[Analysis of respiratory syncytial virus nonstructural protein 1 amino acid variation and clinical characteristics].

Objective: To investigate the relationship between amino acid variations of respiratory syncytial virus (RSV) nonstructural protein (NS) 1 and the clinical characteristics. Method: A retrospective case review was conducted. From December 2018 to January 2020, a total of 81 cases of hospitalized children who were tested only positive for RSV by RT-PCR or PCR at the Department of Respiratory Medicine, Children's Hospital of Chongqing Medical University were included in the study. The NS1 genes of RSV subtype A and subtype B were amplified by PCR and sequenced. The amino acid sequences were analyzed. The Chi-square test and Mann-Whitney rank sum test were used to compare the clinical characteristics and type Ⅰ interferon levels of children with or without NS1 variation in the variation and non-variation groups. Results: Among 81 cases, there were 58 males and 23 females. There were 11 cases in the variation group, the age of onset was 2.0 (1.0, 11.0) months, included 4 cases of subtype A (variant sites were: 2 cases for Lys33Gln, one case for Gly2Asp, Pro67Ser, Leu137Phe, respectively) and 7 cases of subtype B (variant sites were: two cases for Val121Ile, one case for Tyr30Cys, Val65Met, Asn85Ser, Ser118Asn, Asp124Asn, respectively). These variant sites all appeared at a very low frequency 0.08 (0.04, 0.29) % in the NCBI PROTEIN database. There were 70 cases in non-variation group, the onset age was 3.5 (1.0, 7.0) months. The proportion of dyspnea in the variation group was higher than that in the non-variation group (10/11 vs. 47% (33/70), χ2=7.31, P<0.01). Conclusions: There are some variant sites in nonstructural protein NS1 of RSV. Children may be prone to have dyspnea with NS1 variations.

[Metagenomic sequencing for diagnosis of sparganosis mansoni: a case report].

The patient was found to develop a migrating mass in the lower abdomen without any known cause in 2000, and the cause had not been identified following multiple diagnoses since then. The mass was found to migrate to the left anterior axillary regions on August 11, 2020. Then, three segments of incomplete white worms were resected through minimally invasive surgery, and metagenomic sequencing revealed sparganosis mansoni. After surgical resection of complete worms was performed on October 21, 2021, the case was cured and discharged from the hospital. Follow-up revealed satisfactory outcomes and no new mass was found throughout the body.

Evaluation of the efficacy of a novel phytase in short-term digestibility and long-term egg production studies with laying hens.

Three independent trials were conducted to evaluate the efficacy of a novel phytase in laying hens. Trial 1 used a total of 90 laying hens (Lohmann Brown, 33-wk-old) fed either a negative control (NC) diet with 0.09% non-phytate P (NPP) or NC supplemented with 187.5 or 375 FYT phytase/kg feed for 4 d before collection of excreta and ileal digesta to measure ileal digestibility and retention of Ca and P. In trial 2 and 3, a total of 108 laying hens (Hy Line Brown, 25-wk-old) and 360 hens (Lohman Brown, 25-wk-old) were used, respectively. In both trials, the hens were randomly assigned to 3 dietary treatments: NC with 0.1% NPP, positive control (PC) and NC plus 187.5 FYT phytase/kg feed, the experimental diets were fed for 12 wk, and egg production and bone mineralization were measured. The results showed that the ileal digestibility of P increased both linearly (P = 0.012) and quadratically (P = 0.01) with increasing supplementation of phytase in trial 1. In trial 2, phytase supplementation significantly improved egg production, egg weight, and feed conversion ratio and reduced the percentage of broken eggs during the overall trial duration compared with NC. In trial 3, phytase significantly improved egg production, egg weight, and feed intake and reduced the percentage of broken eggs during the entire trial duration. In addition, percentage and weight of bone Ca and P increased significantly with added phytase. In trial 2 and 3, there was no significant difference between PC and the phytase treatment. In conclusion, the novel phytase significantly increased the ileal digestibility of P in a short-term digestibility study and improved egg production and bone mineralization in a 12-wk laying cycle. Ileal digestibility of P rather than P retention in short-term digestibility studies as well as egg production and whole tibia mineralization in long-term studies should be measured to demonstrate the efficacy of phytase in laying hens.

