[Characteristics of seawater nutrients during the occurrence of brown tide in the coastal area of Qinhuangdao, China]. / ç§¦çš‡å²›æµ·åŸŸè¤æ½®ç”Ÿæ¶ˆè¿‡ç¨‹ä¸­è¥å »ç›ç‰¹å¾.

Brown tide that occurred in Qinhuangdao coastal waters from 2009 to 2015 caused huge losses of local marine aquaculture and coastal tourism, with devastating effects on marine ecosystems. Nutrients are important biogenic elements for algal growth. It is of great significance to examine the fluctuation characteristics of nutrients in the process of brown tide to understand the nutritional mechanism of brown tide. Based on the survey data of 30 stations located in Qinhuangdao coastal area from April to June 2014, we analyzed nutrient characteristics during the occurrence of brown tide and its relationship with the population dynamics of Aureococcus anophagefferens. The results showed that the concentration of dissolved nitrogen (DN) in April, May and June 2014 was 265.65, 355.36 and 323.71 µg·L-1 respectively, and the concentration of dissolved organic nitrogen (DON) was 196.98, 242.88 and 177.69 µg·L-1, accounting for 74.2%, 68.3% and 54.9% of DN, respectively. The concentration of dissolved phosphorus (DP) in April, May and June was 15.95, 11.39 and 11.14 µg·L-1 respectively. In April and May, PO43--P accounted for a large proportion of the DP, 74.8% and 80.9% respectively. In June, the proportion of PO43--P in DP fell to 33.8%, and the proportion of dissolved organic phosphorus (DOP) in DP rose to 66.2%. The concentration of SiO32--Si in April, May and June was 70.95, 181.13 and 120.68 µg·L-1, respectively. Except for dissolved inorganic nitrogen (DIN) in May and DON, the distribution of other nutrients had clear characteristics that it decreased gradually from inshore to the offshore, with the relatively high concentrations in river mouth. Through R-factor analysis and nutrient structure analysis, it was found that in April, brown tide was at the development stage, and DOP might be the main driving factor for the growth of A. anophagefferens. In May, brown tide was at the maintenance stage, and water temperature became the main controlling factor. When water temperature was higher than 12 ℃, brown tide could occur. In June, brown tide began to decay, and PO43--P had greater effects on the community structure of phytoplankton. DON was the important factor causing the outbreak of brown tide, with a concentration threshold of 150 µg·L-1 and the ratio DON/DIN being greater than 1.

Impact of multidisciplinary team working on the management of colorectal cancer.

BACKGROUND: The continual and rapid development of techniques which are used for diagnosis and treatment makes management of colorectal cancer more difficult depending on single discipline. Colorectal cancer multidisciplinary team (MDT) working model is recommended by UK and other countries, but there is little information on the impact of MDT working on management of colorectal cancer in China. The aim of this study was to assess the effect on management of colorectal cancer after the inception of an MDT. METHODS: A total of 595 consecutive colorectal cancer patients were referred to the Department of Gastroenterological Surgery, the pre-MDT cohort include 297 patients, recruited from January 1999 to November 2002, and the MDT cohort had 298 patients enrolled from December 2002 to September 2006. Information recorded included: TNM stage from histological reports, degree of differentiation, the number of examined lymph nodes and CT TNM staging performed or not, and its accuracy, including local and distant recurrence. RESULTS: The number of examined lymph nodes and the accuracy of TNM staging by CT in the MDT group were significantly more than those in pre-MDT group. CT TNM staging was more accurate in the MDT group compared to the pre-MDT group (P = 0.044). The rate of tumor recurrence in the MDT group was lower than pre-MDT group (log-rank test, P < 0.001). Multivariate analysis revealed that age (P = 0.001), management after inception of the MDT (P = 0.002), degree of differentiation (P = 0.003), number of examined lymph nodes (P = 0.002), and TNM stage (P = 0.000) were important factors that independently influence overall survival. CONCLUSIONS: The inception of MDT working improved the diagnostic accuracy and overall survival of colorectal cancer patients. MDT working promoted communication and cooperation between disciplines and ensured high-quality diagnosis, evidence-based decision making, and optimal treatment planning.

