Equipping for risk: Lessons learnt from the UK shale-gas experience on assessing environmental risks for the future geoenergy use of the deep subsurface

findings are presented from an investigation to improve understanding of the environmental risks associated with developing an unconventional-hydrocarbons industry in the UK. The EQUIPT4RISK project, funded by UK Research Councils, focused on investigations around Preston New Road (PNR), Fylde, Lancashire, and Kirby Misperton Site A (KMA), North Yorkshire, where operator licences to explore for shale gas by hydraulic fracturing (HF) were issued in 2016, although exploration only took place at PNR. EQUIPT4RISK considered atmospheric (greenhouse gases, air quality), water (groundwater quality) and solid-earth (seismicity) compartments to characterise and model local conditions and environmental responses to HF activities. Risk assessment was based on the source-pathway-receptor approach. Baseline monitoring of air around the two sites characterised the variability with meteorological conditions, and isotopic signatures were able to discriminate biogenic methane (cattle) from thermogenic (natural-gas) sources. Monitoring of a post-HF nitrogen-lift (well-cleaning) operation at PNR detected the release of atmospheric emissions of methane (4.2 ± 1.4 t CH4). Groundwater monitoring around KMA identified high baseline methane concentrations and detected ethane and propane at some locations. Dissolved methane was inferred from stable-isotopic evidence as overwhelmingly of biogenic origin. Groundwater-quality monitoring around PNR found no evidence of HF-induced impacts. Two approaches for modelling induced seismicity and associated seismic risk were developed using observations of seismicity and operational parameters from PNR in 2018 and 2019. Novel methodologies developed for monitoring include use of machine learning to identify fugitive atmospheric methane, Bayesian statistics to assess changes to groundwater quality, a seismicity forecasting model seeded by the HF-fluid injection rate and high-resolution monitoring of soil-gas methane. The project developed a risk-assessment framework, aligned with ISO 31000 risk-management principles, to assess the theoretical combined and cumulative environmental risks from operations over time. This demonstrated the spatial and temporal evolution of risk profiles: seismic and atmospheric impacts from the shale-gas operations are modelled to be localised and short-lived, while risk to groundwater quality is longer-term.

Risk of hospitalisation or death in households with a case of COVID-19 in England: an analysis using the HOSTED data set

Objective

To determine whether household contacts of confirmed cases of COVID-19 have an increased risk of hospitalisation or death.

Methods

We used the HOSTED data set of index cases of COVID-19 in England between June and November 2020, linked to Secondary Uses Service data on hospital episodes and Office for National Statistics’ mortality data. Multivariable logistic regression models of the odds of household contacts being hospitalised or dying within six weeks of an index case, adjusted for case type, age, sex and calendar month were calculated. Excess risk was determined by comparing the first six weeks after the index case with 6–12 weeks after the index case in a survival analysis framework.

Results

Index cases were more likely to be hospitalised or die than either secondary cases or non-cases, having adjusted for age and sex. There was an increased risk of hospitalisation for non-cases (adjusted hazard ratio (aHR) 1.10; 95% confidence interval (CI) 1.04, 1.16) and of death (aHR 1.57; 95% CI 1.14, 2.16) in the first six weeks after an index case, compared to 6–12 weeks after.

Conclusion

Risks of hospitalisation and mortality are predictably higher in cases compared to non-cases. The short-term increase in risks for non-case contacts following diagnosis of the index case may suggest incomplete case ascertainment among contacts, although this was relatively small.

Women's experiences of early pregnancy assessment unit services: a qualitative investigation

OBJECTIVE

To explore the experiences of women who had used an Early Pregnancy Assessment Unit (EPAU) service in the UK and make recommendations for their improvement.

DESIGN

Qualitative interview study.

SETTING

Early Pregnancy Assessment Units in the UK.

SAMPLE

A maximum variation sample of women who had consented to be interviewed having attended one of 26 EPAUs involved in the VESPA study in 2018.

METHODS

In-depth telephone interviews with 38 women. A thematic framework analysis was conducted, with a focus on how experiences varied according to EPAU service configuration and clinical pathway.

MAIN OUTCOME MEASURES

Women's experiences of EPAU services.

RESULTS

We found that EPAUs are highly valued, and women's experiences were generally positive. However, women reported a range of issues that negatively affected their experience. These included difficulties accessing the service, insensitive management of the investigation and treatment options of pregnancy loss, poor communication, insufficient information and a lack of support for their psychological health. These issues were not strongly associated with EPAU configuration or clinical pathway.

CONCLUSIONS

Recommendations to improve women's experiences include the separation of EPAUs from general maternity services, and we make suggestions on how to remove barriers to access by reviewing opening hours, how to provide sensitive patient management, such as automatically cancelling appointments and scans following pregnancy loss, and how to improve communication, both with women and their partners as well as with other parts of the health service.

HOSTED-England's Household Transmission Evaluation Dataset: preliminary findings from a novel passive surveillance system of COVID-19

BACKGROUND

Household transmission of SARS-CoV-2 is an important component of the community spread of the pandemic. Little is known about the factors associated with household transmission, at the level of the case, contact or household, or how these have varied over the course of the pandemic.

METHODS

The Household Transmission Evaluation Dataset (HOSTED) is a passive surveillance system linking laboratory-confirmed COVID-19 cases to individuals living in the same household in England. We explored the risk of household transmission according to: age of case and contact, sex, region, deprivation, month and household composition between April and September 2020, building a multivariate model.

RESULTS

In the period studied, on average, 5.5% of household contacts in England were diagnosed as cases. Household transmission was most common between adult cases and contacts of a similar age. There was some evidence of lower transmission rates to under-16s [adjusted odds ratios (aOR) 0.70, 95% confidence interval (CI) 0.66-0.74). There were clear regional differences, with higher rates of household transmission in the north of England and the Midlands. Less deprived areas had a lower risk of household transmission. After controlling for region, there was no effect of deprivation, but houses of multiple occupancy had lower rates of household transmission [aOR 0.74 (0.66-0.83)].

CONCLUSIONS

Children are less likely to acquire SARS-CoV-2 via household transmission, and consequently there was no difference in the risk of transmission in households with children. Households in which cases could isolate effectively, such as houses of multiple occupancy, had lower rates of household transmission. Policies to support the effective isolation of cases from their household contacts could lower the level of household transmission.

Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of ^{7}Be in Superconducting Quantum Sensors

Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal to the dark sector. We report a new search for the existence of sub-MeV sterile neutrinos using the decay-momentum reconstruction technique in the decay of ^{7}Be. The experiment measures the total energy of the ^{7}Li daughter atom from the electron capture decay of ^{7}Be implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first experiment presents data from a single STJ operated at a low count rate for a net total of 28 days, and provides exclusion limits on sterile neutrinos in the mass range from 100 to 850 keV that improve upon previous work by up to an order of magnitude.

Obesity-Linked PPARγ S273 Phosphorylation Promotes Insulin Resistance through Growth Differentiation Factor 3

The thiazolidinediones (TZDs) are ligands of PPARγ that improve insulin sensitivity, but their use is limited by significant side effects. Recently, we demonstrated a mechanism wherein TZDs improve insulin sensitivity distinct from receptor agonism and adipogenesis: reversal of obesity-linked phosphorylation of PPARγ at serine 273. However, the role of this modification hasn't been tested genetically. Here we demonstrate that mice encoding an allele of PPARγ that cannot be phosphorylated at S273 are protected from insulin resistance, without exhibiting differences in body weight or TZD-associated side effects. Indeed, hyperinsulinemic-euglycemic clamp experiments confirm insulin sensitivity. RNA-seq in these mice reveals reduced expression of Gdf3, a BMP family member. Ectopic expression of Gdf3 is sufficient to induce insulin resistance in lean, healthy mice. We find Gdf3 inhibits BMP signaling and insulin signaling in vitro. Together, these results highlight the diabetogenic role of PPARγ S273 phosphorylation and focus attention on a putative target, Gdf3.

