Association of micropapillary urothelial carcinoma of the bladder and BK viruria in kidney transplant recipients

INTRODUCTION

BK virus (BKV) is an ubiquitous human polyomavirus that establishes latency in urothelium. BKV is known to re-activate in immunosuppressed individuals, and is an increasingly important cause of nephropathy and graft loss in kidney transplant recipients. Animal studies have demonstrated BKV has a potential role as a tumor virus. However, its role in precipitating or facilitating oncogenesis in humans is still debated.

REPORT

We report 2 cases of aggressive micropapillary urothelial carcinoma of the bladder in kidney transplant recipients with persistent BK viruria and preserved graft function.

RESULTS

In both cases, polyomavirus immunohistochemistry performed on the tumor specimens was strongly positive, and limited to the malignant tissue. BKV DNA, viral protein 1, and large T antigen mRNA were detected in the tumor; however, no viral particles were seen on electron microscopy.

CONCLUSION

In one of the cases, BKV integration into the host genome was identified, leading to the truncation of the major viral capsid gene. This finding raises the concern that persisting BK viruria may be a risk factor for this aggressive form of bladder cancer. Further studies to determine screening and management strategies are required.

Histological chorioamnionitis and neurodevelopmental outcome in preterm infants

OBJECTIVE

The objective of this study is to examine the neurodevelopmental outcome at 30 to 42 months corrected age of preterm infants with histological chorioamnionitis (HCA).

STUDY DESIGN

The study design is a retrospective cohort study with a prospective follow-up. All surviving infants with birth gestational age <29 weeks, born between 2000 and 2006, who had a neurodevelopmental assessment at 30 to 42 months corrected age were included. We compared the neurodevelopmental outcomes of infants with or without HCA.

RESULT

Of the 384 infants, 197 (51%) were born to mothers with evidence of HCA. Infants with HCA were of lower gestational age (26 weeks vs 26.6 weeks) and more likely to have intraventricular hemorrhage (27.9% vs 14.4%), periventricular leukomalacia (2.5% vs 0%) and retinopathy of prematurity ≥ stage 3 (31.4% vs 22.4%). On univariate analysis, infants with HCA were more likely to have cerebral palsy (12.6% vs 6.4%, P=0.04). There was no significant difference in the incidence of cognitive delay, deafness, blindness, or total major disabilities between the two groups. After adjusting for perinatal variables, HCA was associated with increased risk of cerebral palsy (odds ratio (OR): 2.45; 95% confidence interval (CI) 1.11 to 5.40), but not for total major disabilities (OR: 1.22; 95% CI: 0.64 to 2.34). There was a trend towards increased risk of cerebral palsy with HCA with funisitis.

CONCLUSION

HCA is associated with increased risk of cerebral palsy at 30 to 42 months corrected age in preterm infants.

The uterine myocyte as a target for prevention of preterm birth

Preterm birth (PTB) remains the most common cause of neonatal morbidity and mortality as well as long-term disability. Current strategies to prevent or arrest spontaneous preterm labor (SPTL) have limited success. For almost three decades, there have been no novel pharmacological agents used clinically to address this important obstetrical complication. In this review, we focus on the uterine myocyte as a target for prevention of spontaneous PTB. After presenting an overview of intracellular signaling pathways that are important in regulation of smooth muscle contractility, we discuss previous and current pharmacological approaches to manage SPTL. We also present recent evidence from our own laboratories suggesting a potentially novel and uterine-specific approach to maintain or impose uterine relaxation. Finally, we briefly discuss extrinsic systems that might affect uterine activity and reinforce the concept that SPTL represents a syndrome that is the end result of a variety of pathophysiologic etiologies leading to PTB. We conclude by emphasizing the need for much more research to provide sufficient understanding of the mechanisms of SPTL and to make inroads towards reducing the incidence and adverse consequences of this common and serious syndrome.

TLR signalling and adapter utilization in primary human in vitro differentiated adipocytes

