BSHI/BTS guidance on crossmatching before deceased donor kidney transplantation.

All UK H&I laboratories and transplant units operate under a single national kidney offering policy, but there have been variations in approach regarding when to undertake the pre-transplant crossmatch test. In order to minimize cold ischaemia times for deceased donor kidney transplantation we sought to find ways to be able to report a crossmatch result as early as possible in the donation process. A panel of experts in transplant surgery, nephrology, specialist nursing in organ donation and H&I (all relevant UK laboratories represented) assessed evidence and opinion concerning five factors that relate to the effectiveness of the crossmatch process, as follows: when the result should be ready for reporting; what level of donor HLA typing is needed; crossmatch sample type and availability; fairness and equity; risks and patient safety. Guidelines aimed at improving practice based on these issues are presented, and we expect that following these will allow H&I laboratories to contribute to reducing CIT in deceased donor kidney transplantation.

The maximum growth rate hypothesis is correct for eukaryotic photosynthetic organisms, but not cyanobacteria.

The (maximum) growth rate (µmax ) hypothesis predicts that cellular and tissue phosphorus (P) concentrations should increase with increasing growth rate, and RNA should also increase as most of the P is required to make ribosomes. Using published data, we show that though there is a strong positive relationship between the µmax of all photosynthetic organisms and their P content (% dry weight), leading to a relatively constant P productivity, the relationship with RNA content is more complex. In eukaryotes there is a strong positive relationship between µmax and RNA content expressed as % dry weight, and RNA constitutes a relatively constant 25% of total P. In prokaryotes the rRNA operon copy number is the important determinant of the amount of RNA present in the cell. The amount of phospholipid expressed as % dry weight increases with increasing µmax in microalgae. The relative proportions of each of the five major P-containing constituents is remarkably constant, except that the proportion of RNA is greater and phospholipids smaller in prokaryotic than eukaryotic photosynthetic organisms. The effect of temperature differences between studies was minor. The evidence for and against P-containing constituents other than RNA being involved with ribosome synthesis and functioning is discussed.

Leaders promote attendance in sport and exercise sessions by fostering social identity.

Sport and exercise participation exert a positive effect on numerous aspects of individuals' health. Although sport and exercise leaders have generally been observed to play a key role in shaping group members' behavior, our understanding of their impact on group members' attendance in sport and exercise sessions is limited. To address this, and building on promising findings in other domains, we examined the associations between perceptions of sport and exercise leaders' engagement in social identity leadership, group identification, and attendance. A sample of 583 participants from sports teams (n = 307) and exercise groups (n = 276) completed questionnaires measuring identity leadership, group identification, and attendance. Analyses demonstrated that perceptions of leader engagement in social identity leadership were positively associated with members' group identification, and that this in turn was positively associated with their attendance in either a sports group or an exercise group. Moreover, there was a significant indirect effect for perceptions of leader engagement in identity leadership on group members' attendance through their greater identification with these groups. Findings highlight the importance of considering the impact sport and exercise leaders have on group members' attendance and suggest that leaders who represent, advance, create, and embed a shared sense of identity (ie, a shared sense of "us") among attendees can promote participation in sport and exercise.

Chronic periodontitis can affect the levels of potential oral cancer salivary mRNA biomarkers.