Impacts of operating conditions on efficiency of electrokinetically enhanced filtration for de-watering of orange juice and malt extract

The effects of operational factors an on an electrokinetic-enhanced filtration (EKEF) application to dewater orange juice (OJ) and malt extract (ME) was investigated. EKEF improved dewatering of both foodstuffs and resulted in net dewatering efficiencies of 7.4% and 4.9% for OJ and 10.7% and 6.3% for ME after 5.5 h processing under 30 V and 15 V, respectively. Dry matter content was increased by 19.2% and 15.6% for OJ after 5.5 h and 14.8% and 12.8% for ME after 3.5 h under 30 V and 15 V, respectively, compared with 14.9% and 10.3% under the control conditions for OJ and ME, respectively. The EKEF process effectively improved dewatering of high moisture-content foods with positive impacts on process efficiency by increased voltage, pressure, and the pore size of filters. The initial distance between electrodes had a negative impact as the distance increased. EKEF is a useful adjunct to improve high pressure filtration of foodstuffs.

Molecular detection of Streptococcus equi subspecies equi in face flies (Musca autumnalis) collected during a strangles outbreak on a Thoroughbred farm

The objective of this study was to detect Streptococcus equi subspecies equi (S. equi) (Lactobacillales: Streptococcaceae) using quantitative polymerase chain reaction (qPCR) in flies collected from a farm with a documented outbreak of strangles. A total of 1856 face flies [Musca autumnalis (Diptera: Muscidae)] were collected using conventional fly traps. The flies were processed for nucleic acid purification and tested for the presence of S. equi by qPCR. A total of 10/1856 flies (0.54%) tested qPCR-positive for S. equi. The results may implicate the presence of face flies as a risk factor for the transmission of S. equi and highlight the need to institute proper husbandry measures, biosecurity protocols and fly control in order to reduce the potential for infection in at-risk horses.

On the Stability of Reported Pregnancy Intentions from Pregnancy to 1 Year Postnatally: Impact of Choice of Measure, Timing of Assessment, Women's Characteristics and Outcome of Pregnancy

OBJECTIVES

Retrospective, cross-sectional estimates of pregnancy intention, as used in the Demographic Health Survey (DHS), are the global norm. The London Measure of Unplanned Pregnancy (LMUP) is a newer, psychometrically validated measure which may be more reliable. This paper assesses the reliability of the LMUP and the DHS question over the first postnatal year and explores the effects of maternal characteristics or pregnancy outcome on reported pregnancy intention.

METHODS

We compared the test-retest reliability of the LMUP (using the AC coefficient) and DHS question (using the weighted Kappa) over the first postnatal year using data from Malawian women. We investigated the effect of maternal characteristics and pregnancy outcome using t-tests, Chi squared or Fisher's exact tests, and calculated odds ratios to estimate effect size.

RESULTS

The DHS question was associated with a statistically significant decrease in the prevalence of unplanned pregnancies from 1-to-12 months postnatally; the LMUP was not. The LMUP had moderate to substantial reliability (0.51-0.66); the DHS had moderate reliability (0.56-0.58). The LMUP's stability was not related to any of the factors examined; the stability of the DHS varied by marital status (p = 0.033), number of children (p = 0.048) and postnatal depression (p < 0.001). Both underestimated unintended pregnancy postnatally vis-à-vis the LMUP in pregnancy.

CONCLUSIONS FOR PRACTICE

The LMUP is a more reliable measure of pregnancy intention than the DHS in the first postnatal year and does not vary by maternal characteristics or pregnancy outcome. The LMUP should become the gold-standard for measuring pregnancy intention and should be collected in pregnancy or at the first postnatal opportunity.

Phosphorylation of Beta-3 adrenergic receptor at serine 247 by ERK MAP kinase drives lipolysis in obese adipocytes

OBJECTIVE

The inappropriate release of free fatty acids from obese adipose tissue stores has detrimental effects on metabolism, but key molecular mechanisms controlling FFA release from adipocytes remain undefined. Although obesity promotes systemic inflammation, we find activation of the inflammation-associated Mitogen Activated Protein kinase ERK occurs specifically in adipose tissues of obese mice, and provide evidence that adipocyte ERK activation may explain exaggerated adipose tissue lipolysis observed in obesity.

METHODS AND RESULTS

We provide genetic and pharmacological evidence that inhibition of the MEK/ERK pathway in human adipose tissue, mice, and flies all effectively limit adipocyte lipolysis. In complementary findings, we show that genetic and obesity-mediated activation of ERK enhances lipolysis, whereas adipose tissue specific knock-out of ERK2, the exclusive ERK1/2 protein in adipocytes, dramatically impairs lipolysis in explanted mouse adipose tissue. In addition, acute inhibition of MEK/ERK signaling also decreases lipolysis in adipose tissue and improves insulin sensitivity in obese mice. Mice with decreased rates of adipose tissue lipolysis in vivo caused by either MEK or ATGL pharmacological inhibition were unable to liberate sufficient White Adipose Tissue (WAT) energy stores to fuel thermogenesis from brown fat during a cold temperature challenge. To identify a molecular mechanism controlling these actions, we performed unbiased phosphoproteomic analysis of obese adipose tissue at different time points following acute pharmacological MEK/ERK inhibition. MEK/ERK inhibition decreased levels of adrenergic signaling and caused de-phosphorylation of the β3-adrenergic receptor (β3AR) on serine 247. To define the functional implications of this phosphorylation, we showed that CRISPR/Cas9 engineered cells expressing wild type β3AR exhibited β3AR phosphorylation by ERK2 and enhanced lipolysis, but this was not seen when serine 247 of β3AR was mutated to alanine.

CONCLUSION

Taken together, these data suggest that ERK activation in adipocytes and subsequent phosphorylation of the β3AR on S247 are critical regulatory steps in the enhanced adipocyte lipolysis of obesity.

Cdkal1, a type 2 diabetes susceptibility gene, regulates mitochondrial function in adipose tissue

Objectives

Understanding how loci identified by genome wide association studies (GWAS) contribute to pathogenesis requires new mechanistic insights. Variants within CDKAL1 are strongly linked to an increased risk of developing type 2 diabetes and obesity. Investigations in mouse models have focused on the function of Cdkal1 as a tRNA^Lys modifier and downstream effects of Cdkal1 loss on pro-insulin translational fidelity in pancreatic β−cells. However, Cdkal1 is broadly expressed in other metabolically relevant tissues, including adipose tissue. In addition, the Cdkal1 homolog Cdk5rap1 regulates mitochondrial protein translation and mitochondrial function in skeletal muscle. We tested whether adipocyte-specific Cdkal1 deletion alters systemic glucose homeostasis or adipose mitochondrial function independently of its effects on pro-insulin translation and insulin secretion.

Methods

We measured mRNA levels of type 2 diabetes GWAS genes, including Cdkal1, in adipose tissue from lean and obese mice. We then established a mouse model with adipocyte-specific Cdkal1 deletion. We examined the effects of adipose Cdkal1 deletion using indirect calorimetry on mice during a cold temperature challenge, as well as by measuring cellular and mitochondrial respiration in vitro. We also examined brown adipose tissue (BAT) mitochondrial morphology by electron microscopy. Utilizing co-immunoprecipitation followed by mass spectrometry, we performed interaction mapping to identify new CDKAL1 binding partners. Furthermore, we tested whether Cdkal1 loss in adipose tissue affects total protein levels or accurate Lys incorporation by tRNA^Lys using quantitative mass spectrometry.

