Two new compounds and anti-HIV active constituents from Illicium verum

Two new compounds named illiverin A (1) and tashironin A (8) were, isolated from the roots of Illicium verum, together with seven known compounds: 4-allyl-2-(3-methylbut-2-enyl)-1,6-methylenedioxybenzene-3-ol (2), illicinole (3), 3-hydroxy-4,5-methylenedi

Quantitative analysis of land mammal zoogeographical regions in China and adjacent regions

Quantitative analysis of land mammal zoogeographical regions in China and adjacent regions. Zoological Studies 43(1): 142-160. In this paper, our aim was to determine, by means of quantitative analysis, the distribution patterns of the land mammals in China and, adjacent regions using physiographical regions as operative geographical units (OGUs). Based, on the pre-sence or absence of 11 orders, 42 families, 197 genera, and 577 species of land mammals in their zoogeographical regions, which were used as OGUs, we studied the biotic boundary between the Oriental Region (OR) and the Palaearctic Region (PR), as well as subregion boundaries. The boundary's statistical significance was tested by G-test as described by McCoy et al. A significantly strong biotic boundary was found to separate the PR from the OR, and there is a weak biotic boundary in the PR, which divides it into 2 subregions. We concluded that the biotic boundary which separates the PR and OR is a strong boundary. We suggest that the Qinghai-Xizang Plateau should be regarded as a subregion of the PR, which can embody its characteristics of high elevations and a frigid climatic, which is called the Qing-Zang subregion of the PR (QZSP).

Expression of VEGFR-2 on HaCaT cells is regulated by VEGF and plays an active role in mediating VEGF induced effects

Vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 play important roles in mitogenesis and chemotaxis of endothelial cells. In normal human skin, VEGF is expressed and secreted by epidermal keratinocytes. Emerging data suggest that keratin

Prolonged cardiac xenograft survival in guinea pig-to-rat model by a highly active cobra venom factor

A highly active cobra venom factor (CVF) was isolated from the venom of Naja kaouthia by sequential column chromatography. It displays strong anticomplementary activity, and has 1515 U of anti complementary activity per mg protein. A single dose of 0.1 mg/kg CVF given i.v. to rats completely abrogated complement activity for nearly 5 days. Given 0.02 mg/kg of CVF. the complement activity of rats was reduced by more than 96.5% in 6 It. In guinea pig-to-rat heart transplant model, rats treated with a single dose of 0.05 mg/kg CVF had significantly prolonged xenograft survival (56.12 +/- 6.27 h in CVF-treated rats vs. 0.19 +/- 0.07 h in control rats, P < 0.001). (C) 2003 Elsevier Ltd. All rights reserved.

Stable RNA hairpins in 88 coding regions of human mRNA

RNA hairpins containing UNCG, GNRA, CUUG (N = A, U, C or G, R = G or A) loops are unusually thermodynamic stable and conserved structures. The structural features of these hairpin loops are very special, and they play very important roles in vivo. They are prevalent in rRNA, catalytic RNA and non-coding mRNA. However, the 5' C(UUCG)G 3' hairpin is not found in the folding structure of 88 human mRNA coding regions. It is also different from rRNA in that there is no preference for certain sequences among tetraloops in these 88 mRNA folding structures.