Toll-like receptors (TLRs) are central to innate immunity and yet their expression is widespread and not restricted to professional inflammatory cells. TLRs have been reported on adipocytes and have been implicated in obesity-associated pathologies such as diabetes. Why TLRs are found on adipocytes is not clear although one hypothesis is that they may coordinate energy utilization for the energy intensive process of an immune response. We have explored TLR signalling in primary human in vitro differentiated adipocytes and investigated the specific adapter molecules that are involved. Only lipopolysaccharide (LPS), poly(I:C), Pam3CSK4 and MALP-2 could induce the production of IL-6, IL-8 and MCP-1 by adipocytes. Poly(I:C) alone caused a strong induction of type I interferons, as assessed by IP-10 production. Using siRNA, it was confirmed that LPS-dependent signalling in adipocytes occurs via TLR4 utilizing the adapter molecules MyD88, Mal and TRIF and caused rapid degradation of IκBα. Pam3CSK4 signalling utilized TLR2, MyD88 and Mal (but not TRIF). However, the response to poly(I:C) observed in these cells appeared not to require TRIF, but MyD88 was required for induction of NFκB-dependent cytokines by Poly(I:C). Despite this, IκBα degradation could not be detected in poly(I:C) stimulated adipocytes at any time-point up to 4 h. Indeed, IL-6 transcription was not induced until 8-16 h after exposure. These data suggest that Pam3CSK4 and LPS signal via the expected routes in human adipocytes, whereas poly(I:C)/TLR3 signalling may act via a TRIF-independent, MyD88-dependent route.

Methodological approaches to the long-term study of antidepressants

It has long been known that most patients with bipolar disorder have a course marked by multiple recurrence of major depressive and manic episodes. More recently, many epidemiological studies have shown that at least 50% of unipolar depressive patients have one or more subsequent episodes of depression in their lifetimes. Likewise, relapse following successful short-term treatment of depression is so common that it is now recommended to prolong treatment in the form of maintenance pharmacotherapy. Interest in preventing the recurrence of depression has been stimulated by the results from long-term trials involving antidepressant drugs and lithium. However, these pharmacological studies suffer somewhat from methodological deficits, making difficult any clear and complete interpretation of their results. While some methodological recommendations have now been established to compensate for previous deficits (eg, definition of relapse and recurrence, duration of acute and maintenance treatments, statistical analysis of efficacy), unfortunately, many key points still remain to be resolved (eg, selection of patients, dosage in maintenance and prophylactic phases, maximum length of a course of treatment, etc).

Diagnostic accuracy of rapid phIGFBP-I assay for predicting preterm labor in symptomatic patients

OBJECTIVE

To estimate sensitivity, specificity, positive and negative predictive values (PPV, NPV) of insulin-like growth factor binding protein-1 (phIGFBP-1) test in predicting preterm delivery in women with symptoms of preterm labor. Secondary objectives were to compare test characteristics of the phIGFBP-1 and fetal fibronectin (fFN) tests.

STUDY DESIGN

Labor and delivery units in two Calgary hospitals. Subjects were 349 women with suspected labor between 24 and 35 weeks gestational age (GA). Women had cervical phIGFBP-1 test +/- and fFN testing. Sensitivity, specificity, PPV and NPV were estimated. Primary outcome was birth <37 weeks GA.

RESULT

Sensitivity of phIGFBP-1 test for delivery <37 weeks was 0.39; specificity, 0.76; PPV, 0.24; NPV, 0.86. NPV of phIGFBP-1 did not differ greatly from that of fFN testing (0.88).

CONCLUSION

NPV did not differ between phIGFBP-1 and fFN for delivery <37 weeks. Neither test improves on pretest probability of delivery <37 weeks, so clinicians must decide whether the use of either test is justified.

Faecal short chain fatty acids in healthy subjects participating in a randomised controlled trial examining a soluble highly viscous polysaccharide versus control

BACKGROUND

Short chain fatty acids (SCFA) are produced by the bacterial fermentation of dietary fibre and have been linked with intestinal health. The present study examined faecal SCFA concentrations in subjects consuming a novel soluble highly viscous polysaccharide (HVP) or control for 3 weeks. A total of 54 healthy adults participated in a randomised, double-blind, placebo-controlled study.

METHODS

Subjects were randomised to consume HVP or control (skim milk powder). A dose of 5 g day(-1) was consumed in the first week, followed by 10 g day(-1) in the second and third weeks (n = 27 per group). The primary outcome was SCFA concentrations in faecal samples collected at baseline (visit 1, V1), at 1 week (V2) and at 3 week (V3).

RESULTS

The reduction in faecal acetate from V1 to V3 in control subjects was not observed in subjects consuming HVP. There were no differences in propionate, butyrate, valerate or caproate concentrations. There was a significant treatment effect (P = 0.03) for total SCFA, with higher concentrations observed in subjects consuming HVP versus control.

CONCLUSIONS

HVP is a viscous functional fibre that may influence gut microbial fermentation. Further work is warranted to examine the fermentative properties of HVP and possible links with appetite regulation and reduced serum low-density lipoprotein cholesterol concentrations.

