Objective To study the relationship between the low level lead exposure of pregnant woman and the gestational age of fetus. Methods The peripheral blood and the umbilical blood samples were collected from 1 000 healthy puerperants and their newborns. The puerperants were divided into three groups according to the blood lead levels: very low-level group(0.483 ?mol/L). Results The rate of premature labor was 9.40% in the very low-level group, 14.07% in the low-level group and 23.81% in the high-level group respectively. The blood lead level of puerperants had a positive correlation with the umbilical blood lead of newborns. The umbilical blood lead of premature was higher than that of mature. As the blood lead level of the pregnants increased, the gestational age shortened and the probability of low age premature increased. Conclusion As for the toxicity of lead to the fetus, there is no a threshold. Low level lead exposure of the pregnant woman is one of the causes of premature labor.

Objective To observe the effects of positive end-expiratory pressure(PEEP) on oxygen utiliza-tion coefficient in patients with acute respiratory distress syndrome(ARDS). Methods 28 ARDS patients with me-chanical ventilation were studied. Catheter of central vein was laid. Increment levels of PEEP(0,5, 10, 15 and 20cmH2O) were applied sequentially. Hemodynamics and oxygen metabolism parameters were measured and calcula-tion of O2 UC [O2 UC = (SaO2 -SvO2.)/SaO2] were carried out respectively. O2 UC in 30 normal subject groups were carried out. Results Arterial oxygen tension(PaO2) increased significantly(P < 0.05) at PEEP 5cmH2O. Oxygen u-tilization coefficient (O2 UC), heart rate(HR) and mean blood pressure (MBP) were not significantly different (P >0.05) at PEEP 10cmH2O. At PEEP 15cmH2 O, O2UC and HR increased significantly (P < 0.05), but M BP reduced obviously(P < 0.05). Conclusions Too high PEEP can result in oxygen utilization coefficient of ARDS patient de-acend furthur, can not really correct oxygen difieiency condition in patients' organization cell. The optimal PEEP should be found, and blood capacity should be appropriately increased.

Objective:To investigate the effect of recombinant Elafin on A549 apoptosis induced by paraquat and the underlying mechanism.Methods:pEGFP-C1-Elafin was transformed into A549 competent cells by electroporation.Transformed A549 was cultured for additional 24 h before Elafin mRNA was detected by RT-PCR and cocultured with or without various concentration of paraquat( PQ ) for different duration.A549 apoptosis percentage and reactive oxygen species ( ROS ) content were tested by flow cytometry .Nuclear factor erythroid like-2(Nrf2) heme oxygenase-1(HO-1) were examed by Western blot .Results:Elafin expressed successfully in A549 after transformation.PQ caused A549 apoptosis in a concentration dependent manner and leaded to ROS content increasing and Nrf2 and HO-1 decreasing.However,elafin could inhibit ROS production and A549 apoptosis,upregulate Nrf2 and HO-1.Conclusion:Elafin could restrict A549 apoptosis to some extent and the possible mechanism lied in its ability to upregulate Nrf2 ex-pression.

Objective To synthesize 11 C-methyldopamine (MDA) and to explore its feasibility as an agent for cardiac sympathetic nerve imaging.Methods 11 C-MDA was synthesized by direct N-methylation method and purified by semi-preparation reverse HPLC.Thirty Kunming mice were divided into five groups by random number table.The mice were respectively sacrificed at 2,5,10,20 and 30 min after injection of 7.4 MBq 11C-MDA.The lung,liver,spleen,kidney,stomach,intestine,brain,muscle,bone tissues and blood of mice were removed and weighed before radioactive γ-counting.The ％ID/g was calculated.Six Chinese mini-swine were divided into normal group (n=3) and inhibition group (n =3) for myocardial imaging.Mini-swine of inhibition group were injected with 10 mg/kg imipramine hydrochloride at 30 min before 11C-MDA (370 MBq) injection.The data were analyzed with SPSS 15.0 software.Results The synthesis of 11 C-MDA took 45 min with radiochemical yields of (20±3)％.The solution of11 C-MDA was colorless and the pH value was 6.5.The radiochemical purity was more than 98％ and the specific activity was 50 GBq/mmol.The myocardial uptake reached the peak value of (8.78± 1.18) ％ID/g at 2 min after injection of 11 C-MDA in mice.11C-MDA was mainly metabolized through liver and kidney.PET/CT imaging showed that 11 C-MDA was highly uptaken in swine myocardium and could be blocked by imipramine hydrochloride.Conclusions 11C-MDA can be synthesized by a simple and economic method.The high uptake rate of 11 C-MDA in the heart suggests it may be a potential agent for cardiac nerve imaging.

