The impacts of intensive mining on terrestrial and aquatic ecosystems: A case of sediment pollution and calcium decline in cool temperate Tasmania, Australia

Mining causes extensive damage to aquatic ecosystems via acidification, heavy metal pollution, sediment loading, and Ca decline. Yet little is known about the effects of mining on freshwater systems in the Southern Hemisphere. A case in point is the region of western Tasmania, Australia, an area extensively mined in the 19th century, resulting in severe environmental contamination. In order to assess the impacts of mining on aquatic ecosystems in this region, we present a multiproxy investigation of the lacustrine sediments from Owen Tarn, Tasmania. This study includes a combination of radiometric dating (¹⁴C and ²¹⁰Pb), sediment geochemistry (XRF and ICP-MS), pollen, charcoal and diatoms. Generalised additive mixed models were used to test if changes in the aquatic ecosystem can be explained by other covariates. Results from this record found four key impact phases: (1) Pre-mining, (2) Early mining, (3) Intense mining, and (4) Post-mining. Before mining, low heavy metal concentrations, slow sedimentation, low fire activity, and high biomass indicate pre-impact conditions. The aquatic environment at this time was oligotrophic and dystrophic with sufficient light availability, typical of western Tasmanian lakes during the Holocene. Prosperous mining resulted in increased burning, a decrease in landscape biomass and an increase in sedimentation resulting in decreased light availability of the aquatic environment. Extensive mining at Mount Lyell in the 1930s resulted in peak heavy metal pollutants (Pb, Cu and Co) and a further increase in inorganic inputs resulted in a disturbed low light lake environment (dominated by Hantzschia amphioxys and Pinnularia divergentissima). Following the closure of the Mount Lyell Co. in 1994 CE, Ca declined to below pre-mining levels resulting in a new diatom assemblage and deformed diatom valves. Therefore, the Owen Tarn record demonstrates severe sediment pollution and continued impacts of mining long after mining has stopped at Mt. Lyell Mining Co.

Non-Amyloid Approaches to Disease Modification for Alzheimer's Disease: An EU/US CTAD Task Force Report

While amyloid-targeting therapies continue to predominate in the Alzheimer’s disease (AD) drug development pipeline, there is increasing recognition that to effectively treat the disease it may be necessary to target other mechanisms and pathways as well. In December 2019, The EU/US CTAD Task Force discussed these alternative approaches to disease modification in AD, focusing on tau-targeting therapies, neurotrophin receptor modulation, anti-microbial strategies, and the innate immune response; as well as vascular approaches, aging, and non-pharmacological approaches such as lifestyle intervention strategies, photobiomodulation and neurostimulation. The Task Force proposed a general strategy to accelerate the development of alternative treatment approaches, which would include increased partnerships and collaborations, improved trial designs, and further exploration of combination therapy strategies.

P212 Computed tomography derived left ventricular outflow tract area downgrades severity of prosthesis-patient mismatch after transcatheter aortic valve replacement

Background

Prosthesis-patient mismatch (PPM) is associated with poor outcomes after surgical aortic valve replacement, but evidence in the era of transcatheter aortic valve replacement (TAVR) is small. Although PPM is conventionally defined by transthoracic echocardiogram (TTE) derived indexed effective orifice area (EOAi), TTE may underestimate left ventricular outflow tract (LVOT) area when compared with cardiac computed tomography angiography (CTA).

Purpose

To evaluate the inter-modality (TTE vs CTA) agreement and inter-valve (balloon-expanding valve (BEV) vs. self-expandable valve (SEV)) differences in EOAi and the severity of PPM after TAVR.

Methods

We analyzed all patients who underwent TAVR between 2015 to 2017and who had both of CTA and TTE at 30-days after TAVR. EOAi was calculated using the continuity equation and then indexed to body surface area as per guidelines using TTE derived LVOT diameter (EOAi-TTE) or post-procedure CTA derived LVOT area (EOAi-CTA). The external LVOT diameter was measured at inflow of TAVR bioprosthetic stent frame as per recommendations. The EOAi was used to define the grading severity of PPM: None (> 0.85 cm²/m²); Moderate (0.65 to 0.85 cm²/m²); and Severe (< 0.65 cm²/m²). Paired or Student t-test and Chi-square test were used to assess the inter-modality and inter-valve difference.