Results

We found that Cdkal1 mRNA levels are reduced in adipose tissue of obese mice. Using adipose-specific Cdkal1 KO mice (A-KO), we demonstrated that mitochondrial function is impaired in primary differentiated brown adipocytes and in isolated mitochondria from A-KO brown adipose tissue. A-KO mice displayed decreased energy expenditure during 4 °C cold challenge. Furthermore, mitochondrial morphology was highly abnormal in A-KO BAT. Surprisingly, we found that lysine codon representation was unchanged in Cdkal1 A-KO adipose tissue. We identified novel protein interactors of CDKAL1, including SLC25A4/ANT1, an inner mitochondrial membrane ADP/ATP translocator. ANT proteins can account for the UCP1-independent basal proton leak in BAT mitochondria. Cdkal1 A-KO mice had increased ANT1 protein levels in their white adipose tissue.

Conclusions

Cdkal1 is necessary for normal mitochondrial morphology and function in adipose tissue. These results suggest that the type 2 diabetes susceptibility gene CDKAL1 has novel functions in regulating mitochondrial activity.

•

Cdkal1 is a gene most strongly expressed in tissues with high mitochondrial content.

•

Cdkal1 is required for normal mitochondrial morphology and function.

•

Deletion of Cdkal1 in adipose tissue impairs the thermogenic response to a cold challenge.

•

Cdkal1 interacts with ANT1, a mitochondrial ATP/ADP transporter.

•

Loss of Cdkal1 does not affect protein translation as predicted for a tRNA modifying enzyme.

A longitudinal study on the acceptance and effects of a therapeutic renal food in pet dogs with IRIS-Stage 1 chronic kidney disease

Currently, nutritional management is recommended when serum creatinine (Cr) exceeds 1.4 mg/dl in dogs with IRIS-Stage 2 chronic kidney disease (CKD) to slow progressive loss of kidney function, reduce clinical and biochemical consequences of CKD, and maintain adequate nutrition. It is unknown if dietary interventions benefit non-azotemic dogs at earlier stages. A prospective 12-month feeding trial was performed in client-owned dogs with IRIS-Stage 1 CKD (n = 36; 20 had persistently dilute urine with urine specific gravity (USG) <1.020 without identifiable non-renal cause; six had persistent proteinuria of renal origin with urine protein creatinine (UPC) ratio >0.5; 10 had both). Ease of transition to therapeutic renal food and effects on renal biomarkers and quality of life attributes were assessed. Dogs were transitioned over 1 week from grocery-branded foods to renal food. At 0, 3, 6, 9, and 12-months a questionnaire to assess owner's perception of their pet's acceptance of renal food and quality of life was completed. Renal biomarkers, including serum Cr, blood urea nitrogen (BUN), and symmetric dimethylarginine (SDMA), and USG and UPC ratio were measured. Of 36 dogs initially enrolled, 35 (97%) dogs were transitioned to therapeutic renal food. Dogs moderately or extremely liked the food 88% of the time, ate most or all of the food 84% of the time, and were moderately or extremely enthusiastic while eating 76% of the time. All renal biomarkers (Cr, BUN, and SDMA) were decreased (p ≤ .05) from baseline at 3-months, and remained decreased from baseline at 12-months in dogs completing the study (n = 20). Proteinuria was reduced in 12 of 16 dogs (p = .045) with proteinuria. Owners reported improvement in overall health and quality of life attributes, and hair and coat quality (all p < .01). In summary, dogs with IRIS-Stage 1 CKD readily transition to renal food. Decreasing serum biomarker concentrations and reduction in proteinuria suggest stabilized kidney function.

Rumen Microorganisms Decrease Bioavailability of Inorganic Selenium Supplements

Despite the availability of selenium (Se)-enriched trace mineral supplements, we have observed low Se status in cattle and sheep offered traditional inorganic Se supplements. Reasons for this may include inadequate intake or low bioavailability of inorganic Se sources. The objective of this study was to determine whether rumen microorganisms (RMO) alter the bioavailability of Se sources commonly used in Se supplements. Rumen microorganisms were isolated from ewes (n = 4) and incubated ex vivo with no Se (control), with inorganic Na selenite or Na selenate, or with organic selenomethionine (SeMet). Total Se incorporated into RMO and the amount of elemental Se formed were determined under equivalent conditions. Incorporation of Se from Na selenite, Na selenate, or SeMet into RMO was measured as fold change compared with control (no added Se). Incorporation of Se into microbial mass was greater for SeMet (13.2-fold greater than no-Se control) compared with inorganic Se supplements (P = 0.02); no differences were observed between inorganic Na selenate (3.3-fold greater than no-Se control) and Na selenite (3.5-fold greater than no-Se control; P = 0.97). Formation of non-bioavailable, elemental Se was less for RMO incubated with SeMet compared with inorganic Se sources (P = 0.01); no differences were observed between Na selenate and Na selenite (P = 0.09). The clinical importance of these results is that the oral bioavailability of organic SeMet should be greater compared with inorganic Se sources because of greater RMO incorporation of Se and decreased formation of elemental Se by RMO.

Serum Concentrations of Symmetric Dimethylarginine and Creatinine in Dogs with Naturally Occurring Chronic Kidney Disease

Background

Serum concentrations of symmetric dimethylarginine (SDMA) detected chronic kidney disease (CKD) in cats an average of 17.0 months before serum creatinine (Cr) concentrations increased above the reference interval.

Objectives

To report on the utility of measuring serum SDMA concentrations in dogs for detection of CKD before diagnosis by measurement of serum Cr.

Animals

CKD dogs (n = 19) included those persistently azotemic for ≥3 months (n = 5), dogs that were azotemic at the time of death (n = 4), and nonazotemic dogs (n = 10). CKD dogs were compared with healthy control dogs (n = 20).

Methods

Retrospective study, whereby serum Cr concentrations were determined by enzymatic colorimetry and serum SDMA concentrations were determined by liquid chromatography‐mass spectrometry in dogs with necropsy confirmed CKD.

Results

Serum SDMA increased before serum Cr in 17 of 19 dogs (mean, 9.8 months; range, 2.2–27.0 months). Duration of elevations in serum SDMA concentrations before the dog developed azotemia (N = 1) or before the dog died (N = 1) was not determined. Serum SDMA and Cr concentrations were linearly related (r = 0.84; P < .001). Serum SDMA (r = −0.80) and serum Cr (r = −0.89) concentrations were significantly related to glomerular filtration rate (both P < .001).

Conclusion and Clinical Importance

Using serum SDMA as a biomarker for CKD allows earlier detection of kidney dysfunction in dogs than does measurement of serum Cr. Earlier detection might be desirable for initiating renoprotective interventions that slow progression of kidney disease.

Novobiocin Analogues That Inhibit the MAPK Pathway

Heat shock protein 90 (Hsp90) inhibition by modulation of its N- or C-terminal binding site has become an attractive strategy for the development of anticancer chemotherapeutics. The first Hsp90 C-terminus inhibitor, novobiocin, manifested a relatively high IC50 value of ∼700 μM. Therefore, investigation of the novobiocin scaffold has led to analogues with improved antiproliferative activity (nanomolar concentrations) against several cancer cell lines. During these studies, novobiocin analogues that do not inhibit Hsp90 were identified; however, these analogues demonstrated potent antiproliferative activity. Compound 2, a novobiocin analogue, was identified as a MAPK pathway signaling disruptor that lacked Hsp90 inhibitory activity. In addition, structural modifications of compound 2 were identified that segregated Hsp90 inhibition from MAPK signaling disruption. These studies indicate that compound 2 represents a novel scaffold for disruption of MAPK pathway signaling and may serve as a useful structure for the generation of new anticancer agents.

