[Spatial Diffusion Mechanism Underlying Peri-urban Cropland Heavy Metal Contamination in the Black Soil Region].

The spatial diffusion mechanism underlying cropland heavy metal contamination in a complex peri-urban environment provides a crucial basis for controlling soil contamination from the source and also for ensuring the quality of black soil croplands. However, previous studies have struggled to locate the contamination sources or trace their diffusion trajectories in space. In this regard, representative peri-urban croplands in the black soil region were selected as a case, and soil As, Pb, Hg, and Cd were deemed as the main research objects. Moreover, an affinity propagation algorithm and spatial autocorrelation regression were adopted to measure the contamination patterns and identify the major determinants, in an attempt to reveal how heavy metals are diffused in the peri-urban cultivated area. The results indicated that ① the average concentrations of soil As and Cd were 39.35 mg·kg-1 and 0.183 mg·kg-1, respectively, which exhibited heavier accumulation in the study area. The Nemerow index indicated that there were 52.38% of croplands indicating slight contamination. ② The affinity propagation algorithm identified three potential sources with a similar impact extent for As, which were situated in the typical cultivated area. Both of the two identified potential sources for Pb were situated in close proximity to Fanjiatun Town. The diffusion patterns for Hg and Cd were complex, particularly for the latter, of which the potential sources were scattered in multiple places. ③ The spatial lag model indicated that the distributions of As and Cd were mainly controlled by the intensive agriculture in peri-urban areas, among which As was related to the application of herbicide and Cd was related to the distribution of protected agriculture. Pb was mainly influenced by urbanization and industrialization, whereas Hg was found to be associated with the migration conditions of the soil. However, the regulating function provided by either croplands or their nearby environment did not play an important role in determining the diffusion patterns of heavy metals. The present study enriches the theory and methods for the spatial analysis of cropland heavy metal contamination and is significant for controlling contamination from the source in peri-urban croplands in the black soil region.

Prostate-specific membrane antigen expression in hepatocellular carcinoma, cholangiocarcinoma, and liver cirrhosis.

BACKGROUND: Primary liver cancer includes three subtypes: Hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (CCA), and combined hepatocellular carcinoma. Patients with primary liver cancer experienced poor prognosis and high mortality, so early detection of liver cancer and improved management of metastases are both key strategies to reduce the death toll from liver cancer. Prostate-specific membrane antigen (PSMA) expression in the tumor-associated neovasculature of nonprostate malignancies including liver cancer has been reported recently, but conclusive evidence of PSMA expression based on the pathological type of liver cancer remains limited. AIM: To study the expression of PSMA in HCC, CCA, and liver cirrhosis. METHODS: A total of 446 formalin-fixed paraffin-embedded (FFPE) liver tumor and liver cirrhosis tissue samples were obtained retrospectively from the Pathology Department of Tongji Hospital. Immunohistochemistry was used to detect PSMA expression in these 446 FFPE liver biopsy specimens (213 HCC, 203 CCA, and 30 liver cirrhosis). The tumor compartment and the associated neovascular endothelium were separately analyzed. PSMA expression was examined by two certified pathologists, and the final results were presented in a 4-point scoring system (0-3 points). Correlation between PSMA expression and clinicopathological information was also assessed. RESULTS: PSMA was expressed primarily in the neovascular endothelium associated with tumors. The positive rate of PSMA staining in HCC was significantly higher than that in CCA (86.8% vs 79.3%; P = 0.001) but was only 6.6% in liver cirrhosis (P = 0.000). HCC cases had more 3-score PSMA staining than CCA had (89/213, 41.8% vs 35/203, 17.2%; P = 0.001). PSMA expression correlated positively with the stage and grade of HCC and CCA. In both liver cancer subtypes, there were more PSMA+ cases in stages III-V diseases than in stages I and II. High staining intensity of PSMA was more frequently observed in liver cancers at high grade and advanced stage. There was no significant association of PSMA expression with sex, age, region, α-fetoprotein, hepatitis B surface antigen, or tumor size in both tumor subtypes. CONCLUSION: Neovascular PSMA may be a promising marker to differentiate HCC from liver cirrhosis and a prognostic marker for anti-tumor angiogenesis therapy for HCC.

[Effect of chronic restraint stress on esophageal epithelial barrier function: experiment with rats].

