Effects of chipping, grinding, and heat on survival of emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), in chips

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), a phloem-feeding insect from Asia, was identified in 2002 as the cause of widespread ash (Fraxinus sp.) mortality in southeastern Michigan and Essex County, Ontario. Most larvae overwinter as nonfeeding prepupae in the outer sapwood or thick bark of large trees. In a series of studies, we evaluated effects of grinding, chipping, and heat treatment on survival of A. planipennis prepupae in ash material. Heavily infested ash bolts containing roughly 8,700 prepupae were processed by a horizontal grinder with either a 2.5- or 10-cm screen. There was no evidence of A. planipennis survival in chips processed with the 2.5-cm screen, but eight viable prepupae were recovered from chips processed with the 10-cm screen. We chiseled additional sentinel chips with prepupae from ash logs and buried 45 in each chip pile. In total, six prepupae in sentinel chips survived the winter, but we found no sign of adult A. planipennis emergence from the processed chips. Subsequently, we assessed prepupal survival in chips processed by a chipper or a horizontal grinder fit with 5-, 10-, or 12.7-cm screens. An estimated 1,565 A. planipennis prepupae were processed by each treatment. Chips from the chipper were shorter than chips from the grinder regardless of the screen size used. No live prepupae were found in chips produced by the chipper, but 21 viable prepupae were found in chips from the grinder. Infested wood and bark chips chiseled from logs were held in ovens at 25, 40, or 60 degrees C for 8, 24, or 48 h. Prepupal survival was consistently higher in wood chips than bark chips at 40 degrees C, whereas no prepupae survived exposure to 60 degrees C for eight or more hours. In a second study, prepupae in wood chips were exposed to 40, 45, 50, 55, or 60 degrees C for 20 or 120 min. Some prepupae survived 20 min of exposure to all temperatures. No prepupae survived exposure to 60 degrees C for 120 min, but 17% survived exposure to 55 degrees C for 120 min, suggesting that some fraction of the population may survive internationally recognized phytosanitary standards (ISPM-15) for treatment of wood packing material.     

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO₂ at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F), the fluorine atom had no influence on genotoxicity. This study contributes to the future search for new and safer prototypes and provide.     

Endogenous membrane phosphorylation increases in serum-stimulated 3T3 cells.

Autophosphorylation of 3T3 cells, utilizing endogenous membrane protein kinase, can be detected by incubating the cells with μgM³²P-ATP. The phosphorylation activity of growing cells is two to four-fold greater than quiescent ones. In this study, the increased phosphorylation activity of serum-stimulated cells was examined. Phosphorylation, measured at times after serum stimulation of quiescent cultures, was found to increase in early G₁ and to reach a maximum prior to DNA synthesis. This increase in stimulated cells was dependent on RNA and protein synthesis but not on DNA synthesis. The increased activity decayed quickly (half-life approximately 2–3 hours) in the presence of cycloheximide, while the basal activity in quiescent cells was relatively unchanged. Insulin, prostaglandin E₁ or prostaglandin F2α were also found to bring about the same increase in phosphorylation as serum, although in contrast with serum they caused only a small percentage of the culture to synthesize DNA. The results suggest that enhanced phosphorylation activity is a G₁ event. It does not depend on subsequent DNA synthesis. Phosphorylation may be one of the biochemical steps in G₁, necessary but not sufficient for cells to move into S phase.     

The influence of aging on the normal oral glucose tolerance

381 glucose intake normal curves were studied according to the Diabetes Data Group new classification in healthy persons between 10 and 80 years in order to assess the influence of the age upon the normal glucose tolerance. Such an influence, which was evident in all the subjects, turned out to be more important in women with respect to me. In fact, males showed an increase, per decade, of about 1 mg/dl in fasting glycemic levels, of about 6 mg/dl at 60', of 4 mg/dl at 120', while in females there was an increase of about 2 mg/dl in fasting glicemic values, of about 6 mg/dl at 60' and of about 5 mg/dl at 120'. No meaningful correlation between age and insulinemic values was found at all considered points, either in males or in females. The reasons of the decreased glucose tolerance with aging and of its different behavior in the two sexes are discussed.     

Synthetic peptide-labelled micelles for active targeting of cells overexpressing EGF receptors

Amino Acids - The goal of nanomedicine is to transport drugs to pathological tissues, reducing side effects while increasing targeting and efficacy. Aggregates grafted by bioactive molecules act as...     

