Neuroprotection of low dose carbon monoxide in Parkinson's disease models commensurate with the reduced risk of Parkinson's among smokers

Paradoxically, cigarette smoking is associated with a reduced risk of Parkinson's disease (PD). This led us to hypothesize that carbon monoxide (CO) levels, which are constitutively but modestly elevated in smokers, might contribute to neuroprotection. Using rodent models of PD based on α-synuclein (αSyn) accumulation and oxidative stress, we show that low-dose CO mitigates neurodegeneration and reduces αSyn pathology. Oral CO administration activated signaling cascades mediated by heme oxygenase-1 (HO-1), which have been implicated in limiting oxidative stress, and in promoting αSyn degradation, thereby conferring neuroprotection. Consistent with a neuroprotective effect of smoking, HO-1 levels in cerebrospinal fluid were higher in human smokers compared to nonsmokers. Moreover, in PD brain samples, HO-1 levels were higher in neurons without αSyn pathology. Thus, CO in rodent PD models reduces pathology and increases oxidative stress responses, phenocopying possible protective effects of smoking evident in PD patients. These data highlight the potential for low-dose CO modulated pathways to slow symptom onset and limit pathology in PD patients.

Uncertainty in phosphorus fluxes and budgets across the U.S. long-term agroecosystem research network

Phosphorus (P) budgets can be useful tools for understanding nutrient cycling and quantifying the effectiveness of nutrient management planning and policies; however, uncertainties in agricultural nutrient budgets are not often quantitatively assessed. The objective of this study was to evaluate uncertainty in P fluxes (fertilizer/manure application, atmospheric deposition, irrigation, crop removal, surface runoff, leachate) and the propagation of these uncertainties to annual P budgets. Data from 56 cropping systems in the P-FLUX database, which spans diverse rotations and landscapes across the U.S. and Canada, were evaluated. Results showed that across cropping systems, average annual P budget was 22.4 kg P ha^-1 (range = -32.7 to 340.6 kg P ha^-1 ), with an average uncertainty of 13.1 kg P ha^-1 (range = 1.0 to 87.1 kg P ha^-1 ). Fertilizer/manure application and crop removal were the largest P fluxes across cropping systems and, as a result, accounted for the largest fraction of uncertainty in annual budgets (61 and 37%, respectively). Remaining fluxes individually accounted for <2% of the budget uncertainty. Uncertainties were large enough that determining whether P was increasing, decreasing, or not changing was inconclusive in 39% of the budgets evaluated. Findings indicate that more careful and/or direct measurements of inputs, outputs, and stocks are needed. Recommendations for minimizing uncertainty in P budgets based on the results of the study were developed. Quantifying, communicating, and constraining uncertainty in budgets among production systems and multiple geographies is critical for engaging stakeholders, developing local and national strategies for P reduction, and informing policy. This article is protected by copyright. All rights reserved.

P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada

Quantifying spatial and temporal fluxes of phosphorus (P) within and among agricultural production systems is critical for sustaining agricultural production while minimizing environmental impacts. To better understand P fluxes in agricultural landscapes, P-FLUX, a detailed and harmonized dataset of P inputs, outputs, and budgets, as well as estimated uncertainties for each P flux and budget, was developed. Data were collected from 24 research sites and 61 production systems through the Long-term Agroecosystem Research (LTAR) network and partner organizations spanning 22 U.S. states and 2 Canadian provinces. The objectives of this paper are to (a) present and provide a description of the P-FLUX dataset, (b) provide summary analyses of the agricultural production systems included in the dataset and the variability in P inputs and outputs across systems, and (c) provide details for accessing the dataset, dataset limitations, and an example of future use. P-FLUX includes information on select site characteristics (area, soil series), crop rotation, P inputs (P application rate, source, timing, placement, P in irrigation water, atmospheric deposition), P outputs (crop removal, hydrologic losses), P budgets (agronomic budget, overall budget), uncertainties associated with each flux and budget, and data sources. Phosphorus fluxes and budgets vary across agricultural production systems and are useful resources to improve P use efficiency and develop management strategies to mitigate environmental impacts of agricultural systems. P-FLUX is available for download through the USDA Ag Data Commons (https://doi.org/10.15482/USDA.ADC/1523365).

COVID-19: using chest CT of major trauma patients to monitor and evaluate the second wave in London and the development of routine monitoring in practice

AIM

To follow-up previous work evaluating incidental findings of COVID-19 signs on computed tomography (CT) images of major trauma patients to include the second wave prior to any major effects from vaccines.

MATERIALS AND METHODS

The study population included all patients admitted following major trauma between 1 January 2020 and 28 February 2021 with CT including the lungs (n=1776). Major trauma patients admitted pre-COVID-19 from alternate months from January 2019 to November 2019 comprised a control group (n=837). The assessing radiologists were blinded to the time period and used double reading in consensus to determine if the patient had signs of COVID-19. Lung appearances were classified as no evidence of COVID-19, minor signs, or major signs.

RESULTS

The method successfully tracked the second wave of the COVID-19 pandemic in London. The estimated population affected by the disease based on those with major signs was similar to estimates of the proportion of the population in London with antibodies (around 30% by end February 2021) and the total of major and minor signs produced a much higher figure of 68%, which may include all those with both antibody and just T-cell responses.

CONCLUSIONS

Incidental findings on CT from major trauma patients may provide a novel and sensitive way of tracking the virus. It is recommended that all major trauma units include a simple question on signs of COVID-19 to provide an early warning system for further waves.

P14.24 Estimating survival outcomes in elderly (70+ years) patients with primary glioblastoma

BACKGROUND

Elderly patients with glioblastoma are perceived to face a poor prognosis, with perceptions around older age and a relative lack of randomized data raising a concern about their undertreatment. The EANO guidelines recommend &gt;70-year-old patients with good performance status to undergo maximal safe resection followed by hypofractionated (40 Gy in 15 fractions, i.e. RT40/15) radiotherapy with or without concurrent and adjuvant Temozolomide (TMZ), depending on MGMT promoter methylation. This study evaluated the relative survival impact of biological, histological, surgical and oncological factors and aimed to devise a scoring system to estimate the survival of elderly glioblastoma patients, with an aim to more accurately guide treatment in this cohort.

