Oxidation–reduction reactions of simple hydroxamic acids and plutonium(IV) ions in nitric acid

Simple hydroxamic acids such as formo- and aceto-hydroxamic acids have been proposed as suitable reagents for the separation of either Pu and/or Np from U in modified or single cycle Purex based solvent extraction processes designed to meet the emerging requirements of advanced fuel cycles. The stability of these hydroxamic acids is dominated by their decomposition through acid hydrolysis. Kinetic studies of the acid hydrolysis of formo- and aceto-hydroxamic acids are reported in the absence and the presence of Pu(IV) ions. The slow reduction of these plutonium(IV) hydroxamate complexes to Pu(III) aquo-ions has been characterised by spectrophotometry and cyclic voltammetry. The reductions of Pu(IV) in the presence of FHA and AHA are consistent with a mechanism in which free hydroxamic acid in solution is hydrolysed whilst Pu(IV) ions remain fully complexed to hydroxamate ligands; then at some point close to a 1 : 1 Pu(IV) : XHA ratio, some free Pu4+ is released from the complex and reduction is initiated. Electrochemical and kinetic data suggest that the reductant is the hydroxamic acid rather than the hydroxylamine.

Multiple novel astrovirus species in human stool

Diarrhoea remains a significant cause of morbidity and mortality in developing countries where numerous cases remain without identified aetiology. Astroviruses are a recently identified cause of animal gastroenteritis which currently includes two species suspected of causing human diarrhoea. Using pan-astrovirus RT-PCR, we analysed human stool samples from different continents for astrovirus-related RNA sequences. We identified variants of the two known human astrovirus species plus, based on genetic distance criteria, three novel astrovirus species all distantly related to mink and ovine astroviruses, which we provisionally named HMOAstV species A-C. The complete genome of species A displayed all the conserved characteristics of mammalian astroviruses. Each of the now three groups of astroviruses found in human stool (HAstV, AstV-MLB and HMOAstV) were more closely related to animal astroviruses than to each other, indicating that human astroviruses may periodically emerge from zoonotic transmissions. Based on the pathogenic impact of their closest phylogenetic relatives in animals, further investigations of the role of HMOAstV, so far detected in Nigeria, Nepal and Pakistan, in human gastroenteritis are warranted.

Preimplantation genetic diagnosis as a source of human embryonic stem cells for disease research and drug discovery

Embryos surplus to therapeutic requirements following preimplantation genetic diagnosis can be used to derive human embryonic stem cell (hESC) lines carrying mutations significant to human disease. These cells provide a powerful in vitro tool for modelling disease progression in a number of cell types as well as having the potential to revolutionise drug discovery. Robust and reproducible directed differentiation protocols are needed to maximise the potential of these cells. In this review, we explore the current use of hESC and induced pluripotent stem cells in disease-specific research and discuss the use of stem cell technology in drug discovery and toxicity testing.

Perceived concepts of continuity of care in people with colorectal and breast cancer--a qualitative case study analysis

We aimed to develop ideas on continuity of cancer care. In-depth qualitative interviews were conducted with 28 people. Seven had cancer. Each person with cancer nominated a close person and a primary and secondary health care professional. We examined from four perspectives: experiences of the initial diagnosis; subsequent treatment; views on continuity of care; information given about the illness; psychological/physical impact of cancer and communication with professionals, family and friends. Perceived continuity of care was influenced by the actions of patients', involvement of close contacts and engagement in shared decision making. Additionally communication between primary and secondary care, the role of various health professionals and hospital administrative systems strongly influenced continuity of care. Informational, management and relational continuity have been previously described. Our data uncovered the effect of patients' actions and the involvement of close friends and families on continuity of cancer care. People with cancer should be enabled to influence continuity of their care. Full recognition of the role of health professionals, different approaches to sharing information with patients and tightening of hospital administrative systems should also be considered.

