A local model based on environmental variables clustering for estimating foliar phosphorus of rubber trees with vis-NIR spectroscopic data.

Existing local models based on multiple environmental variables clustering (LM-MEVC) treat the influences of environmental factors on leaf phosphorus concentration (LPC) of rubber trees (Hevea brasiliensis) equally when grouping samples. In fact, the effects that environmental factors assert on LPC are different. So, environmental factors need to be treated differently so that the different effects can be taken into consideration when dividing samples into clusters or groups. According to this basic idea, a local model based on weighted environmental variables clustering (LM-WEVC) was developed. This approach consists of four steps. Firstly, the most important environmental variables that influence LPC were selected. Then, the weights of the selected environmental variables were determined. In the following, the selected environmental variables were weighted and used as clustering variables to group samples. Finally, within each cluster or group of samples, an estimation model was established. In order to verify its effectiveness in predicting LPC of rubber trees, the proposed method was applied to a case study in Hainan Island, China. Rubber tree (cultivar CATAS-7-33-97) leaf samples were collected from three different sampling periods. Spectral reflectance of the collected leaf samples was measured using an ASD spectroradiometer, FieldSpec 3. Leaf samples collected from the three different sampling periods were used separately to test LM-WEVC. Coefficient of determination (R2), root mean squared error (RMSE), and ratio of prediction deviation (RPD) were employed as evaluation criterion. Performance of LM-WEVC was compared with that of the existing LM-MEVC. Results indicated that for the three sampling periods, the prediction accuracies of LM-WEVC were always higher than those of LM-MEVC. The values of R2 and RPD for LM-WEVC were increased by 8.15%-36.68%, and by 11.33%-59.40% respectively, while values of RMSE were reduced by 9.09%-37.5%, compared with those for LM-MEVC. These results demonstrate that LM-WEVC was effective in estimating LPC of rubber trees, and also confirmed our hypothesis that environmental factors unequally influenced LPC of rubber trees.

Impacts of terrain attributes and human activities on soil texture class variations in hilly areas, south-west China.

Knowledge of soil texture variations is critical for agricultural and engineering applications because texture influences many other soil properties. This study used random forest method to evaluate the effects of human activities and topographic parameters on the spatial variability of soil texture in hilly areas where soil parent material was uniform. The study site covers 252 km2 and is located in the Upper Yangtze River Basin of south-west China. A total of 3636 samples were collected from the cultivated soils at a depth of 20 cm of dryland (sloping field and terraced land) landscape. The soil texture class for each sample was estimated by experienced soil scientists in the field. Two soil texture classes (loam and clay) were observed in the watershed. Eleven terrain parameters were derived from a digital elevation model with a resolution of 30 m. Compared with loamy soils, clayey soils were mostly observed in the areas with lower elevation and gentle slopes. The outcome of random forest indicated that human activities and elevation had strong effects on soil texture class variations across the study site. Further results showed that the relative importance of terrain parameters to soil texture class variations varied with dryland landscape. Topographic wetness index and elevation were the most important variables for sloping field and terraced land landscapes, respectively.

Pleomorphic adenoma gene like-2 induces epithelial-mesenchymal transition via Wnt/ß-catenin signaling pathway in human colorectal adenocarcinoma.

Epithelial-mesenchymal transition (EMT) is a critical step in the acquisition of metastatic and invasive power for tumor cells. Colorectal adenocarcinoma (CRC) is a common cancer where metastasis is directly linked to patient survival. Recent studies show that pleomorphic adenoma gene like-2 (PLAGL2) could induce tumor EMT and is an independent predictive factor associated with poor prognosis in cancer. In the present study, we confirmed the role of PLAGL2 in the prognosis of CRC patients and provide molecular evidence of PLAGL2 promoted EMT in CRC cell line SW480. We found that PLAGL2 expression was upregulated in the paraffin-embedded CRC tissues compared to borderline or benign tissues. Experimental EMT induced by PLAGL2 plasmid transfection proved PLAGL2 protein overexpression could enhance the cell scratch wound-healing and transwell ability and significantly upregulated mesenchymal marker proteins, N-cadherin and vimentin and concurrently downregulated epithelial marker of E-cadherin. Subsequently, through western blot assay, we found that PLAGL2 could activate the wnt-signaling component ß-catenin in the nuclei. More CRC cell metastasis to the lungs was observed when the PLAGL2 overexpressing SW480 cells were injected into the tail vein of rats, compared with the cell control and PLAGL2 silence group. Our findings indicated that PLAGL2 might be a very upstream key molecule regulating EMT involved in Wnt/ß­catenin signaling pathway.

[Serum non-esterified fatty acids to albumin ratio increased significantly in children with nephrotic syndrome].