METHODS

The records of 169 elderly (≥70 years) patients with a new diagnosis of IDH-wild type glioblastoma were retrospectively examined for gender, age, WHO performance status (PS), comorbidities, MGMT methylation, surgical intervention and chemoradiation regime. The adjusted survival impact of these factors was determined using Cox proportional hazards model and used to devise a two-stage scoring system to estimate survival of patients at the stage of surgical (Elderly Glioblastoma Surgical Score, EGSS) and oncological management (Elderly Glioblastoma Oncological Score, EGOS).

RESULTS

The overall median survival (MS) of the cohort was 28.8 weeks. Subtotal resection (MS=27.7 weeks, 95%CI 24.1–31.6 weeks, HR=0.58) and gross-total resection (MS=77.8 weeks, 95%CI 67.0–88.6 weeks, HR=0.36) were associated with significant overall survival benefit compared to biopsy alone (MS=18.2 weeks, 95%CI 15.7–20.7 weeks, HR=5.23), p&lt;0.05. Hypofractionated radiation with Temozolomide (RT40/15+TMZ, MS=60.9 weeks, 95%CI 49.9–71.8 weeks, HR=0.13) was non-inferior to the Stupp protocol (RT60/30+TMZ, MS=50.6 weeks, 95%CI 32.4–66.7 weeks, HR=0.11), p=0.72. Negative prognosticators included age above 75 years, biopsy alone and no chemoradiotherapy. Subgroup analysis revealed that MGMT unmethylated 70–75 year old patients who received the Stupp protocol had significantly improved overall survival (MS=57.6 weeks, 95%CI 27.7–88.1 weeks) compared to standard of care RT40/15 alone (MS=29.7 weeks, 95%CI 7.1–51.6 weeks), p=0.002. EGSS and EGOS scores estimated survival with 65% and 73% accuracy, respectively.

CONCLUSION

When appropriate and safe, a subgroup of elderly glioblastoma patients may benefit from more aggressive surgical and oncological management. The proposed EGSS and EGOS scores takes into account important prognostic factors to help guide which patients should receive such treatment.

Anaesthesia for Robot-Assisted Anatomic Prostatectomy. Experience at a Single Institution

Robot-assisted anatomic prostatectomy is an emerging technique for management of prostate cancer. It requires a coordinated approach by anaesthetist and surgeon as the surgery is performed using a modified laparoscopic technique and is potentially of long duration in a Trendelenberg position. We describe some aspects of the surgical technique and our anaesthetic approach with the first 40 cases at our institution. The mean hospital stay was 4.2 days and none of the patients required blood transfusion. A retrospective audit indicated that the use of epidural analgesia in the early postoperative period reduced opioid analgesic requirements.

The Future Excess Fraction of Cancer Attributable to High Body Mass Index in Australia

Background: High body mass index (BMI > 25 kg/m2) has been found to be associated with an increased risk of many cancers, including cancers of the colon and rectum, liver, and pancreas. Aim: This study aimed to estimate the future burden of cancer resulting from current levels of overweight and obesity in Australia. Methods: The future excess fraction method was used to estimate the future burden of cancer among the proportion of the Australian adult population who were overweight or obese in 2016. Calculations were conducted for 13 cancer types, including cancers of the colon, rectum, kidney, and liver. Results: The cohort of 18.7 million adult Australians in 2016 will develop ∼7.6 million cancers over their lifetime. Of these, ∼402,500 cancers (5.3%) will be attributable to current levels of overweight and obese. The majority of these will be postmenopausal breast cancers (n = 72,300), kidney cancers (n = 59,200), and colon cancers (n = 55,100). More than a quarter of future endometrial cancers (30.3%) and esophageal adenocarcinomas (35.8%) will be attributable to high body mass index. Conclusion: A significant proportion of future cancers will result from current levels of high body mass index. Our estimates are not directly comparable to past estimates of the burden from overweight and obesity because they describe different quantities - future cancers in currently exposed vs current cancers due to past exposures. The results of this study provide us with relevant up-to-date information about how many cancers in Australia could be prevented.

Abstract MIP-070: THE IMPACT OF HBO1 IN OVARIAN CANCER

Epithelial ovarian cancer (OC) is now the fifth leading cause of cancer death among women in the U.S. and the leading cause of death in gynecological cancers. OC comprises a variety of tumor types (histotypes) that differ in morphology, prognosis, etiology and molecular biology. Despite the knowledge of OC heterogeneity, current treatment strategies are very similar, and unfortunately, very ineffectual. New approaches, to inhibit OC growth and progression are therefore being sought, with few obvious targets for directed therapy. Currently, large–scale gene expression, DNA copy number and mutational screens have not been able to pinpoint new high frequency drugable targets.

Epigenetic therapy conceives a whole genome approach, potentially circumventing the reliance on therapies that target infrequently mutated genes. Histone acetyl–transferases like GCN5 and PCAF have been targeted in cancer previously, and the main purpose of this study is to assess the role of one such acetyl–transferase, Histone acetyl–transferase binding to origin of replication complex 1” (HBO1, also known as KAT7 and MYST2) in the progression of OC. HBO1 is a histone acetyltransferase (HAT) that plays important roles in diverse molecular processes including DNA replication, transcription and DNA repair. Importantly, HBO1 is overexpressed in primary cancers (breast, testis, ovarian), although the molecular basis of its role is still unclear.

To better understand HBO1's role in OC, we characterized its expression in well–defined OC cell lines both at the mRNA and protein level. Observed in vitro patterns of HBO1 expression correlate well with previous observations; HBO1 is overexpressed in several OC cell lines. Interestingly, the serous histotype generally shows the highest expression. Thus far, we have now analyzed HBO1's downstream regulatory pathways in several OC cell lines through use of siRNA knock–down coupled to microarray analysis. Comparisons of the various datasets have revealed pathways common to all cell lines studied, as well as distinction.

Our approach aims to identify known epigenomic signatures that may be associated with HBO1 binding and downstream signaling which may drive differentiation toward the most advanced stages of the disease. Translating this new information through epigenetic targeting and structural inhibition may lead to novel, next–generation therapies for this most complex of disease presentations.

