Evaluation of immunomodulatory effects of nisin-containing diets on mice

The effect of nisin on the immune response of mice was studied. Nisin (in the form of the commercial preparation Nisaplin) was incorporated in the diet of experimental mice which were fed for 30, 75 or 100 days. Short-term administration of diets containing Nisaplin induced an increase of both CD4 and CD8 T-lymphocyte cell counts and also a decrease of B-lymphocyte counts. After prolonged diet administration, T-cell counts returned to control levels. Normal levels of B-lymphocytes were also reached after prolonged administration of the lower (but not the higher) Nisaplin concentration. The macrophage/monocyte fraction isolated from peripheral blood became significantly increased after long-term administration (100 days) of Nisaplin-containing diets in a concentration-dependent way. Although the number of peritoneal cells was not affected by the diets, the phagocytic activity of peritoneal cells decreased after prolonged administration of low (but not high) Nisaplin doses.     

Quelques considérations sur une possibilité de stimulation biologique du champignon Eremothecium ashbyii

Résumé La variabilité et l'instabilité des caractères biologiques du champignonEremothecium ashbyii, créent des difficultés dans la production industrielle de la riboflavine. Un mélange du miel d'abeille et de la levure-facteurs complexes à des potences multiples sur le métabolisme-permet qu'on obtient des résultats intéressants, par la stimulation de la croissance et la multiplication du microorganisme, répercutées favorablement sur la riboflavinogénèse.

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Summary The variability and instability of the biological character of the fungusEremothecium ashbyii account for the difficulties encountered in the large scale production of riboflavine. A mixture of honey and yeast — complex factors of many metabolic potencies — has been used and interesting results have been obtained following stimulation of growth and multiplication favourably affecting riboflavinogenesis.

     

GLYCOPROTEINS IN BRAIN TISSUE OF THE O-VARIANT OF GM2 GANGLIOSIDOSIS

Abstract— The dialysableglycopeptide preparation recovered from the glycoproteins in cerebral gray matter of a case of the O-variant form of G_M2 gangliosidosis contained four fold more N -acetylglucosamine and mannose than a similar preparation from normal gray matter. In the O-variant form of G_M2 gangliosidosis, the enzymes β - N -acetylhexosaminidases A and B are missing. A three- and four-fold elevation, respectively, of N -acetylglucosamine and mannose in the dialysable glycopeptide preparation from a case of Tay-Sachs disease (B-variant form of G_M2 gangliosidosis) was noted. The B-variant lacks hexosaminidase A but has ample supplies of hexosaminidase B. The brain level of glycosaminoglycans was not affected in the O- and B-variant forms of G_M2 gangliosidosis.     

Inflammatory and Phagocytic Response to Experimental Campylobacter jejuni Infection in Mice

After intraperitoneal inoculation with Campylobacter jejuni BALB/c, Swiss and DBA mice show a peritoneal inflammatory response of different intensity. Only BALB/c mice have a strong peritoneal response. Simultaneous intraperitoneal inoculation of C. jejuni plus FeCl₃ increase both inflammatory response and phagocytic activity in Swiss mice, without production of diarrhea. Some thermostable compounds of C. jejuni have a very strong chemotactic activity against peritoneal cells of mice, whereas a diffusible, thermolabile and glutaraldehyde-resistant factor has an inhibitory effect over murine peritoneal cell phagocytosis. Bactericidal activity of peritoneal cells increased after in vitro re-challenge with C. jejuni. Bacteremia is present in all the mice strains tested, but the clearance is quick in DBA and slow in BALB/c and Swiss mice. These experiments confirm that in mice, peritoneal non-specific mechanisms of defense, such as macrophages, play an important role in order to control C. jejuni infection.     

Molecular identification of the advanced third-stage larvae (ADV L3) of Gnathostoma lamothei in Tabasco,Mexico

Advanced third-stage larvae (ADV L₃) of Gnathostoma spp. were collected from the muscle tissue of three species of freshwater fish (i.e., Gobiomorus dormitor, Petenia splendida, and Parachromis managuensis) in Swamps of Centla, Tabasco, Mexico. Nine sequences of the ITS2 of the ribosomal DNA of Gnathostoma spp. were compared with sequences obtained from GenBank for G. binucleatum, G. lamothei, G. miyazakii, G. spinigerum, and G. turgidum. Sequences of the ADV L₃ from P. splendida (Isla Chinal), P. managuensis (Isla Chinal), and of two of the six larvae collected from G. dormitor (Tres Brazos), were identical to that of G. binucleatum (GenBank). Sequences from the other four larvae from G. dormitor (Tres Brazos) are identical to the sequence of G. lamothei (GenBank). This is the first record of the intermediate host of G. lamothei. The only species documented to cause human gnathostomiasis in the Americas is G. binucleatum. Our finding of G. binucleatum, and G. lamothei parasitizing the commercially important fish species, G. dormitor in Centla swamps, indicates the possibility of G. lamothei causing human gnathostomiasis in Mexico as well.     

