Bt rice producing Cry1C protein does not have direct detrimental effects on the green lacewing Chrysoperla sinica (Tjeder).

The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from Bacillus thuringiensis (Bt) on Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) were assessed in laboratory bioassays. Survival and development of C. sinica larvae were not adversely affected when the larvae were fed a diet containing purified Cry1C protein at 200 µg/g fresh weight, representing a worst-case exposure scenario; in contrast, C. sinica larvae were adversely affected when the diet contained avidin or potassium arsenate. Life table parameters of C. sinica adults did not differ when the adults were fed with Bt or non-Bt rice pollen together with a 2-M sucrose solution. Life table parameters of C. sinica adults also did not differ when the adults were fed an artificial diet with or without purified Cry1C protein at a nominal concentration that was approximately 20 times higher than that in rice pollen; in contrast, C. sinica adults were adversely affected when the diet contained potassium arsenate. In all bioassays with lacewings, the bioactivity and stability of the Cry1C protein in the diet and Cry1C protein uptake by the lacewings were confirmed by enzyme-linked immunosorbent assay (ELISA) and by bioassays with a Cry1C-sensitive lepidopteran. These results demonstrate that neither larvae nor adults of C. sinica are sensitive to Cry1C protein at concentrations higher than those encountered in the field, demonstrating that the growing of Bt rice producing Cry1C protein is unlikely to pose a risk to C. sinica.

[Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata].

OBJECTIVE: To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate. METHOD: Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated. RESULT: The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100. CONCLUSION: Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.

Systematic identification of synergistic drug pairs targeting HIV.

The systematic identification of effective drug combinations has been hindered by the unavailability of methods that can explore the large combinatorial search space of drug interactions. Here we present multiplex screening for interacting compounds (MuSIC), which expedites the comprehensive assessment of pairwise compound interactions. We examined ∼500,000 drug pairs from 1,000 US Food and Drug Administration (FDA)-approved or clinically tested drugs and identified drugs that synergize to inhibit HIV replication. Our analysis reveals an enrichment of anti-inflammatory drugs in drug combinations that synergize against HIV. As inflammation accompanies HIV infection, these findings indicate that inhibiting inflammation could curb HIV propagation. Multiple drug pairs identified in this study, including various glucocorticoids and nitazoxanide (NTZ), synergize by targeting different steps in the HIV life cycle. MuSIC can be applied to a wide variety of disease-relevant screens to facilitate efficient identification of compound combinations.

A cell-based assay for screening spindle checkpoint inhibitors.

In eukaryotes, the spindle checkpoint acts as a surveillance mechanism that ensures faithful chromosome segregation. The spindle checkpoint prevents premature separation of sister chromatids and the onset of anaphase until every chromosome is properly attached to the mitotic spindle. Tumorigenesis might result from generation of aneuploidy by dysfunction of the spindle checkpoint. Differences of the checkpoint system in normal cells versus tumor cells might provide a new opportunity in cancer drug development; therefore, efforts to identify the spindle checkpoint inhibitors have been fostered. Based on spindle checkpoint inhibitors being able to induce cells to exit mitotic arrest caused by microtubule drug treatment, we developed a cell-based assay to screen compounds that were potential spindle checkpoint inhibitors. This assay was validated with a known spindle checkpoint inhibitor and was easy to adapt to a large-scale screening. It also had the advantages of being high in sensitivity and low in cost.

[Study on thyroid defunctionalization method for the preoperative preparation of hyperthyroid operation].

OBJECTIVE: To set up and publicize the thyroid defunctionalization method for the preoperative preparation of hyperthyroid operation. METHODS: 476 hyperthyroid patients admitted in our hospital from March 1990 to February 2005 were studied by groups. They were divided randomly into a test group (244 patients), in which "preoperative preparation method of sequential thyroid defunctionalization" was applied to hyperthyroid patients, and based on the different drug dosages and treating terms used, further 4 subgroups (A, B, C and D) were divided to observe the treatment efficiency; And a control group (232 patients), in which antithyroid drugs and iodine preparation were applied preoperatively to cases. Thyroid functions in every stage of treatment were tested by radioimmunoassays (RIA), and operative bleeding volumes and postoperative complications were observed. RESULTS: Compared to the control group, the thyroid congestion and surface varices were alleviated in the test groups, in which the thyroid tissue of subgroup A most closed to euthyroidism histologically. The mean operative bleeding volume of test group was less than that of the control group. The bleeding volumes were (324.76 +/- 163.26) mL for the control group, (195.74 +/- 57.07) mL for the subgroup A, (230.00 +/- 70.81) mL for the subgroup B, (240.47 +/- 80.29) mL for the subgroup C and (314.75 +/- 96.46) mL for the subgroup D. There was no significant difference between the control group and subgroup D, but compared with the subgroup A, B, and C, there was the significant difference between control and treated subgroup (P < 0.05). The postoperative complication rate of the test group was 8.61% (21/244), while that of the control group was 17.24 (40/232). There was statistic difference between two groups (P < 0.005). CONCLUSION: The key to "preoperative preparation method of sequential thyroid defunctionalization" is as follows: the synthesis of thyroxin should be fully inhibited to thyroid defunctionalized; sufficient exogenous thyroxin should be supplemented; the term of thyroid function compensation should be long enough. The "preoperative preparation method of sequential thyroid defunctionalization" can decrease perioperational complications effectively and operation risks.