[Variation Characteristics of Surface Water Quality in China in Recent Years].

Based on data from 839 comparable sections (sites) of the national surface water environmental quality monitoring network from 2012 to 2020, the variation tendency of surface water environmental quality over the past nine years was analyzed. The results showed that the environmental quality of surface water in China has continuously improved, the proportion of Grade Ⅰ-Ⅲ water quality increased steadily, and the proportion of inferior Grade Ⅴ water quality decreased in succession. The annual average concentration of ammonia nitrogen, total phosphorus, and permanganate index all showed a decreasing trend annually; compared with those in 2012, the three indicator concentrations respectively declined 75.9%, 48.2%, and 17.5% by 2020. In Guangxi, Hainan, and Ningxia, the proportion of Grade Ⅰ-Ⅲ water quality sections was maintained at 100%, whereas Hubei and Jiangxi showed a consecutive decreasing trend, and the other provinces showed a consecutive increasing trend. In Guangxi, Hainan, Ningxia, Hunan, and Fujian, the proportion of inferior Grade Ⅴ water quality sections remained at 0, and the other provinces showed a decreasing trend yearly. The annual average concentration of total phosphorus in Guangxi and Jiangxi and the permanganate index in Hubei, Hainan, and Liaoning increased annually, whereas that in the other provinces decreased to varying degrees. The proportion of Grade Ⅰ-Ⅲ water quality sections in Ten Major basins showed a fluctuating upward trend. The proportion of inferior Grade Ⅴ water quality in the Zhejiang and Fujian Slice Rivers was maintained at 0, and the other river basins showed a fluctuating and declining trend. The annual average of the main pollution indicators all decreased to varying degrees. In 2020, 53% of 32 important lakes were eutrophic, which increased 12% compared to that in 2012. On the whole, surface water quality has generally improved in China during the past nine years; especially since the 13th Five-Year Plan period, remarkable achievements have been made in the prevention and control of water pollution. However, there are differences among various provinces and basins, the improvement in water environmental quality is unbalanced and uncoordinated, water resources are distributed unevenly, and the eutrophication trend of lakes and reservoirs is not optimistic. In the future, water resources, water environment, and water ecology should be overall managed, and great attention should be focused on precise pollution control and ecological restoration of surface water.

Progressive Changes in the Retinal Structure of Patients with Parkinson's Disease.

BACKGROUND: Many optical coherence tomography (OCT) studies have reported alterations in the retinal nerve fiber layer (RNFL) in Parkinson's disease (PD) and other neurodegenerative diseases. However, whether retinal alterations are a biomarker for PD is still controversial. OBJECTIVE: To investigate potential correlations between PD and morphological changes in retina using OCT and to determine its usefulness as a biomarker of disease progression in PD. METHODS: We performed a cross-sectional study on patients with PD (N = 37) and age-matched controls (N = 42), followed by a longitudinal study of the PD patients (N = 22) over approximately 2.5 years. RESULTS: The average retinal nerve fiber layer (RNFL) thickness (p < 0.001), total macular thickness (p = 0.001), and macular volume (p = 0.001) were decreased in PD patients compared to controls and had further decreased at the follow-up visit (p < 0.05 for all). The average RNFL thickness and the total thickness of macular were negatively correlated with age in PD patients at baseline. Linear regression analysis revealed that age (p = 0.002, p = 0.003, respectively) and LEDD (p = 0.011, p = 0.013, respectively) were correlated to total thickness and volume of macular in 22 PD patients in the follow-up study. However, no correlation was found between RNFL and other parameters. CONCLUSIONS: PD progression is associated with pronounced retinal structure changes, which can be quantified by OCT. Patterns of RNFL and macular damage detected by the noninvasive technology of OCT can be a useful biomarker for evaluating the progression of PD.

Research on human glioma stem cells in China.

Research on human glioma stem cells began early in the 21st century and since then has become a rapidly growing research field with the number of publications increasing year by year. The research conducted by our diverse group of investigators focused primarily on cell culture techniques, molecular regulation, signaling pathways, cancer treatment, the stem cell microenvironment and the cellular origin and function of glioma stem cells. In particular, we put forward our view that there are inverse or forward transformations among neural stem cells, glial cells and glioma stem cells in glioma tissues under certain conditions. Based on the background of the progress of international research on human glioma stem cells, we aim to share our progress and current findings of human glioma stem cell research in China with colleagues around the world.

