Effect of exogenous H2O2 on antioxidant enzymes of Brassica juncea L. seedlings in relation to 24-epibrassinolide under chilling stress.

Hydrogen peroxide is most stable molecule among reactive oxygen species, which play a vital role in growth and development of plant as signaling molecule at low concentration in response to various abiotic and biotic stresses. Exogenous application of H2O2 is known to induce chilling tolerance in plants. Brassinosteroids are plant steroid hormones known for their anti-stress properties. In this study, effect of exogenous H2O2 on antioxidant defense system of Brassica juncea L. seedlings was investigated in 24-epibrassinolide (24-EBL) treated and untreated seedlings under chilling stress. The surface sterilized seeds of B. juncea L. were germinated in petriplates containing different concentrations of H2O2 alone and in combination with 10-8 M 24-EBL. Chilling treatment (4 ºC) was given to 10-days old seedlings grown in different treatments for 6 h daily up to 3 days. 24 h recovery period was given to chilling treated seedlings by placing at 25ºC ± 2ºC and harvested for antioxidant enzymes on 14th day after sowing (DAS). Treatment of 24-EBL in combination with H2O2 (15 and 20 mM) helped in reducing the toxicity of seed and seedlings due to H2O2 exposure on their germination rate, shoot and root length respectively. 24-EBL treatment at seed and seedling stage helped in alleviating the toxic effect of H2O2 through antioxidant defense system by increasing the activities of various enzymes involved in antioxidant defense system such as catalase (CAT, E.C. 1.11.1.6), ascorbate peroxidase (APOX, E.C. 1.11.1.11), and superoxide dismutase (SOD, E.C. 1.15.1.1). In conclusion, exogenous pretreatment of H2O2 to seeds of B. juncea L. adapted the seedlings to tolerate chilling stress, which was further ameliorated in combination of H2O2 with 24-EBL.

Casos clinicos: sindrome de bilis simulando quiste de Colédoco / Clinical cases: bile syndrome mimicking choledochal cyst

Se presenta el caso clínico de un niño de 33 días de vida con síndrome de bilis espesa que simuló ser un quistedel colédoco. Se hace énfasis en el diagnóstico diferencial de la colestasis neonatal y de la observación meticulosadel cuadro clínico.

Recent advances in the study of antifungal lead compounds with new chemical scaffolds / 药学学报

In recent years, the incidence of infections caused by invasive fungal pathogens has increased dramatically. However, most antifungal agents used in clinic have many drawbacks and cannot meet the demand of the clinical use. Therefore, for the development of new generation of antifungal agents, it is of great significance to find antifungal lead compounds with novel chemical scaffolds and new mode of action. Novel antifungal lead compounds reported in recent years are reviewed. Their chemical structures, antifungal activity and structure-activity relationship are discussed in detail, and current problems and trends in future research are also emphasized.

Effects of the plant steroidal hormone, 24-epibrassinolide, on the mitotic index and growth of onion (Allium cepa) root tips

The purpose of the present study was to determine the effects of the steroidal plant hormone, 24-epibrassinolide (BL), on the mitotic index and growth of onion (Allium cepa) root tips. The classical Allium test was used to gather and quantify data on the rate of root growth, the stages of mitosis, and the number of mitoses in control and BL-treated groups of onions. Low doses of BL (0.005 ppm) nearly doubled the mean root length and the number of mitoses over that of controls. Intermediate doses of BL (0.05 ppm) also produced mean root lengths and number of mitoses that were significantly greater than those of the controls. The highest dose of BL (0.5 ppm) produced mean root lengths and number of mitoses that were less than control values, but the differences were not statistically significant. Examination of longitudinally sectioned root tips produced relatively similar results. This study confirms the suppositions of previous authors who have claimed that exogenously applied BL can increase the number of mitoses in plants, but failed to show cytogenetic data. This is the first report detailing the effects of BL on chromosomes and the cell cycle.

Reversing effect of brassinolide on multidrug resistance of-CCRF-VCR1000 cells and a preliminary investigation on its mechanisms / 药学学报