[The correlation study on human respiratory syncytial virus daily incidence and meteorological parameters in the main urban area of Chongqing from 2009 to 2019].

Objective: To explore the relationship between the daily incidence of human respiratory syncytial virus (HRSV) and meteorological parameters in the main urban area of Chongqing. Methods: This study took 3 107 children hospitalized with acute lower respiratory tract infections from June 2009 to June 2019 in department of Respiratory medicine, Children's Hospital of Chongqing Medical University (CHCMU). Nasopharyngeal aspirate (NPA) was collected on the day of admission to detect HRSV and common respiratory virus; combined with the meteorological data of the main urban area of ​​Chongqing during the same period, the correlation and distribution lag nonlinear model analysis of the daily incidence of HRSV and meteorological parameters were carried out. Results: Among 3 107 children, HRSV positive accounted for 34.53% (1 073 cases), the age was 6 (3, 13) months, and males accounted for 64.31% (690 cases). The daily incidence of HRSV was negatively correlated with minimum temperature (r=-0.220, P<0.001), maximum temperature (r=-0.221, P<0.001), average temperature (r=-0.221, P<0.001) and precipitation (r=-0.052, P<0.001), and positively correlated with sunshine time (r=0.011, P<0.001) and average relative humidity (r=0.095, P<0.001). Compared with the reference temperature (20 ℃), when the lowest temperature of 6-10 ℃ lags for 4-8 d, the RR value of HRSV was 1.11-1.14, and when the lowest temperature of 5-19 ℃ lags for 5 d and 2-19 ℃ lags for 10 d, the RR values were 1.02-1.14 and 1.00-1.03. When the cumulative lag is 5, 10, 15 and 21 d, compared with the reference temperature (20 ℃), the RR (95%CI) values at the lowest temperature of 10.4 ℃ were 1.93 (1.08-3.46), 3.49 (1.64-7.45), 5.00 (2.01-12.46) and 6.69 (2.18-20.48); the RR (95%CI) values of the lowest temperature of 22.1 ℃ were 0.87 (0.77-0.98), 0.77 (0.66-0.90), 0.74 (0.62-0.89) and 0.68 (0.55-0.85). In the cumulative effect, compared with the reference temperature (20 ℃), the gender stratification showed that the maximum RR (95%CI) values of the lowest temperature for boys and girls under different lag days were 7.24 (1.84-28.51) and 2.19 (1.07-4.46), the age stratification showed that the maximum RR (95%CI) values of the lowest temperature for children<6 months old and children ≥6 months old under different lag days were 4.72 (1.05-21.23) and 11.98 (1.70-84.35). Conclusions: In the main urban area of Chongqing, the daily incidence of HRSV in children is correlated with climatic parameters. Among them, the lowest temperature has a delayed and cumulative effect on HRSV infection. 6-10 ℃ has a greater impact on the incidence of HRSV when the lag is 4-8 days. The effect has a more obvious impact on the incidence of HRSV in boys and children ≥ 6 months.

Relationship between Wound Age and Serum Marker Metabolites of Rats Skin Incised Wound.

ABSTRACT: Objective To observe the metabolomics changes of serum after skin incision of rats and to determine the wound age of skin incision. Methods A rat skin incision model was established, 21 SD rats were divided into 1 h, 2 h, 4 h, 8 h, 16 h, 24 h after skin incision groups and the control group, then blood was taken from rats in the experimental groups at the corresponding time points after injury, and taken from the control group directly. Gas chromatography-mass spectrometry （GC-MS） technology was used to detect serum metabolites and screen marker metabolites, then orthogonal partial least square-discriminant analysis （OPLS-DA） model was used to establish a regression model for the relationship between marker metabolite content and wound age to determine wound age of skin. Results GC-MS was used to detect the serum collected, and 21 marker metabolites were obtained through initial screening, and 4 marker metabolites were further analyzed and screened using multivariate statistical analysis methods. There was no correspondence between the change rule of the serum content and wound age, therefore it cannot be used directly to determine wound age. OPLS model could be used to obtain regression models of the content and wound age of 21 marker metabolites and 4 marker metabolites, both of which can determine wound age, but the prediction accuracy of the regression model of 21 marker metabolites was significantly higher. Conclusion Using metabolomics to establish a regression model of the metabolite content and wound age has the potential to be applied to skin incision wound age determination.