OBJECTIVE: To analyze serum levels of non-esterified fatty acids (NEFA) and albumin (ALB) in children with nephrotic syndrome (NS) and investigate the clinical significance of altered serum NEFA to ALB ratio in children with NS in acute and remission phases. METHODS: Serum levels of NEFA and ALB were measured in 55 NS children in acute phase, in 33 NS children in remission and in 122 healthy control children, and the ratio of NEFA to ALB was calculated. The other lipid/lipoprotein and renal function parameters were also analyzed in these children. RESULTS: Compared with the healthy control children, children with NS had a significantly decreased serum ALB level (t=11.152, P<0.001) and a significantly increased NEFA to ALB ratio (t=4.991, P<0.001). Compared with NS children in remission, those in acute phase showed a significantly decreased ALB (Z=7.822, P<0.001) and an increased NEFA to ALB ratio (t=4.991, P<0.001). In all the NS children, NEFA to ALB ratio was positively correlated with the levels of TC (r=0.564, P<0.001), TG (r=0.444, P<0.001), LDL-C (r=0.625, P<0.001), urea (r=0.437, P<0.001), creatinine (r=0.278, P=0.013), and uric acid (r=0.397, P<0.001), while negatively correlated with the level of total protein (r=-0.461, P<0.001). Multiple linear regression analyses showed that NEFA to ALB ratio was independently associated with serum urea levels (ß=0.703, P=0.001; adjusted R2=0.494) after adjustment of other related factors. CONCLUSION: Serum NEFA to ALB ratio is significantly increased in NS children in close association with impaired kidney function, and may function as a novel parameter for assessing the development of NS.

Macroscopic serosal classification of colorectal cancer and its clinical significance.

BACKGROUND: Macroscopic serosal classification of gastric cancer has been reported in previous studies, but rarely reported about it of colorectal cancer. The purpose of this study was to propose a macroscopic serosal classification of colorectal cancer and to investigate clinical significance of this classification. MATERIALS AND METHODS: Morphologic features of colorectal cancer were analyzed according to the macroscopic serosal appearance and clinicopathologic characteristics of these patients were retrospectively reviewed. Microscopic serosal structure was compared between different types under light microscope and transmission electron microscope. RESULTS: Macroscopic serosal classification was divided into normal type, reactive type, nodular type and colloid type according to the macroscopic serosal appearance and microscopic structure. There were significant differences in tumor size, tumor gross type, histological type, histological grade, tumor necrosis, pT stage, number of nodes metastasis, lymph node metastasis ratio, pN stage, M stage and peritoneal metastasis between patients with different serosal types. Univariate analysis of prognosis revealed macroscopic serosal classification as one of factors significantly correlated with patient survival. However, multivariate analysis only revealed TNM stage significantly correlated with patient survival, while macroscopic serosal classification did not, maybe due to insufficient samples. CONCLUSIONS: Macroscopic serosal classification of colorectal cancer is preliminarily defined and divided into four types. Different macroscopic serosal types indicate different clinicopathologic features and correlate with prognosis of patients with colorectal cancer, but still cannot be proven as an independent factor.

PDCD4 functions as a suppressor for pT2a and pT2b stage gastric cancer.

Gastric cancer is one of the leading causes of cancer­related mortality worldwide. Loss of programmed cell death 4 (PDCD4) expression has been detected in gastric cancer. However, the effects of PDCD4 on pT2 stage gastric cancer remain unclear. The aim of this study was to identify the relationship between PDCD4 expression and clinicopathological features of patients with pT2 stage gastric cancer. In the present study, 122 pT2 stage gastric cancer specimens were subclassified as pT2a and pT2b stage. The levels of PDCD4 mRNA and protein in gastric cancer tissues were lower compared to that in normal tissues as detected by real­time PCR and western blot analysis, respectively. In addition, both PDCD4 mRNA and protein in pT2b stage gastric cancer were lower when compared to that in pT2a stage gastric cancer. Finally, we used immuno-histochemistry to determine the protein expression and analyzed the relationship between PDCD4 expression and the clinicopathological features of pT2 stage gastric cancer patients. Cumulative survival rate of patients with PDCD4 expression was significantly higher compared to the patients without PDCD4 expression. PDCD4 expression in gastric cancer can be employed to indicate a favorable prognosis for the disease outcome.

Comparison different methods of intraoperative and intraperitoneal chemotherapy for patients with gastric cancer: a meta-analysis.