[Effects of primary deep venous valvular incompetence of lower limb in deep vein thrombus after total knee replacement].

OBJECTIVE: To evaluate the effects of primary deep venous valvular incompetence of lower limb (PDVI) to the occurrence of deep vein thrombosis (DVT) after human total knee replacement (TKR). METHODS: One hundred and twenty-six patients who planed to receive TKR were examined by color doppler flow imaging (CDFI). The patients were divided into 2 groups depending on whether they were found backstreaming in femoral vein or not. When the refluxing time > 1 s, the patients were included in PDVI group; When the refluxing time < or = 1 s, the patients were included in without PDVI group. In 7 d after operation all the patients were re-examined by CDFI to find if there was DVT. The results were tested by chi2 statistical analysis. RESULTS: Among the 126 patients, 54 had PDVI, and 72 without PDVI. Fifty patients had DVT, total incidence rate 39.7% (50/126). In PDVI group 33 patients had DVT (61.1%, 33/54); In without PDVI group 17 patients had DVT (23.6%, 17/72), which was lower than PDVI group (chi2 = 21.227, P < 0.05). CONCLUSIONS: PDVI may be a risk for occurrence of DVT after TKR.

Short-term withdrawal of simvastatin induces endothelial dysfunction in patients with coronary artery disease: a dose-response effect dependent on endothelial nitric oxide synthase.

BACKGROUND: Patients with coronary artery disease (CAD) have impaired endothelial function. Simvastatin therapy has been demonstrated to significantly improve endothelial function in these patients. Although withdrawal of statins is a frequent problem in clinical practice, the effects after discontinuation of statins treatment on endothelial function in patients with CAD are largely unknown. OBJECTIVE: This study investigated the effects after withdrawal of simvastatin on brachial artery endothelial function in patients with CAD and the underlying mechanisms. METHODS: We recruited 30 patients with established CAD. They were treated with 20 mg simvastatin for 4 weeks. Endothelial dependent flow-mediated vasodilation (FMD) was assessed in the brachial artery using high-resolution ultrasound at baseline, 4 weeks during simvastatin treatment, and 1 week after termination of therapy. 20 healthy subjects were also studied as a control group. Furthermore, we investigated underlying mechanisms on human umbilical vein endothelial cells (HUVECs) confluent monolayers at passages 2-3. HUVECs were exposed to simvastatin. After 24 h cells were repeatedly washed to remove the drugs, and the conditioned mediums were collected at the indicated time points. The nitric oxide (NO) production and levels of eNOS mRNA after 24 h of withdrawal of statins were examined. RESULTS: (1) Abrupt discontinuation of simvastatin treatment leads to a rebound of serum total cholesterol (21.3%) and LDL cholesterol (18.2%) in patients within 1 week, but they were still lower than the baseline values (P<0.05 for each parameter). (2) A significant decreased of FMD (-59.3%) was observed in patients after discontinuation of simvastatin in 1 week, and furthermore, the FMD was even lower than the baseline levels (4.6% vs. 5.6%, P<0.05). The reduction of FMD was not correlated with the change of LDL cholesterol (r=-0.343, P=0.081). In contrast to the unchanged LDL cholesterol level, abrupt discontinuation of therapy caused a rapid and significant decrease in FMD from 10.6% to 5.2% in healthy subjects at day 1, but it returned to baseline levels within 1 week. (3) In HUVECs, a maximum decrease of nitrite levels (-80%) was observed at 6 h after stopping simvastatin treatment, which was below the control levels. 24 h after stopping 10(-5) mmol/L and 10(-6) mmol/L simvastatin treatment, eNOS mRNA expression decreased to -71% and -42% (P<0.05), respectively. CONCLUSIONS: Abrupt withdrawal of simvastatin treatment not only acutely and completely abrogates its beneficial effects on endothelial function in patients with CAD, but also induced further vascular injury compared with pretreatment status, independent of cholesterol levels. The underlying mechanism of these negative effects may be related to the suppression of endothelial NO production, which are dose-dependent.