Citation Format: M.Quintela, L.Francis, D.H.Sieglaff, P.Webb, S.Conlan. THE IMPACT OF HBO1 IN OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-070.

3,5-diiodothyronine (3,5-T2) reduces blood glucose independently of insulin sensitization in obese mice

AIM

Thyroid hormones regulate metabolic response. While triiodothyronine (T3) is usually considered to be the active form of thyroid hormone, one form of diiodothyronine (3,5-T2) exerts T3-like effects on energy consumption and lipid metabolism. 3,5-T2 also improves glucose tolerance in rats and 3,5-T2 levels correlate with fasting glucose in humans. Presently, however, little is known about mechanisms of 3,5-T2 effects on glucose metabolism. Here, we set out to compare effects of T3, 3,5-T2 and another form of T2 (3,3-T2) in a mouse model of diet-induced obesity and determined effects of T3 and 3,5-T2 on markers of classical insulin sensitization to understand how diiodothyronines influence blood glucose.

METHODS

Cell- and protein-based assays of thyroid hormone action. Assays of metabolic parameters in mice. Analysis of transcript and protein levels in different tissues by qRT-PCR and Western blot.

RESULTS

T3 and 3,5-T2 both reduce body weight, adiposity and body temperature despite increased food intake. 3,3'-T2 lacks these effects. T3 and 3,5-T2 reduce blood glucose levels, whereas 3,3'-T2 worsens glucose tolerance. Neither T3 nor 3,5-T2 affects markers of insulin sensitization in skeletal muscle or white adipose tissue (WAT), but both reduce hepatic GLUT2 glucose transporter levels and glucose output. T3 and 3,5-T2 also induce expression of mitochondrial uncoupling proteins (UCPs) 3 and 1 in skeletal muscle and WAT respectively.

CONCLUSIONS

3,5-T2 influences glucose metabolism in a manner that is distinct from insulin sensitization and involves reductions in hepatic glucose output and changes in energy utilization.

Sustained zero-order delivery of GC-1 from a nanochannel membrane device alleviates metabolic syndrome

BACKGROUND/OBJECTIVES

Our objective was to assess the sustained, low-dose and constant administration of the thyroid receptor-β (TRβ)-selective agonist GC-1 (sobetirome) from a novel nanochannel membrane device (NMD) for drug delivery. As it known to speed up metabolism, accomplish weight loss, improve cholesterol levels and possess anti-diabetic effects, GC-1 was steadily administered by our NMD, consisting of an implantable nanochannel membrane, as an alternative to conventional daily administration, which is subject to compliance issues in clinical settings.

SUBJECTS/METHODS

Diet-induced obese C57BL/J6 male mice were fed a very high-fat diet (VHFD) and received NMD implants subcutaneously. Ten mice per group received capsules containing GC-1 or phosphate-buffered saline (control). Weight, lean and fat mass, as well as cholesterol, triglycerides, insulin and glucose, were monitored for 24 days. After treatment, plasma levels of thyroid-stimulating hormone (TSH) and thyroxine were compared. mRNA levels of a panel of thermogenic markers were examined using real-time PCR in white adipose tissue (WAT) and brown adipose tissue (BAT). Adipose tissue, liver and local inflammatory response to the implant were examined histologically. Pancreatic islet number and β-cell area were assessed.

RESULTS

GC-1 released from the NMD reversed VHFD-induced obesity and normalized serum cholesterol and glycemia. Significant reductions in body weight and fat mass were observed within 10 days, whereas reductions in serum cholesterol and glucose levels were seen within 7 days. The significant decrease in TSH was consistent with TRβ selectivity for GC-1. Levels of transcript for Ucp1 and thermogenic genes PGC1a, Cidea, Dio2 and Cox5a showed significant upregulation in WAT in NMD-GC-1-treated mice, but decreased in BAT. Although mice treated by NMD-GC-1 showed a similar number of pancreatic islets, they exhibited significant increase in β-cell area.

CONCLUSIONS

Our data demonstrate that the NMD implant achieves steady administration of GC-1, offering an effective and tightly controlled molecular delivery system for treatment of obesity and metabolic disease, thereby addressing compliance.

The thyroid receptor β modulator GC-1 reduces atherosclerosis in ApoE deficient mice

Thyroid hormone reduces plasma cholesterol and increases expression of low-density lipoprotein receptor (LDL-R) in liver, an effect mediated by thyroid receptor β (TRβ). The selective TRβ modulator GC-1 also enhances several steps in reverse cholesterol transport and can decrease serum cholesterol independently of LDL-R. To test whether GC-1 reduces atherosclerosis and to determine which mechanisms are active, we treated ApoE deficient mice with atherogenic diet ± GC-1. GC-1 reduced cholesteryl esters in aorta after 20 weeks. Serum free and esterified cholesterol were reduced after 1 and 10 weeks, but not 20 weeks. Hepatic bile acid synthesis and LDL-R expression was elevated after 1, 10 and 20 weeks, without changes in hepatic de novo cholesterol synthesis. GC-1 increased faecal neutral sterols and reduced serum campesterol after 1 week, indicating reduced intestinal cholesterol absorption. After 20 weeks, GC-1 increased faecal bile acids, but not faecal neutral sterols. Hepatic scavenger receptor B1 (SR-B1) expression was decreased by GC-1. We conclude that GC-1 delays the onset of atherosclerosis in ApoE deficient mice. Since ApoE is needed for hepatic cholesterol reabsorption by LDL-R, this supports the idea that GC-1 reduces serum cholesterol independently of LDL-R by increasing hepatic bile acid synthesis. GC-1 lipid-lowering effects in ApoE deficient mice may also be partly due to reduced intestinal cholesterol absorption. Since reductions in serum cholesterol are reversed at longer times, these GC-1 dependent effects may not be enough for sustained cholesterol reduction in long term treatments.

