The fluctuation-dissipation measurement instrument at the Linac Coherent Light Source

The development of new modes at x-ray free electron lasers has inspired novel methods for studying fluctuations at different energies and timescales. For closely spaced x-ray pulses that can be varied on ultrafast time scales, we have constructed a pair of advanced instruments to conduct studies targeting quantum materials. We first describe a prototype instrument built to test the proof-of-principle of resonant magnetic scattering using ultrafast pulse pairs. This is followed by a description of a new endstation, the so-called fluctuation-dissipation measurement instrument, which was used to carry out studies with a fast area detector. In addition, we describe various types of diagnostics for single-shot contrast measurements, which can be used to normalize data on a pulse-by-pulse basis and calibrate pulse amplitude ratios, both of which are important for the study of fluctuations in materials. Furthermore, we present some new results using the instrument that demonstrates access to higher momentum resolution.

Association of hyperglycaemia with hospital mortality in nondiabetic COVID-19 patients: A cohort study

Objective

Diabetes is a known risk factor for mortality in Coronavirus disease 2019 (COVID-19) patients. Our objective was to identify prevalence of hyperglycaemia in COVID-19 patients with and without prior diabetes and quantify its association with COVID-19 disease course.

Research design and methods

This observational cohort study included all consecutive COVID-19 patients admitted to John H Stroger Jr. Hospital, Chicago, IL from March 15, 2020 to May 3, 2020 and followed till May 15, 2020. The primary outcome was hospital mortality, and the studied predictor was hyperglycaemia [any blood glucose ≥7.78 mmol/L (140 mg/dL) during hospitalization].

Results

Of the 403 COVID-19 patients studied, 51 (12.7%) died; 335 (83.1%) were discharged while 17 (4%) were still in hospital. Hyperglycaemia occurred in 228 (56.6%) patients; 83 of these hyperglycaemic patients (36.4%) had no prior history of diabetes. Compared to the reference group no-diabetes/no-hyperglycaemia patients the no-diabetes/hyperglycaemia patients showed higher mortality [1.8% versus 20.5%, adjusted odds ratio 21.94 (95% confidence interval 4.04–119.0), P < 0.001]; improved prediction of death (P = 0.01) and faster progression to death (P < 0.01). Hyperglycaemia within the first 24 and 48 h was also significantly associated with mortality (odds ratio 2.15 and 3.31, respectively).

Conclusions

Hyperglycaemia without prior diabetes was common (20.6% of hospitalized COVID-19 patients) and was associated with an increased risk of and faster progression to death. Development of hyperglycaemia in COVID-19 patients who do not have diabetes is an early indicator of progressive disease.

Expression of CYP24A1 and other multiple sclerosis risk genes in peripheral blood indicates response to vitamin D in homeostatic and inflammatory conditions

Although genetic and epidemiological evidence indicates vitamin D insufficiency contributes to multiple sclerosis (MS), and serum levels of vitamin D increase on treatment with cholecalciferol, recent metanalyses indicate that this vitamin D form does not ameliorate disease. Genetic variation in genes regulating vitamin D, and regulated by vitamin D, affect MS risk. We evaluated if the expression of vitamin D responsive MS risk genes could be used to assess vitamin D response in immune cells. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy controls and people with MS treated with dimethyl fumarate. We assayed changes in expression of vitamin D responsive MS risk (VDRMS) genes in response to treatment with 25 hydroxy vitamin D in the presence or absence of inflammatory stimuli. Expression of CYP24A1 and other VDRMS genes was significantly altered in PBMCs treated with vitamin D in the homeostatic and inflammatory models. Gene expression in MS samples had similar responses to controls, but lower initial expression of the risk genes. Vitamin D treatment abrogated these differences. Expression of CYP24A1 and other MS risk genes in blood immune cells indicate vitamin D response and could enable assessment of immunological response to vitamin D in clinical trials and on therapy.

Heat-mediated reduction of apoptosis in UVB-damaged keratinocytes in vitro and in human skin ex vivo

Background

UV radiation induces significant DNA damage in keratinocytes and is a known risk factor for skin carcinogenesis. However, it has been reported previously that repeated and simultaneous exposure to UV and heat stress increases the rate of cutaneous tumour formation in mice. Since constant exposure to high temperatures and UV are often experienced in the environment, the effects of exposure to UV and heat needs to be clearly addressed in human epidermal cells.