OBJECTIVE: To investigate the effect of chronic restraint stress (CRS) on the esophageal epithelial barrier function and discuss the role of emotional factors in the pathogenesis of gastroesophageal reflux. METHODS: Twenty-four male SD rats were randomly divided into 4 equal groups: CRS group submitted to partial restraint stress 2 h per day for 7 days, CRS + acid/pepsin perfusion group submitted to partial restraint stress 2 h per day for 7 days and then anesthetization and perfusion of hydrochloric acid (pH=2) and pepsin (1 g/L) into the distal esophagus at the speed of 4 ml/h for 60 min, acid/pepsin perfusion group submitted to acid/pepsin perfusion into the esophagus, and control group. Then the rats were killed to collect the specimens of distal esophagus to undergo HE staining and light microscopy. Histological scoring was conducted. The diameter of intercellular spaces of esophageal epithelium was assessed. RESULTS: The amounts of food intake and body weight increment of the CRS and CRS + acid/pepsin perfusion groups were significantly lower than those of the control and acid/pepsin perfusion groups (all P < 0.01). The histological score of the CRS + acid/pepsin perfusion group was the highest. The diameter of intercellular spaces of esophagus of the CRS + acid/pepsin perfusion group was (0.516 +/- 0.010) microm, significantly greater than those of the CRS, acid/pepsin perfusion, and control groups [(0.457 +/- 0.031) microm, (0.441 +/- 0.021) microm, and (0.235 +/- 0.027) microm respectively, P < 0.01 or P < 0.05]. The histological score of the CRS + acid/pepsin perfusion group was 2.33 +/- 0.33, significantly higher than those of the CRS, acid/ pepsin perfusion, and control groups (1.17 +/- 0.31, 1.33 +/- 0.33; and 0.33 +/- 0.21 respectively, P < 0.05 or P < 0.01). CONCLUSION: CRS enlarges significantly the esophageal DIS and impairs the epithelial barrier function of the esophagus. Psychological factors induce or enhance the reflux symptom in the GERD patients, especially in non-erosive reflux disease and functional heartburn patients.

[Changes of leukotriene B4 in chronic obstructive pulmonary disease and effects of theophylline on leukotriene B4].

OBJECTIVE: To investigate the changes of leukotriene B4 (LTB4) in both the airways and the blood circulation in an animal model of chronic obstructive pulmonary disease (COPD) and the effects of theophylline on LTB4. METHODS: Thirty-two male Wistar rats were divided into four groups by random number meter: Group A (normal controls), group B (COPD), group C (smoking+low dose theophylline), and group D (smoking+high dose theophylline ), with 8 rats in each group. Pulmonary functions of the rats were assessed, and pathological changes of airways were scored. Cell counts and cell differentiation in bronchoalveolar lavage fluid (BALF) were also performed. Concentrations of IL-8 and LTB4 in BALF, plasma and lung tissue were measured by enzyme-linked immunosorbent assay (ELISA) and enzyme immunoassay (EIA). RESULTS: LTB4 concentrations in BALF of COPD rats increased significantly as compared with the normal controls, and positively correlated with the percentage of neutrophil and IL-8 in BALF (r=0.794, 0.863; P=0.007, 0.012), and negatively correlated with peak expiratory flow (PEF) (r=-0.718, P=0.028). Positive correlations were also found between levels of LTB4 in BALF and the scores of inflammatory cell infiltration of COPD rats (r=0.836, P=0.036). Treatment with theophylline decreased the percentage of neutrophil and the concentrations of LTB4 in BALF of the COPD rats, attenuated the pathological changes of small airways, such as airway occlusion, goblet-cell metaplasia, inflammatory cell infiltration, and fibrosis and smooth muscle proliferation. The effect was more significant on goblet-cell metaplasia and inflammatory cell infiltration in the high dose group. However theophylline had little effect on PEF. CONCLUSION: Our results suggest that LTB4 is involved in airway inflammation in COPD. Theophylline is effective in decreasing the levels of LTB4 in BALF of COPD rats, reducing the percentage of neutrophil, and attenuating pathological changes of small airways.

[Persistent intestinal motility disorder after transient intestinal nematode infection in rats].

OBJECTIVE: To investigate the intestinal motor function (distal colonic manometry and gastrointestinal transit time) after T. spiralis infection in rats. METHODS: Sprague-Dawley rats were infected by administering T. spiralis larvae. Rats were studied on 14, 42, and 56 days post-infection (PI). Age matched non-infected animals served as controls. All rats underwent colonic manometry and gastrointestinal transit time test. RESULTS: (1) The small intestinal inflammation became the most severe on day 14 PI, and returned to normal on day 56. (2) The distal colonic manometry showed significantly active motility in acute infected rats either at rest or upon balloon stimulating. (3) Rat colonic motility parameters were not different from those of the control rats either at rest or upon small volume (1mL) balloon stimulating on day 42 and day 56 PI. But when the balloon was inflated with 2 mL of air, the colonic activity increased significantly compared with that of the control. (4) Gastrointestinal transit time was slower in acute and PI rats than that in the control group. CONCLUSION: Intestinal motility function was abnormal persistently after transient intestinal nematode infection in rats either in distal colonic manometry or in gastrointestinal transit time.