Deciphering the Golgi apparatus: from imaging to genes

The Golgi apparatus is a vital organelle in eukaryotic cells. It grabs and processes secretory materials synthesized by the endoplasmic reticulum (ER) before sorting them to their destination. The Golgi also receives materials from vacuoles/lysosomes and the plasma membrane for further recycling to other compartments within the cell (1) (Figure 1). Given the vital role of the Golgi in a cell, it is important to understand how this organelle attains and maintains its structural and functional integrity during the intense processes of membrane traffic. Despite an equally central role of the Golgi in membrane traffic in eukaryotes, the organization of this organelle has some unique features in each cell system. Therefore, the wealth of information available on the structure and activity of the Golgi in one system is not always directly transferable to others. However, certain morphological and functional aspects are common among cell systems. Therefore, studying the factors that regulate organelle biogenesis and organization of the Golgi apparatus is important in basic cell biology of eukaryotes and may also contribute to a better understanding of how different cell systems have evolved. In this study, we report on the identification of Golgi mutants in plant cells. We have developed a screen that is a promising strategy not only for the identification of genes responsible for the morphological and functional integrity of the plant Golgi but could also provide fundamental information on other multicellular systems for which the power of forward genetics cannot be exploited as easily as in Arabidopsis.     

Health behaviours of school children in northwestern Poland in 2000

The 3568 final class primary school in northwestern Poland were investigated between January and June 2000. The youths fulfilled the questionnaire concerned health behaviour issues. The 56% of school children do not drink milk daily, 68% do not eat raw vegetables, and 35% do not take any food at school. Every second boy and every fourth girl brushes his/her teeth too rarely. 23% of boys and 10% of girls smoke cigarettes. About 30% of boys and 20% of girls declare that it “happens” that they drink alcohol. 15% boys and 8% of girls report that they tried to use at least one of the psychoactive substances. Physical exercises are performed by 28% of boys and 36% of girls and 45% and 28% respectively watch TV four or more hours a day.     

Investigations on the biodegradation of alkylpolyglucosides by means of liquid chromatography–electrospray mass spectrometry

The biodegradation of alkylpolyglucosides (APGs) was studied under the conditions of the OECD Screening Test with activated sludge as an inoculum. An influence of alkyl and sugar chain length on the biodegradation rate and a central scission pathway of the biodegradation were investigated. The liquid chromatography-electrospray mass spectrometry technique was used for alkylpolyglucoside analysis and for identification and semiquantitative determination of metabolites. It was found that APGs with a longer alkyl chain were biodegraded faster than those with a shorter one. However, a longer sugar chain caused slower biodegradation of APGs. The central scission pathway of biodegradation was also confirmed.     

Improved production of doubled haploids of winter and spring triticale hybrids via combination of colchicine treatments on anthers and regenerated plants

Double haploids (DH), obtained during androgenesis in vitro or by genome diploidisation in regenerated haploids, are one type of basic materials used in triticale breeding programmes. The aim of this study was to improve DH production by a combination of colchicine treatment methods on a sample of five winter and five spring triticale hybrids. Colchicine was applied in vitro either in the C17 medium to induce embryo-like structures (ELS) or in the 190-2 medium for green plant (GP) development. Regenerants which remained haploid were immersed in a colchicine solution either when placed on the medium prior to transferring to soil or when growing in pots, followed by the application or absence of cooling. Colchicine treatment during anther culture affected neither ELS nor GP development, but significantly increased the number of DH plants in comparison to spontaneous chromosome doubling. The highest efficiency was recorded when colchicine was applied in the induction medium (55%) versus the regeneration medium (44.5%) or no colchicine treatment (30%). The effectiveness of chromosome duplication in haploid plants ranged from 32 to 64.5% and it was the highest for the treatment on the medium followed by cooling. Individual hybrids differed regarding their capability of regeneration and chromosome doubling, which were consistent only to a low or moderate extent. However, taken together, winter and spring hybrids did not differ significantly. Combined colchicine application resulted in a high yield of DH production, 82.6% for all triticale hybrids, and can provide a considerable number of fertile DH lines for triticale breeding programmes.