The synthesis and preclinical evaluation in rhesus monkey of [¹⁸F]MK-6577 and [¹¹C]CMPyPB glycine transporter 1 positron emission tomography radiotracers

Two positron emission tomography radiotracers for the glycine transporter 1 (GlyT1) are reported here. Each radiotracer is a propylsulfonamide-containing benzamide and was labeled with either carbon-11 or fluorine-18. [¹¹C]CMPyPB was synthesized by the alkylation of a 3-hydroxypyridine precursor using [¹¹C]MeI, and [¹⁸F]MK-6577 was synthesized by a nucleophilic aromatic substitution reaction using a 2-chloropyridine precursor. Each tracer shows good uptake into rhesus monkey brain with the expected distribution of highest uptake in the pons, thalamus, and cerebellum and lower uptake in the striatum and gray matter of the frontal cortex. In vivo blockade and chase studies of [¹⁸F]MK-6577 showed a large specific signal and reversible binding. In vitro autoradiographic studies with [¹⁸F]MK-6577 showed a large specific signal in both rhesus monkey and human brain slices and a distribution consistent with the in vivo results and those reported in the literature. In vivo metabolism studies in rhesus monkeys demonstrated that only more-polar metabolites are formed for each tracer. Of these two tracers, [¹⁸F]MK-6577 was more extensively characterized and is a promising clinical positron emission tomography tracer for imaging GlyT1 and for measuring GlyT1 occupancy of therapeutic compounds.

Effect of PGX, a novel functional fibre supplement, on subjective ratings of appetite in overweight and obese women consuming a 3-day structured, low-calorie diet

Introduction:

Dietary factors that help control perceived hunger might improve adherence to calorie-reduced diets.

Objectives:

The objective of the study was to investigate the effect of supplementing a three-day, low-calorie diet with PolyGlycopleX (PGX), a highly viscous fibre, on subjective ratings of appetite compared with a placebo.

Methods:

In a double-blind crossover design with a 3-week washout, 45 women (aged 38±9 years, body mass index 29.9±2.8 kg m⁻²) were randomised to consume a 1000-kcal per day diet for 3 days, supplemented with 5 g of PGX or placebo at each of breakfast, lunch and dinner. Subjective appetite was assessed using 100 mm visual analogue scales that were completed daily before, between and after consumption of meals.

Results:

Thirty-five women completed the study. Consumption of PGX compared with placebo led to significantly lower mean area under the curve for hunger on day 3 (440.4 versus 375.4; P=0.048), prospective consumption on day 3 (471.0 versus 401.8; P=0.017) and the overall 3-day average (468.6 versus 420.2; P=0.026). More specifically, on day 3 PGX significantly reduced total appetite, hunger, desire to eat and prospective consumption for 2.5 and 4.5 h after lunch and before dinner times, with hunger also being reduced 2.5 h after dinner (P<0.05).

Conclusion:

The results show that adding 5 g of PGX to meals during consumption of a low-calorie diet reduces subjective ratings of prospective consumption and increases the feelings of satiety, especially during afternoon and evening. This highly viscous polysaccharide may be a useful adjunct to weight-loss interventions involving significant caloric reductions.

Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5  GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε.

Effects of a 3-month supplementation with a novel soluble highly viscous polysaccharide on anthropometry and blood lipids in nondieting overweight or obese adults

BACKGROUND

High viscosity fibre is known to exert many beneficial effects on appetite and metabolism. It could potentially help in weight management, in dieting or nondieting individuals. The present study investigated the effects of the daily intake of a novel high viscosity polysaccharide (HVP) over 3 months in nondieting obese or overweight men and women.

METHODS

The study comprised a double-blind, randomised controlled clinical trial. Participants ingested 5-15 g per day of either HVP (n = 29, experimental group) or inulin (n = 30, control group) for 15 weeks. Changes in anthropometry (weight, waist and hip circumferences), blood lipids and glucose tolerance were studied from the beginning to the end of administration. Compliance and tolerance were examined.

RESULTS

Differences appeared between HVP and inulin supplementation in female participants only. Mean (SD) decreases in body weight [1.6 (3.2) kg; approximately 2% of initial weight] and hip circumference [2.8 (3.6 ) cm] occurred in women of the HVP group but not in controls (Time × Group interactions, P ≤ 0.002). Total, high-density lipoprotein and low-density lipoprotein-cholesterol were lower at the end of supplementation in the women of the HVP group compared to controls (P ≤ 0.021). No effect appeared in waist circumference and triacylglycerol. No difference was noted in the number or severity of the adverse effects reported in both groups. Adverse effects were mild and agreed with commonly reported reactions to intake of dietary fibre.

CONCLUSIONS

Beneficial although modest effects appeared after several weeks of daily HVP intake in nondieting obese or overweight women. The effects of HVP should be investigated in the context of a weight loss programme.