Identification of a new hormone-binding site on the surface of thyroid hormone receptor

Thyroid hormone receptors (TRs) are members of the nuclear receptor superfamily of ligand-activated transcription factors involved in cell differentiation, growth, and homeostasis. Although X-ray structures of many nuclear receptor ligand-binding domains (LBDs) reveal that the ligand binds within the hydrophobic core of the ligand-binding pocket, a few studies suggest the possibility of ligands binding to other sites. Here, we report a new x-ray crystallographic structure of TR-LBD that shows a second binding site for T3 and T4 located between H9, H10, and H11 of the TRα LBD surface. Statistical multiple sequence analysis, site-directed mutagenesis, and cell transactivation assays indicate that residues of the second binding site could be important for the TR function. We also conducted molecular dynamics simulations to investigate ligand mobility and ligand-protein interaction for T3 and T4 bound to this new TR surface-binding site. Extensive molecular dynamics simulations designed to compute ligand-protein dissociation constant indicate that the binding affinities to this surface site are of the order of the plasma and intracellular concentrations of the thyroid hormones, suggesting that ligands may bind to this new binding site under physiological conditions. Therefore, the second binding site could be useful as a new target site for drug design and could modulate selectively TR functions.

Patterns of chemotherapy treatment for women with invasive epithelial ovarian cancer--a population-based study

OBJECTIVE

Ovarian cancer five-year survival is poor at <40%. In the absence of effective screening or new treatments, ensuring all women receive optimal treatment is one avenue to improve survival. There is little population-based information regarding the primary chemotherapy treatment that women with epithelial ovarian cancer receive. This information is essential to identify potential gaps in care.

METHODS

Cancer registries identified all women diagnosed with invasive epithelial ovarian cancer in Australia in 2005 (n=1192). Histopathology, chemotherapy and comorbidity information was abstracted from medical records. Multivariable logistic regression was used to identify factors associated with chemotherapy commencement, regimen, and completion.

RESULTS

Women >70 years (p<0.0001), those with high-grade, stage IA/IB cancers (vs. stages IC-IV, p=0.003) and those with mucinous cancers (p=0.0002) were less likely to start chemotherapy. Most treated women received platinum-based drugs (97%), but only 68% received combination carboplatin-paclitaxel and only half completed six cycles without treatment modification/delay. Approximately 19% received single-agent carboplatin: mostly those aged >70 (p<0.0001) and/or with co-morbidities (p<0.0001). Age was the strongest predictor of completing six cycles of combination therapy.

CONCLUSIONS

For specific patient groups, particularly older women, there is notable variation from standard treatment. Understanding how treatment variations affect survival and determining optimal regimens for these groups are research priorities.

Abstract P4-08-09: Targeting Thyroid Receptor b in Estrogen Receptor Negative Breast Cancer

Background: The treatment of estrogen receptor (ER)-negative breast cancer (BC) is a major clinical problem due to the lack of useful therapeutic targets. Nuclear receptors (NRs) are potential targets in these patients because they regulate global transcriptional events and many already have agonists/antagonists available.

Material and Methods: We used microarray analysis of 227 ER-negative tumors to identify NR targets, and performed hierarchical clustering using 41 NRs. Expressed receptors were scored using prediction analysis of microarrays (PAM) across clustered groups. Cell lines were matched to subtypes using previously described data (Neve et al. 2006). Candidate gene expression levels were confirmed by qRT-PCR using TaqMan probes. pGIPZ lentiviral vectors encoding shRNA were used to knockdownselected candidates. MTT and soft agar assays were used to measure chemosensitivity and growth following treatment with Docetaxel (Doc), Doxorubicin (Dox), or Cisplatin (Cis). Statistical analysis was performed using Red-R.

Results: The 41 NRs clustered tumors into 5 groups. For each group we selected genes representing the highest ranked discriminators, and examined their effects in cell lines matching each groups' gene signature. Thyroid hormone receptor b (THRβ) was selected from group V. The expression levels of this receptor were confirmed by qRT-PCR and Western blot analysis.

Knockdown of THRβ in ER-negative HCC2185 cells rendered cells more resistant to all chemotherapeutics by using MTT assay. Similar results were confirmed in ER-negative MDA-MB-453 and HCC202 cells. Knockdown of THRβ enhanced colony forming potential in anchorage-independent soft agar assays in MDA-MB-453 and HCC202 cells. Statistical analysis using clinical data from Sabatier et al. (BCRT 2011) showed that patients with low THRb have a worse clinical outcome. In order to translate these findings into the clinic, we treated cells with a specific THRβ agonists, GC-1 and KB-141. GC-1 inhibited cell growth in growth assays, and synergistic effects were observed when cells were treated with GC-1 and Docetaxel in combination. Re-expression of ERα protein was observed in ER-nagative cells lines after treatment with GC-1 and KB141, suggesting that modulation of THRβ may also extend hormonal therapy to this hormonally insensitive group of patients.

Conclusion: Clinical targeting of NRs in ER-negative BCs is a novel strategy since receptors can be specifically targeted with ligands. Our data suggest that chemotherapy response in ER-negative patients overexpressing THRβ could be enhanced with a THRβ agonist. Similarly, functional re-activation of ERα by activating THRβ might extend hormonal therapies to these patients as well.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-08-09.

Thyroid Hormone Analogue Stimulates Keratinocyte Proliferation but Inhibits Cell Differentiation in Epidermis

Gross clinical manifestations of thyroid hormone (TH) imbalance are often first seen in the skin where TH plays an integral role in sustaining natural function. Although mounting evidence suggests that TH plays an important role in epidermal proliferation and wound healing, the physiologic role of thyroid hormone in skin is not well understood. In the current study, we investigated the effect of a natural thyroid hormone analogue-3, 3', 5-triiodo-thyroacetic acid (TRIAC) on regulating proliferation and differentiation and its possible molecular mechanism in normal human epidermal keratinocytes and C57BL/6 mice. We determined that TRIAC could stimulate epidermal thickening in mice and promote human keratinocyte proliferation by activating Cyclin D1 expression and promoting entrance into S phase. Moreover, TRIAC might inhibit cell differentiation through repressing the expression of Casein Kinase 1 (CK1), which is a key regulatory protein involved in the control of cell differentiation. Taken together, our data explored the physiologic effect of TRIAC on skin and the possible molecular mechanism of TRIAC, which might be an interesting compound for the treatment of hyperkeratotic skin disorders.