Retinal nerve fiber layer thinning: a window into rapid eye movement sleep behavior disorders in Parkinson's disease.

PURPOSE: Retinal nerve fiber layer (RNFL) thinning occurs in Parkinson's disease (PD) and other neurodegenerative diseases. Idiopathic RBD (iRBD) is a well-established prodromal hallmark of synucleinopathies and occurs secondary to many neurodegenerative diseases, including PD. The aim of this study is to determine whether or not retinal structures are altered with the onset of rapid eye movement (REM) sleep behavior disorders (RBD). METHODS: In all, a total of 63 patients with PD, 14 patients with idiopathic RBD, and 26 sex- and age-matched healthy controls were enrolled and underwent optical coherence tomography measurements (HD-OCT (Zeiss) ) for the average and every quadrant of RNFL thickness. The REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) was used to classify PD patients with clinically probable RBD (PD + pRBD) or without probable RBD (PD - pRBD). Patients with iRBD were identified by polysomnography. RESULTS: For patients with RBD (idiopathic or secondary to PD), we found a significant decrease in RNFL thickness compared with groups without RBD (PD - pRBD and healthy controls) (all p < 0.05). Average RNFL thickness in patients with iRBD is significantly thinner than in healthy controls (p < 0.05). In PD, the average RNFL thickness was dramatically thinner in the PD + pRBD group than the PD - pRBD group (p < 0.005). Compared with healthy controls, RNFL thickness was slightly thinner in the drug-naive PD group but not the PD group with drug treatment. Multiple linear regression analysis showed that RBDSQ score was negatively associated with average and inferior RNFL variation in PD (all p < 0.005). CONCLUSIONS: The findings show that RNFL was slightly but significantly thinner in idiopathic RBD. In PD, RNFL thickness may vary depending on the presence of RBD.

Clinical outcomes of toe amputation in patients with type 2 diabetes in Tianjin, China.

The aim of this study is to determine the predictors for reulceration, reamputation and mortality in patients with diabetes following toe amputation, and the impact of activities of daily living on clinical outcomes. This prospective cohort study included 245 patients who had undergone toe amputation (202 healing and 43 non-healing) and was followed for a 5-year period. Data regarding new foot ulceration, reamputation and mortality were recorded, and the patients' activities of daily living were evaluated. The rate of wound healing was 82·4%. The rate of follow-up in the healed group was 91·6%. In years 1, 3 and 5, the cumulative incidence of patients who developed a new foot ulcer was 27·3%, 57·2% and 76·4%, respectively, leading to reamputation in 12·5%, 22·3% and 47·1%, respectively. The cumulative mortality was 5·8%, 15·1% and 32·7% at 1, 3 and 5 years, respectively. Multivariate analysis showed that GHbA1c > 9% (75 mmol/mol) was identified as an independent predictor of impaired wound healing, reulceration and reamputation. An age of >70 years was identified as an independent predictor of reamputation, mortality and impairment of activities of daily living. Despite a satisfactory initial healing rate after the first toe amputation, with the extension course after the toe amputation, the long-term outcomes are not optimistic. In developing countries like China, taking measures to prevent reulceration and reamputation is very important for patients with diabetic foot minor amputations, especially following toe amputation.

αB-crystallin malondialdehyde, superoxide dismutase, and lutathione peroxidase changes in X-ray irradiated rat lens.