Methods

In this study, we determined the effects of repeated UVB exposure 1 kJ/m² followed by heat (39 °C) to human keratinocytes. Normal human ex vivo skin models and primary keratinocytes (NHEK) were exposed once a day to UVB and/or heat stress for four consecutive days. Cells were then assessed for changes in proliferation, apoptosis and gene expression at 2 days post-exposure, to determine the cumulative and persistent effects of UV and/or heat in skin keratinocytes.

Results

Using ex vivo skin models and primary keratinocytes in vitro, we showed that UVB plus heat treated keratinocytes exhibit persistent DNA damage, as observed with UVB alone. However, we found that apoptosis was significantly reduced in UVB plus heat treated samples. Immunohistochemical and whole genome transcription analysis showed that multiple UVB plus heat exposures induced inactivation of the p53-mediated stress response. Furthermore, we demonstrated that repeated exposure to UV plus heat induced SIRT1 expression and a decrease in acetylated p53 in keratinocytes, which is consistent with the significant downregulation of p53-regulated pro-apoptotic and DNA damage repair genes in these cells.

Conclusion

Our results suggest that UVB-induced p53-mediated cell cycle arrest and apoptosis are reduced in the presence of heat stress, leading to increased survival of DNA damaged cells. Thus, exposure to UVB and heat stress may act synergistically to allow survival of damaged cells, which could have implications for initiation skin carcinogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12895-016-0043-4) contains supplementary material, which is available to authorized users.

Calcium antagonists: Do they equally protect against kidney injury?

Calcium antagonists are a heterogeneous group of drugs that affect not only different channels but different parts of the same channel. These differences translate into different renal hemodynamic effects. This Commentary discusses the implications of these differences for surrogate markers of outcome.

The transmissible spongiform encephalopathies: emerging and declining epidemics

TSEs (transmissible spongiform encephalopathies) are neurodegenerative diseases of various mammalian species, the best known of which include BSE (bovine spongiform encephalopathies) in cattle, CJD (Creutzfeldt-Jakob disease) in humans, scrapie in sheep and CWD (chronic wasting disease) in deer. This review examines the emergence of various TSE strains and their transmission, and discusses disease surveillance and control.

Beta blockers in the management of chronic kidney disease

The sympathetic nervous system modulates renal function through its receptors namely beta1 (cardiac output and renin release), alpha1 (systemic and renovascular constriction), and beta2 renovascular dilation. Sympathetic overactivity is commonly seen in chronic kidney disease (CKD) and is an important contributor to increasing the risk of cardiovascular events as well as increasing renal disease progression. Recent evaluations of drug use in people with CKD shows a remarkably low percentage of patients receiving beta-blockers, especially in more advanced stage CKD when cardiovascular risk is higher. This is in large part due to tolerability of these agents. Moreover, water-soluble beta-blockers such as atenolol and metoprolol are dialyzable and require supplementation to avoid exacerbation of arrhythmias following dialysis. Newer vasodilating beta-blockers have better tolerability and different effects on renal hemodynamics as well as metabolic variables. These effects are related to the relative alpha1-blocking effect of agents such as carvedilol and labetolol, with carvedilol having relatively greater alpha-blocking effects. Few studies evaluate beta-blockers on cardiovascular risk in CKD patients. Studies with carvedilol demonstrate attenuated increases in albuminuria as well as reduction in cardiovascular events in CKD patients with hypertension. This paper reviews the animal and clinical trial data that evaluate beta-blockers in CKD highlighting the vasodilating beta-blockers. It is apparent that greater use of this drug class for blood pressure control would further enhance reduction of risk of heart failure, the most common cause of death in the first year of starting dialysis.

S100A12 provokes mast cell activation: a potential amplification pathway in asthma and innate immunity

BACKGROUND

The calcium-binding protein S100A12 might provoke inflammation and monocyte recruitment through the receptor for advanced glycation end products.

OBJECTIVE

Because inflammation elicited by S100A12 in vivo had characteristics of mast cell (MC) activation, we aimed to define the mechanism.