Experimental bovine spongiform encephalopathy: detection of PrP(Sc) in the small intestine relative to exposure dose and age

European regulations for the control of bovine spongiform encephalopathy (BSE) decree destruction of the intestines from slaughtered cattle, therefore producers have been obliged to import beef casings from countries with a negligible BSE risk. This study applies immunohistochemical and biochemical approaches to investigate the occurrence and distribution of disease-associated prion protein (PrP(Sc)) in the duodenum, jejunum and ileum of cattle orally exposed to a 1 g or 100 g dose of a titrated BSE brainstem homogenate. Samples were derived from animals at various times post exposure. Lymphoid follicles were counted and the frequency of affected follicles recorded. No PrP(Sc) was detected in the duodenum or jejunum of animals exposed to a 1 g dose or in the duodenum of animals receiving a 100 g dose. PrP(Sc) was detected in the lymphoid tissue of the ileum of 1/98 (1.0%) animals receiving the 1 g dose and in the jejunum and ileum of 8/58 (13.8%) and 45/99 (45.5%), respectively, of animals receiving the 100 g dose. The frequency of PrP(Sc)- positive follicles was less than 1.5% per case and biochemical tests appeared less sensitive than immunohistochemistry. The probability of detecting lymphoid follicles in the ileum declined with age and for the 100 g exposure the proportion of positive follicles increased, while the proportion of positive animals decreased with age. Detection of PrP(Sc) in intestinal neural tissue was rare. The results suggest that the jejunum and duodenum of BSE-infected cattle contain considerably less BSE infectivity than the ileum, irrespective of exposure dose. In animals receiving the low exposure dose, as in most natural cases of BSE, the rarity of PrP(Sc) detection compared with high-dose exposure, suggests a very low BSE risk from food products containing the jejunum and duodenum of cattle slaughtered for human consumption.

Analysis of agonist and antagonist effects on thyroid hormone receptor conformation by hydrogen/deuterium exchange

Thyroid hormone receptors (TRs) are ligand-gated transcription factors with critical roles in development and metabolism. Although x-ray structures of TR ligand-binding domains (LBDs) with agonists are available, comparable structures without ligand (apo-TR) or with antagonists are not. It remains important to understand apo-LBD conformation and the way that it rearranges with ligands to develop better TR pharmaceuticals. In this study, we conducted hydrogen/deuterium exchange on TR LBDs with or without agonist (T(3)) or antagonist (NH3). Both ligands reduce deuterium incorporation into LBD amide hydrogens, implying tighter overall folding of the domain. As predicted, mass spectroscopic analysis of individual proteolytic peptides after hydrogen/deuterium exchange reveals that ligand increases the degree of solvent protection of regions close to the buried ligand-binding pocket. However, there is also extensive ligand protection of other regions, including the dimer surface at H10-H11, providing evidence for allosteric communication between the ligand-binding pocket and distant interaction surfaces. Surprisingly, C-terminal activation helix H12, which is known to alter position with ligand, remains relatively protected from solvent in all conditions suggesting that it is packed against the LBD irrespective of the presence or type of ligand. T(3), but not NH3, increases accessibility of the upper part of H3-H5 to solvent, and we propose that TR H12 interacts with this region in apo-TR and that this interaction is blocked by T(3) but not NH3. We present data from site-directed mutagenesis experiments and molecular dynamics simulations that lend support to this structural model of apo-TR and its ligand-dependent conformational changes.

Detection of Pathologic Prion Protein in the Olfactory Bulb of Natural and Experimental Bovine Spongiform Encephalopathy Affected Cattle in Great Britain

To investigate the relative involvement of the olfactory region in classical bovine spongiform encephalopathy (BSE), immunohistochemical labeling of prion protein scrapie (PrPSc) was scored in the brainstem, frontal cerebral cortex, and olfactory bulb of cattle with natural and experimental clinical cases of BSE in Great Britain. The intensity of immunolabeling was greatest in the brainstem, but PrPSc was also detected in the olfactory bulb and the cerebral cortex. A diffuse, nonparticulate labeling, possibly due to abundance of cellular PrP, was consistently observed in the olfactory glomeruli of the cases and negative controls. Involvement of the olfactory bulb in BSE and other naturally occurring TSEs of animals raises speculation as to an olfactory portal of infection or a route of excretion of the prion agent.

Evidence of self-correcting spiral flows in swimming boxfishes

The marine boxfishes have rigid keeled exteriors (carapaces) unlike most fishes, yet exhibit high stability, high maneuverability and relatively low drag given their large cross-sectional area. These characteristics lend themselves well to bioinspired design. Based on previous stereolithographic boxfish model experiments, it was determined that vortical flows develop around the carapace keels, producing self-correcting forces that facilitate swimming in smooth trajectories. To determine if similar self-correcting flows occur in live, actively swimming boxfishes, two species of boxfishes (Ostracion meleagris and Lactophrys triqueter) were induced to swim against currents in a water tunnel, while flows around the fishes were quantified using digital particle image velocimetry. Significant pitch events were rare and short lived in the fishes examined. When these events were observed, spiral flows around the keels qualitatively similar to those observed around models were always present, with greater vortex circulation occurring as pitch angles deviated from 0 degrees . Vortex circulation was higher in live fishes than models presumably because of pectoral fin interaction with the keel-induced flows. The ability of boxfishes to modify their underlying self-correcting system with powered fin control is important for achieving high levels of both stability and maneuverability. Although the challenges of performing stability and maneuverability research on fishes are significant, the results of this study together with future studies employing innovative new approaches promise to provide valuable inspiration for the designers of bioinspired aquatic vehicles.

The analysis of flue gas treatment residues using non-destructive X-ray fluorescence as a regulatory compliance test

Current and proposed European Union (EU) regulations require the residual material from municipal solid waste incineration to be characterised prior to disposal. X-Ray fluorescence (XRF) provides a rapid and non-destructive technique for analysing such materials.