[Research of SIRT1 on promoting the proliferation, migration and lipid metabolism of nasopharyngeal carcinoma].

Objective: To analyze the differential expression of silent information regulator transcript-1 (SIRT1) in tissues and cells of nasopharyngeal carcinoma (NPC), to explore the effects of SIRT1 on the proliferation and migration of NPC cells, as well as the effects on and mechanisms of lipid metabolism in NPC cells. Methods: Experimental subjects: In this study, tissue specimens were obtained from patients who visited the Department of Otolaryngology and performed nasopharyngeal tissue biopsy in the Affiliated Hospital of Nantong University from 2019 to 2020. Among them, 6 cases were male, 6 cases were female, age range: 27-72 years old, including 7 cases of NPC diagnosed by pathology and 5 cases of normal nasopharyngeal mucosa. Experimental methods and outcome measures: Western Blot and quantitative real time polymerase chain reaction (qRT-PCR) were used to detect the protein and mRNA levels of SIRT1. CNE2 cell line was selected for subsequent experiments. Cell viability and migratory ability were evaluated by CCK8, wound healing and Transwell assays respectively. Animal xenograft tumor model was used to explore the role of SIRT1 inhibitor Ex527 on tumor growth in nude mice. Oil red and Bodipy were used to stain intracellular lipids. For the mechanical investigation, the interactions between SIRT1 and hypoxia inducible factor-1α (HIF-1α) were analyzed by immunoprecipitation (IP) and chromatin immunoprecipitation (ChIP). Finally, statistical analysis was performed by SPSS 26.0 software, P<0.05 was considered statistically significant. Results: The levels of SIRT1 protein (1.005±0.168) and mRNA (5.829±2.395) in NPC tissues were higher than those in normal nasopharyngeal mucosa (0.181±0.042,1.995±1.605). Differences were statistically significant (t values were 6.438 and 2.759, both P<0.05). The mRNA and protein levels of CNE1, CNE2, 5-8F and 6-10B cell lines were also higher than those in normal nasopharynx epithelial cell line NP69. Besides, overexpression of SIRT1 correlated with the proliferation and migration of NPC cells. The tumorigenesis ability of nude mice in the Ex527 group was lower than that in the control group. The low SIRT1 expression reduced the protein level of the key enzymes of liposynthesis in NPC cells, improved the expression of lipolysis enzymes, while HIF-1α overexpression promoted lipid synthesis enzymes in NPC cells. SIRT1 inhibited HIF-1α transcription by enhancing deacetylation levels. The binding ability of HIF-1α to SIRT1 promoter regions decreased when NPC cells were hypoxic. Conclusions: SIRT1 promotes the proliferation, migration and lipid metabolism of nasopharyngeal carcinoma cells, which might be expected to provide new theoretical basis for prognosis judgment and gene therapy.

Research Note: Delay in sampling influences the profile of phytate in gizzard digesta and ileal digestibility of phosphorus in broilers.

