Objective:To observe the effect of high glucose downregulated microRNA(miR)-99a on hepatic sinus dysfunction and metformin intervention, and to explore the pathogenesis of diabetes-induced fatty liver and possible mechanism of metformin.Methods:The cultured human liver sinusoidal endothelial cells were randomly divided into normal control group, high glucose model group, miR-99a overexpression group, miR-99a overexpression negative control group, insulin-like growth factor 1 receptor(IGF-1R) inhibitor group, mammalian target of rapamycin(mTOR) inhibitor group, and metformin treatment group. The mRNA expressions of miR-99a were detected with realtime quantitative PCR(RT-qPCR), and the expression levels and distribution of IGF-1R, phosphorylated(p-)mTOR and vitronectin(VN) were detected by Western blotting and immunofluorescence. The ultrastructure of human liver sinusoidal endothelial cells was observed using scanning electron microscope.Results:Compared with normal control group, the mRNA expression of miR-99a was downregulated( P=0.008), while the protein expressions of IGF-1R, mTOR, and VN were significantly increased, and the diameter and number of fenestrae decreased significantly in high glucose model group. Compared with high glucose model group, after the treatment with metformin, the mRNA expression of miR-99a was upregulated, while the protein expressions of IGF-1R, mTOR, and VN were significantly decreased( P=0.001, P=0.016, P=0.005, respectively), the number of fenestras increased and the diameter became larger in miR-99a overexpression group, IGF-1R inhibitor group, mTOR inhibitor group, and metformin treatment group. After overexpression of miR-99a, the protein expressions of IGF-1R, p-mTOR, and VN were significantly reduced( P=0.007, P=0.013, P=0.003, respectively); After administration of IGF-1R inhibitors, the expressions of p-mTOR and VN significantly decreased( P=0.006, P=0.009, respectively), following treatment with the mTOR inhibitor, the expression of VN was significantly reduced( P=0.008), while the expression of IGF-1R remained unchanged( P=0.553). Conclusions:Downregulating of miR-99a with high glucose induced hepatic sinus dysfunction, which may be related to the regulation of IGF-1R/mTOR pathway. Metformin increased the expression of miR-99a, thereby inhibiting high glucose-induced hepatic sinusoidal dysfunction.

Objective:To assess the risk of COVID-19 foreign imports cases to China.Methods:We collected epidemic data (cumulative daily confirmed cases in each country, cumulative confirmed imported cases), demographic data (population density, population) and information on potential source groups of tourists (the daily estimated number of overseas Chinese, overseas Chinese students, overseas workers, foreign students coming to China and flight passengers) and the global health security index (GHS) to assess and predict risk of imported cases for recent (February 1 st to April 25 th) and future (after April 26 th). Results:Strong positive correlation was found among variables including the number of imported cases, cumulative confirmed cases, attack rate, number of overseas Chinese, number of overseas Chinese students, number of foreign students coming to China, number of flight passengers and GHS. In the recent risk analysis, imported cases of Russian were the highest, followed by United Kingdom, United States, France and Spain. In the future risk prediction, 44 countries including United States and Singapore are evaluated as potential high-risk countries in the future through the attack rate index of each country and the estimated average number of daily passengers.Conclusion:The risk assessment of COVID-19 imported cases can be used to identify high-risk areas in recent and future, and might be helpful to strengthen the prevention and control of the epidemic and ultimately overcome the epidemic.

Objective:To infer the start time of the resurgent COVID-19 epidemic in Xinfadi wholesale market in Beijing in June 2020 and evaluate the effect of comprehensive prevention and control measures in this epidemic.Methods:SEIR dynamics model was used to fit daily onset infections to search the start date of this resurgent COVID-19 epidemic in Beijing. The number of cumulative infections from June 12 to July 1 in Beijing were fitted considering different levels of control strength.Results:The current reemerged COVID-19 epidemic in Beijing probably started between May 22 and May 28 (cumulative probability: 95 %), with the highest probability on May 25 (23 %). The R0 of the current reemerged COVID-19 epidemic was 4.22 (95 %CI: 2.88-7.02). Dynamic model fitting suggested that by June 11, the cumulative number of COVID-19 cases would reached 99 (95 %CI: 77-121), which was in line with the actual situation, and without control, by July 1, the cumulative number of COVID-19 cases would reach 65 090 (95 %CI: 39 068-105 037). Since June 12, comprehensive prevention and control measures have been implemented in Beijing, as of July 1, compared with uncontrolled situation, the number of infections had been reduced by 99 %, similar to the fitting result of a 95 % reduction of the transmission rate. The sensitivity analysis showed consistent results. Conclusions:For the emergent outbreak of COVID-19, the dynamics model can be used to infer the start time of the transmission and help tracing the source of epidemic. The comprehensive prevention and control measures taken in Beijing have quickly blocked over 95 % of the transmission routes and reduced 99 % of the infections, containing the sudden epidemic timely and effectively, which have value in guiding the prevention and control of the epidemic in the future.