METHODS

Various MC populations were used to test S100A12 activation assessed on the basis of morphology, histamine release, leukotriene production, and cytokine induction. MC dependence of S100A12-provoked inflammation was tested in mice and on the rat microcirculation by means of intravital microscopy. Immunohistochemistry localized S100A12 in the asthmatic lung, and levels in sputum from asthmatic patients were quantitated by means of ELISA. Expression of the receptor for advanced glycation end products was evaluated by means of RT-PCR and Western blotting.

RESULTS

S100A12 provoked degranulation of mucosal and tissue MCs in vitro and in vivo and amplified IgE-mediated responses. It induced a cytokine profile indicating a role in innate/T(H)1-mediated responses. S100A12-induced edema and leukocyte rolling, adhesion, and transmigration in the microcirculation were MC dependent. Eosinophils in airway tissue from asthmatic patients were S100A12 positive, and levels were increased in sputum. S100A12 responses were partially blocked by an antagonist to the receptor for advanced glycation end products, but MCs did not express mRNA or protein, suggesting an alternate receptor.

CONCLUSION

This novel pathway highlights the potential importance of S100A12 in allergic responses and in infectious and chronic inflammatory diseases.

CLINICAL IMPLICATIONS

MC activation by S100A12 might exacerbate allergic inflammation and asthma. S100A12 might provide a novel marker for eosinophilic asthma.

Predicting susceptibility and incubation time of human-to-human transmission of vCJD

BACKGROUND

Identification of possible transmission of variant Creutzfeldt-Jakob disease (vCJD) via blood transfusion has caused concern over spread of the disease within the human population. We aimed to model iatrogenic spread to enable a comparison of transmission efficiencies of vCJD and bovine spongiform encephalopathy (BSE) and an assessment of the effect of the codon-129 polymorphism on human susceptibility.

METHODS

Mice were produced to express human or bovine prion protein (PrP) by direct replacement of the mouse PrP gene. Since the human PrP gene has variation at codon 129, with MM, VV, and MV genotypes, three inbred lines with an identical genetic background were produced to express human PrP with the codon-129 MM, MV, and VV genotypes. Mice were inoculated with BSE or vCJD and assessed for clinical and pathological signs of disease.

FINDINGS

BSE was transmitted to the bovine line but did not transmit to the human lines. By contrast, vCJD was transmitted to all three human lines with different pathological characteristics for each genotype and a gradation of transmission efficiency from MM to MV to VV.

INTERPRETATION

Transmission of BSE to human beings is probably restricted by the presence of a significant species barrier. However, there seems to be a substantially reduced barrier for human-to-human transmission of vCJD. Moreover, all individuals, irrespective of codon-129 genotype, could be susceptible to secondary transmission of vCJD through routes such as blood transfusion. A lengthy preclinical disease is predicted by these models, which may represent a risk for further disease transmission and thus a significant public-health issue.

Modulation of respiratory syncytial virus-induced prostaglandin E2 production by n-3 long-chain polyunsaturated fatty acids in human respiratory epithelium

Infection with respiratory syncytial virus (RSV) results in substantial infant morbidity and has been associated with the subsequent development of childhood asthma. Inflammatory mediators produced by both the epithelium and tissue leukocytes during RSV infection stimulate the release of chemotactic factors by the respiratory epithelium and the subsequent influx of inflammatory cells, predominantly neutrophils. We investigated the production of inflammatory mediators [prostaglandin E2 (PGE2), interleukin (IL)-1beta, tumor necrosis factor alpha] and chemokines [IL-8, RANTES (regulation on activation, normal T cell expressed and secreted)] by alveolar epithelial cells in response to RSV infection. Infection of a human alveolar epithelial transformed cell line (A549 cells) with live RSV substantially increased production of PGE2, IL-8, and RANTES. By altering cell membrane FA through incorporation of the long-chain PUFA (LCPUFA) arachidonic acid, EPA, and DHA, we were subsequently able to significantly modulate PGE2 production by the infected epithelium. Because of the dynamic nature of the effects of PGE2 on lung function, regulation of this prostaglandin during RSV infection by n-3 LCPUFA has the potential to significantly alter the disease process.