The objective of this study was to investigate the effect of different durations of time delay when sampling digesta from the gizzard and ileum of broilers on the degradation of myo-inositol hexakisphosphate (InsP6) and digestibility of phosphorus (P). There was 1 experimental diet with a supplemental phytase activity of 1,212 phytase units/kg feed, which was provided to birds from day 13 to 18 after hatching. The diet was formulated to provide 6.6 g/kg Ca and 1.9 g/kg nonphytate P and fed to 24 cages of 6 birds. The 24 cages of birds were further randomly divided into 6 subgroups of 4 cages from which the digesta samples in the gizzard and ileum were collected at 0, 5, 10, or 20 min postmortem. The results showed that the concentration of InsP6 decreased linearly (P = 0.002), InsP5 decreased quadratically (P = 0.038), and the summation of concentrations of P in InsP6-4 decreased linearly (P = 0.028) in the gizzard digesta with the increasing delay of sampling. In the ileum, the digestibility of phytate P tended to decrease linearly (P = 0.087), and the digestibility of total P decreased linearly (P = 0.026) with prolonged delay. In conclusion, delay in sampling could alter the measured profile of InsP esters in gizzard digesta probably because of a continued effect of supplemental phytase, while the ileal digestibility of total P could diminish. Therefore, standard sampling procedures should be implemented to minimize variance.

[Clinical observation of ocular injury caused by chestnut burr].

Objective: To analyze the clinical characteristics and treatment of ocular injury caused by chestnut burr. Methods: Retrospective case series study. Data of 48 patients (48 eyes) with ocular injuries caused by chestnut burrs hospitalized in Qingdao Eye Hospital were collected from January 2013 to March 2019. All patients were followed up for at least 3 months. The time of seeking medical advice, lesion region, and characteristics and treatment methods were analyzed. Results: There were 48 patients, including 33 males and 15 females, aged 19 to 74 years [mean, (56±10) years]. The time of injury was late September (25 cases) and early October (23 cases). The shortest time to visit our hospital was 3 hours after injury, and the longest was 8 months after injury. There were 13 cases (27.1%, 13/48) with corneal and/or scleral foreign bodies. All patients were treated with corneal or scleral foreign body extraction. Twenty-four patients (50.0%, 24/48) developed fungal keratitis. Among them, 18 patients had a corneal ulcer, and the infection involved the superficial or full-thickness corneal layer. Six patients had no corneal ulcer, and the infection involved the deep stroma and corneal endothelial surface. The positive rate of fungal examination by confocal microscopy was 87.5% (21/24). Antifungal drugs (2 cases), corneal debridement (5 cases), conjunctival flap covering (2 cases), corneal stroma injection (1 case), and penetrating keratoplasty(14 cases) were given according to the depth of fungal infection. Most of the pathogens were Alternaria spp. Eleven patients (22.9%, 11/48) with necrotizing scleritis were treated with exploration of the sclera. Three patients had scleral foreign body residues on ultrasound biomicroscopy examination, which were removed by operation. Four patients were found to have fungi at the necrotic site of the sclera. Conclusions: The main types of ocular injuries caused by chestnut burrs are corneal and/or scleral foreign bodies, fungal keratitis, and necrotizing scleritis. Chestnut burr foreign bodies should be removed as soon as possible. In the case of fungal keratitis, a drug or surgical intervention should be carried out as early as possible. Necrotizing scleritis is often induced by long-term foreign body retention. Scleral incision and exploration is an effective form of treatment. (Chin J Ophthalmol, 2020, 56: 370-375).

Hsa_circ_0011946 promotes the migration and invasion of hepatocellular carcinoma by inducing EMT process.