Nutritional Interventions that Slow the Age-Associated Decline in Renal Function in a Canine Geriatric Model for Elderly Humans

OBJECTIVE

To determine the effects of feeding traditional and renal protective foods (RPF) supplemented with functional food bioactives on glomerular filtration rate (GFR), lean body percent (LB%), and selected circulating biomarker and metabolite concentrations in a geriatric dog model.

DESIGN

Randomized block design and cross-sectional study.

SETTING

Hill's Pet Nutrition, Inc. dog colony.

PARTICIPANTS

Eighty-one geriatric dogs (mean age, 10.4; range, 7.9-14.2 years) and 30 mature-adult dogs (mean age, 5.0; range, 3.3-6.9 years).

INTERVENTION

Geriatric dogs were fed one of three foods (n = 27 per group) for 6 months: a traditional RPF (control) that was energy dense and mildly protein-restricted, or control food supplemented with increasing amounts of functional food bioactives: fish oil, lipoic acid, fruits and vegetables, and higher quality protein sources [functional foods one (FF1) and two (FF2)]. Geriatric dogs were compared before and after the feeding trial with mature adult dogs.

MEASUREMENTS

Renal function was assessed by GFR, LB% was determined by dual energy x-ray absorptiometry, and circulating biomarkers and metabolites were measured in blood.

RESULTS

Before the feeding trial, GFR (+28.2%), LB% (+18.6%), and serum total protein (+10.0%) were higher in mature versus healthy geriatric dogs (all P<0.001). Geriatric dogs consuming all three foods increased (P<0.001) GFR over time; group averages ranged from 13.0-16.9%. Dogs fed the highest supplemented level of bioactives (FF2) had lower (P<0.001) symmetric dimethylarginine (SDMA) concentrations (-14.3%). Feeding functional foods did not alter body weight, but increased (P<0.001) serum protein concentration (+6.7%).

CONCLUSION

Supplementation with functional food bioactives can temporarily reverse the age-associated decline in renal function and serum total protein.

Cucurbitacin D Is a Disruptor of the HSP90 Chaperone Machinery

Heat shock protein 90 (Hsp90) facilitates the maturation of many newly synthesized and unfolded proteins (clients) via the Hsp90 chaperone cycle, in which Hsp90 forms a heteroprotein complex and relies upon cochaperones, immunophilins, etc., for assistance in client folding. Hsp90 inhibition has emerged as a strategy for anticancer therapies due to the involvement of clients in many oncogenic pathways. Inhibition of chaperone function results in client ubiquitinylation and degradation via the proteasome, ultimately leading to tumor digression. Small molecule inhibitors perturb ATPase activity at the N-terminus and include derivatives of the natural product geldanamycin. However, N-terminal inhibition also leads to induction of the pro-survival heat shock response (HSR), in which displacement of the Hsp90-bound transcription factor, heat shock factor-1, translocates to the nucleus and induces transcription of heat shock proteins, including Hsp90. An alternative strategy for Hsp90 inhibition is disruption of the Hsp90 heteroprotein complex. Disruption of the Hsp90 heteroprotein complex is an effective strategy to prevent client maturation without induction of the HSR. Cucurbitacin D, isolated from Cucurbita texana, and 3-epi-isocucurbitacin D prevented client maturation without induction of the HSR. Cucurbitacin D also disrupted interactions between Hsp90 and two cochaperones, Cdc37 and p23.

Improving recorded volume in mesial temporal lobe by optimizing stereotactic intracranial electrode implantation planning

PURPOSE

Intracranial electrodes are sometimes implanted in patients with refractory epilepsy to identify epileptic foci and propagation. Maximal recording of EEG activity from regions suspected of seizure generation is paramount. However, the location of individual contacts cannot be considered with current manual planning approaches. We propose and validate a procedure for optimizing intracranial electrode implantation planning that maximizes the recording volume, while constraining trajectories to safe paths.

METHODS

Retrospective data from 20 patients with epilepsy that had electrodes implanted in the mesial temporal lobes were studied. Clinical imaging data (CT/A and T1w MRI) were automatically segmented to obtain targets and structures to avoid. These data were used as input to the optimization procedure. Each electrode was modeled to assess risk, while individual contacts were modeled to estimate their recording capability. Ordered lists of trajectories per target were obtained. Global optimization generated the best set of electrodes. The procedure was integrated into a neuronavigation system.

RESULTS

Trajectories planned automatically covered statistically significant larger target volumes than manual plans [Formula: see text]. Median volume coverage was [Formula: see text] for automatic plans versus [Formula: see text] for manual plans. Furthermore, automatic plans remained at statistically significant safer distance to vessels [Formula: see text] and sulci [Formula: see text]. Surgeon's scores of the optimized electrode sets indicated that 95% of the automatic trajectories would be likely considered for use in a clinical setting.

CONCLUSIONS

This study suggests that automatic electrode planning for epilepsy provides safe trajectories and increases the amount of information obtained from the intracranial investigation.

Comparison of serum concentrations of symmetric dimethylarginine and creatinine as kidney function biomarkers in cats with chronic kidney disease

Background

Symmetric dimethylarginine (SDMA) has been shown to be an accurate and precise biomarker for calculating estimated glomerular filtration rate (GFR) in humans, as well as a more sensitive biomarker than serum creatinine concentration (sCr) for assessing renal dysfunction.

Objectives

The purpose of this retrospective study was to report on the utility of measuring serum SDMA concentrations in cats for detection of chronic kidney disease (CKD) before diagnosis by conventional measurement of sCr.

Animals

Chronic kidney disease cats (n = 21) included those persistently azotemic for ≥3 months (n = 15), nonazotemic cats with GFR >30% decreased from median GFR of normal cats (n = 4), and nonazotemic cats with calcium oxalate kidney stones (n = 2). Healthy geriatric cats (n = 21) were selected from the same colony.

Methods

Symmetric dimethylarginine concentrations (liquid chromatography‐mass spectroscopy) and sCr (enzymatic colorimetry) were determined retrospectively from historical data or banked serum samples in azotemic cats or at the time GFR (iohexol clearance) was measured in nonazotemic cats.

Results

Serum SDMA (r = −0.79) and sCr (r = −0.77) concentrations were significantly correlated to GFR (both P < .0001). Symmetric dimethylarginine became increased before sCr in 17/21 cats (mean, 17.0 months; range, 1.5–48 months). Serum SDMA had higher sensitivity (100%) compared with sCr (17%), but lower specificity (91% versus 100%) and positive predictive value (86% versus 100%).

Conclusion and Clinical Importance

Using serum SDMA as a biomarker for CKD allows earlier detection of CKD in cats compared with sCr, which may be desirable for initiating renoprotective interventions that slow progression of CKD.

Relative seed and fruit toxicity of the Australian cycads Macrozamia miquelii and Cycas ophiolitica: further evidence for a megafaunal seed dispersal syndrome in cycads, and its possible antiquity

An apparent contradiction in the ecology of cycad plants is that their seeds are known to be highly poisonous, and yet they seem well adapted for seed dispersal by animals, as shown by their visually conspicuous seed cones and large seeds presented within a brightly colored fleshy "fruit" of sarcotesta. We tested if this sarcotesta could function as a reward for cycad seed dispersal fauna, by establishing if the toxic compound cycasin, known from the seeds, is absent from the sarcotesta. The Australian cycads Macrozamia miquelii and Cycas ophiolitica were tested (N = 10 individuals per species) using gas chromatography / mass spectrometry. Cycasin was detected at 0.34 % (fresh weight) in seed endosperm of M. miquelii and 0.28 % (fresh weight) in seed endosperm of C. ophiolitica. Cycasin was absent from the sarcotesta of the same propagules (none detected in the case of M. miquelii, and trace quantities detected in sarcotesta of only four of the ten C. ophiolitica propagules). This laboratory finding was supported by field observations of native animals eating the sarcotesta of these cycads but discarding the toxic seed intact. These results suggest cycads are adapted for dispersal fauna capable of swallowing the large, heavy propagules whole, digesting the non-toxic sarcotesta flesh internally, and then voiding the toxic seed intact. Megafauna species such as extant emus or cassowaries, or extinct Pleistocene megafauna such as Genyornis, are plausible candidates for such dispersal. Cycads are an ancient lineage, and the possible antiquity of their megafaunal seed dispersal adaptations are discussed.