Evaluation of Components of Fusarium Head Blight Resistance in Soft Red Winter Wheat Germ Plasm Using a Detached Leaf Assay

A large environmental influence on phenotypic estimates of disease resistance and the complex polygenic nature of Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) are impediments to developing resistant cultivars. The objective of this research was to investigate the utility of a detached leaf assay, inoculated using inoculum from isolates of Microdochium nivale var. majus, to identify components of FHB resistance among 30 entries of U.S. soft red winter wheat in the 2002 Uniform Southern FHB Nursery (USFHBN). Whole plant FHB resistance of the USFHBN entries was evaluated in replicated, mist-irrigated field trials at 10 locations in eight states during the 2001-2002 season. Incubation period (days from inoculation to the first appearance of a dull gray-green water-soaked lesion) was the only detached leaf variable significantly correlated across all FHB resistance parameters accounting for 45% of the variation in FHB incidence, 27% of FHB severity, 30% of Fusarium damaged kernels, and 26% of the variation in grain deoxynivalenol (DON) concentration. The results for incubation period contrasted with previous studies of moderately resistant European cultivars, in that longer incubation period was correlated with greater FHB susceptibility, but agreed with previous findings for the Chinese cultivar Sumai 3 and CIMMYT germ plasm containing diverse sources of FHB resistance. The results support the view that the detached leaf assay method has potential for use to distinguish between specific sources of FHB resistance when combined with data on FHB reaction and pedigree information. For example, entry 28, a di-haploid line from the cross between the moderately resistant U.S. cultivar Roane and the resistant Chinese line W14, exhibited detached leaf parameters that suggested a combination of both sources of FHB resistance. The USFHBN represents the combination of adapted and exotic germ plasm, but four moderately resistant U.S. commercial cultivars (Roane, McCormick, NC-Neuse, and Pat) had long incubation and latent periods and short lesion lengths in the detached leaf assay as observed in moderately FHB resistant European cultivars. The dichotomy in the relationship between incubation period and FHB resistance indicates that this may need to be considered to effectively combine exotic and existing/adapted sources of FHB resistance.

The natural (baseline) quality of groundwater: a UK pilot study

Knowledge of the natural baseline quality of groundwaters is an essential prerequisite for understanding pollution and for imposing regulatory limits. The natural baseline of groundwaters may show a range of concentrations depending on aquifer mineralogy, facies changes, flow paths and residence time. The geochemical controls on natural concentrations are discussed and an approach to defining baseline concentrations using geochemical and statistical tools is proposed. The approach is illustrated using a flowline from the Chalk aquifer in Berkshire, UK where aerobic and anaerobic sections of the aquifer are separately considered. The baseline concentrations for some elements are close to atmospheric values whereas others evolve through time-dependent water-rock interaction. Certain solutes (K, NH(4)(+)), often considered contaminants, reach naturally high concentrations due to geochemical controls; transition metal concentrations are generally low, although their concentrations may be modified by redox controls. It is recommended that the baseline approach be incorporated into future management strategies, notably monitoring.

Association of salivary Streptococcus mutans with caries in young children: effect of dental health education on salivary levels

AIM

This study aimed to determine the effect of a long-term dental health education (DHE) for mothers with young children on the level of salivary Streptococci mutans (SM) and their association with caries in young children.

METHODS

A randomly selected cohort of 228 children born between 1 January and 30 September 1995, in a low socioeconomic high caries suburb of Leeds (UK), was divided into the following groups: A) DHE focused on diet; B) DHE focused on oral hygiene instruction (OHI) using fluoride toothpaste; C) DHE by a combined diet and OHI message. DHE was given using an interview and counselling for at least 15 minutes in each child's home, every three months for the first two years and twice a year in the third year of the study. A fourth group D was given diet and OHI, at home, but once a year only. The children in a fifth group E (control), received no DHE and were never visited, but examined at three years of age only. All children and mothers were examined for caries using the BASCD criteria. The levels of salivary SM were determined by sampling of bacteria from the oral cavity with a 1.8 cm wide wooden spatula, after giving the mother a paraffin pellet to chew for a minute and in children using unstimulated saliva. Bacteria were plated out and counted using image analysis for counting colonies.