Results

A total of 280 patients were included (the mean age, 81.2 ± 8.1 years; 48%, female). BEV was used in 150 patients (54%). The mean EOAi-TTE vs. EOAi-CTA was 1.00 ± 0.32 and 1.41 ± 0.50 cm²/m², respectively, p < 0.001. Prevalence of severe (TTE 9% versus CTA 4%, p < 0.01) and moderate (TTE 28% versus CTA 7%, p < 0.01) PPM was lower when adjudicated by CTA (Figure-Panel A). There was a trends towards smaller EOAi by either TTE (0.97 ± 0.31 vs. 1.04 ± 0.33, p = 0.07) or CTA (1.38 ± 0.45 vs. 1.46 ± 0.56, p = 0.21) for BEV vs. SEV (Figure-Panel B). There was no significant difference in the severity of PPM defined by either EOAi-TTE (Figure-Panel C) or EOAi-CTA (Figure-Panel D) between these patients.

Conclusion

EOAi-CTA was larger and downgraded the severity of PPM than the EOAi-TTE. There was no significant difference in the severity of PPM defined by post-procedure CT between patients treated with BEV and those with SEV.

Abstract P212 Figure.

Identifying Better Outcome Measures to Improve Treatment of Agitation in Dementia: A Report from the EU/US/CTAD Task Force

For the second time in the past 3 years, the EU-US CTAD Task Force addressed challenges related to designing clinical trials for agitation in dementia, which is one of the most disruptive aspects of the condition for both patients and caregivers. Six recommendations emerged from the Task Force meeting: 1 - Operationalizing agitation criteria established by the IPA; 2 - Combining clinician- and caregiver-derived outcomes as primary outcome measures; 3 - Using global ratings to define clinically meaningful effects and power studies; 4 - Improving the accuracy of caregiver reports by better training and education of caregivers; 5 - Employing emerging technologies to collect near real-time behavioral data; and 6 - Utilizing innovative trial designs and increasing the use of biomarkers to maximize the productivity of clinical trials for neuropsychiatric symptoms.

Delignified Wood-Polymer Interpenetrating Composites Exceeding the Rule of Mixtures

Wood is increasingly considered in sustainable structural materials development due to its hierarchical structure, including an oriented reinforcing cellulose phase combined with carbon capturing and renewability. Top-down manufacturing techniques can provide direct access to this hierarchical cellulose scaffold for use in new functional materials. For high-performance load-bearing wood-based materials, the volume content of the reinforcing phase needs to be increased to much higher fiber volume contents (FVCs). This has been achieved by structure-retaining delignification followed by densification. The obtained matrix-free materials possess high tensile stiffness due to preservation of hierarchical fiber alignment; however, they demonstrate low mechanical properties in bending and cannot be used in moist conditions due to their propensity for water absorption. In order to address these two challenges, an interpenetrating wood polymer phase composite is developed using a delignified wood scaffold as a continuous reinforcing phase and epoxy resin as the interconnected matrix phase. We utilize the continuous flow channels in delignified wood for vacuum-assisted matrix infiltration in a condition of open continuous porosity in the wood scaffold. Prior to matrix curing, the material is densified in order to increase the FVC, decrease porosity, and reduce density variations in the wood scaffold. Due to the compressibility of delignified cellulose fibers, interpenetrating phase composites (IPCs) with very high FVCs of up to 80% could be produced, leading to exceptionally high tensile stiffness and strength of up to 70 GPa and 600 MPa. The obtained stiffness values far exceed the upper limit of the rule of mixtures due to an enhanced stress transfer through mechanically interlocked fiber-fiber interfaces combined with the stiffness providing matrix phase that further aids stress transfer between neighboring wood cells via their pits. This new approach paves the way for an efficient production of high-performance sustainable materials that can be used as alternative for glass fiber reinforced composites or natural fiber composites.

Darunavir/ritonavir monotherapy at a low dose (600/100 mg/day) in HIV-1-infected individuals with suppressed HIV viraemia

Background

Darunavir/ritonavir is a potent PI with a high genetic barrier and pharmacological robustness favourably investigated as monotherapy. Whether darunavir could be dose reduced in the context of monotherapy deserves investigation.

Methods

Patients with HIV suppressed viraemia (plasma viral load <50 copies/mL for 12 months) under ART who had switched to darunavir/ritonavir monotherapy at 600/100 mg/day between 2013 and 2015 were included in this observational 48 week single-centre study. The primary outcome was the proportion of patients with virological success (defined as plasma viral load <50 copies/mL) at week 24. Secondary outcomes included treatment strategy success and resistance.