BACKGROUND AND OBJECTIVE: More than 100 salivary constituents have been found to show levels significantly different in patients with oral squamous cell carcinoma (OSCC) from those found in healthy controls, and therefore have been suggested to be potential salivary biomarkers for OSCC detection. However, many of these potential OSCC salivary biomarkers are also involved in chronic inflammation, and whether the levels of these biomarkers could be affected by the presence of chronic periodontitis was not known. The objective of this pilot study was therefore to measure the levels of seven previously reported potential OSCC salivary mRNA biomarkers in patients with chronic periodontitis and compare them to levels found in patients with OSCC and healthy controls. The seven salivary mRNAs were interleukin (IL)-8, IL-1ß, dual specificity phosphatase 1, H3 histone family 3A, ornithine decarboxylase antizyme 1, S100 calcium-binding protein P (S100P) and spermidine/spermine N1-acetyltransferase 1. MATERIAL AND METHODS: Unstimulated whole saliva samples were collected from a total of 105 human subjects from the following four study groups: OSCC; CPNS (chronic periodontitis, moderate to severe degree, non-smokers); CPS (chronic periodontitis, moderate to severe degree, smokers); and healthy controls. Levels of each mRNA in patient groups (OSCC or chronic periodontitis) relative to the healthy controls were determined by a pre-amplification reverse transcription-quantitative polymerase chain reaction approach with nested gene-specific primers. Results were recorded and analyzed by the Bio-Rad CFX96 Real-Time System. Mean fold changes between each pair of patient vs. control groups were analyzed by the Mann-Whitney U-test with Bonferroni corrections. RESULTS: Only S100P showed significantly higher levels in patients with OSCC compared to both patients with CPNS (p = 0.003) and CPS (p = 0.007). The difference in S100P levels between patients with OSCC and healthy controls was also marginally significant (p = 0.009). There was no significant difference in the levels of salivary IL-8, IL-1ß and dual specificity phosphatase 1 mRNAs between patients with OSCC and patients with CPNS (p = 0.510, 0.058 and 0.078, respectively); no significant difference in levels of salivary ornithine decarboxylase antizyme 1 and spermine N1-acetyltransferase mRNAs between patients with OSCC and patients with CPS (p = 0.318 and 0.764, respectively); and no significant difference in levels of the H3 histone family 3A mRNA between patients with OSCC and either CPS (p = 0.449) or healthy controls (p = 0.107). CONCLUSIONS: Salivary S100P mRNA could be a reliable biomarker for OSCC detection, regardless of the presence of chronic periodontitis. The presence of chronic periodontitis could significantly affect the levels of the other six mRNAs, and negatively influence reliability for using them as biomarkers for oral cancer detection.

Prevalence of variants in methylenetetrahydrofolate reductase and the severity of pulmonary vascular disease.

Pulmonary hypertension is a serious disease associated with constriction, cellular proliferation, inflammation, and in situ thrombosis of the small vessels of the lung. Some studies suggest that homozygous 677TT variants and compound heterozygous 677CT/1298AC variants in methylenetetrahydrofolate reductase may increase the risk for systemic vascular disease. We sought to determine the prevalence of variants in methylenetetrahydrofolate reductase in patients with pulmonary hypertension, and whether homozygous or compound heterozygous variants are associated with an increased severity of disease. The medical records of patients with pulmonary hypertension were retrospectively reviewed to identify 105 patients who were evaluated for variants in methylenetetrahydrofolate reductase. The frequency of the minor allele 677C > T was 0.352 and the frequency of the minor allele 1298A > C was 0.295. The number of patients who were homozygous 677TT, homozygous 1298CC or compound heterozygous 677CT/1298AC was similar to the number of control patients with corresponding variants in a meta-analysis of studies. Patients with homozygous or compound heterozygous variants had a significantly higher ratio of pulmonary to systemic vascular resistance (0.75 ± 0.07 vs. 0.56 ± 0.04, p = 0.019) during baseline heart catheterization. Twenty-five of 61 patients without, and 28 of 44 patients with, homozygous or compound heterozygous variants had moderate to severe disease (p = 0.030). Variants in methylenetetrahydrofolate reductase are common in the general population and in patients with pulmonary hypertension. It is unlikely that these variants cause pulmonary vascular disease; however, they may influence the progression or severity of disease.

Appraising the mitogenicity of insulin analogues relative to human insulin-response to: Weinstein D, Simon M, Yehezkel E, Laron Z, Werner H. Insulin analogues display IGF-I-like mitogenic and anti-apoptotic activity in cultured cancer cells. Diabetes Metab Res Rev 2009; 25(1): 41-9.