Objective To explore the clinical features and risk factors of poor prognosis in neonatal necrotizing enterocolitis(NEC).Methods A retrospective study was carried out in the infants with NEC admitted to 6 cooperative hospitals in Guangdong Province between January 2005 and December 2014.The clinical features and risk factors of poor prognosis in preterm and full-term infants diagnosed NEC,early onset and late onset NEC were analyzed.Results A total of 449 cases who met the criteria were admitted during the study time.The mortality was 23.6％ (106/449 cases),of which the preterm group was 24.6％ (58/238 cases) while the full-term group was 22.7％ (48/211 cases),the early onset group was 22.1％ (45/204 cases) while the late onset group was 24.3％ (57/235 cases).The median number of NEC onset in preterm group was 11 d after birth while the number of the full-term group was 6 d.Full-term infants who diagnosed NEC were more likely to manifest themselves as abdominal distension (52.1％ vs.42.0％,x2 =4.597,P =0.032),vomiting(36.5％ vs.17.2％,x2 =21.428,P =0.000) and bloody stool(30.3％ vs.21.4％,x2 =4.653,P =0.031);but in the onset of NEC,preterm infants more likely to have feeding intolerance (21.0％ vs.12.8％,x2=5.309,P =0.021).The early onset group of full-term NEC was much common in twins or multiplets(9.4％ vs.1.1％,x2 =6.226,P =0.013),which rate of surgical therapy was much higher (41.0％ vs.27.0％,P =0.036) and the breast-feeding rate before NEC was lower than the late onset group(14.5％ vs.32.6％,x2 =9.500,P =0.002),the differences were statistically significant.The gestational age and birth weight were bigger in the early onset group of preterm NEC[(33.8 ±2.5) weeks vs.(32.2 ±2.8) weeks,t =4.261,P =0.000;(2.1 ±0.5) kg vs.(1.7 ± 0.5) kg,t =4.735,P =0.000)],but length of stay was shorter than the late onset group (18.0 d vs.26.5 d,P =0.000).Logistic regression analysis showed that the risk factors of poor prognosis of full-term NEC were shock,peritonitis and sepsis;while risk factors of poor prognosis of preterm NEC were small for gestational age infant,pulmonary hemorrhage,shock,intestinal perforation and sepsis;the risk factors of poor prognosis of the early onset group of full-term NEC was shock;while those of the late onset group were shock and peritonitis;the risk factors of poor prognosis in the early onset group of preterm NEC were shock and sepsis,while those in the late onset group were pulmonary hemorrhage,shock,intestinal perforation and sepsis.Conclusions Compared to the preterm NEC,the onset time of full-term NEC was earlier and the clinical manifestations were more typical.Early identification and management of shock,peritonitis,intestinal perforation,sepsis and pulmonary hemorrhage can reduce the risk of poor prognosis of neonate NEC.

Objective To summarize the clinical experience and efficacy of surgical treatment for Stanford type A aortic dissection leading to acute lower limb ischemia.Methods From January 2014 to January 2018,12 patients with severe lower limb ischemia caused by acute type A aortic dissection were treated with Suns surgery.Among them,11 patients were treated with restoration of lower limb blood supply preferentially,including 10 cases of femoral artery bypass and 1 case of abdominal aorta-iliac artery stent graft implantation.Another case was treated with ascending aorta-femoral artery bypass after Sung surgery.Results 3 cases died of ischemia and necrosis of the lower extremities.Two of them died of multiple organ failure due to amputation and one died of low cardiac output due to refractory acidosis.Acute renal failure performed bedside CRRT in 5 patients and ECMO in 1 patient.The remaining 9 patients were discharged from the hospital and the symptoms of lower limb ischemia disappeared.After an average follow-up of 23 months,the re-examination of the aorta CTA showed that the bypass artery was unobstructed and the distal femoral artery was well developed.One patient infecting vascular prosthesis was cured by taking out the unit.Conclusion For acute lower limb ischemia caused by type A aortic dissection,blood flow of lower extremities should be restored as soon as possible to reduce mortality and complications.Femoral artery bypass and abdominal aorta-iliac arterial repair are simple and effective in reconstructing lower limb blood supply.

Discordance, such as overlap, repetition and inconsistent, of standards is one of the major problems in current standardization affair in China. Therefore, improving the unity and authority of standards through reduction of overlap, repetition and inconsistency has become the main goal of deepening standardization reform in China. This paper summarizes the discordance in public health standards in China, analyzes the major reasons and provides specific strategic suggestions through case analysis of public health standards in the ways of comparisons of same kind standards of other deparments and standards in administration documents and guidelines or technical specifications of academic associations or societies.

