[Research on characteristics of soil clay mineral evolution in paddy field and dry land by XRD spectrum].

The present paper took the typical saline-alkali soil in Jilin province as study object, and determinated the soil clay mineral composition characteristics of soil in paddy field and dry land. Then XRD spectrum was used to analyze the evolutionary mechanism of clay mineral in the two kinds of soil. The results showed that the physical and chemical properties of soil in paddy field were better than those in dry land, and paddy field would promote the weathering of mineral particles in saline-alkali soil and enhance the silt content. Paddy field soil showed a strong potassium-removal process, with a higher degree of clay mineral hydration and lower degree of illite crystallinity. Analysis of XRD spectrum showed that the clay mineral composition was similar in two kinds of soil, while the intensity and position of diffraction peak showed difference. The evolution process of clay mineral in dry land was S/I mixture-->vermiculite, while in paddy field it was S/I mixture-->vermiculite-->kaolinite. One kind of hydroxylated 'chlorite' mineral would appear in saline-alkali soil in long-term cultivated paddy field. Taking into account that the physical and chemical properties of soil in paddy field were better then those in dry land, we could know that paddy field could help much improve soil structure, cultivate high-fertility soil and improve saline-alkali soil. This paper used XRD spectrum to determine the characteristics of clay minerals comprehensively, and analyzed two'kinds of land use comparatively, and was a new perspective of soil minerals study.

[Analysis of XRD spectral characteristics of soil clay mineral in two typical cultivated soils].

The present paper took black soil and chernozem, the typical cultivated soil in major grain producing area of Northeast, as the study object, and determinated the soil particle composition characteristics of two cultivated soils under the same climate and location. Then XRD was used to study the composition and difference of clay mineral in two kinds of soil and the evolutionary mechanism was explored. The results showed that the two kinds of soil particles were composed mainly of the sand, followed by clay and silt. When the particle accumulation rate reached 50%, the central particle size was in the 15-130 microm interval. Except for black soil profile of Shengli Xiang, the content of clay showed converse sequence to the central particle in two soils. Clay accumulated under upper layer (18.82%) in black soil profile while under caliche layer (17.41%) in chernozem profile. Clay content was the least in parent material horizon except in black profile of Quanyanling. Analysis of clay XRD atlas showed that the difference lied in not only the strength of diffraction peak, but also in the mineral composition. The main contents of black soil and chernozem were both 2 : 1 clay, the composition of black soil was smectite/illite mixed layer-illite-vermiculite and that of chernozem was S/I mixture-illite-montmorillonite, and both of them contained little kaolinite, chlorite, quartz and other primary mineral. This paper used XRD to determine the characteristics of clay minerals comprehensively, and analyzed two kinds of typical cultivated soil comparatively, and it was a new perspective of soil minerals study.

Clinical significance of protocadherin-8 (PCDH8) promoter methylation in bladder cancer.

OBJECTIVE: To investigate the clinical significance of protocadherin-8 (PCDH8) promoter methylation in bladder cancer. METHODS: Methylation-specific polymerase chain reaction was used to examine the promoter methylation status of PCDH8 in tumour tissue samples obtained from patients with bladder cancer, and in normal bladder epithelial tissue samples obtained from age- and sex-matched control subjects. Methylation status was correlated with demographic, clinical and pathological parameters and disease outcome. RESULTS: PCDH8 promoter methylation was detected in 76/135 (56.3%) patients with bladder cancer and none of 34 (0%) control subjects. Methylation was significantly associated with advanced stage (T2-T4), high grade (G3), tumour recurrence, larger tumour diameter (>3 cm) and nonpapillary morphology. In addition, methylation was associated with significantly shorter survival time and was an independent predictor of overall survival. CONCLUSIONS: PCDH8 promoter methylation is a common occurrence in bladder cancer, and is associated with malignant behaviour and poor prognosis. Determination of PCDH8 promoter methylation status in tumour tissue may assist in the identification of patients who require aggressive postoperative intervention in order to improve prognosis.

A study on retinal angiomatous proliferation and its mechanism in apolipoprotein E-deficient mouse with dyslipidemia / 中华实验眼科杂志