Effect of transport on blood selenium and glutathione status in feeder lambs

Stress from transport may be linked to increased generation of reactive oxygen species, the removal of which requires reduced glutathione and selenium. The aim of this experiment was to examine the effect of transport on glutathione and Se status of feeder lambs. Recently weaned lambs (n = 40) were blocked by gender and BW on d 0 of the experiment and randomly assigned to 2 treatment groups: group 1, no transport and full access to feed and water (control), and group 2, 8-h road transport followed by another 16 h of feed deprivation (transport). After 24 h, both treatment groups were treated the same. All lambs were weighed, and blood samples were collected at 0, 8, 24, and 72 h and analyzed for whole-blood (WB) and serum Se concentrations, serum NEFA concentrations, and erythrocyte concentrations of glutathione. Transport of feeder lambs for 8 h followed by another 16 h of feed deprivation transiently (significant at 24 h but no longer different at 72 h) decreased BW and erythrocyte glutathione concentrations and increased serum NEFA and blood Se concentrations compared with control lambs. Our results suggest that 8 h of transport followed by another 16 h of feed deprivation results in fatty acid and Se mobilization from tissue stores with a coincident decrease in erythrocyte glutathione concentrations.

Cdc2-like kinase 2 suppresses hepatic fatty acid oxidation and ketogenesis through disruption of the PGC-1α and MED1 complex

Hepatic ketogenesis plays an important role in catabolism of fatty acids during fasting along with dietary lipid overload, but the mechanisms regulating this process remain poorly understood. Here, we show that Cdc2-like kinase 2 (Clk2) suppresses fatty acid oxidation and ketone body production during diet-induced obesity. In lean mice, hepatic Clk2 protein is very low during fasting and strongly increased during feeding; however, in diet-induced obese mice, Clk2 protein remains elevated through both fed and fasted states. Liver-specific Clk2 knockout mice fed a high-fat diet exhibit increased fasting levels of blood ketone bodies, reduced respiratory exchange ratio, and increased gene expression of fatty acid oxidation and ketogenic pathways. This effect of Clk2 is cell-autonomous, because manipulation of Clk2 in hepatocytes controls genes and rates of fatty acid utilization. Clk2 phosphorylation of peroxisome proliferator-activated receptor γ coactivator (PGC-1α) disrupts its interaction with Mediator subunit 1, which leads to a suppression of PGC-1α activation of peroxisome proliferator-activated receptor α target genes in fatty acid oxidation and ketogenesis. These data demonstrate the importance of Clk2 in the regulation of fatty acid metabolism in vivo and suggest that inhibition of hepatic Clk2 could provide new therapies in the treatment of fatty liver disease.

Cruentaren A binds F1F0 ATP synthase to modulate the Hsp90 protein folding machinery

The molecular chaperone Hsp90 requires the assistance of immunophilins, co-chaperones, and partner proteins for the conformational maturation of client proteins. Hsp90 inhibition represents a promising anticancer strategy due to the dependence of numerous oncogenic signaling pathways upon Hsp90 function. Historically, small molecules have been designed to inhibit ATPase activity at the Hsp90 N-terminus; however, these molecules also induce the pro-survival heat shock response (HSR). Therefore, inhibitors that exhibit alternative mechanisms of action that do not elicit the HSR are actively sought. Small molecules that disrupt Hsp90-co-chaperone interactions can destabilize the Hsp90 complex without induction of the HSR, which leads to inhibition of cell proliferation. In this article, selective inhibition of F₁F₀ ATP synthase by cruentaren A was shown to disrupt the Hsp90-F₁F₀ ATP synthase interaction and result in client protein degradation without induction of the HSR.

USP7 attenuates hepatic gluconeogenesis through modulation of FoxO1 gene promoter occupancy

Hepatic forkhead protein FoxO1 is a key component of systemic glucose homeostasis via its ability to regulate the transcription of rate-limiting enzymes in gluconeogenesis. Important in the regulation of FoxO1 transcriptional activity are the modifying/demodifying enzymes that lead to posttranslational modification. Here, we demonstrate the functional interaction and regulation of FoxO1 by herpesvirus-associated ubiquitin-specific protease 7 (USP7; also known as herpesvirus-associated ubiquitin-specific protease, HAUSP), a deubiquitinating enzyme. We show that USP7-mediated mono-deubiquitination of FoxO1 results in suppression of FoxO1 transcriptional activity through decreased FoxO1 occupancy on the promoters of gluconeogenic genes. Knockdown of USP7 in primary hepatocytes leads to increased expression of FoxO1-target gluconeogenic genes and elevated glucose production. Consistent with this, USP7 gain-of-function suppresses the fasting/cAMP-induced activation of gluconeogenic genes in hepatocyte cells and in mouse liver, resulting in decreased hepatic glucose production. Notably, we show that the effects of USP7 on hepatic glucose metabolism depend on FoxO1. Together, these results place FoxO1 under the intimate regulation of deubiquitination and glucose metabolic control with important implication in diseases such as diabetes.

Adaptation of innate lymphoid cells to a micronutrient deficiency promotes type 2 barrier immunity

How the immune system adapts to malnutrition to sustain immunity at barrier surfaces, such as the intestine, remains unclear. Vitamin A deficiency is one of the most common micronutrient deficiencies and is associated with profound defects in adaptive immunity. Here, we found that type 3 innate lymphoid cells (ILC3s) are severely diminished in vitamin A-deficient settings, which results in compromised immunity to acute bacterial infection. However, vitamin A deprivation paradoxically resulted in dramatic expansion of interleukin-13 (IL-13)-producing ILC2s and resistance to nematode infection in mice, which revealed that ILCs are primary sensors of dietary stress. Further, these data indicate that, during malnutrition, a switch to innate type 2 immunity may represent a powerful adaptation of the immune system to promote host survival in the face of ongoing barrier challenges.

Decreased genetic dosage of hepatic Yin Yang 1 causes diabetic-like symptoms

Insulin sensitivity in liver is characterized by the ability of insulin to efficiently inhibit glucose production and fatty acid oxidation as well as promote de novo lipid biosynthesis. Specific dysregulation of glucose and lipid metabolism in liver is sufficient to cause insulin resistance and type 2 diabetes; this is seen by a selective inability of insulin to suppress glucose production while remaining insulin-sensitive to de novo lipid biosynthesis. We have previously shown that the transcription factor Yin Yang 1 (YY1) controls diabetic-linked glucose and lipid metabolism gene sets in skeletal muscle, but whether liver YY1-targeted metabolic genes impact a diabetic phenotype is unknown. Here we show that decreased genetic dosage of YY1 in liver causes insulin resistance, hepatic lipid accumulation, and dyslipidemia. Indeed, YY1 liver-specific heterozygous mice exhibit blunted activation of hepatic insulin signaling in response to insulin. Mechanistically, YY1, through direct recruitment to promoters, functions as a suppressor of genes encoding for metabolic enzymes of the gluconeogenic and lipogenic pathways and as an activator of genes linked to fatty acid oxidation. These counterregulatory transcriptional activities make targeting hepatic YY1 an attractive approach for treating insulin-resistant diabetes.

