Foliar sterols in soybeans exposed to chronic levels of ozone

Soybeans (Glycine max) exposed to chronic levels of ozone showed a linear decrease in biomass with increasing concentration. The foliar free sterols increased while the steryl ester, and the steryl glycosides, a minor component, decreased with increasing pollutant concentration. Of the free sterols, stigmasterol showed the largest increase, followed by sitosterol; campesterol, however, decreased. All steryl esters decreased; sitosterol showed the largest decrease and campesterol the least.     

Genetics of salt tolerance in higher plants: theoretical and practical considerations

Summary An interdisciplinary approach to breeding for stress tolerance in plants has gained considerable recognition in the past few years. Accordingly, this article presents a synthesis of the genetic, physiological, and ecological aspects of salt tolerance in plants. An understanding of these aspects and the interrelationships between them is essential for an efficient breeding program.A significant part of the presentation concentrates on the basic problems associated with the genetics of tolerance to stresses and of quantitative characters in general, since many of the unsolved problems relevant to the genetics of salt tolerance are still general. Significant progress in the breeding of quantitative as well as qualitative traits in multicellular organisms depends on an understanding of the genetic and epigenetic dimensions of gene action. The discussion therefore includes an overview of (1) the limited existing knowledge on the genetic control of salt tolerance and (2) the physiological mechanisms and molecular targets central to the control of salt resistance as expressed by the amount and stability of yield.An additional subject emphasized here concerns the main strategies of adaptation of wild species to their natural habitats. An understanding of them is essential to (1) enable distinction between traits that can increase agricultural yield and traits that are favorable only for survival under natural conditions (such a distinction is essential, especially when wild species are used as a gene source), and (2) predict the best combinations of characters for efficient agricultural production in stressful environments.     

Proliferative heterogeneity of vascular smooth muscle cells and its alteration by injury

This study was designed to explore the question of whether the population of morphologically similar smooth muscle cells (SMC) in the vessel wall is functionally homogeneous or heterogeneous with respect to their proliferative response to injury. Using time-lapse video recording we measured interdivision times (IDT) of primary SMC clones, sibling pairs, and mother/daughter pairs. SMC from in vivo undisturbed vessels displayed an interclonal and intraclonal heterogeneity with a wide range in IDT. In vivo balloon injury resulted in a population with homogeneously short IDT. While 80% of IDT of SMC from injured vessels were shorter than 14 h, only slightly more than half of IDT of cells from undisturbed vessels fell into this category. Longitudinal analysis of mother/daughter pairs confirmed the presence of a heterogeneous population of SMC in the undisturbed vessel wall. In vivo balloon injury not only shortened the IDT of the majority of cells, but the shorter IDT persisted much longer than in the case of the undisturbed vessel. We suggest that a morphologically homogeneous SMC population in the aorta can now be subdivided into several groups of functionally different SMC with respect to their proliferative response to injury.     

Quantitative determination of Coomassie R bound to proteins in polyacrylamide gel. A facilitated method for multi-spot analysis of electrograms

Dimethylsulfoxide (DMSO) was found to be an efficient solvent for extraction of Coomassie Blue R 250 (Coomassie R) from stained proteins on polyacrylamide gels. Kinetic measurements show that the extraction of the dye from a 2-D gel reached equilibrium in 48 h. Staining of E. coli ribosomal proteins by Coomassie R dissolved in trichloroacetic acid exhibited two types of dye-protein complexes, the majority of them yield a blue-purple colour, while the rest are stained with a light-blue tone and fluorescent appearance as well. The absorbance spectra of the complexes in the gel matrix differ significantly from each other. However, the DMSO-extracted Coomassie show identical absorbance profiles with lambda max at 602 nm, thus the amount of the bound dye can easily be measured spectrophotometrically.     

Swine chromosomes: flow sorting and spot blot hybridization

Flow cytometry analysis was applied to swine chromosomes prepared from phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes. Flow karyotypes from both sexes and from t(3;7) translocation carrier females were obtained. A certain number of chromosome pairs could be assigned to various peaks. In fact, 13 peaks were observed for 18 autosomal pairs plus X and Y. Moreover, abnormalities owing to the t(3;7) translocation were readily observable. The number of base pairs for chromosomes associated with the various peaks was estimated by comparison with human flow karyotypes. The following four peaks were thus sorted: the peak assumed to represent the translocated chromosome 7 plus the normals associated with it; the corresponding peak from a normal swine; the peak assumed to contain among others the normal chromosome 7; and finally the peak corresponding to swine chromosome 1. Chromosomes of each peak were collected on Pall Biodyne membrane. Following appropriate denaturation and prehybridization, the four samples were hybridized with a human leucocyte antigen (HLA) class I 32P-labelled cDNA probe, representing most of the coding sequence of the HLA B7 gene. The results confirmed previous data from other techniques that assigned the swine MHC(SLA) to chromosome 7. Subsequently, sorted samples were hybridized with a porcine genomic Interferon alpha probe in order to confirm the mapping of this gene family on porcine chromosome 1.     