OBJECTIVE: Recently, the vital role of circular RNAs is discovered in many diseases including tumor progression and metastasis. Hepatocellular carcinoma (HCC) is one of the most ordinary malignant tumors. The purpose of our study is to detect the potential function of hsa_circ_0011946 in HCC to offer new biomarkers and targets. PATIENTS AND METHODS: The level of hsa_circ_0011946 in HCC tissues and cell lines was monitored by Real Time Quantitative Polymerase Chain Reaction (RT-qPCR). Pearson's Chi-square test was used to determine the association between hsa_circ_0011946 expression and several clinicopathological factors. Then, hsa_circ_0011946 was knocked down in HCC cells to uncover its function in metastasis of HCC. Cell migrated and invaded ability was measured through transwell assay, Matrigel assay and wound healing assay. Western blot assay was performed to analyze the effect of hsa_circ_0011946 on the epithelial-to-mesenchymal transition (EMT) process. RESULTS: In this research, the expression level of hsa_circ_0011946 was significantly increased in HCC tissues compared to that in adjacent samples. The expression of hsa_circ_0011946 was also increased in HCC cell lines. The hsa_circ_0011946 expression was associated with lymphatic metastasis in HCC patients. Knockdown of hsa_circ_0011946 led to the inhibition of cell migration and invasion in HCC. In addition, results of further experiments revealed that the EMT-related proteins were regulated via the knockdown of hsa_circ_0011946 in HCC. CONCLUSIONS: The hsa_circ_0011946 could enhance cell migration and invasion of HCC by inducing the EMT process.

[Sequential Changes of Serum Biomarkers after Skeletal Muscle Contusion in Rats].

ABSTRACT: Objective To screen serum biomarkers after skeletal muscle contusion in rats based on gas chromatography-mass spectrometry （GC-MS） metabolomics technology, and support vector machine （SVM） regression model was established to estimate skeletal muscle contusion time. Methods The 60 healthy SD rats were randomly divided into experimental group （n=50）, control group （n=5） and validation group （n=5）. The rats in the experimental group and the validation group were used to establish the model of skeletal muscle contusion through free fall method, the rats in experimental group were executed at 0 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, 96 h, 144 h and 240 h, respectively, and the rats in validation group were executed at 192 h, while the rats in the control group were executed after three days' regular feeding. The skeletal muscles were stained with hematoxylin-eosin （HE）. The serum metabolite spectrum was detected by GC-MS, and orthogonal partial least square-discriminant analysis （OPLS-DA） pattern recognition method was used to discriminate the data and select biomarkers. The SVM regression model was established to estimate the contusion time. Results The 31 biomarkers were initially screened by metabolomics method and 6 biomarkers were further selected. There was no regularity in the changes of the relative content of the 6 biomarkers with the contusion time and the SVM regression model can be successfully established according to the data of 6 biomarkers and the 31 biomarkers. Compared with the injury time ［（55.344±7.485） hï¼½ estimated from the SVM regression model based on the data of 6 biomarkers, the injury time ［（195.781±1.629） hï¼½ estimated from the SVM regression model based on the data of 31 biomarkers was closer to the actual value. Conclusion The SVM regression model based on metabolites data can be used for the contusion time estimation of skeletal muscles.

[Surgical treatment of keratoglobus: key techniques of bridge-shaped flap penetrating keratoplasty and whole lamellar keratoplasty with corneoscleral limbal].

Objective: Introduce the surgical techniques of bridge-shaped flap penetrating keratoplasty and whole lamellar keratoplasty with corneoscleral limbal and the comparison of therapeutic effects on keratoglobus. Methods: Five patients (eight eyes) with keratoglobus from January 2010 to December 2015 were included. Three eyes received bridge-shaped flap penetrating keratoplasty (two eyes with corneal penetrating injury due to trauma, one eye with descemet's membrane detachment) and five eyes received whole lamellar keratoplasty with corneoscleral limbal. Results: The patients (four male, one female) aged 3 to 67 years old. Three younger patients were complicated with blue sclera. The visual acuity of all the patients pre-operation were lower than 0.05. The average visual acuity after whole lamellar keratoplasty (LKP) surgery was 0.2, while the average visual acuity after bridge-shaped flap penetrating keratoplasty (PKP) was 0.5. The corneal epithelium of the three eyes received bridge-shaped flap PKP surgery was completely healed within a week with no recurrence of corneal epithelial defect. Whereas one eye after whole LKP surgery arised persistent corneal epithelial defect and healed after blepharorrhaphy. The corneal epithelial of another eye after whole LKP surgery healed slowly and was completely healed after wearing a bandage lens on corneal for 2 months. The corneal epithelial of the remaining three eyes after whole LKP surgery was completely healed within a week. Two eyes received bridge-shaped flap PKP surgery arised corneal graft rejection 2 months after operation and recovered after anti-rejection treatment. No corneal graft rejection arised in the patients receiving whole LKP surgery. Conclusions: The whole lamellar keratoplasty with corneoscleral limbal could effectively reinforce corneal, avoid corneal penetrating injury caused by minor trauma, and improve visual acuity in keratoglobus whose corneas were gradually thinning and corrected vision cannot be improved. The patients with corneal perforating injury or descemet's membrane detachment could obtain good visual prognosis receiving bridge-shaped flap penetrating keratoplasty. (Chin J Ophthalmol, 2019, 55:916-922).