Interest in mitogenic and potentially carcinogenic effects of insulin and insulin analogues has been renewed by several recent publications that have examined the relationship between cancer and insulin analogues. Actions mediated through the insulin-like growth factor-I receptor in a hyperinsulinaemic state have been implicated mechanistically. Both type 2 diabetes and endogenously elevated insulin-like growth factor-I have been epidemiologically linked to malignancies. Therefore, in vitro mitogenic effects and binding affinities of the various analogues have been analysed. A recent publication by Weinstein et al. studied the in vitro mitogenic and anti-apoptotic activities of insulin analogues, and their conclusion asserts that insulins glargine, detemir, and lispro displayed proliferative and anti-apoptotic effects in a number of malignant cell lines. However, their conclusions are not supported by the data which are not complete and lack clear statistical significance. This data should be interpreted cautiously in light of all other presently available scientific evidence. Prospective, randomized clinical trials will best address any direct relationship between insulin analogues and cancer. Until those studies are designed and completed, clinicians should consider the demonstrated strong benefit of glycaemic control in balance with any alleged risk.

All-optical steering of laser-wakefield-accelerated electron beams.

We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations.

Allometry and stoichiometry of unicellular, colonial and multicellular phytoplankton.

Phytoplankton life forms, including unicells, colonies, pseudocolonies, and multicellular organisms, span a huge size range. The smallest unicells are less than 1 microm3 (e.g. cyanobacteria), while large unicellular diatoms may attain 10(9) microm3, being visible to the naked eye. Phytoplankton includes chemo-organotrophic unicells, colonies and multicellular organisms that depend on symbionts or kleptoplastids for their capacity to photosynthesize. Analyses of physical (transport within cells, diffusion boundary layers, package effect, turgor, and vertical movements) and biotic (grazing, viruses and other parasitoids) factors indicate potential ecological constraints and opportunities that differ among the life forms. There are also variations among life forms in elemental stoichiometry and in allometric relations between biovolume and specific growth. While many of these factors probably have ecological and evolutionary significance, work is needed to establish those that are most important, warranting explicit description in models. Other factors setting limitations on growth rate (selecting slow-growing species) await elucidation.

Generation of stable, low-divergence electron beams by laser-wakefield acceleration in a steady-state-flow gas cell.

Laser-driven, quasimonoenergetic electron beams of up to approximately 200 MeV in energy have been observed from steady-state-flow gas cells. These beams emitted within a low-divergence cone of 2.1+/-0.5 mrad FWHM display unprecedented shot-to-shot stability in energy (2.5% rms), pointing (1.4 mrad rms), and charge (16% rms) owing to a highly reproducible gas-density profile within the interaction volume. Laser-wakefield acceleration in gas cells of this type provides a simple and reliable source of relativistic electrons suitable for applications such as the production of extreme-ultraviolet undulator radiation.

Clinical significance of a positive flow crossmatch on the outcomes of cadaveric renal transplants.

Pretransplantation crossmatching is an integral part of kidney transplantation. Flow cytometric crossmatch (FCXM) is more sensitive than complement-dependent cytotoxic crossmatch (CDC-XM). However, the clinical significance of positive FCXM with negative CDC-XM is controversial. We evaluated FCXM in 455 consecutive deceased donor renal transplants. All had a negative CDC-XM. There were 341 T-cell and B-cell FCXM negative and 38 T-cell and B-cell positive. There was a higher percentage of retransplantations and HLA mismatches (26.3% vs 8.2%, P= .002 and 2.45 vs 1.99, P= .02, respectively) in the FCXM-positive group compared with the FCXM-negative group; 65.8% of the FCXM-positive patients had rejection compared with 49.3% of the FCXM-negative patients (odds ratio [OR]=1.89, P= .06). FCXM-positive patients had a higher incidence of vascular rejection (28.9% vs 12.6%, OR=2.68, P= .008). One- and 5-year graft survivals were 84% and 66% in the FCXM-positive group vs 90% and 75% in the FCXM-negative group. Censoring for patient death, 1- and 5-year graft survivals were 84% and 73% in the FCXM-positive group vs 94% and 82% in the FCXM-negative group. There was no difference in renal function between the 2 groups. In conclusion, a positive T-cell and B-cell FCXM transplant with a negative CDC-XM is associated with a higher incidence of rejection, twice the risk of vascular rejection, and a trend toward poorer graft survival.

