Selective extraction of outer-membrane proteins from membrane complexes of Pseudomonas maltophila by chloroform-methanol

An organic phase partitioning method is described for the selective purification of outer-membrane proteins (OMPs) from the total membrane complex of the opportunistic human and sheep pathogen, Pseudomonas maltophila. SDS-PAGE analysis confirmed that OMPs purified by chloroform-methanol treatment of the total membrane complex were not only identical to OMPs extracted from outer-membrane vesicles separated by sucrose gradient density centrifugation, but also possessed little or non-detectable levels of inner-membrane contaminants. Further analysis by enzyme linked immunosorbent assay (ELISA) and immunoblotting established that OMPs extracted by organic phase partitioning with chloroform-methanol retained antigenicity and serological activity indistinguishable from OMPs that were present in outer-membrane vesicles resolved by isopycnic sucrose density centrifugation of sarkosyl-treated membrane complexes.

[Effects of oleanolic acid on immune system and type I allergic reaction]

Oleanolic acid (OLA)50, 100 mg/kg sc antagonised the inhibitory effect of cortisone on the weights of spleen and thymus, decreased the clearance rate of charcoal particles in mice. The production of serum specific antibody hemolysin was not clearly affected by OLA. The administration of OLA 100 mg/kg enhanced the development of serum antibody immunoglobulin G in mice and showed marked inhibition on the hemolytic activity of the total complement by classical pathway in guinea pigs. In addition, the homologous passive cutaneous anaphylaxis in mice or rats and the degranulation of mast cells of calvarial periosteum in rats were significantly prevented by OLA 50, 100 mg/kg. The increased capillary permeability in the rat skin caused by intradermic injection of histamine was also reduced by OLA 100 mg/kg. These results indicate that OLA inhibited the type I allergic reaction.

[Anti-inflammatory effect of fructus Ligustri Lucidi]

Fructus Ligustri Lucidi (FLL) inhibits the edema of hind Paw induced by injection of 1% carrageenin 0.1 ml, fresh egg 0.1 ml or 2.5% formaldehyde 0.1 ml in rats, and suppresses the increased vascular permeability induced by 0.7% acetic acid in mice and the proliferation of granuloma induced by cottonpellet in rats. The swelling of ear induced by xylene in mice and the content of prostaglandin E in inflammatory tissue of rats are also decreased by FLL. FLL increase the weight of adrenal in rats, but has no marked effect on the weight of thymus of rats.

Semliki Forest virus capsid protein acts as a pleiotropic regulator of host cellular protein synthesis

The Semliki Forest virus capsid (C) protein was introduced into various target cells by electroporation-, liposome-, and erythrocyte-ghost-mediated delivery. Data are presented which show that the incorporated C protein is biologically active and, at low concentrations (10(3) to 10(4) molecules per cell), markedly induces host cellular protein synthesis (average value, up to 90%). On the other hand, high concentrations (10(5) to 10(6) molecules per cell) led to a significant inhibition (average value, up to 60%). The cellular response to C protein was found to be identical in P3X63Ag8 suspension cells, CV-1 cells, and GpBind4 cells. Following electroporation-mediated delivery of C-protein molecules, both induction and repression of cellular protein synthesis were immediate, whereas with liposome-mediated delivery these events were delayed by about 1 h. Maximum stimulation and repression occurred between 0 and 1 h after delivery of C protein and decreased thereafter to reach control values at about 4 h. The analysis of the proteins synthesized suggests that low amounts of microinjected C protein are responsible for the induction of classes with specific Mrs, whereas high amounts lead to an inhibition of overall protein synthesis.

Effect of graded low-dose noradrenaline infusions on noradrenaline clearance in normals and essential hypertensives

1. In normal subjects and essential hypertensives, plasma noradrenaline (NA) levels, and NA clearance (3H-NA constant infusion), were measured during graded infusion of NA. 2. Plasma levels of NA were similar in both groups, with parallel increases to levels approximately three times basal, but still in the upper normal range. 3. Clearance did not increase in either group with increasing plasma NA levels. There was no correlation between plasma NA achieved and NA clearance, which was similar in hypertensives and normotensives. 5. Insofar as plasma clearance reflects tissue clearance, these studies provide no support for the contention that altered NA metabolism might predispose to elevated NA levels in essential hypertension.