Background Retinal angiomatous proliferation (RAP) is a subtype of neovascular age-related macular degeneration (AMD).There are currently very few studies on RAP.Objective This study was to explore the pathogenic mechanism of RAP in apolipoprotein E-deficient (ApoE-/-) mice with dyslipidemia.Methods Twenty-four 2-month-old SPF ApoE-/-mice were randomly divided into the high fat diet group and the normal diet group,and twelve 2-month-old C57BL/6 mice received the normal diet as controls.A diet with a higher content of fat was given for 4 consecutive months in the high fat diet group,and normal diet was given in the same way in the mice of the normal diet group.The mice were sacrificed at 6 months of age.The expression of vascular endothelial growth factor (VEGF) in the retinal pigment epithelial (RPE) cells,the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in the outer plexiform layer (OPL),microvascular density (MVD) and microvascular area (MVA) in the OPL were examined by immunohistochemistry and semi-quantitatively by histopathology with the Mias 2000 Imaging Analyzer System.The expression of VEGF protein in the retina was examined by Western blot.Results The MVD in the retinal OPL were (20.67±3.20) and (19.50± 1.87),respectively,in the ApoE-/-mice of the high fat diet group and the normal diet group,which were significantly higher than that (12.50±1.87) of the C57BL/6 normal diet group (all at P＜0.01).MVA in the retinal OPL were (626.49± 120.99) μm2 and (514.06±88.83) μm2 in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with the (336.52±84.96) μm2 of the C57BL/6 normal diet group (P＜0.01).The staining area of VEGF in RPE cells was (21 048±1849) μm2 in the ApoE-/-mice of the high fat diet group,showing a significant increase in comparison with the (17 116±2023) μm2 of the C57BL/6 normal diet group.However,no significant difference was found in the staining area of VEGF between the ApoE-/-mice with normal diet group and the C57BL/6 normal diet group ([17 854±2967] μm2 vs.[17 116±2023] μm2) (P＞0.05).Significant elevation was also seen in the staining area of VEGFR-2 in the retinal OPL of the ApoE-/-mice of the high fat diet group (12 193±3806)μm2 and the ApoE-/-mice of the normal diet group (11 969± 3616)xm2 compared with C57BL/6 mice of the normal diet group (5387±2225)μm2(all at P＜0.01).The relative expression values (VEGF/β-actin) of VEGF in the retinas were (1.51 ±0.32) and (1.17±0.39) in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with (0.28±0.14) of the C57BL/6 normal diet group (P＜0.01).Conclusions The expression of VEGF and VEGFR-2 in the retinas increases in the ApoE-/-mouse,which leads to the enlargement of MVD and MVA in the retinal OPL and subsequent RAP occurrence.

Effects of tonifying spleen and promoting blood circulation on the retina and Bruch membrane in apolipoprotein E-deficient mouse with dyslipidemia / 中华实验眼科杂志

Background Dyslipidemia is one of the major causes of age-related macular degeneration (AMD).At present,the study of the preventive and treating methods of A MD is still a hot spot.Objective The purpose of this study was to observe the effect of tonifying the spleen and promoting blood circulation on the retina and Bruch membrane in apolipoprotein E-deficient (ApoE-/-) mice with dyslipidemia.Methods Thirty-six ApoE-/-mice aged 2 months were randomly divided into the normal diet group,high fat diet group and medicine group.A diet with a higher content of fat was given for 5 consecutive months to the mice of the high fat diet group and medicine group,and in the last month,a concoction that tonifies the spleen and promotes blood circulation was gavagely administered in the medicine group,and an equivalent volumes of normal saline solution was administered in the same way in the normal diet group and high fat diet group.Total plasma cholesterol (TC),low density lipoprotein (LDL)and triglyceride (TG) were detected by (ELISA? Name of assay?) using the 7170 Hitachi automatic biochemical analyzer,and morphological changes of the retina and Bruch membrane were examined by light microscopy and transmission electron microscopy.The number of outer nuclear layer (ONL) cells,retinal pigment epithelial (RPE) cells and the thickness of the Bruch membrane were examined by semi-quantitative histopathology with the Mias 2000 Imaging Analyzer System.Results The concentrations of TC,LDL and TG were (6.47 ±0.49) mmol/L,(1.46 ±0.10)mmol/L and (0.62 ±0.21) mmol/L,respectively,in 7-month-old mice of the medicine group,showing a significant reduction in comparison with (10.53 ±0.30) mmol/L,(1.90±0.13) mmol/L,(1.15±0.29) mmol/L of the high fat diet group,and (9.63 ± 0.18) mmol/L,(1.12 ± 0.15) mmol/L,(0.88 ± 0.21) mmol/L in the normal diet group (P＜0.05-0.01).The disorder and atrophy of ONL and RPE cells,divergence of fiber of the Bruch membranes were found in both the high fat diet group and normal diet control group under the light microscope,and drusen formed in some of the mice in the high fat diet group.However,ONL and RPE were well organized in the medicine group.The cell numbers in the ONL and RPE layer in the 7-month-old mice were (23 124.00±755.18) and (10.75±0.59),respectively,in the medicine group,(19 107.00 ± 1436.82) and (8.55 ± 1.11),respectively,in the high fat diet group,(21 663.00± 1073.27) and (9.75 ±0.58),respectively,in the normal diet group,with significant differences among them (P＜0.05-0.001).Thickness of the Bruch membrane in the medicine group extensively reduced in high fat diet group and normal diet control group (P＜0.01).The ultrastructures of the RPE and Bruch membrane were much more improved in the mdedicine group.Conclusions Tonifying the spleen and promoting blood circulation can attenuate hyperlipemia in ApoE-/-mouse;furthermore,it lessens the pathological abnormalities in the ONL,RPE and Bruch membrane.