Preventive and Curative Biological Treatments for Control of Botrytis cinerea Stem Canker of Greenhouse Tomatoes

The effects of biological treatments with PlantShield^®, Prestop^®, Quadra 136, RootShield^®, and S33 (Rhodosporidium diobovatum) and chemical treatment with Decree^® applied as a preventive or curative sprays on stem canker caused by Botrytis cinerea on tomato plants grown in sawdust were studied under near-commercial greenhouse conditions. Prestop^® and Decree^®, applied as preventive or curative sprays, PlantShield^® applied as curative spray, and S33 and Q-136 applied as preventive or preventive plus one spray to wounded surface provided season-long protection from B. cinerea stem canker. These treatments also increased fruit yield and decreased the number of dead plants compared with the inoculated control.     

Time-of-day dependent performance efficiency in student nurses

A psychological test battery comprising reasoning ability, name and number checking, letter cancellation and associative recall was administered to a group of 70 student nurses at 2-hr intervals from 0800 to 2000 to determine if their performance varied at different times of day. Simultaneously, their oral temperature was recorded. A 7 x 7 latin square design was utilized, and latin square repeated measure analysis of variance was employed. The results indicated variations in oral temperature as the day advanced. While accuracy of performance in cognitive tasks was found to be superior during the early morning, noon or early evening hours, the speed of performance was highest during the period from late-morning to late-evening.     

Thorium induced testicular changes in rats.

Daily intraperitoneal administration of thorium nitrate produced progressive morphological and biochemical alterations with the increase in thorium concentration in rat testis. The degenerative changes in the seminiferous tubules increased with the duration of treatment and after 90 days calcification occurred in about 25% of the tubules and in the connective tissue of the tunica albuginea. The activity of adenosine triphosphatase and alkaline phosphatase increased markedly as a result of thorium administration. An attempt has been made to interrelate histopathological and enzymatic changes and the metal concentration in the testicular tissue.     

Blue guaran (a chromophore-labeled galactomannan) as a reagent for lectins

A new reagent (blue guaran) for quantitative estimation of lectins, has been derived from a galactomannan (guaran). When the lectin solution is added to an aqueous solution of blue guaran, dye-bound guaran is precipitated from the solution. The difference in absorbance of the blue guaran solution before and after the addition of lectin solution is proportional to the amount of lectin present in the sample. The method of preparation of blue guaran, its spectral characteristics and effect of pH on precipitation have also been described. It gives a simple colorimetric method for the estimation of galactose-specific lectins.     

Role of Melanin in Release of Extracellular Enzymes and Selection of Aggressive Isolates of Bipolaris sorokiniana in Barley

Eighteen barley isolates of Bipolaris sorokiniana belonging to wild and clonal type of black, mixed and white subpopulations were quantitatively assayed for their melanin content and aggressiveness with respect to production of some of the extracellular enzymes such as cellulase, pectinase, amylase and protease. Cellulase and pectinase constituted major portion of the enzymes recovered from the black, mixed and white isolates. Enzyme production and aggressiveness were relatively higher in melanin devoid or low melanin isolates. The melanin deficient isolates were also differentiated from black and mixed isolates on the basis of variation in internal transcribed spacer region of the ribosomal DNA. Higher enzyme productions positively correlated with area under disease progress curve (AUDPC) and lesion development. Melanin content was negatively correlated with extracellular enzymes and aggressiveness of the isolates. Based on melanin content, lesion size, AUDPC and extracellular enzymes, the isolates were grouped in two major clusters (I and II) with further division of cluster II into two sub-clusters (II-A and II-B). The results appears to indicate a possible role of melanin in release of extracellular enzymes and hence in evolution and selection of aggressive isolates of B. sorokiniana in barley.     

Assessment of bacterial diversity in agricultural by-product compost by sequencing of cultivated isolates and amplified rDNA restriction analysis

