Phthaloyl Strategy—A New Approach Towards Oligodeoxyribonucleotide Synthesis

Abstract

A new rapid strategy for machine-aided oligodeoxyribonucleotide synthesis has been established utilizing phthaloyl groups for protection of the heterocyclic amino functions within the phosphoramidite approach. A large number of DNA-sequences has been synthesized. Due to high purity and speed of performance this strategy offers an excellent alternative to the common used acyl approach.     

Nanotechnology—Life-Cycle Risk Management

Scientists, risk practitioners, and regulators have debated the need to be proactive in assessing the potential health and environmental risks and benefits of unregulated nano-scale technologies. Many nanotech-based products and applications are already in use or development. Application of a proactive risk-based approach that considers the life cycle of the product, rather than a precautionary principle approach that would likely restrict the progress and advance of nanoscience, will be useful in helping to assess the unknown and unpredictable risks associated with nano-products, nanotoxicity, and nanopollution.

This article summarizes what is currently known regarding the potential toxicity and hazards of nanomaterials. A life-cycle perspective is used to identify important areas for further consideration and research. A conceptual framework is proposed for linking the strategies of life cycle and risk analysis within the same toolbox. This approach allows for prevention and treatment of a material's life-cycle risks, which can be considered in an integrated manner, thereby promoting continuous improvement, proactive risk reduction, and a flexible and adaptive approach to evaluating nanotechnology without stifling innovation.     

Is There a Role for Risk Assessment within Precautionary Legislation?

Posing the question of whether the precautionary principle has a role in risk assessment effectively constrains any debate of the issue within a framework predicated on the assumption that application of risk assessment is inevitable in the formulation of regulatory decisions. The question can equally validly be expressed in terms of whether there is a role for risk assessment in the formulation of precautionary legislation. This allows the debate then to turn on consideration of two questions: Firstly, does the precautionary principle have a role in policy development? and secondly, is this role consistent and compatible with a risk based approach to regulation? When recast in these terms, a more holistic comparison of the aims and objectives of both approaches and of their relative power in the formulation of regulation becomes possible. This leads to the conclusion that the precautionary principle is, when defined and applied correctly, scientifically more robust than risk assessment. Precautionary approaches utilize scientific information and conform robustly to a scientific process but also explicitly incorporate indeterminacies into the decision making framework. Moreover, the precautionary principle when applied to environmental regulation, is more likely to lead to regulation consistent with global sustainability. On this premise, this paper argues that risk based approaches are essentially incompatible with approaches based on the precautionary paradigm, and that of the two, risk assessment is more likely to lead to unsustainable underprotection of the environment.     

Sediment Toxicity Testing for Prospective Risk Assessment—A New Framework and How to Establish It

There is a recognized need to design a new framework for sediment toxicity testing that meets current scientific standards and regulatory requirements, such as reliable assessment of toxicity, which prevents any harmful effects on biodiversity, a strong capability to predict population- and community-level effects, and applicability of the results to decision-making. We propose a new framework for prospective sediment toxicity testing, and suggest solutions to the key methodological challenges that hinder establishment of this framework (comparison of sensitivities, design of test batteries, consideration of different exposure routes, extrapolations to population and community levels, use of test results for decision-making). The proposed framework consists of the following three units: test-battery system, higher-tier testing systems and additional ecological modeling, and a decision support system. The key methodologies proposed to establish this framework are compound-tailored test-battery use approach, relative sensitivity distribution analysis, toxicity tests that combine bacteria and arthropods, micro- and mesocosms studies, population and community models, and model-driven decision support systems. The proposed framework, as well as the key methods mentioned above, has the potential to improve not only prospective toxicity testing for sediments, but also ecological risk assessment in general.     

Chemical Camouflage– A Frog's Strategy to Co-Exist with Aggressive Ants

Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs'' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.     

Yeast Immobilization in LentiKats®: A New Strategy for Xylitol Bioproduction from Sugarcane Bagasse

Summary A new PVA-hydrogel matrix for yeast cell immobilization for xylitol bioproduction from sugarcane bagasse was studied. Five repeated-batch fermentation runs were carried out in medium based on sugarcane bagasse hemicellulosic hydrolysate with reuse of the entrapped biocatalyst. The system performance as well as the metabolic behaviour of cells entrapped into the matrix were evaluated. The biocatalyst remained stable and exhibited a similar fermentative profile in all the successive batches, demonstrating the viability of the system. At the end of the run, an average xylitol production was observed of 35.1 g l⁻¹ and average xylitol yield and productivity of 0.58 g g⁻¹ and 0.49 g l⁻¹ h⁻¹, respectively.     

PLASMANATE?—A New Plasma Substitute for Pediatric Therapy

Plasmanate®, a human-serum protein solution, appears to have all the attributes of an ideal plasma expander. Freedom from infection, immediate availability in a clear, stable solution and the apparent absence of antigenic properties are particularly valuable qualities. The efficacy and safety of Plasmanate was clinically demonstrated in the treatment of 125 infants and children. This solution seems especially effective in the treatment of acute shock states and for the physiologic correction of hypoproteinemia. Comparison with other plasma expanders makes Plasmanate the agent of choice in the initial treatment of shock states in pediatrics.     

