[Exploration of the high-risk factors of catheter-related thrombosis in breast cancer].

Objective: To explore the high risk factors of catheter-related thrombosis (CRT) in breast cancer patients, and provide the basis for the development of appropriate prevention and treatment strategies. Methods: A total of 1 432 breast cancer patients scheduled to receive central venous catheterization in National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from January 1, 2015 to August 31, 2019 were selected. Baseline information and catheterization information of patients were collected. The occurrence of CRT was confirmed by vascular ultrasound examination, and the influencing factors of CRT were analyzed. Results: The total number of catheter days were 121, 980 days in 1 432 patients with breast cancer, and the average number of catheter days in each patient was 85.2 days. The incidence of CRT was 6.8% (97/1 432), which was 0.79 cases/1 000 catheter days. Among 815 patients with centrally inserted central venous catheters (CICC), 43 (5.3%) had CRT, which was 0.70 cases/1 000 catheter days. Among 617 patients with peripherally inserted central venous catheters (PICC), 54 (8.8%) developed CRT, which was 0.90 cases/1 000 catheter days. CRT was most common in subclavian vein (63.9%). Multivariate regression analysis showed that age ≥ 60 years old (OR=1.712, 95% CI: 1.056-2.775, P=0.029), PICC (OR=1.732, 95% CI: 1.130-2.656, P=0.012), the catheter position except subclavian vein (OR=10.420, 95% CI: 1.207-89.991), secondary adjustment of catheter position (OR=3.985, 95% CI: 1.510-10.521, P=0.005) and high D-Dimer level (OR=1.129, 95% CI: 1.026-1.241, P=0.012)were independent risk factors for CRT. Conclusions: The CRT problem can't be ignored in the clinical treatment of breast cancer patients with central venous catheterization. Screening the appropriate age of patients and the type of central venous catheters, reducing the secondary adjustment of catheter position, and timely monitoring the level of D-dimer are helpful to the prevention and treatment of CRT.

Morphological, structural and physiological differences in heteromorphic leaves of Euphrates poplar during development stages and at crown scales.

Euphrates poplar (Populus euphratica Oliv.) has heteromorphic leaves including strip, lanceolate, ovate, and broad-ovate leaves from base to top in the mature canopy. To clarify how diameter at breast height (DBH) and tree height affect the functional characteristics of all kinds of heteromorphic leaves, we measured the morphological anatomical structure and physiological indices of five crown heteromorphic leaves of P. euphratica at 2, 4, 6, 8, 10, and 12 m from the same site. We also analysed the relationships between morphological structures and physiological characteristics of heteromorphic leaves and DBH and the height of heteromorphic leaves. The results showed that the number of abnormalities regarding blade width, leaf area, leaf thickness, leaf mass per area, cuticle layer thickness, palisade tissue thickness, and palisade tissue/sponge tissue ratio increased with size order and sampling height gradient. Net photosynthetic rate, transpiration rate, stomatal conductance, instantaneous water use efficiency, stable delta carbon isotope ratio, proline and malondialdehyde (MDA) content increased with DBH and sampling height. By contrast, blade length, leaf shape index, and intercellular CO2 concentration decreased with the increase in path order and sampling height gradient. Although MDA content and leaf sponge thickness were not correlated with DBH or sampling height, other morphological structure and physiological parameters were significantly correlated with these variables. In addition, correlations were found among leaf morphology, anatomical structure, and physiological index parameters indicating that they changed with path order and tree height gradient. The differences in the morphology, anatomic structure and physiological characteristics of the heteromorphic leaves ofP. euphratica are related to ontogenesis stage and coronal position.