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.

Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old), while 26 age-matched controls received only vehicle. The livers were removed on either the 10th or the 30th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA) of cathepsins B and L was also decreased on the 10th, but not on the 30th day. Sulfatase decreased 30% on the 30th day, while glycosidases did not vary (or presented a transitory and slight decrease). There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

Plasma chitotriosidase activity in children with lysosomal storage disorders.

Chitotriosidase (ChT) is an enzyme that is selectively activated in tissue macrophage. This property of ChT makes it a potential marker for many disease process and prognostication. Present study has been carried out to know the significance of ChT as a screening marker in lysosomal storage disorders (LSDs) where tissue macrophage activation is commonly observed due to accumulation of substrate in various organs of the body. Study comprises of 20 healthy children in the age range of 10 days to 5 yrs and 56 children in the age range of 2.5 months to 13 yrs with regression of milestones, skeletal dysplasia, neuroregression and hepatosplenomegaly were selected for plasma ChT who had confirmed LSDs as carried out by specific lysosomal enzyme study from the leukocytes or fibroblasts. Plasma ChT was 55.21 ± 20.81 nmol/ml /hr in twenty healthy age matched controls. Plamsa ChT level was 42.88 to 79.78 nmol/ml/hr in thirteen of 56 (23.21%) children with LSDs like Morquio- B, Pompe, Metachromatic leucodystrophy (MLD), Sandhoff and Niemann-Pick disease type C (NPD-C). While in 43 (76.78%) children it was in the range of 213.74 to 23,511.40 nmol/ml/hr. who had LSDs like Morquio-B, Sly syndrome, MLD, GM2 Gangliosidosis, NPD-A/B and Gaucher disease (GD). Marked elevated ChT (4,000 to 23,511 nmol/ml/hr) was observed in all cases of GD (n=7) and NDP-A/B. It can be concluded from the present study that moderately raised activity of ChT can be utilized as a positive predictive test for certain LSD’s. Those with marked elevated ChT have confirmed GD or NPD-A/B making it a strong screening marker for this group of diseases.

Enzymatic N-glycan analysis of 31 kDa molecule in plerocercoid of Spirometra mansoni (sparganum) and its antigenicity after chemical oxidation

A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

Actividad de la chitotriosidasa plasmatica en pacientes argentinos con enfermedad de Gaucher, diversas lisosomopatias y en otras metabolopatias geneticas / Plasma chitotriosidase activity in Argentinean patients with Gaucher disease, various lysosomal diseases and other inherited metabolic disorders

Recientemente, una marcada y aparente específica elevación de la actividad de la chitotriosidasa plasmática (Ch-PI) fue demostrada en pacientes con Enfermedad de Gaucher (EG) Tipo 1 (Mc Kusick 230800); este indicador bioquímico contribuiría además, en la detección de la patología y en la valoración de la terapia de suplementación enzimática (TSE). Datos subsecuentes sugirieron que el incremento de la Ch-PI también era marcador de otras patologías de atesoramiento lisosomal (PAL), aunque las actividades fueron menores que los valores más bajos de la EG Tipo 1. Aquí presentamos nuestra experiencia en la investigación de la actividad de la Ch-PI en una población argentina distribuida en tres grupos: a) 25 controles sanos; b) individuos relacionados con la EG: 3 pacientes con EG Tipo 1, 3 heterocigotas obligadas y 1 pacientes con una variante atípica de EG; c) 42 pacientes con precisa definición nosológica de una Enfermedad metabólica Hereditaria (EMH) y 5 pacientes presumibles de padecer una PAL aunque sin confirmación enzimática. La actividad de la metilumbelliferil tri-N-acetilchitotriosa hidrolasa fue de 600-2000 veces mayor en la plasma de las pacientes con EG Tipo 1 respecto del valor medio normal autóctono (17 nmoles/min/ml; rango de 6-60, 4 nmoles/min/ml); en el paciente con EG atípica el incremento de la Ch-PI fue alrededor de 100 veces. El efecto de la TSE en 2 de las pacientes con EG Tipo 1, una de forma moderada y la otra severa, se manifestaron con un descenso del 50 por ciento de la actividad de la Ch-PI a los 10 meses de tratamiento a la dosis de 30 U/kg/mes de alglucerase. En las heterocigotas obligadas de EG Tipo 1 y en la del Tipo 2 como asimismo en el grupo de pacientes con diferentes EMH, la actividad de la Ch-PI resultó normal. Una deficiencia total de la Ch-PI se demostró en el 8 por ciento de los controles sanos y un 10,6 por ciento en el grupo patológico. La relación entre el incremento de varios cientos de veces de la Ch-PI uy la fisiopatología de la EG no está elucidada como tampoco los posibles efectos de la relativamente común deficiencia de la enzima en el ser humano. La demostración del rol de la enzima en la degradación de patógenos contentivos de chitina, la purificación y clonación de cADN de la enzima, abren interesantes aspectos a investigar en este nuevo capítulo de la genética médica.

Glycosaminoglycan (GAG) level and activities of certain enzymes of GAG metabolism in Culex quinquefasciatus and Setaria digitata.

Significant differences were observed in GAG metabolism of S. digitata and one of its intermediate vectors, C. quinquefasciatus. Distribution of different components such as hyaluronic acid, heparin-sulphate, chondroitin-4-sulphate, chondroitin-6-sulphate, dermatan sulphate and heparin was comparable in both. However, there were quantitative differences; the difference was marked in the activity of enzymes of GAG metabolism in presence and absence of diethylcarbamazine (DEC) a known antifilarial drug. While the activities of beta-galactosidase and beta-N-acetyl glucosaminidase of S. digitata systems showed an inhibition of 96.5 and 92.6% respectively, in the Culex systems they showed an inhibition of 93.3% and an activation of 18% respectively. The differences clearly indicate the existence of basic differences in GAG metabolism of vector and parasite.