Triazole Containing Novobiocin and Biphenyl Amides as Hsp90 C-Terminal Inhibitors

Hsp90 C-terminal inhibitors are advantageous for the development of new cancer chemotherapeutics due to their ability to segregate client protein degradation from induction of the prosurvival heat shock response, which is a major detriment associated with Hsp90 N-terminal inhibitors under clinical investigation. Based upon prior SAR trends, a 1,2,3-triazole side chain was placed in lieu of the aryl side chain and attached to both the coumarin and biphenyl scaffold. Antiproliferative studies against SKBr3 and MCF-7 breast cancer cell lines demonstrated these triazole-containing compounds to exhibit improved activity. These compounds were shown to manifest Hsp90 inhibitory activity through Western blot analysis and represent a new scaffold upon which more potent inhibitors can be pursued.

Synthesis and structure-activity relationships of EGCG analogues, a recently identified Hsp90 inhibitor

Epigallocatechin-3-gallate (EGCG), the principal polyphenol isolated from green tea, was recently shown to inhibit Hsp90; however, structure-activity relationships for this natural product have not yet been produced. Herein, we report the synthesis and biological evaluation of EGCG analogues to establish structure-activity relationships between EGCG and Hsp90. All four rings as well as the linker connecting the C- and the D-rings were systematically investigated, which led to the discovery of compounds that inhibit Hs90 and display improvement in efficacy over EGCG. Antiproliferative activity of all the analogues was determined against MCF-7 and SKBr3 cell lines and Hsp90 inhibitory activity of the four most potent analogues was further evaluated by Western blot analyses and degradation of Hsp90-dependent client proteins. The prenyl-substituted aryl ester of 3,5-dihydroxychroman-3-ol ring system was identified as a novel scaffold that exhibits Hsp90 inhibitory activity.

Influence of contact size on the detection of HFOs in human intracerebral EEG recordings

OBJECTIVE

High frequency oscillations (HFOs) are brief electroencephalographic events associated with epileptic activity, and likely representing biological markers of the epileptogenic zone. HFOs are usually detected with intracranial EEG and detection is influenced by contact size. The size of commercially available intracerebral electrodes varies widely. This study assesses HFO detection rates from adjacent electrode contacts in human intracerebral recordings.

METHODS

Intracerebral recordings were collected from 11 patients undergoing stereoelectroencephalographic investigation using hybrid depth electrodes containing adjacent large (0.8 or 5 mm(2)) and small (0.2 or 0.3 mm(2)) contacts. HFOs were marked manually during 5-min tracings in 131 pairs of adjacent large and small contacts. HFO rates per minute and mean event durations were compared between adjacent contacts.

RESULTS

A minimal but statistically significant advantage in ripple detection was found in a subgroup of large contacts. Otherwise, HFO rates and mean event durations were not statistically different between groups.

CONCLUSION

The size of clinical contacts within the studied range did not influence HFO detection in a clinically relevant manner. Larger contacts provide a minimal advantage for ripple detection.

SIGNIFICANCE

Our findings suggest that commercially available intracerebral electrodes with contacts between 0.2 and 5 mm(2) likely possess similar HFO detection abilities.

The sirtuin family's role in aging and age-associated pathologies

The 7 mammalian sirtuin proteins compose a protective cavalry of enzymes that can be invoked by cells to aid in the defense against a vast array of stressors. The pathologies associated with aging, such as metabolic syndrome, neurodegeneration, and cancer, are either caused by or exacerbated by a lifetime of chronic stress. As such, the activation of sirtuin proteins could provide a therapeutic approach to buffer against chronic stress and ameliorate age-related decline. Here we review experimental evidence both for and against this proposal, as well as the implications that isoform-specific sirtuin activation may have for healthy aging in humans.

Fit for the future? The place of global health in the UK's postgraduate medical training: a review

OBJECTIVES

That health is now global is increasingly accepted. However, a 'mismatch between present professional competencies and the requirements of an increasingly interdependent world' has been identified. Postgraduate training should take account of the increasingly global nature of health; this paper examines the extent to which they currently do.

DESIGN

Trainees across 11 medical specialties reviewed the content of their postgraduate curriculum.

SETTING

Not relevant. PARTCIPANTS: None.

MAIN OUTCOME MEASURES

Competencies were coded as 'UK' (statement only relevant to UK work), 'global' (statement with an explicit reference to aspects of health outside the UK) or generic (relevant both to the UK and international settings).

RESULTS

Six of the 11 curricula reviewed contained global health competencies. These covered the global burden or determinants of disease and appropriate policy responses. Only one College required trainees to 'be aware of the World Health Organization', or 'know the local, national and international structures for health care'. These cross-cutting competencies have applicability to all specialties. All 11 curricula contained generic competencies where a global health perspective and/or experience could be advantageous, e.g. caring for migrant or culturally different patients.

CONCLUSION

Trainees in all specialties should achieve a minimum requirement of global health awareness. This can be achieved through a small number of common competencies that are consistent across core curricula. These should lead on from equivalent undergraduate competencies. Addressing the current gap in the global health content of postgraduate medical curricula will ensure that the UK has health professionals that are trained to meet the health challenges of the future.

Organic and inorganic selenium: IV. passive transfer of immunoglobulin from ewe to lamb

Newborn lambs depend on their dams for passive transfer of immunoglobulins, primarily IgG, for protection from harmful pathogens until their own immunological defenses have developed. Previous studies have suggested that supplementation with Se results in a modest increase in IgG concentration in serum of newborn calves and lambs. To evaluate the effect of the Se source and supplementation rate in ewes during pregnancy on passive transfer of IgG to their lambs, 210 Polypay, Suffolk, or Suffolk × Polypay cross ewes were divided into 7 treatment groups (n = 30 each) and drenched weekly with no Se, at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk), or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk). Ewe serum IgG concentrations were measured within 30 d of parturition, ewe colostrum and lamb serum IgG concentrations were measured at parturition before suckling, and lamb serum IgG concentrations were measured again at 48 h postnatal. Ewes receiving 24.5 mg Se/wk tended to have or had, independent of Se source, greater colostral IgG concentrations than ewes receiving 4.9 mg Se/wk overall (81.3 vs. 66.2 mg/mL; P = 0.08) and for Polypay ewes only (90.1 vs. 60.7 mg/mL; P = 0.03). Polypay ewes receiving Se-yeast at 24.5 mg Se/wk transferred a greater calculated total IgG amount to their lambs than Polypay ewes receiving Se-yeast at 4.9 mg Se/wk (15.5 vs. 11.6 g; P = 0.02), whereas the converse was true (interaction between Se source and dose concentration; P = 0.03) for Polypay ewes receiving inorganic Na-selenite at 24.5 mg Se/wk vs. Na-selenite at 4.9 mg/wk (11.6 vs. 15.7 g; P = 0.08). Our results suggest that supranutritional Se supplementation of Polypay ewes during pregnancy increases colostral IgG concentrations but that the optimal supplementation rate for IgG transfer from ewe to lamb may differ for Na-selenite and Se-yeast.

