ABSTRACT
Plants face constant threats from insect herbivores, which limit plant distribution and abundance in nature and crop productivity in agricultural ecosystems. In recent decades, the whitefly Bemisia tabaci, a group of phloem-feeding insects, has emerged as pests of global significance. In this article, we summarize current knowledge on plant defenses against whitefly and approaches to engineer plant resistance to whitefly. Physically, plants deploy trichome and acylsugar-based strategies to restrain nutrient extraction by whitefly. Chemically, toxic secondary metabolites such as terpenoids confer resistance against whitefly in plants. Moreover, the jasmonate (JA) signaling pathway seems to be the major regulator of whitefly resistance in many plants. We next review advances in interfering with whitefly-plant interface by engineering of plant resistance using conventional and biotechnology-based breeding. These breeding programs have yielded many plant lines with high resistance against whitefly, which hold promises for whitefly control in the field. Finally, we conclude with an outlook on several issues of particular relevance to the nature and engineering of plant resistance against whitefly.
ABSTRACT
Lung injury is the main manifestation of paraquat poisoning. Few studies have addressed brain damage after paraquat poisoning. Ulinastatin is a protease inhibitor that can effectively stabilize lysosomal membranes, prevent cell damage, and reduce the production of free radicals. This study assumed that ulinastatin would exert these effects on brain tissues that had been poisoned with paraquat. Rat models of paraquat poisoning were intraperitoneally injected with ulinastatin. Simultaneously, rats in the control group were administered normal saline. Hematoxylin-eosin staining showed that most hippocampal cells were contracted and nucleoli had disappeared in the paraquat group. Fewer cells in the hippocampus were concentrated and nucleoli had disappeared in the ulinastatin group. Western blot assay showed that expressions of GRP78 and cleaved-caspase-3 were significantly lower in the ulinastatin group than in the paraquat group. Immunohistochemical findings showed that CHOP immunoreactivity was significantly lower in the ulinastatin group than in the paraquat group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining showed that the number of apoptotic cells was reduced in the paraquat and ulinastatin groups. These data confirmed that endoplasmic reticular stress can be induced by acute paraquat poisoning. Ulinastatin can effectively inhibit this stress as well as cell apoptosis, thereby exerting a neuroprotective effect.
ABSTRACT
OBJECTIVE: To investigate the significance of dynamic monitoring of procalcitonin (PCT) in guiding the use of antibiotics for treating patients with sepsis in intensive care unit (ICU). METHODS: Eighty-two patients with sepsis from January 2012 to June 2013 hospitalized in ICU of First Hospital of Jilin University were enrolled, and they were randomly divided into regular antibiotic therapy group (RAT group, n=40) and PCT monitoring in guiding the use of antibiotics group (PCT group, n=42). Patients in RAT group were treated according to principle of antibiotics usage, while in PCT group patients' PCT value was observed everyday. When no active symptoms of infection were shown, and acute physiology and chronic health evaluation II (APACHEII) scores declined, PCT value decreased over 90% or PCT value lower than 0.25 µg/L time point were selected as drug withdrawal indication. The general status of the patient, antimicrobial drug use time, and prognosis were compared between the two groups, and Kaplan-Meier method was used for survival curve analysis. Variance analysis was used for repeating measurement to observe dynamic serum PCT level of the two groups of patients for survival and death during 7 days. RESULTS: Mann-Whitney U test or χ(2) test showed that there were no statistical significance in age, gender, APACHEII score, blood culture positive rate, sputum culture positive rate, cardiac insufficiency, renal failure, respiratory failure, and ventilator and hemofiltration usage (all P>0.05). Log Rank test results showed that the time of antimicrobial drug usage was significantly reduced in PCT group than that in RAT group [days: 8.1±0.3, 95% confidence interval (95%CI 8.3-9.7) vs. 9.3±0.3 (95%CI 8.7-10.1), P=0.013]. Kaplan-Meier univariate survival curves showed that the speed of curve declination in PCT group was faster significantly than that in RAT group, suggesting that the time of using antimicrobial drug was shortened. There was no significant difference in length of hospital stay, ICU stay time, number of death in 28 days, number of cases of recurrence in 28 days and clinical cure rate between two groups (all P>0.05). PCT level in non-survivors in both groups was significantly higher than that in the survivors, exceeding more than 10 µg/L in the early and late stages of treatment. CONCLUSIONS: Dynamic monitoring of PCT can effectively reduce antimicrobial drug use in ICU patients with sepsis, but there is no significant difference in patients' prognosis.