Crystallization and preliminary X-ray diffraction analysis of the protease from Southampton norovirus complexed with a Michael acceptor inhibitor

Noroviruses are the predominant cause of human epidemic nonbacterial gastroenteritis. Viral replication requires a cysteine protease that cleaves a 200 kDa viral polyprotein into its constituent functional parts. Here, the crystallization of the recombinant protease from the Southampton norovirus is described. Whilst the native crystals were found to diffract only to medium resolution (2.9 Å), cocrystals of an inhibitor complex diffracted X-rays to 1.7 Å resolution. The polypeptide inhibitor (Ac-EFQLQ-propenyl ethyl ester) possesses an amino-acid sequence designed to match the substrate specificity of the enzyme, but was synthesized with a reactive Michael acceptor group at the C-terminal end.

Identification of an Orally Bioavailable, Potent, and Selective Inhibitor of GlyT1

Amalgamation of the structure-activity relationship of two series of GlyT1 inhibitors developed at Merck led to the discovery of a clinical candidate, compound 16 (DCCCyB), which demonstrated excellent in vivo occupancy of GlyT1 transporters in rhesus monkey as determined by displacement of a PET tracer ligand.

Effects of PGX, a novel functional fibre, on acute and delayed postprandial glycaemia

Background:

Viscous fibre in food has established health benefits, but few functional fibre preparations are both effective and palatable. Our objective was to determine the most effective dose, formulation and timing of consumption of a novel fibre supplement (PolyGlycopleX (PGX)) in reducing postprandial glycaemia.

Subjects/methods:

Three trials were undertaken, each with 10 subjects (8M and 8F; age 24.4±2.6 years). Granular supplement was tested at four doses (0, 2.5, 5.0 and 7.5 g) with breakfast (study 1). Granular and capsule forms of the supplement were given in a single dose (5 g for granules and 4.5 g in capsules) at −60, −45, −30, −15 and 0 before, and +15 min after a bread meal (study 2). Capsules at increasing doses (1.5, 3, 4.5 and 6 g) were consumed with the evening meal to determine effects on glucose tolerance at breakfast (study 3). Incremental area under the blood glucose curve was determined.

Results:

Granular PGX at breakfast time at doses of 2.5, 5 and 7.5 g reduced the incremental area under the curve by up to 50% in a linear dose–response fashion (P<0.001). The granular form of PGX (5 g), but not the capsules, reduced glycaemia by up to 28% when consumed from −45 to +15 min (P<0.001). Capsules containing 3, 4.5 and 6 g PGX consumed with the evening meal reduced glycaemia at breakfast by up to 28% (P<0.001).

Conclusions:

PGX has biologically important, dose-related effects on acute and delayed (second meal) postprandial glycaemia.

Investigation of nuclear factor-κB inhibitors and interleukin-10 as regulators of inflammatory signalling in human adipocytes

The poor prognosis of obesity is now known to involve a proinflammatory state associated with elevated circulating levels of cytokines and with macrophage infiltration of adipose tissue. In particular, Toll-like receptor (TLR)-4-driven adipose inflammation has been implicated recently in obesity and the development of diabetes. Adipocytes are now recognized as an important source of cytokine and chemokine production, including interleukin (IL)-6 and monocyte chemotractant protein (MCP)-1, and this appears to be a key step in the development of the obesity-associated inflammatory state. Interventions targeted at adipocyte inflammation may therefore form novel therapies to treat or prevent medical complications of obesity. We set out to explore whether anti-inflammatory interventions which are effective in conventional immune cells would operate on primary human cultures of in-vitro differentiated adipocytes. IL-10 was ineffective against TLR-4-induced cytokine secretion due to lack of IL-10 receptor on human adipocytes, in contrast to the widely used murine 3T3-L1 adipocyte model, which is known to respond to IL-10. Adenoviral delivery of an IL-10 receptor construct to the cells restored IL-10 responsiveness as assessed by signal transducer and activator of transcription-3 (STAT-3) phosphorylation. However, the small molecule nuclear factor (NF)-κB inhibitors 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA)-1 and carbobenzoxyl-Ile-Glu(O-t-butyl)-Ala-leucinal (PSI) as well as adenovirally delivered dominant negative inhibitor of IkappaB kinase 2 (IKK2) and wild-type IκBα were effective inhibitors of TLR-4-driven IL-6 and MCP-1 induction. These data identify a central role for canonical NF-κB signalling in adipocyte cytokine induction and indicate that small molecule inhibitors of NF-κB may form the basis of future treatments for obesity-related conditions where adipocyte inflammatory signalling is implicated.

Probing quark-gluon interactions with transverse polarized scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.