Hishot Display—A New Combinatorial Display for Obtaining Target-Recognizing Peptides

Display technologies are procedures used for isolating target-recognizing peptides without using immunized animals. In this study, we describe a new display method, named Hishot display, that uses Escherichia coli and an expression plasmid to isolate target-recognizing peptides. This display method is based on the formation, in bacteria, of complexes between a polyhistidine (His)-tagged peptide including random sequences and the peptide-encoding mRNA including an RNA aptamer against the His-tag. When this system was tested using a sequence encoding His-tagged green fluorescent protein that included an RNA aptamer against the His-tag, the collection of mRNA encoding the protein was dependent on the RNA aptamer. Using this display method and a synthetic library of surrogate single-chain variable fragments consisting of VpreB and Ig heavy-chain variable domains, it was possible to isolate clones that could specifically recognize a particular target (intelectin-1 or tumor necrosis factor-α). These clones were obtained as soluble proteins produced by E. coli, and the purified peptide clones recognizing intelectin-1 could be used as detectors for sandwich enzyme-linked immunosorbent assays. The Hishot display will be a useful method to add to the repertoire of display technologies.     

The Latex Serologic Test for Syphilis—A New Screening Procedure

A new macroscopic screening test for syphilis, the Latex-sts test, is extraordinarily simple. After inactivation of the patient''s serum for 30 minutes at 56°C the test is performed by mixing the patient''s serum with latex particles coated with cardiolipin and a protein fraction obtained from the non-pathogenic Reiter strain of Treponema pallidum. Two to three minutes after mixing, the result of the test is observed on a ringed serologic plate. The sensitivity, specificity and reproducibility of the new test are equivalent to those of the qualitative Venereal Disease Research Laboratory tube test. The advantages of the Latex-sts are that it can be done in a short time, it is simple and it requires a minimum of laboratory equipment. The coated latex particles are stable for 12 months.     

Tonsillectomy and the Risk for Deep Neck Infection—A Nationwide Cohort Study

Background

Although the tonsils contribute to first line immunity against foreign pathogens in the upper aero-digestive tract, the association of tonsillectomy with the risk of deep neck infection remains unclear. The aim of this study was to assess the incidence rate and risk of deep neck infection among patients who had undergone a tonsillectomy.

Methods

This retrospective cohort study evaluated all patients who had undergone tonsillectomy between 2001 and 2009 as identified from the Taiwan National Health Insurance Research Database. For each post-tonsillectomy patient, 10 age-, sex-, and index date-matched controls without a history of tonsillectomy were randomly selected. Cox Proportional hazard model and propensity score model were performed to evaluate the association between tonsillectomy and deep neck infection after adjusting for demographic and clinical data.

Results

There were 34 (71.6 cases per 100,000 person-years) and 174 (36.6 cases per 100,000 person-years) patients that developed deep neck infection in the tonsillectomized and comparison cohorts, respectively. After adjusting for covariates, patients who had undergone a tonsillectomy had a 1.71-fold greater risk of deep neck infection by both Cox proportional hazard model (95% confidence interval, 1.13-2.59) and propensity score model (95% confidence interval, 1.10-2.66). This association was not altered regardless of the indication for tonsillectomy (i.e. chronic/recurrent tonsillitis or sleep apnea/hypertrophy of tonsil) (p = 0.9797).

Conclusions

Based on our review of a nationwide cohort study we identified that the risk of deep neck infection is significantly increased among patients who have undergone a tonsillectomy. Additional research is needed to explore the possible mechanisms behind these findings.     

Environmental Stochasticity and Long-Term Livestock Viability—Herd-Accumulation as a Risk Reducing Strategy

This study tests the hypothesis that herd accumulation can be a risk reducing strategy aimed at increasing security in an unpredictable environment. Saami reindeer husbandry in Norway is characterized by environmental unpredictability and occasionally harsh winters can have dramatic negative effects on reindeer population densities. While herd accumulation has been found to be an adaptive risk reducing strategy in stochastic environments (i.e., individually rational), the accumulation of large herds may also result in collectively negative density dependent effects, which may negatively affect individual herders (i.e., collectively irrational). We found that individual husbandry units’ strategies, such as accumulating reindeer, have a larger effect on individual husbandry units’ herd size than a negative density-dependent effect.     

Cumacean Lamprops pumilio—A New Species for the Sea of Japan

The treatment of materials collected in Srednyaya Bight (Peter the Great Bay) revealed in a sample taken on December 3, 1986, a female Lamprops pumilioZimmer with oostegites (3.5 mm long). The sample was obtained using an Okean bottom sampler (with the mouth area of 0.25 m²), at a depth of 10 m, from fine sand, at a temperature of –1.5°C.