RESULTS

At three years of age the difference in the level of salivary SM between groups was not statistically significant. However, in group E there was a statistically significant relationship (p<0.05) between salivary SM and caries in children.

CONCLUSION

The difference in the level of salivary SM between groups given various programs of dental health education was not statistically significant. There was a statistically significant (p<0.05) relationship between salivary MS and caries in children.

Urinary retention in patients in a geriatric rehabilitation unit: prevalence, risk factors, and validity of bladder scan evaluation

The purpose of this study was to identify risk factors for urinary retention (UR) in frail, elderly patients, to determine its prevalence, and to assess the validity of the use of the BladderScan BVI 2500+ ultrasound scanner to measure postvoid residual urine volumes of > or = 150 ml. Probable UR was defined as two consecutive ultrasound scans with postvoid residual urine estimations of > or = 150 ml. The estimates were confirmed by in- and out-catheterization of actual postvoid residual urine (PVR). Risk factors for UR were the independent variables used in the regression analysis. Nineteen of the 167 people (11%) had UR. The risk of UR was greatest among patients who were older, or who were on anticholinergic medication, or who had diabetes of long standing, or who had fecal impaction. The correlation between paired scans and catheter volumes of > or = 150 ml was 0.87. The results suggest that the BladderScan BVI 2500+ ultrasound scanner, when used by trained nursing staff, provides conservative and valid estimates of PVR of > or = 150 ml in people undergoing geriatric rehabilitation.

Incorporation of alpha-linolenic acid and linoleic acid into human respiratory epithelial cell lines

Animal and human studies designed to examine the effects of alpha-linolenic acid (ALA) and linoleic acid (LA) supplementation on the fatty acid composition of plasma and tissues have demonstrated a marked difference in incorporation into phospholipids of these 18-carbon precursors of the long-chain polyunsaturates. Whereas tissue phospholipid levels are linearly related to dietary ALA and LA, the levels of tissue LA can be 10-fold higher than tissue ALA even when dietary levels are equivalent. There is some dispute whether this disparity is due to ALA being more rapidly metabolized to its products or substantially oxidized by the liver, or whether LA but not ALA is readily incorporated into cellular phospholipids. We examined the level of incorporation of polyunsaturated fatty acids into human respiratory epithelial cell lines (A549, 16HBE) by determining the dose-dependent incorporation of ALA and LA as free fatty acid (5-150 microg FFA/mL). Cell membrane phospholipid ALA and LA were both increased up to approximately 20-30% total fatty acids, with a concomitant decrease predominantly in monounsaturated membrane fatty acids, before significant toxicity was observed (50 microg/mL). Our data support the concept that rather than any inherent inability by human cells to incorporate ALA into membrane phospholipids, the lack of ALA content in human and animal tissues in vivo is due to the rapid metabolism or oxidation of this fatty acid in the liver.

Visualization of secreted Hrp and Avr proteins along the Hrp pilus during type III secretion in Erwinia amylovora and Pseudomonas syringae

Pili are required for protein and/or DNA transfer from bacteria to recipient plant or bacterial cells, based on genetic evidence. However, it has never been shown directly that the effector proteins or DNA are localized along or inside the pili in situ. Failure to visualize an association of effector proteins/DNA with pili is the central issue in the debate regarding the exact function of pili in protein and DNA transfer. In this study, a newly developed in situ immunogold labelling procedure enabled visualization of the specific localization of type III effector proteins of Erwinia amylovora and Pseudomonas syringae pv. tomato along the Hrp pilus, but not along the flagellum or randomly in the intercellular space. In contrast, PelE, a pectate lyase secreted via the type II protein secretion system, was not associated with the Hrp pilus. These results provide direct evidence that type III secretion occurs only at the site of Hrp pilus assembly and that the Hrp pilus guides the transfer of effector proteins outside the bacterial cell, favouring the 'conduit/guiding filament' model.

Frequency of celiac disease in individuals with Down syndrome in the United States

Ninety-three individuals with Down syndrome (DS) were screened to investigate the prevalence of celiac disease (CD) in the United States. Five of the 93 individuals were antiendomysial antibody (EMA) positive. Of the 5 who tested positive for EMA, 4 were biopsied, 1 refused biopsy. Three of the 4 individuals biopsied manifested changes of CD on small bowel biopsy. This gives a frequency of 3.2% of confirmed CD in our DS individuals and suggests the need for periodic screening for celiac disease in this population.