AIM: To evaluate αB-crystallin malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) changes in X-ray irradiated rat lens. METHODS: Eight-week-old Sprague-Dawley male rats received X-ray irradiation to the head with rest of the body protected. The exposure dose ranged from 2 to 25 Grays (Gy). The cataract status were examined by slit lamp and rated with "four-grade systems" post-irradiation. The lens MDA level, and the activities of SOD and GPx were measured in a short-term experiment post-irradiation, and αB-crystallin protein levels were quantified. RESULTS: The lenses of normal control and the X-ray irradiated groups with the dose up to 10 Gy remained transparent throughout the experiment. The lens first appeared tiny scatters, and even lamellar opacities in the posterior capsule 45 days post-irradiation with the dose of 15 Gy, and progressed slowly to the advance stage of cataract; while, for the higher dose (25 Gy), the opacity of lens appeared much earlier, and progressed more rapidly to mature stage of cataract within 1 month. At the end of the observation (90 days post-irradiation), almost all lenses became complete opacity with the higher dose (25 Gy). The degree of lens opacity was rated accordingly. The lens MDA level was increased, and SOD and GPx activities were decreased with a dose-dependent manner post-irradiation. The αB-crystallin protein level was decreased dose-dependently at the end point of observation. CONCLUSION: Oxidative events and αB-crystallin may play important roles in the pathogenesis of cataract in X-ray irradiated rat lens.

[Studies on the target cells and molecules with sodium valproate induced differential of human glioma cells].

OBJECTIVE: To investigate the target cells and molecules with sodium valproate induced differentiation of human glioma cells. METHODS: Nude mice bearing human glioma xenogenic graft subcutaneously were treated with sodium valproate. The expressions of HDAC1 and Tob genes of xenografts were analyzed with semiquantitative RT-PCR. The CD133+ cells (BTSCs) were isolated from glioma specimens by immunomagnetic sorting, and cultured in the medium containing FCS or in the serum-free medium supplemented with growth factors, respectively, followed by treatment with sodium valproate in vitro for 21 days. The cell surface markers were detected with flow cytometry and confocal microscopy. RESULTS: Sodium valproate inhibited the growth of subcutaneous xenografs bearing on nude mice (P<0.05), and up-regulated the HDAC1 expression (P<0.01), down-regulated the Tob expression (P<0.05). The cell surface markers of BTSCs were detected by flow cytometry after sodium valproate treatment for 21 days. In the FCS group, the GFAP or beta-tubulin III positive cells increased significantly (P<0.01), but in the growth factor group, no statistical differences were observed in the GFAP or beta-tubulin III expression (P>0.05). The results of confocal microscopy indicated that the GFAP+ or beta-tubulin III+ cells coexpressed with Nestin. CONCLUSIONS: HDAC1 and Tob genes were the potential target molecules in reversion of the differential inhibition of human glioma cells with sodium valproate. The BTSCs undergoing the processes of differentiation were the target cells for sodium valproate.

[Measurement of the CO2 flux on the water-air interface of Taihu Lake].

Based on the measurement of the CO2 flux on the water-air interface of Taihu Lake by closed chamber technique from January 2003 to June 2005, variation characteristics of the CO2 flux on the water-air interface in Taihu Lake are analyzed. Diurnal variation of the CO2 flux on the water-air interface is obvious. The CO2 flux is -0.79 mg/(m2 x h) in spring, -4.89 mg/(m2 x h) in summer, -4.06 mg/(m2 x h) in autumn and -2.56 mg/(m2 x h) in winter. Taihu Lake is the sink of carbon monoxide. The CO2 flux gets larger in severer polluted area of the lake. Seasonal variation is not apparent in the algae type lake, but obvious in grass type lake. It is high in summer and autumn, and low in spring and winter. Correlative factors of CO2 flux on the water-air interface of Taihu Lake possibly include weather, solar radiation, wind velocity, temperature, pH, TA, Chla, TC, TN and TP.

Differentiation profile of brain tumor stem cells: a comparative study with neural stem cells.

Understanding of the differentiation profile of brain tumor stem cells (BTSCs), the key ones among tumor cell population, through comparison with neural stem cells (NSCs) would lend insight into the origin of glioma and ultimately yield new approaches to fight this intractable disease. Here, we cultured and purified BTSCs from surgical glioma specimens and NSCs from human fetal brain tissue, and further analyzed their cellular biological behaviors, especially their differentiation property. As expected, NSCs differentiated into mature neural phenotypes. In the same differentiation condition, however, BTSCs exhibited distinguished differences. Morphologically, cells grew flattened and attached for the first week, but gradually aggregated and reformed floating tumor sphere thereafter. During the corresponding period, the expression rate of undifferentiated cell marker CD133 and nestin in BTSCs kept decreasing, but 1 week later, they regained ascending tendency. Interestingly, the differentiated cell markers GFAP and beta-tubulinIII showed an expression change inverse to that of undifferentiated cell markers. Taken together, BTSCs were revealed to possess a capacity to resist differentiation, which actually represents the malignant behaviors of glioma.

