External evaluation of population pharmacokinetic models for ciclosporin in adult renal transplant recipients.

AIMS: Several population pharmacokinetic (popPK) models for ciclosporin (CsA) in adult renal transplant recipients have been constructed to optimize the therapeutic regimen of CsA. However, little is known about their predictabilities when extrapolated to different clinical centres. Therefore, this study aimed to externally evaluate the predictive ability of CsA popPK models and determine the potential influencing factors. METHODS: A literature search was conducted and the predictive performance was determined for each selected model using an independent data set of 62 patients (471 predose and 500 2-h postdose concentrations) from our hospital. Prediction-based diagnostics and simulation-based normalized prediction distribution error were used to evaluate model predictability. The influence of prior information was assessed using Bayesian forecasting. Additionally, potential factors influencing model predictability were investigated. RESULTS: Seventeen models extracted from 17 published popPK studies were assessed. Prediction-based diagnostics showed that ethnicity potentially influenced model transferability. Simulation-based normalized prediction distribution error analyses indicated misspecification in most of the models, especially regarding variance. Bayesian forecasting demonstrated that the predictive performance of the models substantially improved with 2-3 prior observations. The predictability of nonlinear Michaelis-Menten models was superior to that of linear compartmental models when evaluating the impact of structural models, indicating the underlying nonlinear kinetics of CsA. Structural model, ethnicity, covariates and prior observations potentially affected model predictability. CONCLUSIONS: Structural model is the predominant factor influencing model predictability. Incorporation of nonlinear kinetics in CsA popPK modelling should be considered. Moreover, Bayesian forecasting substantially improved model predictability.

Lipid-rich enteral nutrition controls intestinal inflammation, improves intestinal motility and mucosal barrier damage in a rat model of intestinal ischemia/reperfusion injury.

BACKGROUND: It has been reported that lipid-rich enteral nutrition (EN) could ameliorate inflammation in various diseases. In this study, we investigated whether lipid-rich EN could control intestinal inflammation, improve intestinal motility and mucosal barrier injury after intestinal ischemia/reperfusion (I/R) injury. METHODS: Male adult rats received saline, conventional EN, or lipid-rich EN via gavage before and after intestinal I/R injury. The superior mesenteric artery was occluded for 60 min. The sham group underwent laparotomy without superior mesenteric artery occlusion and was administrated saline. Intestinal motility was measured 4 h after intestinal I/R injury by fluorescein isothiocyanate-dextran transit assay; the intestinal and systemic inflammation were assessed by analyzing intestinal and serum concentrations of tumor necrosis factor α, interleukin (IL)- 6, and IL-10, separately. The intestinal mucosal barrier injury was assessed by analyzing the serum levels of intestinal fatty acid-binding protein (I-FABP) and intestinal mucosal tight junction (TJ) proteins. RESULTS: The intestinal I/R injury decreased intestinal motility and intestinal mucosal TJs expression significantly when compared with the sham group (P < 0.05). The intestinal and systemic inflammatory parameters and the serum I-FABP were also significantly higher in the I/R groups than those in the sham group (P < 0.05). Both conventional and lipid-rich EN increased the intestinal motility and the intestinal mucosal TJs expression and decreased the intestinal and systemic inflammatory parameter and serum I-FABP levels to different degrees when compared with the I/R group (P < 0.05). However, lipid-rich EN significantly improved the negative alterations in these biochemical parameters when compared with the conventional EN (P < 0.05). CONCLUSIONS: These results suggest that lipid-rich EN might be able to control intestinal inflammation, improve intestinal motility and mucosal barrier injury after intestinal I/R injury. Thus, the administration of lipid-rich EN may be an effective treatment for promoting gastrointestinal function recovery after intestinal I/R injury.

External evaluation of published population pharmacokinetic models of tacrolimus in adult renal transplant recipients.