Objective To investigate the size and diversification of peripheral nerve measured by high frequency ultrasound in di-abetic peripheral neuropathy patient .Methods The endings of the medial branch of deep peripheral nerves(DPN) were interrogated by high frequency ultrasound and nerve electrophysiology ,and the nerve conduction characters were studied in a cohort of 150 clini-cally diagnosed diabetic peripheral neuropathy patients and a control group of 100 healthy volunteers .At the sametime these cases underwent electrophysiological examination .Results Distinct echoic appearances were consistently detected between the DPN nerves of diabetic peripheral neuropathy patients and healthy volunteers .The sensitivity rate of high frequency ultrasound and nerve electrophysiological examination in diagnosis of diabetic peripheral neuropathy were 91 .33% and 74 .67% ,and the specificity rate were 91% and 82% .Conclusion High frequency ultrasound may play a role in the diagnosis of diabetic peripheral neuropathy .

Objective:To explore the calvarial critical size defect (CSD)in rats with type 2 diabetes mellitus(T2DM).Methods:T2DM model of SD rats(weighted 300-320 g)was induced by high fat and high sugar diet and low dose intraperitoneal streptozotocin (STZ)injection.The rats with T2DMand the normal controls were divided into 4 groups(n=3)respectively.Defects with the diame-ter(mm)of 2,3,4 and 5 were made on the central calvaria of each rat.General observation,X-ray examination and histological study were performed 8 weeks postoperatively.Results:In the T2DM group,only the defects of 2 mm diameter were healed completely,X-ray resistance and new bone formation were observed;the defects of 3,4 and 5 mm diameter were unhealed,X-ray transmission was observed and newly formed bone was insufficient.In the control group,the defects of 2,3 and 4 mm diameter were healed completely, X-ray resistance and new bone formation were observed;the defects of 5 mm diameter were unhealed,X-ray transmission was ob-served,newly formed bone was insufficient.Conclusion:The calvarial CSD of T2DM rat model can be defined as the defect with the diameter of 3 mm.

Chronic obstructive pulmonary disease(COPD)is a common respiratory disease with a high disability and mortality rate, and it has become one of the major public health issues of concern worldwide.It includes small airway disease and emphysema caused by abnormal tissue repair, but its pathogenesis is still unclear.COPD is currently viewed as a disease of accelerated lung aging and is closely associated with aging mechanisms such as telomere/telomerase, epigenetic changes and mitochondrial dysfunction.This article reviews research progress on the mechanisms linking COPD and aging-related regulation.

