Vascular endothelial growth factor (VEGF), an established angiogenesis factor, is expressed in allografts undergoing rejection, but its function in the rejection process has not been defined. Here, we initially determined that VEGF is functional in the trafficking of human T cells into skin allografts in vivo in the humanized SCID mouse. In vitro, we found that VEGF enhanced endothelial cell expression of the chemokines monocyte chemoattractant protein 1 and IL-8, and in combination with IFN-γ synergistically induced endothelial cell production of the potent T cell chemoattractant IFN-inducible protein-10 (IP-10). Treatment of BALB/c (H-2d) recipients of fully MHC-mismatched C57BL/6 (H-2b) donor hearts with anti-VEGF markedly inhibited T cell infiltration of allografts and acute rejection. Anti-VEGF failed to inhibit T cell activation responses in vivo, but inhibited intragraft expression of several endothelial cell adhesion molecules and chemokines, including IP-10. In addition, whereas VEGF expression was increased, neovascularization was not associated with acute rejection, and treatment of allograft recipients with the angiogenesis inhibitor endostatin failed to inhibit leukocyte infiltration of the grafts. Thus, VEGF appears to be functional in acute allograft rejection via its effects on leukocyte trafficking. Together, these observations provide mechanistic insight into the proinflammatory function of VEGF in immunity

No abstract

No abstract

This paper examines the stability of the day of the week effect in returns and volatility at the Indian capital market, covering the period January 1991-September 2000. The paper specifies a generalized autoregressive conditional heteroscedasticity (GARCH) model on returns and introduces separate dummies for days in alternate weeks in the specification of both the mean and the conditional variance to examine the robustness of the day of the week effect in return and in volatility within a fortnight. Results are compared to those based on ordinary least squares (OLS) procedure to examine how erroneous the inference on day-level seasonality could be when the aspect of volatility is ignored. The paper finds evidence in favour of significant positive returns on non-reporting Thursday and Friday, in sharp contrast to the finding of significant positive returns only on non-reporting Monday by OLS procedure. Separate subperiod analyses reveal that there have been changes in daily seasonality in both returns and volatility since the mid-1990s at the Indian capital market, manifested in the opposite signs and changes in the level of significance of some similar coefficients across periods. These findings on the day of the week effects along with its variation within a fortnight suggest that stock exchange regulations and the nature of interaction between the banking sector with the capital market could possibly throw valuable insights on the origin of the day of the week/fortnight effect in returns, while interexchange arbitrage opportunities due to differences in settlement period could lead to a seasonality in volatility.

Experiments involving fusion between the Staphylococcus aureus plasmid p1258-encoded mer operon and the reporter gene P-lactamase, mutational analysis, and trans-complementation studies have shown that the merR gene of p1258, which shows DNA sequence similarity with known merR genes from other bacteria, regulates the expression of the mer operon in vivo. The merR gene product is a trans-acting protein that activates mer operon transcription in the presence of the inducers Hg2' and Cd2+. A glutathione-S-transferase-MerR fusion protein specifically bound and protected a 27-nucleotide operator sequence from DNase I digestion. This operator sequence is highly homologous with mer operator sequences of other known systems.Mercury-resistant bacteria from environmental and clinical isolates enzymatically detoxify inorganic mercury salts and sometimes organomercurial compounds (for recent reviews, see references 3, 13, 20, 22, 23, 25, and 26). The mercury resistance (mer) genes are often found on plasmids and transposons and are usually clustered in an operon. The highly substrate-specific mercuric ion reductase catalyzes the reduction of Hg2f to chemically inert elemental Hg°, which is water insoluble and volatilizes because of its high vapor pressure. The organomercurial resistance operon encodes another enzyme, organomercurial lyase, that catalyzes the cleavage of the C-Hg bond from organomercurials such as phenylmercury to yield benzene and Hg2e.