Laser-driven acceleration of electrons in a partially ionized plasma channel.

The generation of quasimonoenergetic electron beams, with energies up to 200 MeV, by a laser-plasma accelerator driven in a hydrogen-filled capillary discharge waveguide is investigated. Injection and acceleration of electrons is found to depend sensitively on the delay between the onset of the discharge current and the arrival of the laser pulse. A comparison of spectroscopic and interferometric measurements suggests that injection is assisted by laser ionization of atoms or ions within the channel.

Metabolic interactions between algal symbionts and invertebrate hosts.

Some invertebrates have enlisted autotrophic unicellular algae to provide a competitive metabolic advantage in nutritionally demanding habitats. These symbioses exist primarily but not exclusively in shallow tropical oceanic waters where clear water and low nutrient levels provide maximal advantage to the association. Mostly, the endosymbiotic algae are localized in host cells surrounded by a host-derived membrane (symbiosome). This anatomy has required adaptation of the host biochemistry to allow transport of the normally excreted inorganic nutrients (CO2, NH3 and PO43-) to the alga. In return, the symbiont supplies photosynthetic products to the host to meet its energy demands. Most attention has focused on the metabolism of CO2 and nitrogen sources. Carbon-concentrating mechanisms are a feature of all algae, but the products exported to the host following photosynthetic CO2 fixation vary. Identification of the stimulus for release of algal photosynthate in hospite remains elusive. Nitrogen assimilation within the symbiosis is an essential element in the host's control over the alga. Recent studies have concentrated on cnidarians because of the impact of global climate change resulting in coral bleaching. The loss of the algal symbiont and its metabolic contribution to the host has the potential to result in the transition from a coral-dominated to an algal-dominated ecosystem.

Transverse interferometry of a hydrogen-filled capillary discharge waveguide.

Transverse interferometric measurements are presented of the plasma channel formed in a hydrogen-filled capillary discharge waveguide recently used to generate 1 GeV electrons in a laser-driven plasma accelerator for the first time. The measurements were found to be in good agreement with nonlocal thermal equilibrium simulations, but showed significant differences with the results of a quasistatic model developed by Bobrova et al. [Phys. Rev. E. 65, 016407 (2001)]. The measurements are used to determine scaling laws for the axial electron density and matched spot size of the plasma channel, enabling optimization of the channel to specific applications.

A high-resolution polymerase chain reaction-sequence-specific primer HLA-B*27 typing set and its application in routine HLA-B27 testing.

We designed a set of 35 polymerase chain reaction sequence-specific primers (PCR-SSP) in 29 SSP mixtures to assign 29 HLA-B*27 4-digit level alleles (B*2701-B*2721 and B*2723-B*2730). This was used in conjunction with our 41 PCR-SSP primer mixture low-resolution HLA-B typing set to fully differentiate B*27 from all other HLA-B alleles. Successful typing set validation used 521 B*27 samples covering 13 (B*2701-B*2710 and B*2712, B*2717, B*2723) alleles. The distribution of B*27 alleles was determined in a random population of 4020 local blood donors and the use of PCR-SSP B*27 typing in our routine flow cytometry-based HLA-B27/B2708 typing strategy is described.

Managing chronic headaches in the clinic.