Organic and inorganic selenium: III. Ewe and progeny performance

Selenium is an essential micronutrient in sheep, and deficiency can limit lamb growth and survival. To evaluate how different chemical forms of Se administered to mature ewes at comparative dosages affect ewe and progeny performance, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly with no Se; at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk); with inorganic Na-selenate (8.95 mg Se/wk); or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk, respectively). The treatment period started approximately 2 wk before breeding and lasted for 62.5 wk. Ewes of the no-Se and Se-yeast groups continued treatments for another 21 to 24 wk through a second lambing season. Chemical form or dosage of Se did not affect ewe reproductive performance based on proportion of ewes lambing in each treatment group, or number of lambs born, nursed, or weaned per ewe (all P > 0.10). Ewes receiving the highest supplementation rate of Se-yeast at 24.5 mg Se/wk had higher BCS (scale 1 to 5) at the end of yr 1 (2.95 vs. 2.66; P = 0.05) than ewes receiving Se-yeast at 4.9 mg Se/wk. Performance was better in lambs from ewes receiving Se-yeast at 24.5 mg Se/wk than in lambs from ewes receiving Se-yeast at 4.9 mg Se/wk or no Se. In yr 1, lambs from ewes receiving Se-yeast at 24.5 vs. 4.9 mg Se/wk were heavier at 120 d of age (37.0 vs. 34.2 kg; P = 0.05). In yr 2, lambs from ewes receiving Se-yeast at 24.5 mg Se/wk were or tended to be heavier at 60 d of age than lambs from ewes receiving no Se (21.2 vs. 19.0 kg; P = 0.04) or lambs from ewes receiving Se-yeast at 4.9 mg Se/wk (19.2 kg; P = 0.09). This effect was more pronounced in ewes raising multiple lambs. We conclude that supranutritional supplementation of ewes with Se-yeast at 24.5 mg Se/wk improves lamb growth and ewe health without negatively affecting reproductive performance.

Organic and inorganic selenium: I. Oral bioavailability in ewes

Although the essentiality of dietary Se for sheep has been known for decades, the chemical source and Se dosage for optimal health remain unclear. In the United States, the Food and Drug Administration (FDA) regulates Se supplementation, regardless of the source of Se, at 0.3 mg of Se/kg of diet (as fed), which is equivalent to 0.7 mg of Se/d or 4.9 mg of Se/wk per sheep. The objectives of this study were to evaluate the effects of Se source (inorganic vs. organic) and supplementation rate (FDA vs. supranutritional rates of 14.7 and 24.5 mg of Se/wk) on whole-blood (WB) and serum-Se concentrations. Mature ewes (n = 240) were randomly assigned to 8 treatment groups (n = 30 each) based on Se supplementation rate (4.9, 14.7, and 24.5 mg of Se•wk(-1)•sheep(-1)) and source [Na-selenite, Na-selenate (4.9 mg/wk only), and organic Se-yeast] with a no-Se control group (0 mg of Se/wk). Treatment groups were balanced for healthy and footrot-affected ewes. For 1 yr, ewes were individually dosed once weekly with 0, 4.9, 14.7, or 24.5 mg of Se, quantities equivalent to their summed daily supplementation rates. Serum- and WB-Se concentrations were measured every 3 mo in all ewes; additionally, WB-Se concentrations were measured once monthly in one-half of the ewes receiving 0 or 4.9 mg of Se/wk. Ewes receiving no Se showed a 78.8 and 58.8% decrease (P < 0.001) in WB- (250 to 53 ng/mL) and serum- (97 to 40 ng/mL) Se concentrations, respectively, over the duration of the study. Whole-blood Se decreased primarily during pregnancy (-57%; 258 to 111 ng/mL) and again during peak lactation (-44%; 109 to 61 ng/mL; P < 0.001). At 4.9 mg of Se/wk, Se-yeast (364 ng/mL, final Se concentration) was more effective than Na-selenite (269 ng/mL) at increasing WB-Se concentrations (P < 0.001). Supranutritional Se-yeast dosages increased WB-Se concentrations in a dose-dependent manner (563 ng/mL, 14.7 mg of Se/wk; 748 ng/mL, 24.5 mg of Se/wk; P < 0.001), whereas WB-Se concentrations were not different for the Na-selenite groups (350 ng/mL, 14.7 mg of Se/wk; 363 ng/mL, 24.5 mg of Se/wk) or the 4.9 mg of Se/wk Se-yeast group (364 ng/mL). In summary, the dose range whereby Se supplementation increased blood Se concentrations was more limited for inorganic Na-selenite than for organic Se-yeast. The smallest rate (FDA-recommended quantity) of organic Se supplementation was equally effective as supranutritional rates of Na-selenite supplementation in increasing WB-Se concentrations, demonstrating the greater oral bioavailability of organic Se.

Disruption of thyroid hormone activation in type 2 deiodinase knockout mice causes obesity with glucose intolerance and liver steatosis only at thermoneutrality

OBJECTIVE

Thyroid hormone accelerates energy expenditure; thus, hypothyroidism is intuitively associated with obesity. However, studies failed to establish such a connection. In brown adipose tissue (BAT), thyroid hormone activation via type 2 deiodinase (D2) is necessary for adaptive thermogenesis, such that mice lacking D2 (D2KO) exhibit an impaired thermogenic response to cold. Here we investigate whether the impaired thermogenesis of D2KO mice increases their susceptibility to obesity when placed on a high-fat diet.

RESEARCH DESIGN AND METHODS

To test this, D2KO mice were admitted to a comprehensive monitoring system acclimatized to room temperature (22°C) or thermoneutrality (30°C) and kept either on chow or high-fat diet for 60 days.

RESULTS

At 22°C, D2KO mice preferentially oxidize fat, have a similar sensitivity to diet-induced obesity, and are supertolerant to glucose. However, when thermal stress is eliminated at thermoneutrality (30°C), an opposite phenotype is encountered, one that includes obesity, glucose intolerance, and exacerbated hepatic steatosis. We suggest that a compensatory increase in BAT sympathetic activation of the D2KO mice masks metabolic repercussions that they would otherwise exhibit.

CONCLUSIONS

Thus, upon minimization of thermal stress, high-fat feeding reveals the defective capacity of D2KO mice for diet-induced thermogenesis, provoking a paradigm shift in the understanding of the role of the thyroid hormone in metabolism.

Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens

Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens. A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte antigen (HLA) HLA-DQ2 or HLA-DQ8 molecules develop inflammatory T-cell and antibody responses against dietary gluten, a protein present in wheat. The mechanisms underlying this dysregulated mucosal immune response to a soluble antigen have not been identified. Retinoic acid, a metabolite of vitamin A, has been shown to have a critical role in the induction of intestinal regulatory responses. Here we find in mice that in conjunction with IL-15, a cytokine greatly upregulated in the gut of coeliac disease patients, retinoic acid rapidly activates dendritic cells to induce JNK (also known as MAPK8) phosphorylation and release the proinflammatory cytokines IL-12p70 and IL-23. As a result, in a stressed intestinal environment, retinoic acid acted as an adjuvant that promoted rather than prevented inflammatory cellular and humoral responses to fed antigen. Altogether, these findings reveal an unexpected role for retinoic acid and IL-15 in the abrogation of tolerance to dietary antigens.

Absence of thyroid hormone activation during development underlies a permanent defect in adaptive thermogenesis

Type 2 deiodinase (D2), which is highly expressed in brown adipose tissue (BAT), is an enzyme that amplifies thyroid hormone signaling in individual cells. Mice with inactivation of the D2 pathway (D2KO) exhibit dramatically impaired thermogenesis in BAT, leading to hypothermia during cold exposure and a greater susceptibility to diet-induced obesity. This was interpreted as a result of defective acute activation of BAT D2. Here we report that the adult D2KO BAT has a permanent thermogenic defect that stems from impaired embryonic BAT development. D2KO embryos have normal serum T3 but due to lack of D2-generated T3 in BAT, this tissue exhibits decreased expression of genes defining BAT identity [i.e. UCP1, PGC-1alpha and Dio2 (nonfunctional)], which results in impaired differentiation and oxidative capacity. Coinciding with a reduction of these T3-responsive genes, there is oxidative stress that in a cell model of brown adipogenesis can be linked to decreased insulin signaling and decreased adipogenesis. This discovery highlights the importance of deiodinase-controlled thyroid hormone signaling in BAT development, where it has important metabolic repercussions for energy homeostasis in adulthood.

