Isozymes in Aegilops kotschyi and Ae. biuncialis x Secale cereale hybrids and Ae. kotschyi x S. cereale amphiploids in relation to their parents

Seven enzymatic systems in F1 Aegilops kotschyi and Ae. biuncialis x Secale cereale hybrids, Aegilops kotschyi x S. cereale amphiploids and their parental species (Ae. kotschyi, Ae. biuncialis and S. cereale) were analysed by starch and polyacrylamide gel electrophoresis. Five of them (phosphoglucose isomerase, glutamic oxalacetic transaminase, esterase, acid phosphatase, and diaphorase) were polymorphic and two (malic dehydrogenase and superoxide dismutase) were monomorphic. Several isophorms of phosphoclucose isomerase, esterase, acid phosphatase, and diaphorase were detected in some hybrids and amphiploids, but absent in the parents. The role of regulators, translocations and recombination is discussed in relation to the origin of these new isophorms. Some parental isozymes were absent both in hybrids and amphiploids, probably as a result of the suppression of structural genes in new combinations of the three genomes.     

Cytokine regulation of pulmonary fibrosis in scleroderma

Pulmonary fibrosis occurs in up to 70% of scleroderma patients and progresses to cause severe restrictive lung disease in about 15% of patients. The mechanisms that cause pulmonary fibrosis in scleroderma remain incompletely understood. Increased amounts of mRNA or protein for multiple profibrotic cytokines and chemokines have been identified in lung tissue or broncholveolar lavage samples from scleroderma patients, when compared to healthy controls. These cytokines include transforming growth factor (TGF)-β, connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), oncostatin M (OSM), monocyte chemotactic factor-1 and pulmonary and activation-regulated chemokine (PARC). Potential cellular sources of these profibrotic cytokines and chemokines in scleroderma lung disease include alternatively activated macrophages, activated CD8+ T cells, eosinophils, mast cells, epithelial cells and fibroblasts themselves. This review summarizes the literature on involvement of cytokines and chemokines in the development of pulmonary fibrosis in scleroderma.     

The influence of phytohormones on the properties of wheat phospholipid monolayers at the water-air interface

The surface behaviour of monolayers of wheat phospholipids in the presence of phytohormones introduced into the water phase was studied using Langmuir's method. The phospholipids were extracted from the plasmalemma of non-embryogenic (NE) and embryogenic (E) calli initiated from two types of explant: immature inflorescences (inf) and embryos (emb). The surface properties were investigated in model systems of monolayers of mixed phospholipids with: 1) natural amphiphile composition (PL); 2) a determined hydrophobic part (16:0) and the natural percentage composition of the hydrophilic part (PPL); and 3) a determined hydrophilic part (PC) and the natural percentage composition of the hydrophobic part (HPL). The lower limit values of the molecular area (A(lim)) were observed for NE rather than for E monolayers in all the investigated systems (PL, PPL and HPL). The collapse pressure (pi(coll)) of the monolayer decreased in the order PPL>PL>HPL, indicating the high stability of monolayers containing saturated hydrocarbon chains. The injection of non-surface-active phytohormones into the water subphase and the subsequent formation of natural and also artificial phospholipid monolayers of E and NE causes a decrease in monolayer stability against collapse and molecular close packing. As a result of their amphipathic (hydrophilic-hydrophobic) structure, the surface properties of E phospholipids are probably optimal for these systems. The decreasing stability of the NE monolayer caused by the presence of the phytohormone seems to be advantageous in terms of membrane preparation for the differentiation process. All the investigated lipid monolayers (highly) stimulated the adsorption of indole-3-acetic acid (to the highest extent/degree) (among the examined phytohormones) from the subphase. Zearalenone had a significant influence on the surface properties of NE PPL and NE HPL monolayers. This may be connected with the ability of this phytohormone to affect the non-embryogenic structure of wheat. An anomalous temperature effect was observed in the presence of indole-3-acetic acid (IAA) in the bulk; phospholipid monolayers of embryogenic calli induced from embryos (E emb) when the temperature decreased from 25 to 15 degrees C. This phenomenon is ascribed to the dehydration of the polar groups in the monolayer     

Clinical relevance of matrix metalloproteinase-13 determined with a new highly specific and sensitive ELISA in ascitic fluid of advanced ovarian carcinoma patients

Matrix metalloproteinases (MMPs) are involved in many physiological and pathophysiological processes, including tumor cell invasion and metastasis. For one member of this family, MMP-13 (collagenase-3), a new, highly specific ELISA with a sensitivity of 0.5 ng MMP-13/ml was established. The protein levels of MMP-13 in ascitic fluids of 30 patients with advanced ovarian cancer FIGO stage III (n = 19) and IV (n = 11) were measured with this ELISA. Using a cut-off value of 0.5 ng MMP-13/mg total protein, two patient subpopulations with short (median 16 months) and long (median 36 months) overall survival were identified. Together with other prognostic markers, determination of MMP-13 in ascitic fluid may help to identify patients at risk for early death and help to individualize adjuvant therapy.     