Chronic daily headache (CDH), which is often linked to a history of migraine, tension-type headache and the abuse of headache medications, and cluster headache are the best known of the chronic headaches. These headaches may not be well recognised or well treated in primary care. This article outlines the development of management algorithms for these headache subtypes, designed for use by the primary care physician with an interest in headache. Principles of care for chronic headaches include implementation of screening procedures, differential diagnosis, tailoring of management to the individual's needs, proactive follow-up and a team approach to care. These principles can be customised to the headache subtype by the selection of appropriate therapies. The optimal treatments for CDH include physical therapy to the neck if there is any stiffness there, withdrawal of abused medications and treatment of any subsequent withdrawal symptoms and headache prophylaxis, together with the provision of acute medications as rescue therapy. Optimal treatments for cluster headache include short- and long-term prophylaxis to prevent the headaches developing and acute medications for use as rescue. If treatment is ineffective, alternative medications can be provided at follow-up, with the possibility of referral for refractory patients.

An evaluation of Com-B27, a fluorescein-conjugated mouse anti-HLA-B27 reagent.

We evaluated the HLA-B27 typing reagent Com-B27, which is claimed to show minimal cross-reactivity with HLA-B7, for use in flow cytometry-based typing. This combination reagent consists of the fluorescein-conjugated HLA-B27 mouse monoclonal antibody ABC-m3 and a non-conjugated HLA-B7 monoclonal antibody that is claimed to block the reactivity of ABC-m3 to B7 without affecting its reactivity to B27. It reacted well with B27 (B*2702, B*2705) and B2708 [mean median channel fluorescence intensity (MCFI) 8.40] and weakly with B7 (including cells from homozygous B*07 donors), B42/B73 and B22/B37/B44 reference cells (mean MCFI 2.05, 3.09 and 1.10, respectively). It showed a uniform discrimination between B7 and B27/B2708 with no 'overlap' in MCFI values, which was seen with the standard ABC-m3 antibody. There was complete agreement when our standard three-antibody-based B27/B2708 flow cytometry assay and the Com-B27 reagent alone were used to independently assign B27/B2708 status to 651 random patients. Thus, the Com-B27 reagent provided improved discrimination between B7 and B27/B2708 over the ABC-m3 antibody, and its B27/B2708 assignments were comparable with our standard flow cytometry assay. However, for consistently reliable B27/B2708 typing we continue to recommend the use of a minimum of two B27 reagents in a protocol that includes DNA-based testing of 'equivocal' B27/B2708 assignments.

Acetylcholinesterase promotes beta-amyloid plaques in cerebral cortex.

Studies in vitro have suggested that acetylcholinesterase (AChE) may interact with beta-amyloid to promote deposition of amyloid plaques in the brain of patients with Alzheimer's disease. To test that hypothesis in vivo, we crossed Tg2576 mice, which express human amyloid precursor protein and develop plaques at 9 months, with transgenic mice expressing human AChE. The resulting F1 hybrids (FVB/N x [C57B6 x SJL/J]) expressed both transgenes in brain. By 6 months of age, their cerebral cortex showed authentic plaques that stained both by thioflavin S and by beta-amyloid 1-40 and 1-42 immunohistochemistry. The plaques also stained positively for other components including Cd11b, GFAP, and AChE. Plaque onset in the hybrids occurred 30-50% sooner than in the parental lines. Plaque numbers increased with age and plaques remained more numerous in the doubly transgenic animals at 9 and 12 months. Quantitative immunoassay via ELISA also showed an increase of total amyloid content in brain at 9-12 months. These histological and biochemical results support the conclusion that AChE may play a role in pathogenesis of Alzheimer's disease

Mitochondrial oxidative phosphorylation is required for ammonium assimilation in light in a marine diatom.

