Histochemical identification of non-culturable mycobacteria (M. leprae and M. lepramurium)

Summary The possibility of the histochemical demonstration of the dopa-oxidase reaction in Mycobacterium leprae from the granulomas of untreated cases of human lepromatous leprosy was studied. Fresh frozen sections were taken, fixed for one hour, and incubated with DOPA (3,4-dihydroxyphenylalanine) for two hours at pH 6.8 and at 37° C. The results obtained did not confirm the biochemical phenomena observed in human liver and spleen.Investigation supported by Grant No. DF. S1-153 from Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICIT)     

Volatile components from European liverworts Marsupella emarginata,M. aquatica and M. alpina

The hydrodistillation products of the liverworts Marsupella emarginata, M. aquatica and M. alpina were investigated by spectroscopic methods. A number of new compounds could be isolated by preparative gas chromatography (GC) and identified by spectroscopic techniques including GC-mass spectrometry, NMR and chemical correlations in conjunction with enantioselective GC. From M. emarginata, in addition to many known compounds, the sesquiterpene hydrocarbon (-)-7-epi-eremophila-1(10),8,11-triene (1) and the sesquiterpene derivatives (-)-4-epi-marsupellol (2), (-)-marsupellol acetate (18), (-)-4-epi-marsupellol acetate (4), (+)-5-hydroxymarsupellol acetate (5) and (-)-9-acetoxygymnomitr-8(12)-ene (24) could be identified. In M. aquatica the sesquiterpene hydrocarbons (-)-myltayl-8(12)-ene (7), ent-(+)-amorpha-4,11-diene (8), (-)-amorpha-4,7(11)-diene (9), the sesquiterpene alcohol (+)-9-hydroxyselina-4,11-diene (10) and (-)-2-acetoxyamorpha-4,7(11)-diene (11) were identified. In M. alpina (-)-trans-selina-4(15),11-dien-5-ol (12), (+)-8,9-epoxyselina-4,11-diene (13) and (+)-cis-selina-4(15),11-dien-5-ol (14) were found as new natural products.     

Isolation and chemical characterization of lipopolysaccharides from four Mycoplana species (M. bullata,M. segnis,M. ramosa and M. dimorpha)

Lipopolysaccharides (LPS), isolated from four Mycoplana species, i.e. the type strains of M. bullata, M. segnis, M. ramosa and M. dimorpha, were characterized onto their chemical composition and their respective lipid A-types. Those of M. bullata and M. segnis showed on DOC-PAGE an R-type character and had lipid A's of the Lipid A_DAG-type which exclusively contained 2,3-diamino-2,3-dideoxy-d-glucose as lipid A sugar. LPS's of M. ramosa and M. dimorpha showed, although only weakly expressed, ladder-like patterns on DOC-PAGE indicating some S-type LPS's and lipid A of the d-glucosamine type (Lipid A_GlcN). M. bullata LPS contained mannose and glucose in major amounts and additionally l-glycero-d-mannoheptose, whereas M. segnis LPS was composed of rhamnose, mannose and glucose together with both, d-glycero-d-manno- and l-glycero-d-manno-heptoses in a molar ratio of 1:2. All LPS's contained 2-keto-3-deoxy-octonic acid (Kdo), phosphate and an unidentified acidic component X. In addition to X, M. segnis LPS contained glucuronic and galacturonic acids, whereas M. ramosa LPS contained only galacturonic acid. Acetic acid hydrolysis of the LPS resulted in splitting off lipid A moieties, very rich in 3-hydroxy fatty acids, in particular in 3-OH-12:0 (in Lipid A_DAG), or in 3-OH-14:0 (in Lipid A_GlcN). Analysis of the 3-acyloxyacyl residues revealed major amounts of amide-linked 3-OH(3-OH-13:0)12:0 in lipid A of M. bullata and 3-OH(12:0)12:0 in lipid A of M. segnis. The rare 4-oxo-myristic acid (4-oxo-14:0) was observed only in M. bullata LPS, where it is ester-linked. Amide linked diesters could not be traced in M. ramosa and M. dimorpha. All four lipid A's lacked erster-bound acyloxyacyl residues.Non-standard abbreviations DAG 2,3-diamino-2,3-dideoxy-d-glucose - Kdo 2-keto-3-deoxy-octonate - LPS lipopolysaccharide - PITC phenyl isothiocyanate - NANA N-acetyl neuraminic acid     

Unstable B-chromosomes in a European population of Allium schoenoprasutn L. (Liliaceae)

In Allium schoenoprasum , small, dichromatic B-chromosomes occur in 74% of plants at Lac de Tracens, Pare National des Pyrénées. B-chromosomes from Lac de Tracens were compared with the previously well characterized Bs from British populations of A. schoenoprasum at the River Wye, Powys, and were found to differ in terms of both their morphology and the level of mitotic instability. At Lac de Tracens, two morphological types of B-chromosome were observed: a telocentric of about 1.15 μm in length and a metacentric of about 1.35 μm in length; the most frequent B-type in the River Wye populations (B^-1) was not found. B-chromosomes from the River Wye are essentially stable at root tip mitosis, whereas 25 out of 29 plants from Lac de Tracens (86%) showed between-cell variation in B-number, with non-modal numbers in 330 out of 794 cells (41.6%). Most of the variability occurred within individual roots, rather than between roots of single bulbs or of sister bulbs. No meiotic pairing was observed between the different Bs in hybrids from the geographically isolated populations, suggesting a lack of homology. An independent origin of B-chromosomes in the British and French populations is suggested.     

The European Bioinformatics Institute (EBI) databases.

The European Bioinformatics Institute (EBI) maintains and distributes the EMBL Nucleotide Sequence database, Europe's primary nucleotide sequence data resource. The EBI also maintains and distributes the SWISS-PROT Protein Sequence database, in collaboration with Amos Bairoch of the University of Geneva. Over fifty additional specialist molecular biology databases, as well as software and documentation of interest to molecular biologists are available. The EBI network services include database searching and sequence similarity searching facilities.     

The European Bioinformatics Institute (EBI) databases.

This paper describes the databases and services of the European Bioinformatics Institute (EBI). In collaboration with DDBJ and GenBank/NCBI, the EBI maintains and distributes the EMBL Nucleotide Sequence Database, Europe's primary nucleotide sequence data resource. The EBI also maintains and distributes the SWISS-PROT Protein Sequence Database, in collaboration with Amos Bairoch of the University of Geneva. Over thirty additional specialist molecular biology databases, as well as software and documentation of interest to molecular biologists, are also available. The EBI network services include database searching, entry retrieval, and sequence similarity searching facilities.