Acute fatty liver of pregnancy associated with short-chain acyl-coenzyme A dehydrogenase deficiency

There is a correlation between pregnancy complications such as acute fatty liver of pregnancy and long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) deficiency. We diagnosed another fatty acid beta-oxidation defect, short-chain acyl-coenzyme A dehydrogenase deficiency, in an infant when evaluating him because his mother had acute fatty liver of pregnancy. Other beta-oxidation defects, in addition to LCHAD deficiency, should be considered in children born after pregnancies complicated by liver disease.

Immunogold labeling of Hrp pili of Pseudomonas syringae pv. tomato assembled in minimal medium and in planta

Hypersensitive reaction and pathogenicity (hrp) genes are required for Pseudomonas syringae pv. tomato (Pst) DC3000 to cause disease in susceptible tomato and Arabidopsis thaliana plants and to elicit the hypersensitive response in resistant plants. The hrp genes encode a type III protein secretion system known as the Hrp system, which in Pst DC3000 secretes HrpA, HrpZ, HrpW, and AvrPto and assembles a surface appendage, named the Hrp pilus, in hrp-gene-inducing minimal medium. HrpA has been suggested to be the Hrp pilus structural protein on the basis of copurification and mutational analyses. In this study, we show that an antibody against HrpA efficiently labeled Hrp pili, whereas antibodies against HrpW and HrpZ did not. Immunogold labeling of bacteria-infected Arabidopsis thaliana leaf tissue with an Hrp pilus antibody revealed a characteristic lineup of gold particles around bacteria and/or at the bacterium-plant contact site. These results confirm that HrpA is the major structural protein of the Hrp pilus and provide evidence that Hrp pili are assembled in vitro and in planta.

Acylcarnitines in plasma and blood spots of patients with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase defiency

The acylcarnitines in plasma and blood spots of 23 patients with proven deficiency of long-chain 3-hydroxyacylcoenzyme A dehydrogenase were reviewed. Long-chain 3-hydroxyacylcarnitines of C14:1, C14, C16 and C18:1 chain length, and long-chain acylcarnitines of C12, C14:1, C14, C16, C18:2 and C18:1 chain length were elevated. Acetylcarnitine was decreased. In plasma, elevation of hydroxy-C18:1 acylcarnitine over the 95th centile of controls, in combination with an elevation of two of the three acylcarnitines C14, C14:1 and hydroxy-C16, identified over 85% of patients with high specificity (less than 0.1% false positive rate). High endogenous levels of long-chain acylcarnitines in normal erythrocytes reduced the diagnostic specificity in blood spots compared with plasma samples. The results were also diagnostic in asymptomatic patients, and were not influenced by genotype. Treatment with diet low in fat and high in medium-chain triglyceride decreased all disease-specific acylcarnitines, often to normal, suggesting that this assay is useful in treatment monitoring.

The utility of the Digi-walker step counter to assess daily physical activity patterns

PURPOSE

The Digi-Walker step counter is a promising and cost-effective tool to measure physical activity under free-living conditions. Two specific studies were conducted to evaluate the number of steps required to meet current physical activity guidelines.

METHODS

Thirty-one adults (17 men, 14 women) served as participants. In study 1, we determined the number of steps to complete a mile under two different conditions and three paces. In study 2, we conducted a field trial to examine the relationship between daily step counts and other indices of physical activity. Participants in this study wore a Digi-Walker for 2 consecutive weeks and completed the 7-d physical activity recall (PAR) after each week.

RESULTS

In study 1, there were no differences in step counts by site, but steps were inversely related to pace, with values ranging from 1330 to 1996. Individual step counts at a specific pace were negatively correlated with height, weight, leg length, and stride length and were positively correlated with body fatness. In study 2, participants had average daily step counts of 11,603 when structured vigorous activity was included and 8265 when only light and moderate activity were measured. Modest correlations were found between step counts and estimated energy expenditure. Similar correlations were observed when step counts were related to minutes of activity per day and minutes of sitting per day.

CONCLUSIONS

Pedometers provide a useful indicator of daily step counts but variability in activity patterns make it difficult to establish step count guidelines that correspond with other public health guidelines.

