Plasma esterase activities in rats fed magnesium-deficient diets

In a study with rats it was determined whether dietary magnesium concentration affects plasma esterase activities. The feeding of a diet with 0.01% (w/w) instead of 0.04% magnesium reduced plasma magnesium concentration by 50%. Plasma total esterase, arylesterase and butyrylcholinesterase activities were significantly decreased in the magnesium-deficient rats. In rats fed a diet containing 0.02% magnesium, plasma magnesium concentration was lowered by 30%, and group mean plasma total esterase activity was decreased, but not the activities of arylesterase and butyrylcholinesterase.     

EFFECTS OF FERTILIZATION ON EPICUTICULAR WAX MORPHOLOGY OF NEEDLE LEAVES OF DOUGLAS FIR,PSEUDOTSUGA MENZIESII (PINACEAE)

Fertilized stands of Pseudotsuga menziesii were found to have glaucous needles. We investigated the morphological and quantitative characteristics of the epicuticular waxes of needles of fertilized and control trees. Glaucousness was caused by ornate tubular epicuticular wax. Dipping needles in chloroform, which dissolves waxes, eliminated the glaucous appearance. Based on cryostage scanning electron microscopic observations, the epicuticular waxes in the nonstomatal region were much more ornate on the needles of the fertilized trees (experimental needles) than in unfertilized trees (control needles). The stomatal region in both experimental and control needles showed similarly ornate waxes. Quantities of waxes were similar in experimental and control needles. The glaucousness was not the result of greater quantities of wax; rather, fertilization altered wax morphology in the nonstomatal regions.     

Revision of Bomarea subgenus Sphaerine (Alstroemeriaceae)

The subgenus Sphaerine of Bomarea (Alstroemeriaceae) recently contains 33 validly published names. Extended field studies in Peru and extensive investigation of herbarium material revealed the urgent necessity for a revision. As a result, the number of species is reduced to 12, among them two species are newly described. 9 species are members of an other subgenus. A key to determine the species is given in English and Spanish. The typical growth form and its variability, habitat preferences and distribution are discussed separately for each species.     

Quantitation of chloramphenicol acetyl transferase (CAT) messenger RNA by filter hybridisation using a digoxigenin label

Summary Slot- and dot-blotting are commonly used to evaluate levels of messenger ribonucleic acid (mRNA). Quantitation of bacterially-expressed chloramphenicol acetyl transferase (CAT) mRNA by this method is highly dependent on total RNA immobilised onto the solid support as well as mRNA concentration. mRNA quantitation by comparison with a pure standard results in underestimation. An improved protocol for CAT mRNA detection is described.     

Production of urinary tumour necrosis factors and soluble tumour necrosis factor receptors in bladder cancer patients afterbacillus Calmette-Guerin immunotherapy

Intravesical immunotherapy for bladder cancer is the most effective form of tumour immunotherapy. Following repeated instillations of bacillus Calmette-Guérin (BCG) organisms into the bladder large 0quantities of several cytokines are detected in the urine. These cytokines include interleukins IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor α (TNFα), interferon γ (IFNγ) and also soluble intercellular adhesion molecule ICAM-1. In the work reported here we simultaneously quantified urinary levels of TNFα, TNFβ, TNF receptor I and TNF receptor II by enzyme-linked immunosorbent assay (ELISA) techniques and compared this with bioactive levels of TNF. This was undertaken with a limited number of patients throughout a course of six instillations of immuno therapy. Sequential instillations of BCG induced secretion of TNFα and TNFβ into urine. These cytokines were not always secreted simultaneously, perhaps suggesting differential regulation of their synthesis. Maximal concentrations of TNFα were 675 pg/ml and TNFβ 47 pg/ml. High levels of both species of soluble TNF receptor were readily identified in urine. Maximal levels of sTNF-RI were 6200 pg/ml (range from 0) and for sTNF-RII 7800 pg/ml (range from 0). Contrasting with earlier published observations concerning cytokine levels, the concentration of soluble receptor did not increase with repeated instillation. In apparent contrast with the ELISA data, very low levels of bioactive TNF were identified by the L929 bioassay (maximum concentration 1 U/ml) despite the elevated concen t ration of immunoreactive TNF. The large concentrations of soluble TNF receptor in patients’ urine samples could account for the apparently low bioactivity as determined by the L929 cytotoxicity assay. The precise nature of the role of TNF in BCG immunotherapy remains undetermined; however, it is thought that proinflammatory cytokines are in part responsible for the clinical efficacy of this therapeutic approach. Whether other cytokines are antogonised by soluble binding proteins remains to be determined. Furthermore, whether TNF is bioactive in the bladder wall and only neutralised in the urine also requires investigation. Received: 24 August 1994 / Accepted: 17 October 1994     

Identification of a novel cellulose-binding domain the multidomain 120 kDa xylanase XynA of the hyperthermophilic bacterium Thermotoga maritima

A segment of Thermotoga maritima strain MSB8 chromosomal DNA was isolated which encodes an endo-1,4-β-D-xylanase, and the nucleotide sequence of the xylanase gene, designated xynA, was determined. With a half-life of about 40 min at 90°C at the optimal pH of 6.2, purified recombinant XynA is one of the most thermostable xylanases known. XynA is a 1059-amino-acid (?120 kDa) modular enzyme composed of an N-terminal signal peptide and five domains, in the order A1-A2-B-C1-C2. By comparison with other xylanases of family 10 of glycosyl hydrolases, the central ?340-amino-acid part (domain B) of XynA represents the catalytic domain. The N terminal ?150-amino-acid repeated domains (A1-A2) have no significant similarity to the C-terminal ?170-amino-acid repeated domains (C1-C2). Cellulose-binding studies with truncated XynA derivatives and hybrid proteins indicated that the C-terminal repeated domains mediate the binding of XynA to microcrystalline cellulose and that C2 alone can also promote cellulose binding. C1 and C2 did not share amino acid sequence similarity with any other known cellulose-binding domain (CBD) and thus are CBDS of a novel type. Structurally related protein segments which are probably also CBDs were found in other multi-domain xylanolytic enzymes. Deletion of the N-terminal repeated domains or of all the non-catalytic domains resulted In substantially reduced tbermostability while a truncated xylanase derivative lacking the C-terminal tandem repeat was as thermostable as the full-length enzyme. It is argued that the multidomain organization of some enzymes may be one of the strategies adopted by thermophiles to protect their proteins against thermal denaturation.     

Euhemerobe Kalk-Kieferngesellschaften der Kleinen Karpaten

Man made stands withPinus nigra Arn. were studied on limestone bedrock. They were planted out on biotops of previous calciphilous beech or xerothermophilous oak forests. The analysis of present phytocenological composition and the changes in ecological conditions, especially of nitrogen content in the soil, conduce to their classification, following the conception ofHada? andSofron (1980), as a new euhemerobic forest community, associationClematidi vitalbae-culti-Pinetum nigrae.     

Einige neue oder bemerkenswerte Flechten mit gyalectoiden Apothecien von Nord-Indien und Nepal

This paper presents the results of taxonomic investigation of 8 species of lichens with gyalectoid apothecia collected in North-India and Nepal. Four species are recognized as new:Dimerella isidiata (sp. nova),D. nepalensis (sp. nova),Gyalideopsis lithophila (sp. nova) andRamonia nepalensis (sp. nova). Four species are reported for the first time from Nepal:Coenogonium moniliforme, Gyalectidium caucasicum, Gyalidea lecideopsis andG. scutellaris.