Comparison of a commercial biochemical kit and an oligonucleotide probe for identification of environmental isolates of Vibrio vulnificus

A. DALSGAARD, I. DALSGAARD, L. HØI AND J.L. LARSEN. 1996. Methods for the identification and isolation of environmental isolates of Vibrio vulnificus were evaluated. Alkaline peptone water supplemented with polymyxin B and colistin-polymyxin B-cellobiose agar were employed for the isolation of suspected V. vulnificus from water, sediment and shellfish samples. When comparing the identification of putative V. vulnificus obtained with the API 20E assay and an oligonucleotide probe, 29 API 20E profiles were obtained with only four profiles (representing 20 isolates) reaching the identification threshold of V. vulnificus among a total of 66 isolates hybridizing with the probe. The results indicated that, compared with colony hybridization, the API 20E assay was not adequate for the identification of environmental isolates of V. vulnificus .     

Cardiac phosphocreatine deficiency induced by GPA during postnatal development in rat

The effect of chronic administration of -guanidinopropionic acid (GPA) on the protein profiling, energy metabolism and right ventricular (RV) function was studied in the rat heart during the weaning and adolescence period. GPA was given in tap water (1–1.5%) using pair drink controls. The feeding of animals with GPA solution for a six week period resulted in elevation of heart to body weight ratio due to body growth retardation. GPA accumulated in the myocardium up to 67.37 ± 5.3 moles.g dry weight and the tissue content of total creatine, phosphocreatine and ATP was significantly decreased to 15%, 9% and 65% of control values respectively. Total activity of creatine kinase (CK) was not changed, but the proportion of mitochondrial (Mi) CK isoenzyme was decreased; the percentage of MB isoenzyme of CK was significantly higher. GPA treatment resulted in an elevation of the content of cardiac collagenous proteins and decrease of non-collagenous proteins in the heart; in parallel, a decrease of the collagen I to collagen III ratio was detected. The function of the RV was assessed using an isolated perfused heart with RV performing pressure-volume work. As compared to pair-drink controls, RV function was significantly impaired the GPA group: at any given right atrial filling pressure, the RV systolic pressure and the rate of pressure development were decreased by almost a factor of two. Elevation of the RV diastolic pressure with increasing pulmonary artery diastolic pressure was also significantly steeper in the GPA group which also showed decrease of cardiac output, especially at high outflow resistance. It may be assumed that chronic administration of GPA deeply influenced metabolic parameters, protein profiles and contractile function of the developing heart. On the other hand, concentrations of glucose, total lipids and triglycerides in blood plasma were not affected. All these data confirm the concept that the CK system is of central importance both for heart function and for the regulation of normal growth of cardiac myocytes.     

Genomic organization of a mouse MHC class II region including theH2-M andLmp2 loci

The region encompassing theMa, Mb1, Mb2, andLmp2 genes of the mouse class II major histocompatibility complex (MHC) was sequenced. Since this region contains clusters of genes required for efficient class I and class II antigen presentation, it was interesting to search for putative additional genes in the 21 kilobase gap between theMb1 andLmp2 genes. Computer predictions of coding regions and CpG islands, exon trapping experiments, and cross-species comparison with the corresponding human sequence indicate that no additional functional gene is present in that stretch. However, computer analysis revealed the possible existence of an alternative 3 exon forMb1. Except for the fact that the mouse MHC contains twoMb genes, the genomic organization of theH2-M loci was found to be almost identical to the organization of the humanHLA-DM genes. The promoter regions of theMa andMb genes also resemble classical class II promoters, containing typical S, X, and Y boxes. Like the human genes, the threeH2-M genes displayed very limited polymorphism when we compared the cDNA sequences from six haplotypes. Finally, comparison ofDMB withMb1 andMb2, both at the genomic level and in their coding regions, suggests that theMb gene was recently duplicated, probably only in certain rodents.     

The origin and recycling of sedimented biogenic debris in a subalphine eutrophic lake (Lake Bled, Slovenia)

