In vitro organogenesis from leaf explants of Annona squamosa Linn

Multiple shoot formation was induced from excised leaf explants of Annona squamosa Linn. (custard apple) seedlings on a Murashige and Skoog basal medium containing benzylaminopurine and kinetin. Various auxins in combination with the above medium produced callusing of the explants. In an investigation of environmental factors affecting shoot induction it was seen that the maximum number of shoots were obtained using the leaf base with petiole at a temperature of 27°C and a light intensity of 1000 lux. Roots were initiated erratically when individual shoots were treated with an auxin and then transferred to an auxin free medium. The process of the development of adventitious buds in leaf culture was analysed histologically.NCL Communication No. 3104.     

Acute administration of the organochalcogen 3‐methyl‐1‐phenyl‐2‐(phenylseleno)oct‐2‐en‐1‐one induces biochemical and hematological disorders in male rats

Organochalcogens are extensively produced and employed by industry and agriculture, and the risk of occupational and environmental toxicity to them has been poorly understood. Here, we investigated the acute effect of a new organochalcogen 3‐methyl‐1‐phenyl‐2‐(phenylseleno)oct‐2‐en‐1‐one on biochemical and hematological parameters in male Wistar rats. The animals were treated with a single intraperitoneal injection of the organochalcogen at doses of 125, 250 or 500 µg·kg^–1. After 60 min, the animals were sacrificed by decapitation, and the trunk blood was collected for determination of glucose, triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase, lactate dehydrogenase, urea, creatinine, C‐reactive protein, red blood cells, hematocrit, hemoglobin and white blood cells (WBC). Our results showed a reduction in cholesterol levels in all treated groups, an increase in ALT activity at doses of 250 and 500 µg·kg^–1, a decrease of hemoglobin and an increase in WBC in animals that received 250 and 500 µg·kg^–1 of the organoselenium. In addition, we observed an increase in neutrophil counts at 125 µg·kg^–1 dose and a decrease at 500 µg·kg^–1 dose. We also verified an increase in lymphocyte counts at the dose of 500 µg·kg^–1. Thus, the present study shows that the acute treatment with this new organochalcogen causes biochemical changes and hematological disorders in male rats. Copyright © 2012 John Wiley & Sons, Ltd.     

Deletion of pgi alters tryptophan biosynthesis in a genetically engineered strain of Escherichia coli.

Deletion of the structural gene for phosphoglucose isomerase (pgi) of Escherichia coli dramatically alters the path of glucose catabolism by diverting carbon into the hexose monophosphate shunt. The effect of this genetic alteration on the conversion of glucose to tryptophan by strains optimized for the biosynthesis of this amino acid was determined by using 13C-nuclear magnetic resonance spectroscopy in vivo. Pgi- strains converted glucose to tryptophan almost twice as efficiently as did their Pgi+ counterparts.