Selective killing of transformed rat cells by minute virus of mice does not require infectious virus production.

Fischer rat fibroblasts, naturally resistant to killing by the fibrotropic strain of minute virus of mice [(parvovirus MVM(p)], became sensitive to MVM when transformed by polyomavirus. This sensitization did not involve an increase in the percentage of cells which synthesized viral capsid antigens or in the percentage of cells which produced infectious virus. The addition of anti-MVM antiserum to the growth medium of MVM-infected cells had only a small effect on their survival rates, indicating that the majority of the killing effect of MVM occurs in a single cycle of infection. The data indicate that cell killing by MVM is independent of infectious virus production and thus support the notion that the preferential cytolytic effect is affected by viral cytotoxic gene products which accumulate to intolerable levels in transformed cells but not in normal ones. Finally, using cells transformed with polyomavirus and genomic and subgenomic clones of polyomavirus, we showed that the extent of sensitization to killing by MVM depended on the transforming agent used.     

A new method for stoichiometric analysis of proteins in complex mixture--reevaluation of the stoichiometry of E. coli ribosomal proteins

A novel way is presented for determination of the stoichiometry of ribosomal proteins in the ribosome. The 70S E. coli r-proteins, completely separated on a two-dimensional gel system, were used throughout our experiments. The method is based on our previous observation that the amount of Coomassie R bound to a protein molecule is directly proportional to the number of positive charges on that protein. By plotting the amount of bound Coomassie as a function of the number of positive charges of each r-protein, and relating the experimental amount of the dye bound to each r-protein to the value obtained from the linear regression line based on all (a total of some 50 proteins), one can obtain the molar concentration of every protein in the ribosome. A parallel experiment can be carried out, which relates the radioactivity contributed by 3H-labeled amino acid in each r-protein to its amino acid content in that molecule. The two sets of data, which are completely independent of each other, are well correlated. Further verification of the validity of our procedure is provided by the fact that we found the known proportions of four copies of L7/L12 and one copy of S6 per ribosome. The rationale behind the present study was our finding that recalculation of Hardy's data (Hardy, S.J.S. (1975) Mol. Gen. Genet. 140, 253-274), with the accurate molecular weight value of the r-proteins provided by Giri et al. (Adv. Protein Chem. (1984) 36, 1-78), raises some doubt with regard to his experimental results, although we agree with his final conclusion that E. coli ribosome is homogeneous with respect to its proteins.     

In vivo anti inflammatory effects of the M20 IL-1 Inhibitor: I. Effects on acute inflammatory parameters

Previous studies have described an IL-1 Inhibitor produced by a myelomonocytic line developed in our laboratory (Eur J Immunol 1986; 16: 1449). This IL-1 Inhibitor was secreted by the M20 line constitutively in addition to IL-1, from which it could be separated. We have recently shown that the M20 IL-1 Inhibitor is distinct from the IL-1ra.In vitro this factor inhibited IL-1 induced proliferative responses as well as PGE₂ secretion by IL-1 induced fibroblasts. We also showed for the first time (Lymphokine Research 1988; 7(3): 268) that an IL-1 inhibitor can reduce IL-1 induced inflammatory effects. This study describes the specific effect of the M20 IL-1 Inhibitor on IL-1 induced parameters of inflammation: fever, leukocytosis and local foot pad swelling or lymph node enlargement. Purified preparations of the IL-1 Inhibitor, when injected together with IL-1, or before the IL-1, reduced fever, leukocytosis, foot pad swelling and lymph node enlargement caused by IL-1. Similar responses were obtained by injection of IL-6 or TNF, but were unaffected by the IL-1 Inhibitor, when injected together.These results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responsesin vivo. The potential importance of this factor as an anti-inflammatory and immune regulatory factor, is supported by the findings of this study.Abbreviations IL-1 Interleukin 1 - IL-6 Interleukin 6 - IL-1ra Interleukin 1 receptor antagonist - TNF tumor necrosis factor