Insecticidal and cytotoxic activities of extracts of Cacalia tangutica and its two active ingredients against Musca domestica and Aedes albopictus.

The insecticidal activities of extracts from different parts of Cacalia tangutica (Franch.) H.-M. and two active ingredients, friedelin and stigmasterol, against Musca domestica L., Aedes albopictus (Skuse), and Spodoptera litura (F.) cells (SL cells) are reported. Extracts from leaves, flowers, and roots are highly active against adult M. domestica and the fourth-instar larvae of Ae. albopictus. The foliar extract was the most active with LC50 values of 1.74 mg/g and 196.94 microg/ml against adult M. domestica and fourth-instar larvae of Ae. albopictus, respectively. Extracts from stems were the least active. Friedelin and rotenone were highly active and equitoxic to these two insect species. The LC50 value of friedelin in adult M. domestica 48 h after treatment was 129.27 microg/g. The activity of stigmasterol on these two insect species was not obvious. However, the cytotoxicity of stigmasterol to S. litura cells was significantly greater than that of either friedelin or rotenone. At 25 microg/ml, the mortality of cells 24 h after treatment with stigmasterol was 23.0%. In contrast, friedelin and rotenone at the same concentration produced 16 and 18% mortality, respectively. Our results indicate differences between cytotoxicity in vitro and insect toxicity in vivo.

Lichen planus pemphigoides associated with Chinese herbs.

We report a 62-year-old Chinese woman with a 2-year history of lichen planus presenting with extensive violaceous maculopapules and plaques 1 week after taking an oral preparation of Chinese herbs. The patient developed vesiculobullous skin lesions 7 weeks later. Histopathological examination showed subepidermal blisters and adjacent bandlike lymphocytic infiltration. Direct immunofluorescence revealed linear deposits of IgG and C3 along the basement membrane zone. Indirect immunofluorescence showed IgG antibody deposition along the epidermal side of salt-split human skin. Circulating anti-bullous pemphigoid 180 antibodies were detected by ELISA. Lichen planus pemphigoides (LPP) was diagnosed. To our knowledge, this is the first report of LPP associated with oral Chinese herbs.

Transgenic GFP as a molecular marker for approaches to quantify pollination mechanism and gene flow in Arabidopsis thaliana.

Arabidopsis thaliana is commonly regarded as a self-pollinated plant. We observed that the stigma in each flower of A. thaliana cannot be pollinated by its own pollen in the early phases of the flowering process, when the anthers had dehisced but the filaments were still too short for the pollen to be deposited on the stigma. In the later stages, after elongation of the filaments, self-pollination can occur. After artificial pollination of the flower of a wild plant with GFP transgenic pollen grains in earlier stages of flowering, GFP expressed within epidermal cells was detected in some of the offspring (26.1-57.1 %). Wind-mediated pollen dispersal was poor but is likely to exist in natural habitats, while insects were observed visiting flowers of A. thaliana in natural and experimental populations. We constructed an experimental population consisting of 28 GFP transgenic plants and 240 wild plants and examined gene flow in the population. The result was that the distance of gene flow was limited to 0.5 m. 22 offspring with expressed GFP were found in 28,299 filial individuals examined, which suggested a relatively low outcrossing rate (0.74%). We conclude that outcrossing in populations of A. thaliana is mainly due to insect pollination. The data on gene flow could be useful to assess the ecological hazards of experimental transgene combinations.

[Influence of the blight of Morinda officinalis How on microscopic structure and constituents of the host].

The results showed that microscopic structure in biennial roots, the contents of B and Mn in nutritive organ and beta-sitosterol content in roots, stems of Morinda officinalis were affected markedly. The total sugar content in the roots and aerial stems was decreased by 5.42%-15.29%.