Involvement of rpoS in the survival of Escherichia coli in the viable but non-culturable state

When exposed to stress-provoking environmental conditions such as those of ground waters, many medically important bacteria have been shown to be capable of activating a survival strategy known as the viable but non-culturable (VBNC) state. In this state bacteria are no longer culturable on conventional growth media, but the cells maintain their viability and pathogenicity genes/factors and can start dividing again, in a part of the cell population, upon restoration of favourable environmental conditions. Little is known about the genetic mechanisms underlying the VBNC state. In this study we show evidence of involvement of the rpoS gene in persistence of Escherichia coli in the VBNC state. The kinetics of entry into the non-culturable state and duration of cell viability were measured in two E. coli mutants carrying an inactivated rpoS gene and compared with those of the parents. For these experiments, laboratory microcosms consisting of an artificial oligotrophic medium incubated at 4 degrees C were used. The E. coli parental strains reached the non-culturable state in 33 days when the plate counts were evaluated on Luria-Bertani agar containing sodium pyruvate, whereas cells of the rpoS mutants lost their culturability in only 21 days. Upon reaching unculturability the parents yielded respiring cells and cells with intact membranes for at least the next three weeks and resuscitation was allowed during this time. In contrast, the RpoS- mutant cells demonstrated intact membranes for only two weeks and a very restricted (<7 days) resuscitation capability. Guanosine 3',5'-bispyrophosphate (ppGpp) acts as a positive regulator during the production and functioning of RpoS. A mutant deficient in ppGpp production behaved like the rpoS mutants, while overproducers of ppGpp displayed a vitality at least comparable to that of RpoS+ strains. These results suggest that the E. coli parental strains enter the VBNC state which lasts for, at least, three weeks, after which apparently all the cells die. The rpoS mutants do not activate this survival strategy and early die. This implies involvement of the rpoS gene in E. coli persistence in the VBNC state.     

The concept of multiple-nutrient-limited growth of microorganisms and its application in biotechnological processes

The "law of the minimum" (Liebig's law) states that usually one nutrient restricts the maximum quantity of biomass that can be produced within a system, whereas all other nutrients are in excess. This general rule has been applied also to the growth of microorganisms, e.g., by adjusting the relative concentrations of the individual nutrients in growth media such that one of them, in the case of heterotrophic microbes, usually the carbon source, determines the maximum cell density that can be obtained in a culture. However, experimental data demonstrated that growth of microbial cultures can be limited simultaneously by two or more nutrients. These authors reported that during growth of bacteria and yeasts at a constant dilution rate in the chemostat, three distinct growth regimes were recognised as a function of the C:N ratio in the inflowing medium: (1) a clearly carbon-limited regime with the nitrogen source in excess, (2) a transition ("double-nutrient-limited") growth regime where both the carbon and the nitrogen source were below the detection limit, and (3) a clearly nitrogen-limited growth regime with the carbon source in excess. Subsequent calculations suggested that the extension and position of this double-nutrient-limited zone should be strongly dependent on the imposed growth rate: Whereas it is very narrow at high growth rates it should become very broad during slow growth. This pattern as a function of growth rate has now been confirmed for a number of different organisms. In industrial processes, microbial growth is always in some way controlled by the limited availability of nutrients, and limitation of specific nutrients is frequently used to force microbial cultures into a productive physiological state. This article will discuss what the consequences of multiple-nutrient-limited growth are for industrial processes and how the concept might be applied. Specific examples will be given that demonstrate the advantages and the potential of multiple nutrient-limited growth conditions for industrial production processes.     

Triterpenoidal lupin saponins from the Chilean legume Lupinus oreophilus Phil

Two lupin saponins, 3beta,21alpha,22beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-arabinopyranoside and 3beta,21alpha,22beta,24-tetrahydroxyolean-12-en-3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside, along with eight other saponins and one triterpene previously reported from other legumes, were isolated from the aerial parts of Lupinus oreophilus collected in northern Chile. The structures of the isolated compounds were established with the help of extensive spectroscopic techniques.     

Enhancing phytoremediative ability of Pisum sativum by EDTA application

The aim of our research was to demonstrate how the presence of EDTA affects resistance of pea plants to Pb and Pb-EDTA presence, and to show the effectivity of lead ions accumulation and translocation. It was determined that EDTA not only increased the amount of Pb taken up by plants but also Pb ion transport through the xylem and metal translocation from roots to stems and leaves. It can be seen in the presented research results that addition of the chelator with Pb limited metal phytotoxicity. We also demonstrated a significant effect of EDTA not only on Pb accumulation and metal transport to the aboveground parts but also on the profile and amount of thiol compounds: glutathione (GSH), homoglutathione (hGSH) or phytochelatins (PCs), synthesized by the plants. We observed a significant effect of the synthetic chelator on increasing the level of Pb accumulation in roots of plants treated with Pb including EDTA (0.5 and 1 mM). Pisum sativum plants treated only with 1 mM Pb(NO3)2 accumulated over 50 mg Pb x g(-1) dry wt during 4 days of cultivation. Whereas in roots of pea plants exposed to Pb+0.5 mM EDTA 35% more Pb was observed. When 1 mM EDTA was applied roots of pea accumulated over 67% more metal. The presence of EDTA also increased metal uptake and transport to the aboveground parts. In pea plants treated only with 1 mM lead nitrate less than 3 mg Pb x g(-1) dry wt was transported, whereas in P. sativum treated with Pb-EDTA doubled amount of Pb was observed in stems and leaves.