AIM: Several tacrolimus population pharmacokinetic models in adult renal transplant recipients have been established to facilitate dose individualization. However, their applicability when extrapolated to other clinical centres is not clear. This study aimed to (1) evaluate model external predictability and (2) analyze potential influencing factors. METHODS: Published models were screened from the literature and were evaluated using an external dataset with 52 patients (609 trough samples) collected by postoperative day 90 via methods that included (1) prediction-based prediction error (PE%), (2) simulation-based prediction- and variability-corrected visual predictive check (pvcVPC) and normalized prediction distribution error (NPDE) tests and (3) Bayesian forecasting to assess the influence of prior observations on model predictability. The factors influencing model predictability, particularly the impact of structural models, were evaluated. RESULTS: Sixteen published models were evaluated. In prediction-based diagnostics, the PE% within ±30% was less than 50% in all models, indicating unsatisfactory predictability. In simulation-based diagnostics, both the pvcVPC and the NPDE indicated model misspecification. Bayesian forecasting improved model predictability significantly with prior 2-3 observations. The various factors influencing model extrapolation included bioassays, the covariates involved (CYP3A5*3 polymorphism, postoperative time and haematocrit) and whether non-linear kinetics were used. CONCLUSIONS: The published models were unsatisfactory in prediction- and simulation-based diagnostics, thus inappropriate for direct extrapolation correspondingly. However Bayesian forecasting could improve the predictability considerably with priors. The incorporation of non-linear pharmacokinetics in modelling might be a promising approach to improving model predictability.

Upregulation of miR-194 contributes to tumor growth and progression in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of human cancer worldwide. In the present study, we investigated the diagnostic and biological significance of microRNA-194 (miR-194) in PDAC. miRNA expression profiling of human PDACs and adjacent normal pancreatic tissues identified a total of 16 genes including miR-194 with >1.15-fold expression changes (8 overexpressed and 8 underexpressed). Quantitative real-time polymerase chain reaction (PCR) revealed elevation of serum miR-194 levels were significantly greater in PDAC patients than in duodenal adenocarcinoma patients and healthy controls. Receiver operating characteristic analysis demonstrated that serum miR-194 had a sensitivity of 54.3% and a specificity of 57.5% for discriminating PDAC patients from healthy controls. Combined analysis of the 3 groups yielded a sensitivity of 84.0 and a specificity of 75.0% for the combined detection of miR-192 and miR-194 in the diagnosis of PDAC. Ectopic expression of miR-194 in PANC-1 pancreatic cancer cells enhanced cell proliferation, migration and colony formation, which was coupled with decreased expression of the tumor suppressor DACH1. miR-194 overexpression increased tumor growth and local invasion and suppressed the expression of DACH1 in an orthotopic pancreatic cancer mouse model. In conclusion, upregulation of miR-194 contributes to tumor growth and progression in PDAC, possibly through suppression of DACH1. However, serum miR-194 has a low capacity for detection of PDAC. Combined detection of serum miR-192 and miR-194 levels may serve as a sensitive diagnostic biomarker for PDAC.

Role of heat shock protein 27 in gemcitabine-resistant human pancreatic cancer: comparative proteomic analyses.

The most notable obstacle hindering the effective treatment of human pancreatic cancer is intrinsic chemoresistance. In order to identify the candidate protein(s) responsible for the intrinsic chemoresistance, the protein expression profiling of human pancreatic adenocarcinoma cell line Capan-1 and its distinct surviving cells following primary treatment with gemcitabine (GEM) were compared by two-dimensional electrophoresis (2-DE) combined with liquid chromatography-mass spectrometry (LC-MS) or mass spectrometry (MS). In total, nine proteins were identified, and heat shock protein B1 (HSP27), one of the differentially expressed proteins, was selected for further validation. Furthermore, the results of western blotting and immunohistochemical staining indicated that HSP27 may be significant in pancreatic intrinsic chemoresistance to GEM. The findings of this study provide a platform for further elucidation of the underlying mechanisms of pancreatic cancer intrinsic chemoresistance and demonstrate that HSP27 may be a valid target for anticancer drug development.

Expression of fibroblast activation protein in human pancreatic adenocarcinoma and its clinicopathological significance.