Ammonium assimilation in plants occurs via the glutamine synthetase (GS, EC 6.3.1.2)/glutamine 2-oxoglutarate aminotransferase (GOGAT, EC 1.4.1.13 + 1.4.1.14 + 1.4.7.1) pathway. Rates of in vivo ammonium assimilation were measured in the marine diatom Phaeodactylum tricornutum by a recently developed technique that uses the protonophore carbonyl cyanide m-chlorophenylhydrazone to release unassimilated ammonium from the cells. In nitrogen-replete cells of P. tricornutum, there was a poor relationship between uptake and in vivo assimilation of ammonium, with the rate of uptake decreasing and the rate of assimilation increasing with time in the presence of ammonium. Ammonium uptake and assimilation were markedly light dependent, with assimilation inhibited by 77% in darkness. Oligomycin (5 micro g ml-1), an inhibitor of the mitochondrial ATPase, had no effect on the rate of photosynthesis, the maximum endogenous ammonium pool or GS activity in Phaeodactylum, but inhibited respiration by 24-27%. In the light, oligomycin inhibited ammonium assimilation by 55-70% and growth rate by 52%. One possible explanation for these results, namely that mitochondrial ATP is required to sustain activity of the cytosolic isoform of GS, is discussed.

New guidelines for the management of migraine in primary care.

Despite repeated initiatives over the past decade, migraine remains under-recognised, under-diagnosed and under-treated in everyday clinical practice. The Migraine in Primary Care Advisors (MIPCA) group has produced new guidelines for migraine management to attempt to rectify this situation. MIPCA is a group of physicians, nurses, pharmacists and other healthcare professionals dedicated to the improvement of headache management in primary care, who have also worked closely with the Migraine Action Association (the UK patients' group) in the development of these guidelines. The principles of the new MIPCA guidelines are: To arrange specific consultations for headache. To institute a system of detailed history taking, patient education and buy-in at the outset of the consultation. To utilise a new screening algorithm for the differential diagnosis of headache, which can be confirmed by further questioning, if necessary. To institute a process of management that is individualised for each patient, using a new algorithm. Assessing the impact on the patient's daily life is a key aspect of diagnosis and management. To prescribe only treatments that have objective evidence of favourable efficacy and tolerability. To utilise prospective follow-up procedures to monitor the success of treatment. To organise a team approach to headache management in primary care.

Usage of triptans among migraine patients: an audit in nine GP practices.

A retrospective audit was carried out to investigate triptan usage over a period of one year among 360 adult patients with migraine in nine GP practices in the UK and the Republic of Ireland. Data from patient records were analysed, in conjunction with replies to a questionnaire about patients' perceptions of their migraine and its treatment. The majority of patients included in the audit were women (83%), and most patients (81%) were aged between 35 and 64 years. Most patients in the audit population (60%) were in the lowest band of triptan usage (1-36 tablets prescribed over 12 months); 7% had moderate usage (37-53 tablets). A minority of patients appeared to be taking triptans in higher quantities: about 15% of patients had been prescribed 54-94 triptan tablets over a year, 9% had received prescriptions for 95-149 tablets and 7% had received prescriptions for 150 or more tablets. These results indicated that some migraine patients were using triptans at higher than expected rates, and suggested that some patients might have been using their prescribed triptans inappropriately to treat a headache that they incorrectly perceived as migraine (e.g. chronic daily headache). Analyses were carried out to identify predictors of high usage. Predictors identified included the use of several other (non-triptan) medications to treat conditions other than migraine, one triptan dose being reported as sufficient to treat an attack, patient's perception of all headaches as migraine and lack of concern about taking too much medication. Patients identified as using triptans at a higher than expected rate can be called in for review of migraine diagnosis, identification of possible causes of any increased frequency of attacks, and investigation of suspected non-migrainous headaches, such as chronic daily headache and medication-induced headaches. For GPs, such actions would help achieve and maintain a high standard of care for their migraine patients, thus helping to contribute towards meeting the demands of the clinical governance agenda. Audit of triptan usage may also offer financial benefits for the practice, since helping patients to avoid the inappropriate use of triptans could lead to reductions in the overall costs of triptan prescribing within the practice. The high usage predictors could be developed into a checklist of potential indicators for GPs to identify patients who may become high users if prescribed triptans and who might require closer monitoring. We recommend that patients identified as having a potential for high usage should be routinely reviewed, every 3-6 months, to ensure that they are using triptans appropriately to treat migraine. Although triptans are generally safe and well tolerated, unnecessary use of any medication should be avoided.