Laboratory findings associated with thrombophilia are not more common in inflammatory bowel disease

Thromboembolic disease (TED) has been recognized as a complication of inflammatory bowel disease (IBD) since the 1930s (Bargen & Barker 1936). The relative contributions of inherited or acquired thrombophilia and the inflammatory response to the mechanism of this tendency is unclear. Thrombotic events are more common in active disease although significant numbers also occur spontaneously, when the disease is in clinical remission (Talbot et al. 1986; Jackson et al. 1997). Studies looking at the prevalence of specific thrombophilic states such as Antithrombin III deficiency (Jackson et al. 1997; Lake, Stauffer & Stuart 1978; Cianco et al. 1996; Ghosh et al. 1983), Factor V Leiden mutation (APC Resistance) (Jackson et al. 1997; Probert et al. 1997; Ardizzone et al. 1998; Liebman et al. 1998), anticardiolipin antibodies (Ciancio et al. 1996), Protein C (Wyshock, Caldwell & Crowley 1988; Korsten & Reis 1992) and Protein S deficiencies (Jorens et al. 1990; Aadland et al. 1992) in IBD have been contradictory or equivocal. We had previously found that IBD patients with a history of TED are not more likely to have a laboratory thrombophilic abnormality than those with uncomplicated disease. We also demonstrated that the prevalence of heterogenous laboratory thrombophilic abnormalities (usually minor) in all IBD patients may be as high as 60%, much higher than the recognized prevalence of TED (Lim, Jones & Gould 1996). We wondered how this would compare with the healthy non-IBD population. We have therefore explored the prevalence of such thrombophilic abnormalities in a group of IBD patients who had no history of TED and compared them with healthy age and sex matched controls.

Conversion from tacrolimus to cyclosporin in stable renal transplant patients: safety, metabolic changes, and pharmacokinetic comparison

BACKGROUND

Conversion from tacrolimus to cyclosporin has not previously been reported as routine clinical practice, but only as indicated by rejection or adverse effects.

METHODS

The safety and metabolic outcome of elective conversion from tacrolimus to cyclosporin was examined in 19 recipients of cadaver renal transplants. Conversion was performed in stable patients at 3-6 months after transplantation.

RESULTS

Patient and graft survival was 100% at 3 months after conversion, with no rejection episodes. Three patients have been subsequently converted back to tacrolimus, two for rejection and one for hirsutism. There were no significant changes in creatinine, urate, or blood sugar levels after conversion, but the mean plasma magnesium rose from 0.73 (0.63-0.97) to 0.82 (0.65-1) mmol/liter (P=0.037), and the mean plasma cholesterol rose from 5.2 (3.4-6.8) to 5.5 (3.8-7.6) mmol/liter (P=0.033). Pharmacokinetic profiles were measured before and after conversion, and showed that cyclosporin (Neoral) exhibited significantly less interpatient and intrapatient variability than tacrolimus, for area under the curve (AUC), maximum concentration postdose (Cmax), minimum concentration postdose (Cmin), time to maximum concentration (Tmax).

CONCLUSION

This is the first study that has examined the outcome of conversion from tacrolimus- to cyclosporin-based immunosuppression in stable patients after renal transplantation. This conversion was performed without early immunological hazard, but there was a small rise in blood cholesterol levels after conversion. Pharmacokinetic studies showed cyclosporin in the form of Neoral showed less inter- and intrapatient variability than tacrolimus, although this is of uncertain clinical significance.

Conversion from tacrolimus to cyclosporine in stable renal transplant patients: safety, metabolic changes, and pharmacokinetic comparison

BACKGROUND

Although conversion between tacrolimus and cyclosporine has been performed when indicated for rejection or adverse effects, the safety and metabolic outcome of elective conversion from tacrolimus to cyclosporine has not previously been examined.

METHODS

Conversion from tacrolimus to cyclosporine was performed in 19 recipients of cadaver renal transplants at 3-6 months after transplantation. Pharmacokinetic profiles and biochemical studies were performed three times, in steady state, before, and after conversion.