Crystallization and preliminary X-ray diffraction studies of isoform α1 of the human thyroid hormone receptor ligand-binding domain

Thyroid hormone receptors (TR) play critical roles in virtually all tissues. The TR ligand-binding domain (LBD) participates in important activities, such as transcriptional activation and repression, through conformational changes induced by hormone binding. Two crystal forms of isoform alpha1 of the human thyroid hormone receptor LBD (hTRalpha1) in complex with the thyroid hormones T3 and Triac were obtained. The hTRalpha1-T3 complex was crystallized in a previously unobserved crystal form (space group P2(1)2(1)2(1), a = 59.98, b = 80.80, c = 102.21 A), with diffraction patterns extending to 1.90 A resolution on a rotating-anode X-ray source, and in space group C2 (a = 117.54, b = 80.66, c = 62.55 A, beta = 121.04 degrees), with data extending to 2.32 A resolution. The hTRalpha1-Triac complex was also crystallized in the new space group P2(1)2(1)2(1), with unit-cell parameters a = 60.01, b = 80.82, c = 102.39 A; its resolution limit extended to 2.20 A on a home source. Phasing was carried out by the molecular-replacement method and structural refinement is currently in progress. The refined structures may provide insight into the design of new thyromimetics.

Spatial variations in the composition of formation waters from the central North Sea: implications for fluid flow in the deep high-pressure high-temperature hydrocarbon play

Formation water composition data and formation pressure data from oil, gas and gas condensate fields covering an area of approximately 15000 km2in the Central Graben Area of the UK North Sea have been analysed. The purpose was to determine whether large-scale barriers to flow influence the compositional distribution of formation waters and how this aids understanding of overpressure distribution and potential hydrocarbon migration pathways. Analyses (Na, K, Mg, Ca, Sr, Ba and Cl) of water and Elemental Residual Salt Analysis (ERSA) samples from both the water and hydrocarbon legs of wells were analysed statistically to reveal eight different water types in the study area. These were located in distinct geographical areas. Aquifer overpressure from formation pressure data for numerous wells in the area were plotted on large-scale regional maps to reveal the distribution of pressure ‘cell’ or compartments. An integrated interpretation of the location of pressure cells, salinity variations and water types provided information on the current and past fluid flow across the pressure cell boundaries, the operational longevity of these boundaries and the nature of the Mesozoic aquifer. The implications of the work are important for understanding: (a) the usefulness of the new ERSA technique for estimating formation water compositions; (b) the effectiveness of integrating fluid composition and pressure data to understand compartmentalization; (c) fluid flow dynamics in the HPHT sector of the Central North Sea; and (d) likely hydrocarbon migration routes and the character and distribution of overpressured basin compartments.

[Thermoregulation in the comfort temperature zone]

Under constant adequate temperature conditions (comfortable for a man) the retention of temperature homeostasis was shown to require a continuous functioning of the physiological thermoregulation system to prevent short-term and whole day deviations of the temperature from the physiological level. Under adequate temperature conditions the thermoregulation system was shown to attain its highest sensitivity and accuracy. It is possible that this occurs owing to physiological control over the total body heat content being included into the process of thermoregulation. The data are given on the existence and "structure" of the physiological mechanisms of such a control.

Comparison of intradermal and serum testing for allergen-specific IgE using a Fcepsilon RIalpha-based assay in atopic dogs in the UK

Atopic dermatitis in dogs is a common allergic skin disease that affects substantial numbers of dogs in the UK. The purpose of this study was to compare the results of an intradermal test (IDT) and an in vitro test in a large cohort of dogs. Dogs were intradermal tested with Greer allergens (Greer Labs Inc, Lenoir, NC, USA) using standard techniques. At the same time blood samples were drawn and submitted for evaluation by ELISA using the ALLERCEPT Definitive Allergen Panels for allergen-specific IgE, a commercial assay that uses a biotinylated recombinant extracellular domain of the high affinity Fc-epsilon receptor alpha chain protein (Fcepsilon RIalpha). The allergens used in the two tests included grass, tree and weed pollens, moulds, flea saliva/whole flea extract and house dust mite species. The optical density readings from the ELISA for each allergen were compared with the results of the IDT for 265 dogs. The prevalence of positive reactions in the ELISA was equal to or greater than the results of the IDT in the case of almost all of the allergens, but two notable exceptions were the house dust mites Dermatophagoides farinae and Dermatophagoides pteronyssinus. These two allergens were the most common positive reactions by IDT (prevalence D. farinae 78.9%, D. pteronyssinus 66.4%). The results of the two tests were significantly different (McNemar's test, P<0.05) for 16 of the 22 allergens. The sensitivities of the ELISA compared to the IDT (where there were more than 3 dogs with positive reactions in both tests) varied between 19.3 and 77.1% (D. pteronyssinus 19.3% and D. farinae 67.9%) and the specificities varied between 64.2 and 96.6% (D. pteronyssinus 96.6% and D. farinae 89.3%).

Estrogen receptor action through target genes with classical and alternative response elements

The estrogen receptors alpha and beta (ERα and ERβ) mediate the changes in gene expression from physiological and environmental estrogens. Early studies identified classical estrogen response elements (EREs) in the promoter region of target genes whose expression is regulated by estrogen and to which the ERs bind via their DNA-binding domain (DBD). EREs in the pituitary prolactin promoter, for example, mediate an activation by both ERα and ERβ albeit with different affinities for different ligands. Full activation in most cell types requires the integrity of the activation function 2 (AF-2) in the receptors ligand binding domain (LBD), which is engaged by estrogens and disengaged by tamoxifen, raloxifene, and other antiestrogens. However, in some cells and ERE contexts, the AF-1 in the ERα amino terminal domain (NTD) is sufficient.

We now know that ERs also regulate expression of target genes that do not have EREs, but instead have various kinds of alternative response elements that bind heterologous transcription factors whose activity is regulated by interactions with ERs. Thus, ERα activates genes, including collagenase and cyclin D1, an important mediator of cellular proliferation, by AP-1 and CRE sites, which bind Jun/Fos or Jun/ATF-2 transcription factors. ERα also activates gene expression through GC-rich elements that bind the SP1 transcription factor. Finally, we also know that ERs mediate inhibition of the expression of many genes. In one well-studied instance, ERs counterexpression of genes involved in the inflammatory response by inhibiting the action at tumor necrosis factor response elements (TNF-REs) that bind the NFkappaB transcription factor. ERβ is especially efficient at this inhibition.