Objective:To explore the therapeutic mechanism of Mongolian medicine Sendeng-4 decoction for rheumatoid arthritis by 99Tc m-hydrazinonicotinamide-(polyethylene glycol) 4-E[(polyethylene glycol) 4-c((Arg-Gly-Asp)fk)] 2 (3PRGD 2) imaging. Methods:A total of 200 female SD rats (age: 6-7 weeks) were divided into collagen-induced arthritis (CIA) group ( n=176) and blank control group ( n=24). Rats in the CIA group were divided into Sendeng-4 decoction treatment group ( n=24), etanercept treatment group ( n=24), and negative control group ( n=24) by simple random sampling method. 99Tc m-3PRGD 2 SPECT/CT imaging was performed before and after modeling and treatment. The differences of target/non-target (T/NT) ratio and serological, pathological, and immunohistochemical results among groups were compared by one-way analysis of variance or Kruskal-Wallis rank sum test. The correlation was analyzed by Pearson correlation or Spearman correlation analysis. Results:There were 95 (95/176) CIA models successfully established. The T/NT ratios of Sendeng-4 decoction treatment group and etanercept treatment group were lower than that of negative control group (0.260± 0.094, 0.238±0.099, 0.766±0.144 ; F=163.00, P<0.001), while there was no significant difference between the two drug treatment groups ( P>0.05). After drug treatment, serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α) and α vβ 3 were significantly lower than those of negative control group ( F values: 49.43-92.36, all P<0.001), pathological score was also lower than that of negative control group ( H=34.25, P<0.001), and levels of immunohistochemical makers (VEGF, TNF-α, α vβ 3, CD31, CD34) were also lower than those of negative control group ( H values: 13.51-26.84, all P<0.001), while there were no significant differences between the two drug treatment groups (all P>0.05). The T/NT ratios were positively correlated with above indictors in Sendeng-4 decoction treatment group ( r values: 0.56-0.59, rs values: 0.49-0.69), etanercept treatment group ( r values: 0.50-0.55, rs values: 0.46-0.70) and negative control group ( r values: 0.55-0.80, rs values: 0.58-0.86, P<0.001 or P<0.05). Conclusion:Verified by 99Tc m-3PRGD 2 SPECT/CT imaging and molecular pathology, Mongolian medicine Sendeng-4 decoction can inhibit neovascularization by down-regulating vascular factors such as VEGF, resulting in delaying the progression of the disease and improving clinical symptoms.

Objective To construct a regulatory network of competing endogenous RNA(ceRNA)with prognostic value for bladder urothelial carcinoma(BLCA),and analyze the relationship between key messenger RNA(mRNA)and immune function.Methods The UCSC Xena database was used to download mRNA expression data from 404 BLCA patients and 28 normal individuals and key mRNAs were screened by differential analysis.ENCORI database was utilized to search microRNAs(miRNAs)that bind to key mRNAs and all long non-coding RNAs(LncRNAs)that bind to miRNAs.The expression data of miRNA and LncRNA were downloaded from TCGA database,co-expression analysis was performed to identify key mRNA with all miRNAs and miRNA with all LncRNAs,and thus key miRNAs and LncRNAs were screened out.Survival analysis was conducted based on the differences in expression levels of these key mRNAs,miRNAs,and LncRNAs between tumor patients and normal individuals,and finally a ceRNA regulatory network was constructed.The correlation between key mRNAs and immune cells,immune checkpoints(CD274,PDCD1 and CTLA4),and immune cell marker genes(IG)was analyzed using the TIMER 2.0 database.Results A total of 22 key mRNAs were screened,with the most significant difference being proline 3-hydroxylase 4(P3H4).The expression of P3H4 in patients with BLCA was high,and survival time was shorter in patients with high expression.A sum of 33 miRNAs and 14 LncRNAs were screened using the key mRNAs as the central link.Through co-expression analysis and survival analysis,hsa-miR-151a-3p and MIR100 HG were identified as the key miRNA and key LncRNA with prognostic value.The differences in the above analysis results were statistically significant(all P＜0.05).Based on these findings,a ceRNA regulatory network consisting of 1 mRNA,1 miRNA,and 1 LncRNA was constructed.Immunoassay firstly revealed a significant positive correlation between double positive T cells and P3H4 expression in the tumor microenvironment of BLCA.Moreover,there were 3 types of immune cells(tumor-associated neutrophils,and tumor-associated macrophages,dendritic cells),3 immune checkpoints(CD274,PDCD1,CTLA4),and 15 IGs with significant correlation with P3H4.These differences were statistically significant(all P＜0.01).Conclusion This study could help to reveal the progression mechanism of BLCA.The constructed ceRNA network and immune analysis can offer new insights into potential biological targets and immunotherapy directions for the diagnosis,treatment,and prediction of BLCA patients.