PURPOSE: To investigate the efficacy and safety of intraperitoneal chemotherapy (IPC) for patients with gastric cancer and to compare effects between different regimens of IPC. METHOD: Randomized controlled trials comparing the effects of surgery plus intraperitoneal chemotherapy with surgery alone or comparing the efficacy between different regimens of intraperitoneal chemotherapy were searched for in Medline, Embase, Pubmed, the Cochrane Library and the Chinese BioMedical Disc and so on by two independent reviewers. After quality assessment and data extraction, data were pooled for meta-analysis using RevMan5.16 software. Tests of interaction were used to test for differences of effects among subgroups grouped according to different IPC regimens. RESULTS: Fifteen RCTs with a total of 1713 patients with gastric cancer were included for quality assessment and data extraction. Ten studies were judged to be of fair quality and entered into meta-analysis. Hyperthermic intraoperative intraperitoneal chemotherapy (HR=0.60, P<0.01), hyperthermic intraoperative intraperitoneal chemotherapy plus postoperative intraperitoneal chemotherapy (HR=0.47, P<0.01) and normothermic intraoperative intraperitoneal chemotherapy (HR=0.70, P=0.01) were associated with a significant improvement in overall survival. Tests of interaction showed that hyperthermia and additional postoperative intraperitoneal chemotherapy did not impact on its effect. Further analysis revealed that intraperitoneal chemotherapy remarkably decrease the rate of postoperative hepatic metastasis by 73% (OR=0.27, 95% CI=0.12 to 0.67, P<0.01). However, intraperitoneal chemotherapy increased risks of marrow depression (OR=5.74, P<0.01), fever (OR=3.67, P=0.02) and intra-abdominal abscess (OR=3.57, P<0.01). CONCLUSION: The present meta-analysis demonstrates that hyperthermic intraoperative intraperitoneal chemotherapy and normothermic intraoperative intraperitoneal chemotherapy should be recommended to treat patients with gastric cancer because of improvement in overall survival. However, it is noteworthy that intraperitoneal chemotherapy can increase the risks of marrow depression, intra-abdominal abscesses, and fever.

Hepatitis B virus X protein plays an important role in gastric ulcers.

Hepatitis B virus (HBV) infects many individuals globally each year. Researchers usually focus on the relationship between HBV and liver diseases. In this study, we investigated the effects of HBV infection on gastric mucosa. We detected the levels of HBX protein and mRNA in specimens from sixty-four chronic hepatitis B patients (CHB) with gastric ulcers. We confirmed that HBX could aggravate gastric ulcers according to clinicopathological parameters. In addition, we constructed the pcDNA3.1-HBX plasmid and transfected it into GES-1, a gastric mucosal cell line. The results indicated that HBX could induce apoptosis and G1 arrest in GES-1 cells. Insights into the mechanism of HBX action in GES-1 cells were obtained using western blot analysis.

A novel subclassification of pT2 gastric cancers according to the depth of muscularis propria invasion: superficial muscularis propria versus deep muscularis propria/subserosa.

PURPOSE: To propose a novel subclassification of pT2 gastric cancers according to the depth of muscularis propria (MP) invasion (superficial MP vs. deep MP/subserosa [SS]) and to investigate its impact in prognostic assessment. SUMMARY BACKGROUND DATA: The major change in the sixth edition of the International Union Against Cancer (UICC)/American Joint Committee on Cancer (AJCC) TNM classification concerned the pT (primary tumor) category. Specifically, pT2 lesions were divided into pT2a (invading the MP) and pT2b (invading the SS) to discriminate these intramural locations. However, the value of the modification is still debated. METHODS: One thousand two hundred fifty-six patients with pT2 cancers classified according to the UICC/AJCC pT staging system were reviewed. Among them, 214 (17.0%) were classified as invasion of the superficial MP (sMP) or inner circular muscle, 163 (13.0%) as invasion of the deep MP (dMP) or outer longitudinal muscle, and 879 (70.0%) as invasion of SS. Clinicopathologic features were compared between patients with sMP, dMP, and SS invasion. Overall survival rates were compared between the pT2a and pT2b stage cancers, according to the UICC/AJCC and the novel pT2 system. Two-step multivariate analysis was performed to identify the significantly important prognostic factors. RESULTS: There was significant difference in most of the clinicopathologic features between sMP and SS cancers. Although, only 5 factors (tumor location, tumor size, Borrmann type, metastasis number, and metastasis ratio) were significantly different between dMP and SS cancers. In step 1 of the multivariate analysis, the UICC/AJCC pT2 system was an independent factor that correlated with prognosis, but was substituted by the novel pT2 system in step 2 of the multivariate analysis. With a certain metastasis ratio of lymph nodes, the novel pT2 system discriminated 2 subsets of patients with significantly different prognoses, whereas the UICC/AJCC pT2 system did not. CONCLUSIONS: The novel pT2 staging system, which was subclassified as sMP and dMP/SS cancers, had more potential to identify the different prognoses for patients with pT2 gastric cancers.