Results

Thirty-one patients were included with the following baseline characteristics [median (IQR)]: age 52 years (47-57), CD4+ 649 cells/mm3 (463-813), ART duration 16.3 years (9.2-22.3), nadir CD4+ 195 cells/mm3 (144-261) and duration of HIV suppression 7.8 years (4.8-9.7). Prior to switch, ART consisted of PI monotherapy for 28 of 31 patients [darunavir/ritonavir 800/100 mg/day (n = 26), lopinavir/ritonavir (n = 1) and atazanavir/ritonavir (n = 1)] and a triple drug regimen for 3 of 31 patients. Within the 48 weeks of follow-up, no virological failure occurred and two patients discontinued 600/100 mg of darunavir/ritonavir due to side effects at week 16 and 40, leading to a virological suppression rate of 100% (95% CI = 89-100) at weeks 24 and 48. Strategy success rates were 96.8% (95% CI = 83.3-99.9) at week 24 and 93.5% (95% CI = 78.6-99.2) at week 48. Median (IQR) Ctrough values of 800/100 mg of darunavir/ritonavir and 600/100 mg of darunavir/ritonavir were 1537 ng/mL (1286-1724) and 1255 ng/mL (873-2161), respectively.

Conclusions

A lower dose of darunavir/ritonavir used as monotherapy (600/100 mg/day) was highly effective in virologically suppressed HIV-infected patients. Further studies are needed to confirm these data.

Designing Trials of Disease Modifying Agents for Early and Preclinical Alzheimer's Disease Intervention: What Evidence is Meaningful to Patients, Providers, and Payers?

BACKGROUND

Drug development for disease modifying agents in Alzheimer's disease (AD) is focused increasingly on targeting underlying pathology in very early stages of AD or in cognitively normal patients at elevated risk of developing dementia due to Alzheimer's. Very early interventional studies of this type have many uncertainties, including whether they can provide the clinical results that payers, providers, and patients will wish to see for decisions. This paper describes an initiative to create greater transparency for researchers to anticipate these decision needs.

OBJECTIVE

To create multi-stakeholder-vetted recommendations for the design of studies in later phases of drug development to evaluate the ability of disease modifying agents to delay or prevent the onset of dementia due to Alzheimer's disease (AD).

DESIGN

A multi-stakeholder expert workgroup and overseeing steering group were convened to discuss current advances in early interventional clinical trial design and the evidence needs of patients, providers, and payers. Eight teleconferences and one in-person all-day meeting were held. Meetings were recorded and summary notes prepared between sessions. Final conclusions were consolidated by the project team with the workgroup Chair based on these discussions and were reviewed by group members.

SETTING

The in-person meeting was held in Baltimore, MD.

PARTICIPANTS

In total, 36 stakeholders representing life sciences industry, payers or health technology assessors, patient advocates and research advocacy organizations, regulators, clinical experts and academic or NIH researchers.

INTERVENTION

N/A.

MEASUREMENTS

N/A.

RESULTS

Certain aspects of clinical trial design were deemed important to address stakeholder decision needs for future Alzheimer's prevention drugs even as the field rapidly progresses. These include the need for more robust behavioral and psychological outcome data in early symptomatic disease and the need to update activities of daily living measures to include "digital independence."

CONCLUSIONS

Amyloid, tau, and biomarkers of neurodegeneration should be included in trials and studied in relation to other early measures of change meaningful to individuals with AD, their families, and health plans. These measures include early sensitive changes in behavioral and psychological measures and ability to navigate the contemporary digital landscape. Additional work is needed to generate more robust behavioral and psychological outcome data in early symptomatic disease, and to generate multi-stakeholder consensus on early measures of change and magnitudes of change that will be meaningful to patients, providers, and payers.

EU/US/CTAD Task Force: Lessons Learned from Recent and Current Alzheimer's Prevention Trials

At a meeting of the EU/US/Clinical Trials in Alzheimer's Disease (CTAD) Task Force in December 2016, an international group of investigators from industry, academia, and regulatory agencies reviewed lessons learned from ongoing and planned prevention trials, which will help guide future clinical trials of AD treatments, particularly in the pre-clinical space. The Task Force discussed challenges that need to be addressed across all aspects of clinical trials, calling for innovation in recruitment and retention, infrastructure development, and the selection of outcome measures. While cognitive change provides a marker of disease progression across the disease continuum, there remains a need to identify the optimal assessment tools that provide clinically meaningful endpoints. Patient- and informant-reported assessments of cognition and function may be useful but present additional challenges. Imaging and other biomarkers are also essential to maximize the efficiency of and the information learned from clinical trials.