The use of atropine for facilitation of direct current cardioversion from atrial fibrillation--results of a pilot study

BACKGROUND

The importance of the role of the autonomic nervous system (ANS) in the initiation and propagation of atrial fibrillation has been demonstrated in the condition of paroxysmal atrial fibrillation. However, the role of the ANS in patients with chronic atrial fibrillation is less clear. Some patients with chronic atrial fibrillation are resistant to the standard techniques of direct current (DC) cardioversion.

HYPOTHESIS

We sought to investigate whether excessive vagal tone might prevent the restoration of sinus rhythm and to establish that the abolition of vagal tone using intravenous atropine will facilitate DC cardioversion in patients with atrial fibrillation who are resistant to the standard cardioversion techniques.

METHODS

Beginning in August 1994, a change in the protocol for elective DC cardioversion of atrial fibrillation was made to include the use of intravenous atropine for patients resistant to the standard techniques of DC cardioversion.

RESULTS

Over a 2-year period, 140 elective cardioversions were performed for atrial fibrillation. Sinus rhythm could not be restored on 31 occasions. Intravenous atropine prior to a further 360 J shock with paddles in the anteroposterior position allowed sinus rhythm to be restored on nine occasions. Patients with successful cardioversion after atropine had significantly better left ventricular function than those who remained in atrial fibrillation (p = 0.001) as well as a tendency toward a smaller left atrium.

CONCLUSION

This study suggests that high vagal tone, which is dominant in patients with structurally normal hearts, may prevent the termination of atrial fibrillation by standard techniques of DC cardioversion, and that the abolition of high vagal tone by atropine facilitates the restoration of sinus rhythm.

Effect of parenteral selenium administration to sheep on prevalence and recovery from footrot

BACKGROUND

Insufficient intake of selenium (Se) is common in many regions, and can contribute to increased susceptibility to and prolonged recovery from infectious diseases.

OBJECTIVE

To determine the effect of Se administration in decreasing the severity and prevalence of footrot in sheep.

ANIMALS

Thirty-eight footrot-affected and 19 nonaffected sheep from a commercial flock of known high incidence of footrot.

METHODS

Placebo-controlled, prospective, 15-month clinical trial. Footrot-affected sheep were randomly assigned into 2 groups (n = 19) and injected with either 5 mg Se (footrot [FR]-Se) or saline (FR-Sal) at 1-month intervals for the duration of the study. Unaffected sheep (controls) received no treatment. Sheep feet were examined, trimmed, and scored for footrot with a scale of 0 (no footrot) to 4 (extensive) at 0, 3, 6, 9, and 15 months. Sheep were also bled at time 0 and then at 3, 6, and 15 months to assess whole blood Se concentrations.

RESULTS

At time 0, control sheep (255 +/- 11 ng/mL) had higher (P < .05) whole blood Se concentrations compared with FR-Se (205 +/- 12 ng/mL) and FR-Sal (211 +/- 14 ng/mL) sheep. By 6 months, FR-Se sheep (317 +/- 9 ng/mL) had whole blood Se concentrations greater (P < .05) than both control (281 +/- 14 ng/mL) and FR-Sal (277 +/- 16 ng/mL) sheep. FR-Se ewes showed a faster decline in highest lesion score at 3 (P= .012) and 6 (P= .0036) months, and a greater decrease in the number of feet with foot score >0 at 6 (P= .020) months compared with FR-Sal ewes. Sheep with blood Se concentrations <300 ng/mL were at 3.5 times greater risk (1.1-12.1 confidence interval, odds ratio) for FR, although this relationship was only significant (P= .04) at 6 months of the study.

CONCLUSIONS AND CLINICAL IMPORTANCE

In sheep with footrot, improved Se status in conjunction with routine control practices result in more rapid improvement of foot lesions.

DNA perseverance of microorganisms exposed to silica: an experimental study

The persistence of DNA from microorganisms exposed to various concentrations of SiO2 (ranging from 0 to 3000 p.p.m.) was monitored over time. The impact of silica mineralization or silicification on the longevity of 16S rRNA and 16 s rDNA genes from whole cells of Bacillus subtilis and Escherichia coli K12 was quantified using real-time polymerase chain reaction (RT-PCR), and cells were visualized using optical microscopy. For B. subtilis, DNA longevity decreased in experiments with higher levels of SiO2 (1000 and 3000 p.p.m.), in comparison to zero or low (100 p.p.m.) levels. For B. subtilis, cell viability was greatest in the absence of silica, and markedly decreased in the presence of any concentration of silica. Survival of Escherichia coli cells, on the other hand, was not sensitive to silica in the solution. All cells died at similar rates over the 180 days they were monitored, decreasing to about 1% survival. DNA longevity for E. coli did appear to be enhanced to some degree by the presence of 1000 p.p.m. silica, but higher or lower concentrations showed no increased longevity in comparison to the no-silica control. Overall, findings of this study do not support the hypothesis that siliceous environments provide enhanced protection and preservation of DNA over time. However, results of this study do provide guidelines on the persistence of DNA that might be expected in modern silica-rich environments, which may be an important factor for proper characterization of present-day microbial communities.

Simultaneous presentation of coronary heart disease in identical twins

The development of coronary artery disease involves a complex interplay between environmental and genetic factors, with premature coronary artery disease having a strong genetic component. We present the case a pair of monozygotic identical twins presenting near simultaneously with coronary artery disease and identical atherosclerotic lesions despite significant differences in environmental risk factors and being divided geographically by 12,000 miles. This is of enormous importance and not merely curiosity value as it will have implications for the prevention of coronary artery disease, provide an opportunity for the development of new therapeutic strategies, and aid targeted primary prevention through family screening.

Drug facilitated sexual assault--a review

This review was undertaken to identify the evolutionary process in the current understanding of allegations of drug facilitated sexual assault (DFSA), so that those who work in this field may gain a better understanding of the complexities involved in such cases. Several definitions of DFSA are provided as well as a list of intoxicating substances which have so far been incriminated in this crime. Perception and alcohol use is addressed, whilst an examination of intoxication and victim outcomes reveals disturbing but important information which needs to be centrally placed within health education campaigns with a degree of urgency. The review identifies the effects of alcohol on sexual behaviour, drinking patterns and specific quantitative research indicating very high alcohol levels in some instances. In practical terms, suggestions are made following Operation Matisse, to address prevention, early detection and easier identification of DFSA cases so that victims' needs are prioritised and appropriately addressed.

Lymphocyte blastogenic response to ovalbumin in a model for canine allergy

Lymphocyte stimulation tests (LST) were performed in five dogs sensitised with ovalbumin (OVA) and seven healthy dogs. In addition, all five OVA-sensitised and two control dogs were tested after two in vivo provocations with OVA-containing eye drops. The isolated cells were suspended in culture media containing OVA and were cultured for up to 12 days. Proliferation was measured as reduction in 5,6-carboxylfluorescein diacetate succinimidyl ester (CFSE) intensity by flow cytometry on days 0, 3, 6, 9 and 12. A cell proliferation index (CPI) for each day and the area under the curve (AUC) of the CPI was calculated for each dog. All OVA-sensitised dogs demonstrated increased erythema after conjunctival OVA application. The presence of OVA-specific lymphocytes was demonstrated in 2/5 OVA-sensitised dogs before and 4/5 after in vivo provocation. Using the AUC, the difference between OVA-sensitised and control dogs was significant in all three LST before in vivo provocation (P<0.05) and borderline significant (P=0.053) in 2/3 LST after provocation. The most significant difference in CPI was observed after 9 days of culture (P=0.001). This pilot study indicates that the LST allows detection of rare antigen specific memory T-cells in dogs previously sensitised to, but not concurrently undergoing challenge by a specific antigen.