LncRNA BCAR4 up-regulates EGFR and thus promotes human thyrocyte proliferation.

This article has been withdrawn at the request of the authors. The Publisher apologizes for any inconvenience.

Prevalence of Ureaplasma urealyticum, Chlamydia trachomatis, Neisseria gonorrhoeae and herpes simplex virus in Beijing, China.

The prevalence of sexually transmitted infection (STI) pathogens in Beijing, China, is rarely reported. In this study, 34 911 symptomatic outpatients with suspected genital infections who attended outpatient clinics in a tertiary care hospital were included to investigate the updated prevalence of Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and herpes simplex virus (HSV) from 1 January 2013 to 31 December 2016 in Beijing, China. Results indicated that a decrease trend (UU, CT, NG and HSV) in male and an increase trend (UU, CT and NG) in female were observed during the period. Patients aged 20-39 years old were mostly affected by these pathogens, while the prevalence in patients aged 20-29 years old was the highest, The prevalence of UU in male was significantly lower than in female (31.5% vs. 49.3%, P < 0.05), while the prevalence of NG in male was significantly higher than in female (2.5% vs. 0.8%, P < 0.05). In patients with co-infections, 60.6% of male and 71.4% of female were co-infected by UU + CT. In total, 11.9% and 88.1% of patients with HSV infections were confirmed to be infected by HSV-1 and HSV-2. This study could contribute to a better understanding of the current epidemiological features of UU, NG, CT and HSV among symptomatic patients attending an outpatient clinic in Beijing, China, and thus facilitate to develop more effective intervention, prevention and treatment of STI.

Is lower low-density lipoprotein cholesterol associated with lower androgen and erectile dysfunction in men?

BACKGROUND AND AIMS: Therapeutic possibilities now exist to lower low-density lipoprotein cholesterol (LDL-C) to very low levels. However, substantial controversy remains in clinical practice with regard to its safety, and the question of whether low LDL-C levels per se may provoke adverse effects in humans arises. We aimed to explore the association of LDL-C with androgen and erectile dysfunction (ED) in a general population of men. METHODS AND RESULTS: A total of 4203 men without hormone replacement therapy were enrolled from 22 sites in East China. Total testosterone (T) and Free T were assessed. Free androgen index (FAI) was calculated. The IIEF-5 questionnaire was used to assess ED. We found that free T and FAI gradually and markedly increased with increasing LDL-C levels. Using linear regression, after adjusting for age, educational level, economic status, smoking status, drinking status, BMI, diabetes, and use of lipid-lowering medication, LDL-C was positively associated with free T (B = 0.175, 95% CI: 0.084, 0.266) and FAI (B = 0.064, 95% CI: 0.016, 0.112). Meanwhile, there was a U-shaped curvilinear relationship between LDL-C and prevalence of ED. In the logistic regression analysis, compared to those with LDL-C among the 10th-90th percentile, the ORs of ED in men in the lowest and highest deciles were 1.938 (95% CI: 1.121, 3.349) and 1.804 (95% CI: 1.117, 2.916), respectively. CONCLUSION: Lower LDL-C levels were significantly associated with lower free T and lower FAI in a general population of men. Moreover, both low and high levels of LDL-C might be risk factors for ED.

Voltammetric determination of phenylephrine hydrochloride using a multi-walled carbon nanotube-modified carbon paste electrode.