ERα activation of AP-1/CRE target genes is of special interest because of the putative role of these target genes in mediating proliferation. The AF-1 and AF-2 functions of ERα are both needed for this activation in most cell types. However, in uterine cells, the AF-1 function is sufficient. Thus, the antiestrogen tamoxifen, which allows AF-1, mimics estrogen and drives activation of AP-1/CRE target genes and proliferation of uterine cells. This estrogen-like action, which can increase the risk of uterine cancer, complicates the use of tamoxifen to prevent breast cancer. Surprisingly, ERβ inhibits AP-1/CRE target genes in the presence of estrogen. When both receptors are present, ERβ efficiently opposes activation by ERα. Moreover, ERβ activates the AP-1/CRE target genes in the presence of antiestrogens especially so-called "complete" antiestrogens raloxifene, and ICI 182, 780.

We here review the evidence for different kinds of promoter elements that mediate ER action, for the differential ligand preferences of ERα and ERβ at these different elements, and the potential mechanisms by which they are mediated. One attractive strategy for the investigation and comparison of potential environmental estrogens is to assay their activity in cell culture systems using reporter genes with simplified promoter elements. Thus, the findings of complexity in ERα and ERβ activation at different types of response elements needs to be taken into account in the development and interpretation of assays using simplified promoter elements systems.

Heel pad stiffness in runners with plantar heel pain

OBJECTIVE

To evaluate significant differences in heel pad stiffness within a cohort of runners with diagnosed plantar heel pain and to explore the clinical importance of maximum heel pad stiffness values.

DESIGN

A cross-sectional design was used to quantify the heel pad stiffness of 166 runners with 33 diagnosed with plantar heel pain.

BACKGROUND

Palpation is still widely used to evaluate heel pad stiffness subjectively in everyday clinical practice. However, there is limited quantifiable data pertaining to heel pad stiffness measurements in runners and those with heel pain.

METHODS

A portable hand-held device measured force applied by a metal probe, and its displacement into the plantar surface of the heel pad. Non-linear modelling allowed curve coefficients b0 and b1 to be evaluated and was described by an exponential function using a non-linear regression equation. Exploratory analysis was used to describe a single-point approximation for clinical use.

RESULTS

An independent t-test demonstrated a statistically significant difference between the curve coefficient b1 (p<0.05). No significant difference was found for coefficient b0 between the plantar heel pain group and the non-plantar heel pain group (p>0.05). Exploratory analysis demonstrated maximum mean stiffness of 3.22 N/mm for the non-plantar heel pain group and 2.87 N/mm for the plantar heel pain-group, an 11% mean difference.

CONCLUSION

The results suggested that heel pad stiffness may be associated with plantar heel pain subjects.

RELEVANCE

Heel pad stiffness measurements may give a better insight into the mechanical properties of the heel pad in subjects with plantar heel pain.

A splice variant of estrogen receptor beta missing exon 3 displays altered subnuclear localization and capacity for transcriptional activation

There are two separate estrogen receptors (ERs), ERalpha and ERbeta. The ERbeta gene is variably spliced, and in some cases variant expression is high. Besides the full-length ERbeta (equivalent to ERbeta1), splice variants can encode proteins bearing an insert within the ligand-binding domain (beta2), a deletion of exon 3 (ERbeta1delta3) disrupting the DNA-binding domain, or both (ERbeta2delta3). Here we examine the intracellular localization and transcriptional properties of each of the ERbeta splice variants heterologously expressed in cultured cells. In accordance with ERalpha, ERbeta1 and ERbeta2 are both distributed in a reticular pattern within the nucleus after exposure to ligand. In contrast, ERbeta1delta3 and ERbeta2delta3 localize to discrete spots within the nucleus in the presence of ER agonists. In the presence of ER antagonists, the delta3 variants are distributed diffusely within the nucleus. We also show that the spots are stable nuclear structures to which the delta3 variants localize in a ligand-dependent manner. Coactivator proteins of ER colocalize with delta3 variants in the spots in the presence of agonists. The delta3 variants of ERbeta can activate luciferase reporter constructs containing an activator protein complex-1 site, but not an estrogen response element (ERE). These data suggest that without an intact DNA-binding domain, ERbeta is functionally altered, allowing localization to discrete nuclear spots and activation from activator protein-1-containing reporter genes.

Oestrogen receptor function at classical and alternative response elements

The oestrogen receptor (ER), bound to classical response elements (EREs) in the promoter of target genes, activates transcription by recruiting coactivator proteins. We will describe structural studies that show that oestrogens allow the formation of a hydrophobic cleft on the surface of the ER that serves as a docking site for coactivators. Anti-oestrogens displace part of the receptor, which then occludes the site, blocking coactivator access. In addition to activating at classical EREs, the ER activates transcription at alternative elements such as AP-1 sites. These bind the Jun/Fos proteins but not ER. Interestingly both oestrogen and tamoxifen activate transcription at AP-1 sites. We propose a mechanism whereby oestrogen and anti-oestrogen allow ER to activate transcription from alternative response elements. ER binds to the coactivators, CBP and GRIP1, that have been recruited by Jun/Fos and through this contact 'triggers' these coactivators into full activity. In this circumstance the ER is part of the coactivator complex for Jun/Fos.

Role of direct interaction in BRCA1 inhibition of estrogen receptor activity

The BRCA1 gene was previously found to inhibit the transcriptional activity of the estrogen receptor [ER-alpha] in human breast and prostate cancer cell lines. In this study, we found that breast cancer-associated mutations of BRCA1 abolish or reduce its ability to inhibit ER-alpha activity and that domains within the amino- and carboxyl-termini of the BRCA1 protein are required for the inhibition. BRCA1 inhibition of ER-alpha activity was demonstrated under conditions in which a BRCA1 transgene was transiently or stably over-expressed in cell lines with endogenous wild-type BRCA1 and in a breast cancer cell line that lacks endogenous functional BRCA1 (HCC1937). In addition, BRCA1 blocked the expression of two endogenous estrogen-regulated gene products in human breast cancer cells: pS2 and cathepsin D. The BRCA1 protein was found to associate with ER-alpha in vivo and to bind to ER-alpha in vitro, by an estrogen-independent interaction that mapped to the amino-terminal region of BRCA1 (ca. amino acid 1-300) and the conserved carboxyl-terminal activation function [AF-2] domain of ER-alpha. Furthermore, several truncated BRCA1 proteins containing the amino-terminal ER-alpha binding region blocked the ability of the full-length BRCA1 protein to inhibit ER-alpha activity. Our findings suggest that the amino-terminus of BRCA1 interacts with ER-alpha, while the carboxyl-terminus of BRCA1 may function as a transcriptional repression domain. Oncogene (2001) 20, 77 - 87.

