. The detection rate was the highest in the 30‒39 age group and cadre staff occupation（13.53%，13.49%）. The detection rates of foodborne bacteria and virus were 5.39% （Vibrio parahaemolyticus）， 3.25% （salmonella），1.44% （norovirus）， 1.06%（Escherichia coli）， 0.56% （Campylobacter jejuni）， 0.34% （mixed infection） and 0% （Shigella）. During this 5-year period， the positive rate of Vibrio parahaemolyticus decreased significantly， while the positive rate of salmonella and Escherichia coli and Campylobacter jejuni increased significantly. The main suspected food were aquatic products （29.44%）， meat （25.80%） and fruits （10.78%）. The main processing methods of suspected food were family workshop （41.12%） and restaurants （37.55%）. The total detection rate of the cases was the highest in the canteen， reaching 20.51%. ConclusionFoodborne disease cases have a seasonal peak. The positive detection of pathogens tends to be similar year by year. The main suspected food is aquatic products. The main resources of suspected food are family workshop， restaurants， and canteen. Targeted health education， supervision and management should be taken to prevent the occurrence of foodborne diseases and the outbreak of food poisoning