Oxidative Protective Mechanisms and Resistance to the Dicarboximide Fungicide, Iprodione, in Alternaria alternata

The free radical scavengers α-tocopherol and butylated hydroxytoluene, but not ascorbate, diminished the growth-inhibiting effects of the dicarboximide fungicide, iprodione in Alternaria alternata. Growth of A. alternata in the presence of iprodione increased the activities of superoxide dismutase and glutathione reductase while catalase was unaffected. Four iprodione sensitive and four iprodione resistant isolates of A. alternata were compared for activity of free radical enzymes. The isolates of A. alternata resistant to iprodione had more catalase activity than those which were sensitive, but did not differ in superoxide dismutase of glutathione reductase, activities. 3-Amino-1.24.-triazole, a specific inhibitor of catalas, reduced the ability of DAR 69775, a dicarboximide resistant isolate of A. alternata. to grow in the presence of iprodione. In A. alternata dicarboximide resistance appeats to be at least partially mediated by enhanced activitiesof, catalase.     

A simplified method for culture of human fetal heart tissue

Human fetal heart tissue obtained consequent to suction termination of pregnancy between 6 and 12 weeks of gestation were cultured as explants and maintained in a viable state, with spontaneous contractions up to 75 days. Ultrastructural morphology of the explant revealed that the cells remained healthy up to 21 days in culture. The model can therefore be used for experimental studies during the first 3 weeks in culture.     

Changes in ploidy level of epidermal cells during last larval instar of the tobacco hornworm, Manduca sexta

The relative DNA content of Manduca sexta abdominal epidermal nuclei during the final larval instar was measured by cytophotometry of whole-mount preparations of the epidermis. In the middle intrasegmental region, epidermal cells showed a ploidy level of 4C to 32C on the day of ecdysis. During the subsequent period of feeding, the proportion of higher ploidy cells, such as 16C and 32C, increased. This situation remained until the day of apolysis preceding pupal cuticle formation when mitoses reduced the cells to 2C, 4C, 8C and 16C, except for the pupal pock-mark cells, which increased to 32C or 64C. Metaphase cells showed various ploidy levels, correlated with the size of their mitotic figures. By contrast, in the anterior and posterior margin of a segment where no mitoses occurred, the cells continued to increase in ploidy throughout the instar.     

Molecular approach for the rapid detection of Bacillus and Pseudomonas genera—dominant antagonistic groups—from diverse ecological niches using colony multiplex PCR

Bacillus and Pseudomonas are the dominant groups of bacteria known for their antagonistic potential against many plant and animal pathogens. Presently, exploration of these genera with antagonistic property for disease management of aquaculture system is gaining more importance to overcome the use of antibiotics and related resistance issues. Rapid screening and identification of these genera from diverse bacterial populations by conventional methods is laborious, cost-intensive, and time-consuming. To overcome these limiting factors, in the present study, a colony multiplex PCR (cmPCR) method was developed and evaluated for the rapid detection of Bacillus and Pseudomonas. The technique amplifies the partial 16S rRNA gene of Bacillus and Pseudomonas with a product size of ~1,100 and ~375 bp, respectively, using single forward (BSF2) and two reverse primers (PAGSR and BK1R). Reliability of the cmPCR method was confirmed by screening 472 isolates obtained from ten different eco-stations, of which 133 isolates belonged to Bacillus and 32 to Pseudomonas. The cmPCR method also helped to identify six different Pseudomonas spp. and 14 different Bacillus spp. from environmental samples. Of the total 472 isolates studied, 46 showed antagonistic activity, among which 63 % were Bacillus and 17.4 % were Pseudomonas. Thus, the newly developed molecular approach provides a quick, sensitive, and potential screening tool to detect novel, antagonistically important Bacillus and Pseudomonas genera for their use in aquaculture. Further, it can also act as a taxonomic tool to understand the distribution of these genera from wide ecological niches and their exploitation for diverse biotechnological applications.     

Effect of nitrous oxide and methionine on hepatic S-adenosylmethionine levels and in vivo histidine oxidation in rats.

Nitrous oxide (N2O) decreased in vivo oxidation of histidine in rats fed a basal diet marginally deficient in methionine, although hepatic levels of S-adenosylmethionine (AdoMet) were not significantly altered. Excess dietary methionine increased hepatic levels of AdoMet and increased histidine oxidation. However, it did not protect histidine oxidation when the rats were treated with N2O. Parenteral administration of methionine greatly increased hepatic levels of AdoMet and increased histidine oxidation in normal and N2O treated rats. This indicates that when hepatic levels of AdoMet are greatly elevated by administration of methionine, N2O does not affect in vivo histidine oxidation.     

Dinucleotides Incorporating Isomeric Nucleosides: Synthesis,Structural and Stereochemical Characterization,and Enzymology

Abstract

The synthesis, stability toward nucleases, and conformational properties of 3′→5′ and 5′→5′ dinucleotides bearing an isomeric nucleoside component is described.