Selective modulation of thyroid hormone receptor action

Thyroid hormones have some actions that might be useful therapeutically, but others that are deleterious. Potential therapeutically useful actions include those to induce weight loss and lower plasma cholesterol levels. Potential deleterious actions are those on the heart to induce tachycardia and arrhythmia, on bone to decrease mineral density, and on muscle to induce wasting. There have been successes in selectively modulating the actions of other classes of hormones through various means, including the use of pharmaceuticals that have enhanced affinities for certain receptor isoforms. Thus, there is reason to pursue selective modulation of thyroid hormone receptor (TR) function, and several agents have been shown to have some beta-selective, hepatic selective and/or cardiac sparring activities, although development of these was largely not based on detailed understanding of mechanisms for the specificity. The possibility of selectively targeting the TRbeta was suggested by the findings that there are alpha- and beta-TR forms and that the TRalpha-forms may preferentially regulate the heart rate, whereas many other actions of these hormones are mediated by the TRbeta. We determined X-ray crystal structures of the TRalpha and TRbeta ligand-binding domains (LBDs) complexed with the thyroid hormone analog 3,5,3'-triiodithyroacetic acid (Triac). The data suggested that a single amino acid difference in the ligand-binding cavities of the two receptors could affect hydrogen bonding in the receptor region, where the ligand's 1-position substituent fits and might be exploited to generate beta-selective ligands. The compound GC-1, with oxoacetate in the 1-position instead of acetate as in Triac, exhibited TRbeta-selective binding and actions in cultured cells. An X-ray crystal structure of the GC-1-TRbeta LBD complex suggests that the oxoacetate does participate in a network of hydrogen bonding in the TR LBD polar pocket. GC-1 displayed actions in tadpoles that were TRbeta-selective. When administered to mice, GC-1 was as effective in lowering plasma cholesterol levels as T(3), and was more effective than T(3) in lowering plasma triglyceride levels. At these doses, GC-1 did not increase the heart rate. GC-1 was also less active than T(3) in modulating activities of several other cardiac parameters, and especially a cardiac pacemaker channel such as HCN-2, which may participate in regulation of the heart rate. GC-1 showed intermediate activity in suppressing plasma thyroid stimulating hormone (TSH) levels. The tissue/plasma ratio for GC-1 in heart was also less than for the liver. These data suggest that compounds can be generated that are TR-selective and that compounds with this property and/or that exhibit selective uptake, might have clinical utility as selective TR modulators.

Potentiation of estrogen receptor activation function 1 (AF-1) by Src/JNK through a serine 118-independent pathway

Estrogen receptor (ER) is activated either by ligand or by signals from tyrosine kinase-linked cell surface receptors. We investigated whether the nonreceptor Src tyrosine kinase could affect ER activity. Expression of constitutively active Src or stimulation of the endogenous Src/JNK pathway enhances transcriptional activation by the estrogen-ER complex and strongly stimulates the otherwise weak activation by the unliganded ER and the tamoxifen-ER complex. Src affects ER activation function 1 (AF-1), and not ER AF-2, and does so through its tyrosine kinase activity. This effect of Src is mediated partly through a Raf/mitogen-activated ERK kinase/extracellular signal-regulated kinase (Raf/MEK/ERK) signaling cascade and partly through a MEKK/JNKK/JNK cascade. Although, as previously shown, Src action through activated ERK stimulates AF-1 by phosphorylation at S118, Src action through activated JNK neither leads to phosphorylation of S118 nor requires S118 for its action. We therefore suggest that the Src/JNK pathway enhances AF-1 activity by modification of ER AF-1-associated proteins. Src potentiates activation functions in CREB-binding protein (CBP) and glucocorticoid receptor interacting protein 1 (GRIP1), and we discuss the possibility that the Src/JNK pathway enhances the activity of these coactivators, which are known to mediate AF-1 action.

The development of a conceptual framework for advancing cancer nursing practice in Europe

Continued professional development through formal education programmes is essential for improving the quality of care provided to patients with cancer. This paper describes a European Oncology Nursing Society project concerned with advanced cancer nursing education. While the development of an education programme for advanced cancer nursing practice in Europe proves difficult at this time, this project has provided the opportunity to examine some of the key elements of advanced cancer nursing work. In turn, the information gained has enabled the development of a conceptual framework for advancing cancer nursing practice in Europe to be constructed.

The nuclear receptor corepressor (N-CoR) contains three isoleucine motifs (I/LXXII) that serve as receptor interaction domains (IDs)

Unliganded thyroid hormone receptors (TRs) repress transcription through recruitment of corepressors, including nuclear receptor corepressor (N-CoR). We find that N-CoR contains three interaction domains (IDs) that bind to TR, rather than the previously reported two. The hitherto unrecognized ID (ID3) serves as a fully functional TR binding site, both in vivo and in vitro, and may be the most important for TR binding. Each ID motif contains a conserved hydrophobic core (I/LXXII) that resembles the hydrophobic core of nuclear receptor boxes (LXXLL), which mediates p160 coactivator binding to liganded nuclear receptors. Although the integrity of the I/LXXII motif is required for ID function, substitution of ID isoleucines with leucines did not allow ID peptides to bind to liganded TR, and substitution of NR box leucines with isoleucines did not allow NR box peptides to bind unliganded TR. This indicates that the binding preferences of N-CoR for unliganded TR and p160s for liganded TR are not dictated solely by the identity of conserved hydrophobic residues within their TR binding motifs. Examination of sequence conservation between IDs, and mutational analysis of individual IDs, suggests that they are comprised of the central hydrophobic core and distinct adjacent sequences that may make unique contacts with the TR surface. Accordingly, a hybrid peptide that contains distinct adjacent sequences from ID3 and ID1 shows enhanced binding to TR.