Genetic structure,admixture and invasion success in a Holarctic defoliator,the gypsy moth (Lymantria dispar,Lepidoptera: Erebidae)

Characterizing the current population structure of potentially invasive species provides a critical context for identifying source populations and for understanding why invasions are successful. Non‐native populations inevitably lose genetic diversity during initial colonization events, but subsequent admixture among independently introduced lineages may increase both genetic variation and adaptive potential. Here we characterize the population structure of the gypsy moth (Lymantria dispar Linnaeus), one of the world's most destructive forest pests. Native to Eurasia and recently introduced to North America, the current distribution of gypsy moth includes forests throughout the temperate region of the northern hemisphere. Analyses of microsatellite loci and mitochondrial DNA sequences for 1738 individuals identified four genetic clusters within L. dispar. Three of these clusters correspond to the three named subspecies; North American populations represent a distinct fourth cluster, presumably a consequence of the population bottleneck and allele frequency change that accompanied introduction. We find no evidence that admixture has been an important catalyst of the successful invasion and range expansion in North America. However, we do find evidence of ongoing hybridization between subspecies and increased genetic variation in gypsy moth populations from Eastern Asia, populations that now pose a threat of further human‐mediated introductions. Finally, we show that current patterns of variation can be explained in terms of climate and habitat changes during the Pleistocene, a time when temperate forests expanded and contracted. Deeply diverged matrilines in Europe imply that gypsy moths have been there for a long time and are not recent arrivals from Asia.     

Dynamic interaction between breast cancer cells and osteoblastic tissue: comparison of two- and three-dimensional cultures

Breast cancer cell colonization of osteoblast monolayers grown in standard tissue culture (2D) is compared to colonization of a multi-cell-layer osteoblastic tissue (3D) grown in a specialized bioreactor. Colonization of 3D tissue recapitulates events observed in clinical samples including cancer penetration of tissue, growth of microcolonies, and formation of "Single cell file" commonly observed in end-stage pathological bone tissue. By contrast, adherent cancer cell colonies did not penetrate 2D tissue and did not form cell files. Thus, it appears that 3D tissue is a more biologically (clinically) relevant model than 2D monolayers in which to study cancer cell interactions with osteoblastic tissue. This direct comparison of 2D and 3D formats is implemented using MC3T3-E1 murine osteoblasts and MDA-MB-231 human metastatic breast cancer cells, or the metastasis-suppressed line, MDA-MB-231BRMS1, for comparison. When osteoblasts were co-cultured with metastatic cells, production of osteocalcin (a mineralization marker) decreased and secretion of the pro-inflammatory cytokine IL-6 increased in both 2D and 3D formats. Cancer cell penetration of the 3D tissue coincided with a changed osteoblast morphology from cuboidal to spindle-shaped, and with osteoblasts alignment parallel to the cancer cells. Metastasis-suppressed cells did not penetrate 3D tissue, did not cause a change in osteoblast morphology or align in rows. Moreover, they proliferated much less in the 3D culture than in the 2D culture in a manner similar to their growth in bone. In both systems, the cancer cells proliferated to a greater extent with immature osteoblasts compared to more mature osteoblasts.     

Mitogen and co-mitogen stimulation of lymphocytes inhibited by three Ca++ antagonists

The Ca++ requirement for in vitro lymphocyte stimulation by lectins is well known and can be demonstrated by the use of Ca++ chelators. In this study, three Ca++ antagonists were examined for their effects on lymphocyte proliferation. [3H]-thymidine incorporation was employed to measure DNA synthesis in several systems. Stimulation and proliferation were achieved by the addition of one of the following: the mitogenic lectin concanavalin A (ConA); the combination of two co-mitogens, the calcium ionophore A23187 and the phorbol ester, 12-0-tetradecanoylphorbol-13-acetate (TPA), neither of which is mitogenic alone; or the non-mitogenic lectin, wheat germ agglutinin (WGA) with TPA. These mitogenic systems were tested for their sensitivity to the Ca++ channel blockers verapamil and nicardipine and the intracellular Ca++ antagonist TMB-8. We found that the ConA and WGA plus TPA treated cells were inhibited approximately 50% by 10 microM verapamil, nicardipine or TMB-8. The stimulation caused by A23187 and TPA was only inhibited by TMB-8 and nicardipine. The inhibitory effects caused by the Ca++ antagonists could not be reversed by the addition of exogenous Ca++ (0.1-1.5 mM), but were reversed by repeated washings in antagonist free media. Using TMB-8 we saw an apparent intracellular Ca++ dependence throughout the G1 phase. Previous studies using Ca++ chelators or Ca++ antagonists suggested an endpoint at about halfway through this period.     

Mitogenic activity of snake venom lectins

Five lactose-inhibitable lectins have been isolated from snake venoms. These five share certain biochemical properties but are not identical (Gartner, Stocker & Williams, 1980; Gartner & Ogilvie, 1984). In this study the lectins were tested for their ability to stimulate lymphocytes to undergo DNA synthesis. We found that three of the lectins were comparable in mitogenic activity to the T cell lectin, concanavalin A (Con A). The mitogenic activity was blocked by lactose, a sugar which also blocks the haemagglutination activity of these lectins. Although mitogenic response appeared to be due to T cells, it depended on the presence of accessory cells in the culture. This requirement for macrophages could be replaced by the phorbol ester tumour promoter, 12-o-tetradecanoylphorbol-13-acetate (TPA).