The areal distribution of organic C contents, ¹³C values, total N and P and biogenic Si contents in surficial sediments were used to study the distribution, origin and diagenetic transformations of sedimented biogenic debris in the eutrophic subalpine Lake Bled (Slovenia), which for most of the yearhas an anoxic hypolimnion. The influence of an allochthonous input, restricted to the western basin, was clearly traced by higher organic C and total N and P contents, higher ¹³C values, and higher sedimentation rate in comparison to the eastern basin. The low ¹³C values of sedimentary organic matter in the major part of the lake, lower than the ¹³C values of different types of organic matter, suggest that this sedimentary organic matter is most probably the product of a microbial community and not a residue of primary production.The temporal variation of benthic diffusive fluxes of NH₄, Si and PO₄, derived from modelling the pore water profiles, was related to sedimentation of phytoplanktonic blooms, while the PO₄ fluxes were also dependent on changing redox conditions at the sediment-water interface in the period of the winter-spring overtum. The removal of PO₄ in pore waters is probably due to the adsorption of phosphate and precipitation of apatite and vivianite. The budget of C, N and P at the sediment-water interface revealed a high recycling efficiency (>70%), also confirmed by the rather uniform (or only slightly decreasing) vertical profiles of organic C, total N and P in sediment cores and C/N and C/P ratios. The percentage of biogenic Si recycling is low (<10%), suggesting its removal in sediments.     

Structural and functional homology between the 29 kD rat liver nucleoprotein and the high mobility group 1 protein

A 29 kD soluble rat liver nucleoprotein (p29) has increased binding affinity for the hormone responsive element (RE) of the rat haptoglobin (Hp) gene during the acute-phase reaction. In this work the possibility of its structural and functional homology to the high mobility group 1 (HMG1) nonhistone protein constituent of chromatin was examined. The results of two-dimensional gel electrophoresis, Southwestern and Western immunoblot analyses, showed that p29 and HMG1 are homologous protein species. On the basis of in vitro and in vivo phosphorylation/dephosphorylation experiments, we discuss the modulatory role of phosphate groups in view of the structure and function of p29.     

Letters to the metanarrative: Totalitarian “enjoyment” and self representation in postcommunist Serbia

Conclusion This outline of the instrumentality of the technology/technique of representation in postcommunist Serbia is but a brief attempt to address the modes of production of identity in postmodernism, its legitimation in/of dominant discourse, and their embedding in common sense language and practice. Postcommunist Serbia is obviously a special situation:²³ a particular case of the social appropriation and construction of enjoyment and desire, intimately related to the desires and various enjoyments of the members of the community, precarious in its collective affirmation. Based on the idea of contingent collectivity, faction-fiction, in its meta-critique seems to signal the emergence of a new régime in the relation between historical reality and its representation in historical narratives.This new régime, obviously, cannot be exhaustively (or even extensively) discussed in a brief paper like this one. Nevertheless, some (three) points of departure for the general discussion of postmodern modes of representation are still possible. One such point of departure is the contingence of representation, another the apparent paradigmatic similarity between trash talk-shows and Echoes and Reactions. And finally, much of iek's discussion does not seem to be restricted to the totalitarian metanarrative, and can be a significant contribution to the debate on power relations.Nikola Stojin is a Serbian Writer and Graduate Student in Comparative Literature at Rutgers University, New Brunswick, New Jersey.     

Oxidation and amidation of salicylate by Streptomyces species

Seven streptomycete strains were tested for biotransformation of salicylate. The products were identified by nuclear magnetic resonance spectroscopy and three types of conversion were found. Streptomyces cinnamonensis and Streptomyces spectabilis formed gentisate and salicylamide concurrently. Streptomyces rimosus transformed salicylate to salicylamide. Streptomyces lividans, Streptomyces coelicolor, Streptomyces griseus and Streptomyces avermitilis produced only gentisate. Time course studies of salicylate conversion by thin-layer chromatography and high pressure liquid chromatography showed that salicylamide was accumulated in the culture broth, whereas gentisate was further metabolized.Key words: salicylate, gentisate, salicylamide, biotransformation, Streptomyces spp.     

Variance deficit is not reliable evidence for niche limitation

Variance deficit in the number of species per sampling unit, as compared to a null model with species occurring independently of each other has been considered by various authors to be evidence for niche limitation. I show that simpler mechanisms could explain this phenomenon. Of those, the competition of individuals for space limits the number of individuals per sampling unit, resulting in decrease of variance in species richness. Testing the proportions of species belonging to various guilds seems to be more ecologically interesting, although here also the variance deficit can hardly be taken as reliable evidence for niche limitation.     

The growth form of the inducing microorganism and chitin addition affect mycolytic enzyme production byTrichoderma harzianum

The effect of the growth form of the inducing microorganism on specificTrichoderma harzianum mycolytic enzyme production was studied. The pelleted form ofRhizopus nigricans gave a better product concerning protoplast formation ability. The maximum yield of protoplasts from the target fungusCochliobolus lunatus was 1×10⁸ ml^–1. Analysis of individual specific enzyme activities inTrichoderma mycolytic enzyme preparations confirms the importance of high chitinase and low protease activity for high protoplast yields. Supplementation of the production medium with chitin increased the chitinase activity in theTrichoderma exoenzyme mixture.