Macrofaunal recovery following TBT ban. Long-term recovery of subtidal macrofaunal communities in relation to declining levels of TBT contamination

In the United Kingdom, the use of TBT-based anti-fouling paints on small vessels was banned in 1987, and a biological study of the Crouch Estuary, a yachting centre on the south-eastern coast of the UK, was conducted in order to determine the ecological improvements resulting from this legislation. We present the changes in the macro-infaunal communities along the estuary in relation to declining TBT concentrations between 1987 and 2005. Although the major changes in response to the ban were observed within the first 3 years (primarily an increase in the number of crustacean taxa and a shift in community structure), with changes still apparent between three and 5 years, the temporal duration of this study allowed the rapidity of the response to be truly determined.

Building comparative gene expression databases for the mouse preimplantation embryo using a pipeline approach to UniGene

To understand early mammalian development there is a need to compare profiles of gene expression from different stages of the preimplantation mouse embryo. We describe here a method that uses gene expression data held in the UniGene database of the National Institutes of Health (NIH). The full mouse UniGene database (build #151) contains 43,104 gene clusters generated from approximately 4.1 million sequences. The Expressed Sequence Tags (EST) used to build UniGene are derived from cDNA libraries that are archived separately in the database of Expressed Sequence Tags (dbEST) database, with their own catalogue numbers. The mouse dbEST database contains 32 non-normalized dbEST libraries constructed from preimplantation stages (unfertilized oocyte, fertilized oocyte, 2-, 4-, 8- and 16-cell embryo and blastocyst). These libraries contain 219,852 EST sequences mapping to 15,731 UniGene clusters. We have developed a computational pipeline approach that imports and aggregates inventories of gene expression contained in these dbEST libraries. It uses these data to build an annotated web-based database of preimplantation gene expression with an in-built capacity for comparison of expression profiles. Comparison of gene expression profiles obtained for each developmental stage show statistically significant changes in gene expression during preimplantation development. These in silico-generated profiles were validated using RT-PCR.

Use of tunnelled catheters for malignant pleural effusions in patients fit for pleurodesis

The aim of the present study was to examine the effectiveness of tunnelled pleural catheters (TPC) in patients with malignant pleural effusions who would otherwise be candidates for pleurodesis. Patients were selected from a previously reported database of 250 TPC insertions. The study group was selected based on lung re-expansion and survival as a surrogate maker of eligibility for pleurodesis procedure, as defined by survival of > or =90 days and lung re-expansion > or =80% post-drainage on a standard chest radiograph 2 weeks post TPC placement. There were 109 procedures in 97 patients that met the entry criteria. Spontaneous pleurodesis (SP) was achieved following 70% of procedures and correlated with symptom control. The mean time to SP was 90 days. There was no need for a repeat procedure in 87% of cases overall and in 92% of patients experiencing SP. There were few complications and no procedure-related deaths. Tunnelled pleural catheters are an effective way of controlling malignant pleural effusions when used as first-line treatment in patients who appear to be candidates for pleurodesis procedures.

Regenerative medicine. The industry comes of age

The regenerative medicine industry has moved into a new era in which commercialisation and not research is the number one priority. To achieve its new goal, much has had to change, including the introduction of expert business management, simpler but superior products and scalability of manufacture. Mass public and political support is supplying both long-term resources and the market demand to finally create a sustainable new health-care sector.

The Korean stem cell fiasco: shifting the focus

No one could have failed to have seen the dramatic headlines surrounding Professor Woo Suk Hwang of the Seoul National University. Hwang claimed first place in the race to create patient-specific stem cells from cloned human embryos, only to be discredited shortly afterwards. This article discusses whether such high-profile negative publicity has damaged the regenerative medicine industry in general or whether it has merely shifted the stem cell focus away from South Korea.

Ectodermal dysplasia--an unusual dental presentation

Ectodermal dysplasia (ED) is a rare group of disorders affecting the hair, teeth, nails and sweat glands to a variable degree. There is a wide range of clinical presentation of ED. Missing teeth or abnormal tooth form may be the first indicator of the presence of the disorder. There is typically hypodontia with microdontia. We present an unusual case of ED with severe hypodontia and macrodontia affecting all first permanent molar teeth. We also consider the classification and presentation of this disorder.

Other approaches to fighting cardiovascular disease: stem cells and engineered tissue

Technologies such as vessels and cardiac patches grown in the laboratory are being developed to treat heart disease. This article reviews the progress so far with these and other regenerative-medicine products.