RESULTS

Patient and graft survival was 100% at 3 months after conversion, with no rejection episodes. Three patients have been subsequently converted back to tacrolimus, two for rejection and one for hirsutism. There were no significant changes in creatinine, urate, or blood sugar levels after conversion, but the mean plasma magnesium rose from 0.73 (0.63-0.97) to 0.82 (0.65-1) mmol/L (P=0.037), and the mean plasma cholesterol rose from 5.2 (3.4-6.8) to 5.5 (3.8-7.6) mmol/L (P=0.033). Pharmacokinetic profiles were measured before and after conversion, and showed that cyclosporine (Neoral) exhibited significantly less interpatient and intrapatient variability than tacrolimus, for area under the curve (AUC), maximum concentration after dose (Cmax), minimum concentration after dose (Cmin), and time to maximum concentration (Tmax).

CONCLUSION

This is the first study that has examined the outcome of conversion from tacrolimus- to cyclosporine-based immunosuppression in stable patients after renal transplantation. This conversion was performed without early immunological hazard, but there was a small rise in blood cholesterol levels after conversion. Pharmacokinetic studies showed that cyclosporine in the form of Neoral exhibited less inter- and intrapatient variability than tacrolimus, although this is of uncertain clinical significance.

Acute and subacute changes in the ultrasound measurements of the calcaneus following intense exercise

The amount of exercise necessary to cause bone structural change in humans is unknown. We examined whether a single bout of intense exercise in vivo leads to acute and subacute changes in the physical properties of bone as measured by ultrasound. It was hypothesized that structural changes such as accumulation of fatigue microdamage would result in a decrease in velocity of sound (VOS) and broadband ultrasound attenuation (BUA) across the calcaneus. We performed a prospective cohort study in 111 (97 M, 14 F) entrants of the 1996 Melbourne marathon (42.3 km) and 28 (10 M, 18 F) nonrunning controls. Runners had a mean (SD) age of 45.3 +/- 11.4 years (range 20-75), had completed 15.2 +/- 17.3 prior marathons (0-88), and had been running regularly for 14.2 +/- 9.2 years (0.25-50). An ultrasound densitometer (Cuba Clinical, McCue) was used to measure VOS and BUA across the right calcaneus. Runners were tested on three occasions: 1-3 days prior to, immediately after (<2 hours), and 5-6 days following the marathon. Seventy-three (66%) runners presented for all three measurements. Controls were tested on three occasions with the same time intervals as the runners. BUA values in the runners were significantly elevated by 5.0% immediately after the marathon but returned to baseline levels by the third test session (P = 0. 0001). Changes in BUA values in the controls were not significant and all were less than 0.7% (P = 0.88). Age was a significant independent predictor of the BUA change between test 1 and test 2 in the runners (beta = 0.2094; SE = 0.0917; P = 0.03). VOS measurements were not significantly different across the three testing sessions in both the runners (P = 0.07) and the controls (P = 0.33). Therefore, ultrasound measurements of BUA and VOS did not detect evidence of lasting structural change in the calcaneus following a marathon.

A microbiological investigation following the disinfection of alginate and addition cured silicone rubber impression materials

The antimicrobial efficacy of four commercially available disinfectants (Haz-tabs, chlorhexidine, Virkon and C&J Algisept Spray) was investigated. It was shown that all were effective in decontaminating the impressions whilst those placed only in sterile water, used as a control, showed variable levels of bacterial growth. Moreover, alginate appeared to carry significantly higher numbers of bacteria than addition cured silicone rubber.

Preventing Groupthink Revisited: Evaluating and Reforming Groups in Government

This article critically examines Janis's recommendations for preventing groupthink in high-level policymaking. It puts forward three models of small group functioning in government, each of which highlights different dimensions of collegial policymaking and distinct criteria for evaluating group performance. Each model also inspires different proposals for groupthink prevention and improvement of group performance in general. Proposals for designing and managing high-level groups in government need to take into account these multiple perspectives. Furthermore, their proponents should be aware of the institutionalized and competitive context in which political decision groups operate. Evaluations of their performance and proposals for reforming them are inevitably tied up in this process. This has important implications for the feasibility of recommendations set forth by small group analysts. The article concludes with an agenda for increasing the policy relevance and practical feasibility of research on political decision groups. Copyright 1998 Academic Press.