Element specific determination of the magnetic properties of two macrocyclic tetranuclear 3d-4f complexes with a Cu3Tb core by means of X-ray magnetic circular dichroism (XMCD)

We apply X-ray magnetic circular dichroism to study the internal magnetic structure of two very promising star shaped macrocyclic complexes with a CuII3TbIII core. These complexes are rare examples prepared with a macrocyclic ligand that show indications of SMM (Single Molecule Magnet) behavior, and they differ only in ring size: one has a propylene linked macrocycle, [CuII3TbIII(LPr)(NO3)2(MeOH)(H2O)2](NO3)·3H2O (nickname: Cu3Tb(LPr)), and the other has the butylene linked analogue, [CuII3TbIII(LBu)(NO3)2(MeOH)(H2O)](NO3)·3H2O (nickname: Cu3Tb(LBu)). We analyze the orbital and spin contributions to the Cu and Tb ions quantitatively by applying the spin and orbital sum rules concerning the L2 (M4)/L3 (M5) edges. In combination with appropriate ligand field simulations, we demonstrate that the Tb(iii) ions contribute with high orbital magnetic moments to the magnetic anisotropy, whereas the ligand field determines the easy axis of magnetization. Furthermore, we confirm that the Cu(ii) ions in both molecules are in a divalent valence state, the magnetic moments of the three Cu ions appear to be canted due to 3d-3d intramolecular magnetic interactions. For Cu3Tb(LPr), the corresponding element specific magnetization loops reflect that the Cu(ii) contribution to the overall magnetic picture becomes more important as the temperature is lowered. This implies a low value for the 3d-4f coupling.

Modalidades fisioterapêuticas na reabilitação de cães com doença do disco intervertebral toracolombar submetidos à cirurgia descompressiva: 30 casos (2008-2016)

RESUMO Este estudo retrospectivo teve como objetivo demonstrar as modalidades fisioterapêuticas empregadas no tratamento de cães com doença do disco intervertebral (DDIV) toracolombar após descompressão cirúrgica da medula espinhal, bem como relatar os fatores que determinaram as alterações das modalidades. Foram incluídos 30 cães que apresentavam sinais neurológicos desde paraparesia ambulatória a paraplegia com dor profunda na primeira sessão de fisioterapia. As modalidades utilizadas nos protocolos de todos os pacientes foram a crioterapia, massagem, alongamento passivo, movimentação passiva articular, estímulo do reflexo flexor e estimulação elétrica neuromuscular. A inclusão ou exclusão de exercícios terapêuticos, como a tipoia corporal, a plataforma proprioceptiva circular, a natação, a hidroesteira, os obstáculos e a caminhada em colchão, foi de acordo com a evolução clínica e a adaptação de cada paciente. Oitenta por cento (80%) dos cães alteraram o grau de disfunção neurológica antes de iniciar a fisioterapia e 93% retornaram à habilidade de caminhar (paraparesia ambulatória) ao final da fisioterapia. O número de sessões e o tempo de recuperação foram maiores quanto pior foi o grau de lesão do paciente.

Oral immunotherapy with omalizumab reverses the Th2 cell-like programme of regulatory T cells and restores their function

BACKGROUND

Oral immunotherapy (OIT) successfully desensitizes patients with food allergies, but the immune mechanisms mediating its efficacy remain obscure.

OBJECTIVES

We tested the hypothesis that allergen-specific regulatory T (Treg) cell function is impaired in food allergy and is restored by anti-IgE antibody (omalizumab)-supplemented OIT.

METHODS

Peanut-specific T effector (Teff) and Treg cell proliferative responses, activation markers and cytokine expression were analysed by flow cytometry in 13 peanut-allergic subjects before the start of omalizumab-supplemented OIT and periodically in some subjects thereafter for up to 2 years. Peripheral blood regulatory T cells (Treg cells) were analysed for their peanut-specific suppressor function before and at 1 year following OIT. This study was registered on ClinicalTrials.gov (NCT01290913).