AIM: To examine fibroblast activation protein (FAP) expression in pancreatic ductal adenocarcinoma (PDAC) and to analyze its relationship with the clinicopathology of PDAC. METHODS: FAP expression was examined in 134 PDAC specimens by immunohistochemistry, and in four pancreatic cancer cell lines (SW1990, Miapaca-2, AsPC-1 and BxPC-3) by Western blotting assay. We also analyzed the association between FAP expression in PDAC cells and the clinicopathology of PDAC patients. RESULTS: The results showed that the FAP was ex-pressed in both stromal fibroblast cells (98/134, 73.1%) and carcinoma cells (102/134, 76.1%). All 4 pancreatic cancer cell lines expressed FAP protein at different levels. Protein bands corresponding to the proteolytically active 170-kDa seprase dimer and its 88-kDa seprase subunit were identified. Higher FAP expression in carcinoma cells was associated with tumor size (P < 0.001), fibrotic focus (P = 0.003), perineural invasion (P = 0.009) and worse clinical outcome (P = 0.0085). CONCLUSION: FAP is highly expressed in carcinoma cells and fibroblasts in PDAC tissues, and its expression is associated with desmoplasia and worse prognosis.

Surviving cells after treatment with gemcitabine or 5-fluorouracil for the study of de novo resistance of pancreatic cancer.

One of the hallmarks of pancreatic cancer is its inherent insensitivity to chemotherapy. This study was undertaken to develop a cell model for the study of de novo resistance of pancreatic cancer. The surviving pancreatic cancer cells after a 3-day exposure to gemcitabine or 5-fluorouracil followed by another 7-day recovery were potentially drug-resistant. They had similar morphology and comparable growth and tumorigenic potentials to their untreated parental cells. Repeated subculture affected the cell-cycle profile and growth characteristics of the surviving cells. Our data suggest that surviving pancreatic cancer cells after drug treatment are a useful model for exploring intrinsic resistance.

[The preliminary analysis on immunogenicity of DNA vaccines against human papillomavirus 58].

In order to evaluate the immunogenicity of HPV 58 L1 DNA vaccines, five DNA vaccines had been constructed with pcDNA3.1 vector containing different L1 genes of HPV 58, which were designated as L1h, L1hDeltac, L1S, L1SM and L1wt. The protein expression of DNA vaccines in vitro was tested by Western blot. The ability of forming pseudovirus was evaluated by transfecting DNA vaccine together with pcDNA3.1-h58L2 and pcDNA3.1-GFP into 293FT cells. The neutralizing antibodies and cellular immune response produced in BALB/c mice immunized with the DNA vaccines were detected by using pseudovirus-based neutralization assay and ELISPOT respectively. The results showed that the five DNA vaccines had been successfully constructed; the level of protein expression of L1hDeltac was the highest and those for L1S and L1SM were of medium, while no expressed target protein of L1wt was detected. Only L1S could form the pseudovirus while the other four vaccines could not. L1S and L1h could induce neutralizing antibody. However, the average titer of neutralizing antibody for L1S (1:6,400) was much higher than that for L1h (1:48) and the other three vaccines could not induce neutralizing antibody. No cellular immune response for all five DNA vaccines was detectable by ELISPOT. The results indicated that DNA vaccine against HPV 58 can form pseudovirus in vitro, also can induce high level of neutralizing antibodies. This provides reference for screening HPV vaccine in future.

[Epidemiological survey on the infection of hepatitis E virus among pigs in Henan province].

OBJECTIVE: To investigate hepatitis E virus (HEV) infection among pigs in Henan province. METHODS: A total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively. The sera positive for HEV antigen were tested for HEV RNA with RT-PCR. The positive products of RT-PCR were cloned and sequenced. RESULTS: The positive rates of anti-HEV antibody of the groups under 3-month and over 3-month of age were 90.27% and 92.55%, respectively, without statistical difference, while those of HEV antigen were 15.93% and 5.69%, respectively, with significant difference. The positive rates of anti-HEV antibody and HEV antigen were significantly different among different districts. HEV RNA was detectable in 5 of 47 HEV antigen positive samples. The sequence analysis showed that in 4 of 5 specimens the sequence belonged to genotype 4 while in the remaining one the sequence was genotype 1. CONCLUSION: The prevalence rate of HEV infection in pigs was high in Henan province and the rate differed in different districts.

[Analysis of the changing trends of frequency and localization of gastric cancers arising from different sites of the stomach in population of the high incidence area of esophageal and gastric cancers in Hebei province].