An investigation of bacterial diversity in compost was performed using molecular chronometer in order to reveal its phylogeny. Thirty-three bacterial isolates isolated from compost were analyzed by 16S rRNA gene sequencing which revealed phylogenetic lineage of class Bacilli, γ, β-Proteobacteria, and Actinobacteria. Among these lineages, isolates belonging to class Bacilli consisted of species from genera Staphylococcus, Bacillus, Terribacillus, and Lysinibacillus. From phylum Actinobacteria: Microbacterium barkeri and Kocuria sp. were identified. Other bacterial groups had phylogenetic linkage with genera Comamonas and Acidovorax (class β-Proteobacteria); Serratia, Klebsiella, and Enterobacter (class γ-Proteobacteria). Similar isolates were analyzed through ARDRA. Amplified product of 16S rRNA gene from each isolates was subjected to cleavage by enzymes HpaII, HinfI, and MspI in separate reaction tubes. HpaII generated 2–6 bands ranging from 90–688 bp, HinfI generated 2–5 bands of 71–1,038 bp, and MspI 2–7 bands of 69–793 bp. The restriction patterns from HpaII, HinfI, and MspI were normalized separately and combined by means of pattern recognition software “Diversity Database.” HpaII had highest discrimination index (0.72) than HinfI (0.68) and MspI (0.65), and the combination of all three showed discrimination index (0.69). Numerical analysis of ARDRA patterns demonstrated sufficient phylogenetic information for characterizing bacterial diversity. Phylogenetic relationship obtained among isolates through ARDRA was compared with 16S rRNA gene sequence and ARDRA results showed sufficiently similar 16S rRNA gene sequence analysis, but not an overlapping. It has been observed that ARDRA technique facilitates the identification of bacteria in less than 36 h as compared to traditional 16S rRNA gene sequencing.     

Alpha,beta-dehydrophenylalanine containing cecropin-melittin hybrid peptides: conformation and activity.

Synthesis and conformational studies of a cecropin-melittin hybrid pentadecapeptide CA(1-7)MEL(2-9), and its three alpha, beta-dehydrophenylalanine (DeltaPhe) containing analogs in water-TFE mixtures are described. DeltaPhe is placed at strategic positions in order to preserve the amphipathicity of the molecule. The wild type CAMEL0 and its three analogs, containing one, two and three DeltaPhe residues namely CAMELDeltaPhe1, CAMELDeltaPhe2 and CAMELDeltaPhe3 respectively were synthesized in solid phase and their conformation determined by CD and NMR. CAMELDeltaPhe2 and CAMELDeltaPhe3 peptides exhibit the presence of 3(10)-helix and beta-turns in the former and only turns in the latter. CAMELDeltaPhe1 peptide was found to have a largely extended conformation. Antibacterial and hemolytic activities of the peptides were also evaluated. CAMELDeltaPhe2 peptide is maximally potent against both Staphylococcus aureus ATCC 259230 and Escherichia coli ATCC 11303. CAMELDeltaPhe1 with a single DeltaPhe at the center shows minimal hemolysis.     

Thymus-dependent in vivo suppression of IgE synthesis in a murine IgE-secreting hybridoma

In previous studies we demonstrated that BALB/c mice bearing ascitic tumors of the IgE-secreting hybridoma B53 (epsilon, kappa, anti-dinitrophenyl) developed large numbers of Lyt-1-2+ Fc epsilon R(+) T lymphocytes (T cells with membrane Fc receptors) in response to the elevated serum IgE concentration. The development of Fc epsilon R(+) T lymphocytes was followed by a progressive decrease in the levels of serum IgE in spite of continued proliferation of the hybridoma cells. This sequence of events suggested that the IgE-secreting hybridoma triggered a suppressive immunoregulatory circuit of the host that inhibited IgE expression by the hybridoma cells. The present studies were undertaken to investigate the basis for the subsequent decline in serum IgE levels in mice with B53 tumors and to identify host factors that might be involved in this process. We observed that ascitic B53 cells recovered at increasing time points from BALB/c mice exhibited a selective decline in steady state levels and rates of synthesis of epsilon-heavy chain protein and mRNA. The expression of kappa-light chain protein and mRNA appeared relatively unchanged. The decrease in epsilon-heavy chain gene expression did not occur when B53 tumors were passaged in nu+/nu+ mice or in BALB/c mice depleted of Lyt-2+ cells (suppressor/cytotoxic cell lineage), but did occur in nu+/nu+ mice reconstituted with neonatal BALB/c thymus and in BALB/c mice depleted of L3T4+ cells (helper/inducer cell lineage). That Fc epsilon R(+) T lymphocytes were directly involved in the inhibition of IgE expression was supported by the earlier and more pronounced inhibition of B53 IgE in mice infused with Fc epsilon R(+) T lymphocytes. We conclude from these findings that: 1) the decline in serum IgE levels that occurs toward the end of each generation of in vivo passage of the B53 hybridoma is due to decreased production of IgE by the hybridoma cells, 2) the decreased production of IgE is due to a selective loss of epsilon mRNA expression, 3) the decrease production of IgE by B53 cells is dependent on the presence of Lyt-2+ cells, and 4) Fc epsilon R(+) T lymphocytes participate in the mechanism by which IgE production is suppressed.