Biological control of the grapevine diseases ‘grey mold’ and ‘powdery mildew’ by Bacillus B27 and B29 strains.

Uncinula necator and Botrytis cinerea are the most destructive pathogens of the grapevine in Tunisia and elsewhere. We used two strains of Bacillus subtilis group, B27 and B29 to control powdery mildew and the grey mold disease of the grapevine. Green house experiments showed that B29 and B27 strains of the bacteria efficiently reduced the severity of powdery mildew up to 50% and 60%, respectively. Further, they decreased Botrytis cinerea development on grape leaf by 77% and 99%, respectively. The mode of action has been shown to be chitinolytic. These two bacteria showed significant production of total proteins discharged into the culture medium. Determination of some chitinolytic enzymes revealed the involvement of N-acetyl glucosaminidase (Nagase), the chitin-1,4-chitobiosidase (Biase) and endochitinase in degrading the mycelium of B. cinerea.

Production of fungal cell wall degrading enzymes by a biocontrol strain of Bacillus subtilis AF 1.

Fungal cell wall degrading chitinases and glucanases attained significance in agriculture, medicine, and environment management. The present study was conducted to describe the optimum conditions required for the production of beta-1,4-N-acetyl glucosaminidase (NAGase) and beta-1,3-glucanase by a biocontrol strain of Bacillus subtilis AF 1. B. subtilis AF 1 was grown in minimal medium with colloidal chitin (3.0%) and yeast extract (0.3% YE ) and incubated at pH 7.0 and 30 degrees C on constant shaker at 180 rpm for 6 days produced highest amounts of NAGase. Presence of 0.5 mM of phenyl methyl sulfonyl fluoride (PMSF) and 0.04% of Tween 20 further improved the enzyme production. B. subtilis AF 1 grown in minimal medium with laminarin (1%) and yeast extract (0.3%) for 3 days produced maximum amount of beta-1,3-glucanase. These conditions can be further scaled-up for large-scale production of NAGase and beta-1,3-glucanase by B. subtilis AF 1.

Lysosomal enzyme activity during development of carbon tetrachloride induced cirrhosis in rats.

The present study was undertaken to determine whether there is any alteration in the activities of lysosomal enzymes in the liver and sera of rats during the course of carbon tetrachloride (CCl4) induced cirrhosis in rats. Cirrhosis was induced by the chronic administration of carbon tetrachloride plus phenobarbitone. N-acetyl glucosaminidase, P-glucuronidase and acid phosphatase were assayed spectrophotometrically in the liver homogenates and in the sera at different stages of liver injury i.e., necrosis, fibrosis, and cirrhosis. Significant increase in the "basal" activities of N acetyl glucosaminidase, beta-glucuronidase, and acid phosphatase were observed in the livers of rats during the course of development of cirrhosis. As the liver injury progressed from necrosis to cirrhosis, the 'free' activities of these three enzymes also increased. The 'total' activities of the enzymes studied were either decreased or remained unaltered. The increased 'free' activities of the lysosomal enzymes in the liver of CCl4 treated rats may contribute to cellular autophagy and tissue catabolism, which may subsequently lead to cirrhosis.

Exposicion ocupacional y efectos a la salud del mercurio metalico entre odontologos y asistentes dentales: un estudio preliminar: Valencia, Venezuela; 1998 / Occupational exposure and health effects of metallic mercury among dentists and dental assistants: a preliminary study, Valencia, Venezuela; 1998

Esta investigación pretendió establecer los efectos del Hg sobre la salud de odontólogos y asistentes dentales, su relación con condiciones de exposición, y el posible daño renal debido al Hg. La población fue de 66 personas, la muestra, 37 (56 por ciento), 22 odontólogos (59,5 por ciento, 19 hombres, 3 mujeres) y 15 asistentes dentales mujeres (40,5 por ciento). Se realizaron: encuesta opcional, Hg en orina (Hg-O) y actividad de N-Acetil-beta-D-glucosaminidasa en orina (BAG-O), como biomarcador precoz de daño renal. Los valores de HgO para los odontólogos fueron 22.4 más o menos 6,4 micra g/g creatinina, para los asistentes, 22,2 más o menos 6,1 mu g/g creatinina (p>0.05), y los de BAG-O, de 2,9 más o menos 3 U/L y de 5,2 más o menos 8,1 U/L, respectivamente, no existiento diferencias estadísticamente significativas (p0,05). No se detectó correlación entre el námero de amalgamas preparadas y de horas trabajadas con Hg-O y NAG-O. Los síntomas más frecuentes referidos por los odontólogos fueron irritabilidad, 54,5 por ciento, cefalea, 45,4 por ciento y artralgias, 40,9 por ciento. Por los asistentes, artralgia, 53,5 por ciento, irritabilidad, 46,7 por ciento, y cefalea, 46,7 por ciento, no existiendo riesgo significativo de sufrirlo para ningún grupo. Se requieren nuevas investigaciones que incluyan monitoreo ambiental del Hg, evaluación médica y pruebas neuroconductuales para detectar efectos precoces, asá como la aplicación de medidas de control en pro de la salud del personal.

Canatoxin induces activation on mice peritoneal macrophages

Canatoxin (CNTX), the toxic protein from Canavalia ensiformis seeds, injected into the peritoneal cavities of mice (10 micrograms/cavity) induced a significant neutrophil migration (10.5 +/- 0.5 x 10(6) cells/cavity) after 4 h. A later migratory effect (48 h) on mononuclear cells, predominantly macrophages, was also observed (controls: 7 +/- 0.9; CNTX: 17 +/- 2.0 x 10(6) cells/cavity). These CNTX-elicited macrophages, when compared to resident cells (R) or cells elicited by thioglycollate (TG), had an increased content of the lysosomal enzyme N-acetyl-beta-D-glucosaminidase (R: 4.5 +/- 0.5; TG: 7.2 +/- 1.0; CNTX: 20.2 +/- 3.0 mU/10(6) cells) and a greater (> or = 100%) phagocytic activity. The data suggest that CNTX-stimulated macrophages presented some characteristics of activated cells