<p><b>AIM</b>To investigate the effect of brassinolide, a plant growth modulator, on multidrug resistance (MDR) of human T lymphoblastoid cell line CCRF-VCR 1000 which was obtained by progressively addition of vincristine (VCR) to sensitive CCRF-CEM cells, and to explore preliminarily the mechanism of reversing action.</p><p><b>METHODS</b>MTT method was used to detect the resistant factor of resistant cell line and the reversing fold after addition of brassinolide. The intracellular accumulation of rhodamine 123, a fluorescent dye transported by P-glycoprotein was detected by flow cytometry, the catalytic activity of topoisomerase II was assessed by Sulliven method to find the effect of brassinolide on resistance. The protein expression of p53 was measured using Western blotting in the sensitive cells and resistant cells to explore the effect of brassinolide.</p><p><b>RESULTS</b>The resistant factors of CCRF-VCR cells on adriamycin, VP-16 and VCR are respectively as 153.1, 55.9 and 8123.1 folds comparing to the sensitive cell line CCRF-CEM. After treatment of brassinolide under the concentration of 0.001 - 10.0 microg x mL(-1), the resistance of CCRF-VCR was reversed partly with the reversing folds respectively as 4.4 - 11.6. The intracellular accumulation of rhodamine 123 was significantly reduced in the resistant cells. After treatment of brassinolide, the accumulation increased, the level of fluorescent dye was situated between resistant cells and sensitive cells. No alteration of the catalytic activity of topoisomerase II was found among three groups. The level of protein expression of p53 in resistant cells was higher than that of sensitive cells. After brassinolide treatment, the expression of p53 in CCRF-VCR cells restored to the level of sensitive cells.</p><p><b>CONCLUSION</b>Brassinolide could effectively reverse the resistance of CCRF-VCR cells by inhibiting the effusion of drug transported by P-glucoprotein. To down regulate the abnormal expression of p53 maybe one of the mechanisms of reversing MDR for brassinolide.</p>

Effect of 24-epibrassinolide on pollen viability during heat-stress in tomato.

Tomato pollen when treated with 24-epibrassinolide (EBR), it was observed that in vitro pollen germination was more tolerant to high temperature. A significantly higher in vitro pollen germination, enhanced tube growth and low pollen bursting were observed in presence of EBR at 35 degrees C. Since a preconditioning treatment of tomato plant was not required for these effects, it is concluded that EBR treatment increased basic thermotolerance of germinating pollen. This study provided the first evidence for EBR induced thermotolerance in germinating pollen.

Effects of salvianolic acids on endothelial cells against damage induced by cholestane-3beta-5alpha-6beta-triol / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effects of salvianolic acids on human umbilical vein endothelial cells (HUVEC) against damage induced by cholestane-3beta-5alpha-6beta-triol (chol-triol).</p><p><b>METHODS</b>The viability of HUVEC was measured by MTT method. The apoptosis of HUVEC induced by chol-triol was detected by flow cytometry and TUNEL assay. The production of malondialdehyd (MDA) in HUVEC was tested by thiobarbaturic acid (TBA) assay.</p><p><b>RESULTS</b>The viability of HUVEC treated with chol-triol 100 micro mol/L decreased by 39.8% while salvianolic acids 100 micro g/ml increased by 27.9%. The apoptotic rate of HUVEC measured by PI staining increased from 6% - 8% to 17% - 20% after chol-triol treatment for 12 h. Salvianolic acids 100 micro g/ml reduced the apoptotic rate to 10% - 14% after treatment HUVEC for 1 h prior to chol-triol treatment. In another experiment, chol-triol increased the number of TUNEL-positive cells 5 times, but salvianolic acids 10 micro g/ml and 100 micro g/ml reduced the number of TUNEL-positive cells by 36.9% and 61.2%, respectively. The production of MDA in HUVEC increased by 120.7% after chol-triol treatment for 12 h. Salvianolic acids 10 micro g/ml and 100 micro g/ml also decreased the concentration of MDA by 28.7% and 39.8%, respectively.</p><p><b>CONCLUSION</b>Salvianolic acids has protective effect on endothelial cells against damage induced by chol-triol.</p>

A Case of Cerebrotendinous Xanthomatosis / 대한피부과학회지

Cerebrotendinous xanthomatosis is a rare, inherited lipid-storage disease clinically characterized by tendon xanthoma, progressive neurologic dysfunction(cerebellar ataxia, spinal cord involvement, mental retardation), premature atherosclerosis and cataracts. Substantial elevation of serum cholestanol and urinary bile alcohols with low to normal plasma cholesterol concentrations establishes the diagnosis. Up to now, there have not been any reported case of cerebrotendinous xanthomatosis in Korea. So, we report herein a 36-year-old Korean woman with the clinical features of cerebrotendinous xanthomatosis.

Determination of IAA in brassinolide treated coleoptiles of wheat by a modified indirect ELISA with polyclonal antibodies.

An indirect enzyme immunoassay for detection of as little as 10-50 pmole IAA is described for the first time. The assay is based on the development of highly specific polyclonal antibodies against the carboxyl site of IAA. The binding specificity is nearly as high as the radioimmunoassay and the titre of the specific antibody was also remarkably high (1:40,000 of the primary antibody). Such an easy, rapid, specific and highly sensitive assay would be extremely useful in gaining more information on the mode of action of phytohormones, and their effects on physiological processes.