Objective To investigate the safety and efficacy of preoperative ultra-short-course chemotherapy combined with surgical treatment of chest wall tuberculosis. Methods The clinical data of 216 patients with chest wall tuberculosis from January 2013 to June 2016 in our hospital were retrospectively analyzed, including 121 males and 95 females with an average age of 35±15 years (range, 4-74 years). Results All patients were treated with anti-tuberculosis drugs for 17.0±11.3 days preoperatively, including 12.5±5.0 days in simple chest wall tuberculosis and 19.4±12.3 days in combined chest wall tuberculosis. The postoperative recurrence rate of chest wall tuberculosis was 3.7%, which was close to or lower than that of routine preoperative antituberculous therapy in patients with ultra-short-course anti-tuberculosis treatment before surgery. Conclusion Preoperative ultra-short-course chemotherapy combined with surgical treatment for chest wall tuberculosis will not increase the recurrence rate of chest wall tuberculosis, and can effectively shorten the hospital stay. Timely adjustment of anti-tuberculosis chemotherapy based on thorough debridement, postoperative drugs, not the preoperative drugs, is the key to reinforce the surgical outcome.

Objective: To establish a new model of hepatic steatosis cells by optimizing the original ethanol or high fat, the present study proposed an in vitro hepatocyte steatosis model for the study of fatty liver. Methods: Oil red O staining was used to observe the effects of fetal bovine serum, oleic acid and ethanol on lipid accumulation in human liver cell line L02 in a concentration- and time-dependent manner. RT-PCR was used to detect the mRNA expression levels of PPAR-γ and AP-2, and the suitable conditions for the establishment of hepatocyte steatosis model were screened out. A t-test was used for comparison between the two groups, and one-way Analysis of Variance (ANOVA) was used in more than three groups. Results: Oil red O staining showed the number of reddish-orange lipid droplets in L02 cells gradually increased with the increase of fetal bovine serum, oleic acid and ethanol in a concentration - and time-dependent manner. Compared with 0.00% oleic acid and 2% ethanol, the count value of red particle was 100.00% ± 17.63% at the beginning and after 24 h, 0.003% oleic acid and 2% ethanol jointly acted in L02 cells. After incubation for 48 hours with 2% ethanol and serum-free DMEM medium, the accumulation of lipid droplets was the highest with a count value of 802.38%+71.06%(t = 42.36, P < 0.001). RT-PCR analysis showed the lipid accumulation induced by this method was positively correlated with the mRNA expression of PPAR-γ and AP-2. Conclusion L02 cells were successfully exposed to high fat and ethanol, and the hepatocyte steatosis model was established and optimized, suggesting that the occurrence of hepatic cell steatosis was related to the up-regulation of PPAR-γ and AP-2.

Objective To explore whether the pattern of neuron's auditory response to a sound stimulus affects the characteristics of stimulus-specific adaptation (SSA) in awake mice. Methods The auditory responses of the neurons in the inferior colliculus to sound stimuli were recorded using microelectrodes in awake mice. The sequence of sound stimuli consisted of random combinations of pure tones of two different frequencies (f1 and f2) with different repetition rates. The auditory responses of the neurons to standard and deviant stimuli were calculated, namely s(f2)/s(f2) and d(f1)/d(f2), respectively. Three indexes of the responses were also calculated, including the firing difference index (FDI), frequency-specific index (SI), and common SSA index(CSI). Results The CSI of neurons with a greater FDI was significantly higher than that of neurons with a smaller FDI (P<0.05). The primary-like neurons showed different characteristics of SSAs in different time periods; SSA was significantly increased in the phase of sustained response compared with that at the onset of response (P<0.05). Conclusion The auditory response pattern to sound stimuli is also an important factor that affect SSA of inferior colliculus neurons in awake mice.

Objective To explore whether the pattern of neuron's auditory response to a sound stimulus affects the characteristics of stimulus-specific adaptation (SSA) in awake mice. Methods The auditory responses of the neurons in the inferior colliculus to sound stimuli were recorded using microelectrodes in awake mice. The sequence of sound stimuli consisted of random combinations of pure tones of two different frequencies (f1 and f2) with different repetition rates. The auditory responses of the neurons to standard and deviant stimuli were calculated, namely s(f2)/s(f2) and d(f1)/d(f2), respectively. Three indexes of the responses were also calculated, including the firing difference index (FDI), frequency-specific index (SI), and common SSA index(CSI). Results The CSI of neurons with a greater FDI was significantly higher than that of neurons with a smaller FDI (P<0.05). The primary-like neurons showed different characteristics of SSAs in different time periods; SSA was significantly increased in the phase of sustained response compared with that at the onset of response (P<0.05). Conclusion The auditory response pattern to sound stimuli is also an important factor that affect SSA of inferior colliculus neurons in awake mice.