[Isolation and culture of tumor stem cells from human brain glioma tissues].

OBJECTIVE: To isolate and culture tumor stem cells from glioma tissues obtained at surgical operation and to study their biological characteristics. METHODS: Glioma tissues obtained from surgically resected specimens of 8 patients were fully chopped, trypsinized, and filtered to prepare single cell suspensions. The cells were cultured in serum-free medium with EGF, LIF and bFGF. CD133(+) cells were purified by magnetic cell sorting, and cultured continuously in vitro to obtain tumor cell spheres. Tumor stem cells of the 5th passage were induced to differentiate with 10% FBS, and expression of cell differentiation markers such as Nestin, MAP2, GFAP was evaluated with immunocytochemistry techniques. RESULTS: CD133(+) cells were successfully separated and cultured from one anasplastic mixed astrocyte-ependymocyte type glioma specimen. These cells maintained a sphere-like growth status in vitro (3 months, 14 passages), and can self-renew, proliferate and conditionally differentiate into MAP2(+) and GFAP(+) cells. However, CD133(-) cells did not possess these properties. CONCLUSION: Glioma tissue contains tumor stem cells. Those cells can be cultured and passaged in vitro for a long term, and therefore to offer new approaches for studying cellular and molecular biology of glioma.

[Characteristics of morphology, differentiation related marker, and proliferation dynamics of differentiated brain tumor stem cells in vitro].

OBJECTIVE: To pursue the changes of cell morphology, expression of differentiation related markers, and proliferation cycles of brain tumor stem cells (BTSCs) after differentiation in vitro. METHODS: Tumor stem cells of the line CD133(+) were obtained from two specimens from one clinical case with anaplasia ependymocytoma during operation, one specimen being obtained during the first operation and then second specimen being obtained during the second operation 6 months later on the recurrent tumor. CD133(+) cells were acquired by using magnetic sorting and then cultured to differentiate in medium containing 10% fetal bovine serum. The morphology of the cells was observed under phase contrast microscope. Cells were collected respectively before differentiation and 3, 7, 10, and 21 days after the differentiation. The cell surface markers such as CD133, nestin, glial fibrillary acidic protein (GFAP), and beta-tubulin III were detected with flow cytometry. Proliferation cycles were examined before differentiation and in the 7th day after differentiation. Normal neural stem cells (NSCs) obtained from fetal brain tissues were used as controls. RESULTS: (1) The BTSCs were round shape at the beginning, then changed to short fusiform, polygon and long fusiform. Seven days later the cells reversed to short fusiform and round shape. The cells accumulated into cell spheres and floated in the culture medium again. While the NSCs differentiated along their routine rules. (2) Both the undifferentiated BTSCs and NSCs showed high level expression of CD133 and nestin. After differentiation the BTSCs expressed CD133 and nestin, the expression levels decreased first and then increased. The expression rates of CD133 and nestin were (3.65 +/- 0.17)% and (28.99 +/- 1.26)% in the 7th day, (14.63 +/- 1.16)% and (45.46 +/- 1.27)% in the 21st day. While the positive expression rate of GFAP was higher than that of beta-tubulin III. In the 10th day the NSCs under differentiation lost the expression of CD133 and nestin. The percentage of GFAP positive cells and beta-tubulin III positive cells were (88.94 +/- 1.23)% and (11.94 +/- 0.36)% respectively. (3) All undifferentiated BTSCs were hypodiploid. After differentiation majority of the BTSCs were hypodiploid or hyperdiploid, The percentages of S phase and G(2)-M phase cells in the BTSCs were higher than that in the NSCs. The cell composition of recrudescent BTSCs was more complex than that of the primary BTSCs. All NSCs were diploid whether differentiated or not. Most of the NSCs were G(0)-G(1) phase cells. CONCLUSION: The differentiation direction of BTSCs is quietly different from that of the NSCs. There is an obvious dysdifferentiation in BTSCs.