Insecticidal heterolignans—Tubuline polymerization inhibitors with activity against chewing pests

Starting from natural product podophyllotoxin 1 substituted heterolignans were identified with promising insecticidal in vivo activity. The impact of substitution in each segment of the core structure was investigated in a detailed SAR study, and variation of substituents in both aromatic moieties afforded derivatives 5 and 43 with broad insecticidal activity against lepidopteran and coleopteran species. In vitro measurements supported by modeling studies indicate that heterolignans 3–134 act as tubuline polymerization inhibitors interacting with the colchicine-binding site. Insect specific structure–activity effects were observed showing that the insecticidal SAR described herein differs from reported cytotoxicity studies.     

Interactions between cells and titanium surfaces

The interaction between cells and implant materials is determined by the surface structure and/or surface composition of the material. In the past years, titanium and titanium alloys have proved their superiority over other implant materials in many clinical applications. This predominant behaviour is caused by a dense passive oxide layer which forms within milliseconds in oxidizing media. Titanium dioxide layers of 100 nm thickness were produced on the surface of cp-titanium grade 2, and on an experimental alloy of high vanadium content (Ti1.5Al25V) as a harmful control. The layers were produced by thermal and anodic oxidation and by coating by means of the sol-gel process. The resulting oxide layers were characterized with respect of their structure and chemical composition. In cell tests (proliferation, MTT, morphology, actin staining), the reaction of the cells was examined. It was shown that the sol-gel-produced titanium oxide layer is able to shield the cells from toxic alloying elements, with the result that the cell reaction is influenced only by the thin titanium oxide surface layer and not by the composition of the bulk material.     

Desiccation tolerance in bryophytes: a reflection of the primitive strategy for plant survival in dehydrating habitats?

Bryophytes are a non-monophyletic group of three major lineages (liverworts, hornworts, and mosses) that descend from the earliest branching events in the phylogeny of land plants. We postulate that desiccation tolerance is a primitive trait, thus mechanisms by which the first land plants achieved tolerance may be reflected in how extant desiccation-tolerant bryophytes survive drying. Evidence is consistent with extant bryophytes employing a tolerance strategy of constitutive cellular protection coupled with induction of a recovery/repair mechanism upon rehydration. Cellular structures appear intact in the desiccated state but are disrupted by rapid uptake of water upon rehydration, but cellular integrity is rapidly regained. The photosynthetic machinery appears to be protected such that photosynthetic activity recovers quickly. Gene expression responds following rehydration and not during drying. Gene expression is translationally controlled and results in the synthesis of a number of proteins, collectively called rehydrins. Some prominent rehydrins are similar to Late Embryogenesis Abundant (LEA) proteins, classically ascribed a protection function during desiccation. The role of LEA proteins in a rehydrating system is unknown but data indicates a function in stabilization and reconstitution of membranes. Phylogenetic studies using a Tortula ruralis LEA-like rehydrin led to a re-examination of the evolution of desiccation tolerance. A new phylogenetic analysis suggests that: (i) the basic mechanisms of tolerance seen in modern day bryophytes have changed little from the earliest manifestations of desiccation tolerance in land plants, and (ii) vegetative desiccation tolerance in the early land plants may have evolved from a mechanism present first in spores.     

The proteasomal substrate Stm1 participates in apoptosis-like cell death in yeast

We have identified the yeast gene STM1 in an overexpression screen for new proteasomal substrates. Stm1 is unstable in wild-type cells and stabilized in cells with defective proteasomal activity and thus a bona fide substrate of the proteasome. It is localized in the perinuclear region and is required for growth in the presence of mutagens. Overexpression in cells with impaired proteasomal degradation leads to cell death accompanied with cytological markers of apoptosis: loss of plasma membrane asymmetry, chromatin condensation, and DNA cleavage. Cells lacking Stm1 display deficiency in the apoptosis-like cell death process induced by treatment with low concentrations of H(2)O(2). We suggest that Stm1 is involved in the control of the apoptosis-like cell death in yeast. Survival is increased when Stm1 is completely missing from the cells or when inhibition of Stm1 synthesis permits proteasomal degradation to decrease its amount in the cell. Conversely, Stm1 accumulation induces cell death. In addition we identified five other genes whose overexpression in proteasomal mutants caused similar apoptotic phenotypes.     

Impact of Response Shift on Time to Deterioration in Quality of Life Scores in Breast Cancer Patients

Background

This prospective multicenter study aimed to study the impact of the recalibration component of response-shift (RS) on time to deterioration (TTD) in health related quality of life (QoL) scores in breast cancer (BC) patients and the influence of baseline QoL expectations on TTD.

Methods

The EORTC-QLQ-C30 and BR-23 questionnaires were used to assess the QoL in a prospective multicenter study at inclusion (T0), at the end of the first hospitalization (T1) and, three (T2) and 6 months after the first hospitalization (T3). Recalibration was investigated by the then-test method. QoL expectancy was assessed at diagnosis. Deterioration was defined as a 5-point decrease in QoL scores, considered a minimal clinically important difference (MCID). TTD was estimated using the Kaplan-Meier method. Cox regression analyses were used to identify factors influencing TTD.

Results

From February 2006 to February 2008, 381 women were included. Recalibration of breast cancer patients'' internal standards in the assessment of their QoL had an impact on TTD. Median TTD were significantly shorter when recalibration was not taken into account than when recalibration was taken into account for global health, role-functioning, social-functioning, body-image and side effects of systemic therapy. Cox multivariate analyses showed that for body image, when recalibration was taken into account, radiotherapy was associated with a shorter TTD (HR: 0.60[0.38–0.94], whereas, no significant impact of surgery type on TTD was observed. For global health, cognitive and social functioning dimensions, patients expecting a deterioration in their QoL at baseline had a significantly shorter TTD.

Conclusions

Our results showed that RS and baseline QoL expectations were associated with time to deterioration in breast cancer patients.     

High-throughput DNA extraction method suitable for PCR

PCR has become one of the most popular techniques in functional genomics. Projects in both forward and reverse genetics routinely require PCR amplification of thousands of samples. Processing samples to extract DNA of sufficient purity for PCR is often a limiting step. We have developed a simple 96-well plate-based high-throughput DNA extraction method that is applicable to many plant species. The method involves a simple incubation of plant tissue samples in a DNA extraction buffer followed by a neutralization step. With the addition of a modified PCR buffer, the extracted DNA enabled the robust amplification of genomic fragments from samples of Arabidopsis, tobacco, sorghum, cotton, moss, and even pine needles. Several thousand DNA samples can be economically processed in a single day by one person without the use of robotics. This procedure will facilitate many technologies including high-throughput genotyping, map-based cloning, and identification of T-DNA or transposon-tagged mutants for known gene sequences.     

The generation and analysis of clones containing bacteriophage T4 DNA fragments

Cytosine-containing DNA of bacteriophage T4 was digested with three restriction endonucleases: endo R · EcoRI, endo R · HindIII and endo R · PstI, and each digestion ligated with a cloning vector to generate three independent collections of T4 DNA-containing clones. The T4 clones were screened for their T4 genetic content by recombinational analysis using amber mutants of T4. Complementation of T4 amber mutant growth and labeling of proteins in vivo provided evidence of expression of specific (g30, g39, g44 and g46) cloned T4 genes.