RESULTS

Proliferation of allergen-specific Teff and Treg cells precipitously declined following the initiation of omalizumab therapy prior to OIT, followed by partial recovery after the initiation of OIT. At baseline, peanut-specific Treg cells exhibited a Th2 cell-like phenotype, characterized by increased IL-4 expression, which progressively reversed upon OIT. Peanut-specific Treg cell suppressor activity was absent at the start of omalizumab/OIT therapy but became robust following OIT. Absent peanut-specific Treg cell function could also be recovered by the acute blockade of IL-4/IL-4R receptor signalling in Treg cells, which inhibited their IL-4 production.

CONCLUSIONS AND CLINICAL RELEVANCE

OIT supplemented by omalizumab promotes allergen desensitization through an initial omalizumab-dependent step that acutely depletes allergen-reactive T cells, followed by an increase in allergen-specific Treg cell activity due to the reversal of their Th2 cell-like programme. Improved Treg cell function may be a key mechanism by which OIT ameliorates food allergy.

Chemical stabilization of polymers: Implications for dermal exposure to additives

Technical benefits of additives in polymers stand in marked contrast to their associated health risks. Here, a multi-analyte method based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) was developed to quantify polymer additives in complex matrices such as low-density polyethylene (LDPE) and isolated human skin layers after dermal exposure ex vivo. That way both technical aspects and dermal exposure were investigated. The effects of polymer additivation on the material were studied using the example of LDPE. To this end, a tailor-made polymer was applied in aging studies that had been furnished with two different mixtures of phenol- and diarylamine-based antioxidants, plasticizers and processing aids. Upon accelerated thermo-oxidative aging of the material, the formation of LDPE degradation products was monitored with attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) spectroscopy. Compared to pure LDPE, a protective effect of added antioxidants could be observed on the integrity of the polymer. Further, thermo-oxidative degradation of the additives and its kinetics were investigated using LDPE or squalane as matrix. The half-lives of additives in both matrices revealed significant differences between the tested additives as well as between LDPE and squalane. For instance, 2-tert-butyl-6-[(3-tert-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenol (Antioxidant 2246) showed a half-life 12 times lower when incorporated in LDPE as compared to squalane. As a model for dermal exposure of consumers, human skin was brought into contact with the tailor-made LDPE containing additives ex vivo in static Franz diffusion cells. The skin was then analyzed for additives and decomposition products. This study proved 10 polymer additives of diverse pysicochemical properties and functionalities to migrate out of the polymer and eventually overcome the intact human skin barrier during contact. Moreover, their individual distribution within distinct skin layers was demonstrated. This is exemplified by the penetration of the procarcinogenic antioxidant N-phenylnaphthalen-2-amine (Neozon D) into the viable epidermis and the permeation through the skin of the neurotoxic plasticizer N-butylbenzenesulfonamide (NBBS). In addition, the analyses of additive degradation products in the isolated skin layers revealed the presence of 2-tert-butyl-4-methylphenol in all layers after contact to a polymer with substances of origin like Antioxidant 2246. Thus, attention needs to be paid to absorption of polymer additives together with their degradation products when it comes to dermal exposure assessment.

Combined use of a wristband and a smartphone to reduce body weight in obese children: randomized controlled trial

BACKGROUND

Technological instruments may help control paediatric obesity.

OBJECTIVE

We tested whether a personalized programme based on the energy expenditure obtained from a wristband (WB) and the energy intake obtained from a smartphone application (APP) is superior to a standard approach at promoting weight loss.

METHODS

We performed a randomized controlled trial in obese children aged 10-17 years. The experimental (EXP) and control (CTR) groups were given a low-energy diet and a prescription for physical activity. The EXP group was equipped with a WB and an APP and given personalized feedback every 7 days. The main outcome was weight loss at 3 months.

RESULTS

The mean (standard deviation) z-score of body mass index at the enrollment was 2.20 (0.47) in the EXP (n = 16 out of 23) and 2.09 (0.34) in the CTR group (n = 14 out of 20) of children who completed the trial. The mean (95%CI) difference in weight loss at 3 months was 0.07 kg (95%CI: 2.81 to 2.96) for EXP vs. the CTR.

CONCLUSION

A personalized lifestyle programme based on a WB and an APP was not superior to a standard lifestyle programme at promoting weight loss in obese children.