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.

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.

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.

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.

Characterization of plutonium in maxey flats radioactive trench leachates.

Plutonium in trench leachates at the Maxey Flats radioactive waste disposal site exists as dissolved species, primarily complexes of the tetravalent ion with strong organic ligands such as ethylenediaminetetraacetic acid. The complexes are not sorbed well by sediment and are only partly precipitated by ferric hydroxide. These results indicate the importance of isolating radioactive waste from organic matter.

Plutonium speciation in water from mono lake, california.

The solubility of plutonium in Mono Lake water is enhanced by the presence of large concentrations of indigenous carbonate ions and moderate concentrations of fluoride ions. In spite of the complex chemical composition of this water, only a few ions govern the behavior of plutonium, as demonstrated by the fact that it was possible to duplicate plutonium speciation in a synthetic water containing only the principal components of Mono Lake water.

Neptunium and americium speciation in selected basalt, granite, shale, and tuff ground waters.

Neptunium and americium are relatively insoluble in ground waters containing high sulfate concentrations, particularly at 90 degrees C. The insoluble neptunium species is Np(IV); hence reducing waters should enhance its formation. Americium can exist only in the trivalent state under these conditions, and its solubility also should be representative of that of curium.

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.

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.

Plant physiology. Virtue on both sides.

Experiments with transgenic plants are beginning to unravel how the products of photosynthesis get into the phloem from transport throughout the living tissues of the plant.

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.

Phosphoenolpyruvate carboxykinase and gluconeogenesis in cotyledons of Cucurbita pepo.

1. The aim of this work was to investigate the role of phosphoenolpyruvate carboxykinase (ATP:oxaloacetate carboxy-lyase (transphosphorylating) EC 4.1.1.49) in the conversion of fat to sugar by the cotyledons of seedlings of Cucurbita pepo. 2. The enzyme was partially purified from the cotyledons of 5-day-old seedlings. The Michaelis constants for oxaloacetate and ATP were 56 and 119 micron, respectively. The decarboxylation reaction was optimum at pH 7.4. A range of intermediary metabolites did not affect the activity of the enzyme, but 3-mercaptopicolinic acid at micron concentrations was an effective inhibitor. 3. Centrifugation of extracts of 5-day-old cotyledons sedimented appreciable proportions of the ribuloseibisphosphate carboxylase, isocitrate lyase and fumarate hydratase present but very little of the phosphoenolpyruvate carboxykinase. 4. Measurements of phosphoenolpyruvate carboxykinase of cotyledons during germination showed that the maximum catalytic activity exceeded, and changed coincidently with, the rate of gluconeogenesis. 5. 3-Mercaptopicolinic acid inhibited gluconeogenesis from [1-14C]- and [2-14C]acetate supplied to excised cotyledons. The detailed distribution of 14C indicated inhibition of the conversion of oxaloacetate to phosphoenolpyruvate. 6. It is concluded that in marrow cotyledons phosphoenolpyruvate carboxykinase is in the soluble phase of the cytoplasm and catalyses a component reaction of gluconeogenesis.

Identification of the regulatory steps in gluconeogenesis in cotyledons of Cucurbita pepo.

1. The aim of this work was to discover the steps at which the conversion of oxaloacetate to glucose 6-phosphate during gluconeogenesis is regulated in the cotyledons of 5-day-old seedlings of Cucurbita pepo. 2. We estimated the maximum catalytic activities of all the enzymes in the above sequence and also the amounts of their substrates present in vivo. The results show that the reactions catalysed by fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase are the only ones in the sequence that are substantially displaced from equilibrium in vivo. 3. We also determined the effects of 3-mercaptopicolinic acid, an inhibitor of gluconeogenesis, on the amounts of the gluconeogenic intermediates present in vivo. The results show that the enzyme system, fructose-1,6-bisphosphatase: phosphofructokinase, and the system phosphoenolpyruvate carboxykinase: phosphoenolpyruvate carboxylase make major contributions to the regulation of gluconeogenesis in the cotyledons. 4. Possible mechanisms for the above regulation are discussed.

Carbohydrate breakdown by chloroplasts of Pisum sativum.

1. The aims of this work were to discover the pathways of starch breakdown and carbohydrate metabolism in intact isolated chloroplasts from shoots of Pisum sativum. 2. 14C from starch, labelled by supplying [14C]glucose to chloroplasts, appeared, during starch breakdown, in CO2, maltose and the fraction of the acidic compounds that contained 3-phosphoglycerate and sugar phosphates. 3. When intact chloroplasts were incubated in the dark, 3-phosphoglycerate, triose phosphates and, to a lesser extent, hexose 6-phosphates accumulated in the medium at rates comparable to those of starch breakdown in leaves. This accumulation was dependent upon orthophosphate. 4. The patterns of 14CO2 production from specifically labelled [14C]glucose supplied to isolated chloroplasts were those expected of the oxidative pentose phosphate pathway with extensive recycling, and glycolysis. The respone of this pattern to lack of orthophosphate, addition of unlabelled intermediates, and 2-phosphoglycollate confirmed this view. 5. Starch breakdown in pea chloroplasts is held to be dominantly phosphorolytic with the products being metabolized via the oxidative pentose phosphate pathway and glycolysis to 3-phosphoglycerate, triose phosphates and CO2 that are exported to the cytoplasm.

Pathway of starch breakdown in photosynthetic tissues of Pisum sativum.

1. The aim of this work was to discover the pathway of starch breakdown in the photosynthetic tissues of Pisum sativum. 2. Measurements of the starch in the leaves of plants grown in photoperiods of 12 or 18 h showed that starch, synthesized in the light, was rapidly metabolized in the dark at rates of 0.04--0.06 mumol glucose/min per g fresh weight. 3. The maximum catalytic activities of alpha-amylase, beta-amylase, hexokinase, alpha-glucan phosphorylase and phosphoglucomutase in extracts of leaves showed no diurnal variation in either photoperiod, and exceeded estimates of the rate of net starch breakdown in the dark. 4. Studies with intact chloroplasts, isolated from young shoots and from leaves, indicated that pea chloroplasts do not contain significant activities of alpha-amylase, beta-amylase and hexokinase, although some of the latter may be attached to the outside of the chloroplast envelope. These studies also showed that pea chloroplasts contained sufficient alpha-glucan phosphorylase and phosphoglucomutase to mediate the observed rates of starch breakdown. 5. It is proposed that starch breakdown in pea chloroplasts is phosphorolytic.

Pathways of carbohydrate oxidation during thermogenesis by the spadix of Arum maculatum.

1. The aims of this work were to discover the pathways of carbohydrate oxidation prior to and during thermogenesis by the club of the spadix of Arum maculatum, and whether there was coarse control of these pathways. 2. 14C02 production from [1-14C]-, [3,4-14C]-, and [6-14C]glucose, the detailed distribution of 14C from [1-14C]- and [6-14C]glucose, and the maximum catalytic activities of phosphofructokinase, fructose-1,6-diphosphate aldolase, glucose-6-phosphate dehydrogenase, and phosphogluconate dehydrogenase were determined at different stages in the development of the spadix. The results indicate that in the early stages carbohydrate is oxidized via both the pentose phosphate pathway and glycolysis, and that a shift to glycolysis occurs during development so that just before and during thermogenesis glycolysis predominates almost exclusively. 3. During development the activities of phosphofructokinase and glucose-6-phosphate dehydrogenase per club increased 100- ans during spadix development, and indicated that the onset of rapid glycolysis at thermogenesis is regulated by fine control or availability of substrate.