A chemically modified carbon paste electrode (CPE) was designed by mixing graphite and multi-walled carbon nanotubes (MWCNT). The electrochemical behaviour was studied, and the determination method of phenylephrine hydrochloride (PHE) on this sensor was established. According to the results, the optimal ratio of MWCNTs was approximately 12.5% (w/w). MWCNT-modified carbon paste electrodes (MWCNT-CPEs) showed high electrochemical activity for PHE, producing a sharp oxidation peak current (I p) at approximately +0.816 V versus a saturated calomel electrode (SCE) reference electrode in phosphate buffer solution (PBS, pH 6.45), and the I p increased by approximately two times compared to that of the bare CPE. The anodic I p was linearly related with 5.0 × 10-6-7.5 × 10-4 mol l-1 PHE, with a detection limit of 3.7 × 10-7 mol l-1. Furthermore, MWCNT-CPEs were successfully applied to the determination of PHE in injection, eye drop and nasal spray liquid samples as a simple, rapid and low-cost method.

[Changes of intestinal mucosal barrier in mice with chronic ulcerative colitis].

Objective: To study the damage and mechanism of intestinal mucosal barrier function in mice with ulcerative colitis induced by Dextran sulphate sodium (DSS). Methods: Mice models of chronic ulcerative colitis induced by DSS were established. The mice were completely randomized into normal control group and DSS group, 25 mice in each group. The body weight and colon length of the mice were monitored. The pathological examination of colon tissue was confirmed the success of the model and assessed the integrity of the colonic mucosal barrier; Evan's Blue's intestinal permeability analysis assessed the function of colon mucosal barrier; immunofluorescence staining and Western blot were used to evaluate the expression of intestinal mucosal barrier integrity-related proteins. Results: Compared with the normal control group, the DSS group had lower body weight [(25.6±0.7)g vs (23.5±0.7)g, t=2.14, P<0.05], and the colon length was shorter [(7.3±0.4)cm vs (5.6±0.2)cm, t=3.975, P<0.001]; colonic pathological results showed that the intestinal mucosa became thinner and part of the intestinal mucosa was defective; Evan's Blue instilled into the intestinal lumen was more abundant into the intestinal mucosa, and the optical density at 620 nm (OD(620))/colon tissue weight (g) was higher [(0.11±0.01) vs (0.15±0.01), t=4.174, P<0.05]; immunofluorescence and Western blot results showed lower expression of ZO-1, Claudin-1, and F-actin in colonic mucosa. Conclusion: The structure and function of intestinal mucosal barrier in DSS-induced chronic ulcerative colitis mice is impaired.

Preparation and characterization of molecularly imprinted solid-phase extraction column coupled with high-performance liquid chromatography for selective determination of melamine.

We synthesized a selective molecularly imprinted solid-phase extraction (MIP-SPE) column and established an extraction and enrichment method using this MIP-SPE column. By coupling with HPLC, we developed a new method to detect trace amounts of melamine in eggs. The MIP-SPE column was synthesized by in situ thermal-initiated polymerization using melamine as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and azodiisobutyronitrile as the initiator. HPLC was used to evaluate the identification and enrichment capability of the MIP-SPE column and for the measurement of melamine in the sample. The melamine concentration exhibited an excellent linear relationship in the range of 0.1-25.0 µg ml-1 (r = 0.9983). The identification capability of the MIP-SPE column was apparently superior to that of the non-imprinted polymer solid-phase extraction column; an average enrichment factor of 46.8-fold (RSD = 3.5%) was obtained for 0.4 µg ml-1 melamine by the MIP-SPE column. When the MIP-SPE HPLC method was applied to the detection of melamine in eggs, an average recovery rate of 93.5-102.0% (RSD = 3.6-4.9%) and a limit of detection of 0.05 µg kg-1 were obtained. This method is simple, fast and cost-effective; thus, it can greatly simplify the pre-treatment of complex samples and can be used in the detection of residual melamine in eggs and other products.