Objective:To investigate the clinical characteristics of first-episode and recurrent acute hypertriglyceridemic pancreatitis (HTGP).Methods:The retrospective cohort study was con-ducted. The clinical data of 313 patients with HTGP admitted to 26 medical centers in China in the Chinese Acute Pancreatitis Clinical Research Group (CAPCTG)-PERFORM database from November 2020 to December 2021 were collected. There were 219 males and 94 females, aged 38(32,44)years. Of the 313 patients, 193 patients with first-episode HTGP were allocated into the first-episode group and 120 patients with recurrent HTGP were allocated into the recurrent group. Observation indica-tors: (1) propensity score matching and comparison of general data of patients between the two groups after matching; (2) comparison of severity and prognosis in the course of disease within 14 days between the two groups; (3) the association between recurrent HTGP and the risk of persistent organ failure (POF); (4) follow-up. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Wilcoxon rank sum test. Count data were expressed as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the Wilcoxon rank sum test. The Kaplan-Meier method was used to plot the cumulative recurrence rate curve and Log-Rank test was used for survival analysis. The Logistic regression model was used for multivariate analysis, and continuous variables were converted into categorical variables according to the mean value or common criteria. Propensity score matching was performed by 1∶1 nearest neighbor matching method, with caliper value of 0.02. Paired t test or Wilcoxon rank sum test and McNemar′s test were used for comparison between matched groups. Results:(1) Propensity score matching and comparison of general data of patients between the two groups after matching. Of the 313 patients,208 cases were successfully matched, including 104 cases in the first-episode group and 104 cases in the recurrent group. After propensity score matching, there was no significant difference in demographic characteristics, severity of illness scores and laboratory test between the two groups ( P>0.05). The elimination of gender, acute physiology and chornic health evaluation (APACHE) Ⅱ score, computed tomography severity index score, systemic inflammatory response syndrome score, sequential organ failure assessment score, apolipoprotein E, C-reactive protein, creatinine, lactic acid dehydrogenase, procal-citonin confounding bias ensured comparability between the two groups. (2) Comparison of severity and prognosis in the course of disease within 14 days between the two groups. There were signifi-cant differences in POF and local complications between the first-episode group and the recurrent group ( P<0.05). (3) The association between recurrent HTGP and the risk of POF. Results of uncor-rected univariate analysis showed that there was no association between recurrent HTGP and the risk of POF ( odds ratio=0.78, 95% confidence interval as 0.46-1.30, P>0.05). Results of multivariate analysis after adjusting for covariates such as gender, age, APACHE Ⅱ score, C-reactive protein, triglyceride and total cholesterol showed that compared with first-episode HTGP, recurrent HTGP was associated with a higher risk of POF ( odds ratio=2.22, 95% confidence interval as 1.05-4.71, P<0.05). Results of subgroup analysis showed that age<40 years was associated with an increased risk of POF ( odds ratio=3.31, 95% confidence interval as 1.09-10.08, P<0.05). (4) Follow-up. Twelve of the 313 patients died during hospitalization, including 9 cases in the first-episode group and 3 cases in the recurrent group. The rest of 301 surviving patients, including 184 cases in the first-episode group and 117 cases in the recurrent group, were followed up for 19.2(15.5, 21.9)months. Results of follow-up showed that for 184 survived patients of the first-episode group, 164 cases were followed up and 24 cases experienced recurrence, for 117 survived patients of the recurrent group,29 cases experienced recurrence, showing a significant difference between the two groups ( χ2=4.67, P<0.05). Conclusion:Compared with first-episode HTGP, patients with recurrent HTGP are more prone to POF and local complications, and are more prone to recurrence after discharge. The risk of POF in recurrent HTGP patients is 2.22 times that of those with first-episode, and the risk is higher in patients with age <40 years.