OBJECTIVE: To analyze the changing trends of frequency and localization of gastric cancers arising from the gastric cardia, corpus and antrum during the past 14 years in population of the high incidence area of esophageal and gastric carcinoma in Hebei province, China. METHODS: The clinicopathological data of 4334 cases of gastric carcinomas among the local residents of Cixian and Zanhuang counties, initially diagnosed in our department from 1993 to 2006, were retrospectively analyzed. The proportion of gastric carcinomas arising from the gastric cardia, corpus and antrum in different years and in patients with different sex and ages were analyzed and compared, and the changing trends of the frequency of gastric carcinoma arising from different sites of the stomach were statistically analyzed. RESULTS: Among all the 4334 gastric carcinomas, gastric cardia carcinoma accounted for 68.0%, significantly higher than that of corpus (24.2%) and antrum (7.9%; chi(2) = 124.396, P < 0.0001). An increasing tendency in the proportion of gastric cardia carcinoma from 1993 to 2006 was seen. The percentage of cardiac carcinoma in the high incidence area of esophageal carcinoma (Cixian county) was higher than that in the high incidence area of gastric cancer (Zanhuang county) (71.2% vs. 51.2%; chi(2) = 109.648, P < 0.0001). The increase in the incidence of cardiac carcinoma in Cixian county was mainly due to the increase of cardiac carcinoma from 1993 to 2006, while the contributing factor for the increase in the proportion of cardiac carcinomas was resulted from the decrease of incidence of antrum carcinoma in Zanhuang county during the same period. The occurring site of gastric carcinoma was related with age of patients (chi(2) = 58.380, P < 0.0001). The percentage of carcinoma of the gastric body was highest in < 50 year age group, while that in the gastric cardia was highest in 61 - 70 year age group (71.6%). CONCLUSION: The major occurring site of gastric carcinoma is the gastric cardia among the local residents in population of the high incidence areas of esophageal and gastric carcinomas during the past 14 years in Hebei province, China. The increasing trend of cardiac carcinoma and decreasing trend of corpus carcinoma in Cixian county and antrum carcinoma in Zanhuang county will be maintained in the coming years if the epidemiological conditions will not be changed.

[Comparison of the reliability of two ELISA kits for detecting IgM antibody against hepatitis E virus].

OBJECTIVE: To study the reliability of two ELISA kits for detecting IgM antibody against hepatitis E virus (HEV). METHODS: Serum samples from 92 healthy subjects, 71 cases suspected of hepatitis E, 55 patients with confirmed diagnosis of acute hepatitis E, 50 individuals with rheumatoid factor (RF) positive and 54 persons with anti-HAV IgM positive were detected with three hepatitis E diagnostic kits. MP-IgM (MP, Singapore), Wantai-IgM and anti-HEV IgG (Wantai, China). HEV RNA was analyzed with RT-PCR in 52 of 71 cases suspected of hepatitis E. RESULTS: In healthy subjects,cases suspected of hepatitis E and confirmed acute hepatitis E, the concordance between the two anti-HEV IgM reagents was 73.39% (160/218) and the significant differences in the positive rates of two assays were not observed [46.79% (102/218) vs 44.04% (96/218), chi2 = 0.62, P > 0.05]. Of 71 patients suspected of hepatitis E, the sensitivity for diagnosing acute hepatitis E of Wantai-IgM and MP-IgM were 83.08% (54/65) and 78.46% (51/65) (chi2 = 0.16, P > 0.05), respectively. Among those suspected of hepatitis E with HEV RNA positive, the sensitivity of Wantai-IgM was obviously higher than that of MP-IgM [(97.14%, 34/35) vs (74.29%, 26/35), chi2 = 4.9, P < 0.05]. 48 of 55 patients (87.27%) with confirmed diagnosis of hepatitis E were Wantai-IgM positive while 37 (67.27%) was MP-IgM positive (chi2 = 4.0, P < 0.05). The specificity of Wantai-IgM was higher than MP-IgM [100.00% (202/202) vs 89. 11% (180/202), chi2 = 20.05, P < 0.005]. RF and anti-HAV IgM might cause MP-IgM false positive without interference on Wantai-IgM. CONCLUSION: Wantai-IgM should be a good ELISA kit for the diagnosis of acute hepatitis E.