The ROSAS Cohort: A Prospective, Longitudinal Study of Biomarkers for Alzheimer's Disease. Strategy, Methods and Initial Results

OBJECTIVE

The aims of the Research Of biomarkers in Alzheimer's diseaSe (ROSAS) study were to determine the biofluid and imaging biomarkers permitting an early diagnosis of Alzheimer's disease and better characterisation of cognitive and behavioural course of the pathology. This paper outlines the overall strategy, methodology of the study, baseline characteristics of the population and first longitudinal results from the ROSAS cohort.

METHODS

Longitudinal prospective monocentric observational study performed at the Alzheimer's disease Research centre in Toulouse. A total of 387 patients were studied and analyzed in 3 groups: 184 patients with dementia of Alzheimer's type, 96 patients with memory disorders without dementia (Mild Cognitive Impairment) and 107 patients without abnormal memory tests (control group), and were followed up during 4 years. Patient's sociodemographic characteristics, risk factors, medical conditions, previous and current medications, neuropsychological assessment and overall cognitive status were recorded. Blood and urine samples were collected at every year, Magnetic Resonance Imaging were performed at inclusion, after one year of follow-up and at the end of the study.

RESULTS

At baseline, three different groups of the cohort differed interestingly in age, level of education, and in percentage of ApoEε4 carriers whereas the history of cardiovascular and endocrine pathologies were similar among the groups. During the follow-up period (3-4 years) 42 mild cognitive impairment patients (43.8%) progressed to dementia, 7 controls progressed into mild cognitive impairment and 1 patient in the control group converted from mild cognitive impairment group to dementia of Alzheimer's type group. During the first year of follow up, the incidence of progression from mild cognitive impairment to dementia of Alzheimer's type was 12.7 per 100, during the second year 33.9 per 100 and 46.7 per 100 for the third year.

CONCLUSION

This paper presents the baseline characteristics of the unique French prospective monocenter study in which the natural course of dementia of Alzheimer's type was evaluated. Future analysis of blood and urine samples collection from the ROSAS study will permit to identify possible biofluid biomarkers predicting the early stages of the dementia of Alzheimer's type and risk of progression from Mild Cognitive Impairment to Alzheimer's disease.

Nitrogen losses and chemical parameters during co-composting of solid wastes and liquid pig manure

The aim of this research was to study nitrogen losses during the treatment of the liquid fraction (LF) of pig manure by co-composting and to establish the best conditions for compost production with higher nitrogen and low heavy metal contents. Windrows were constituted with the solid fraction (SF) of pig manure, different organic waste (SF of pig manure, sawdust and grape bagasse) as co-substrate and Populus spp. wood chips as bulking material and watered intensely with the LF. Results show that nitrogen losses ranged from 30% to 66% of initial nitrogen and were mainly governed by substrate to bulking mass ratio and liquid fraction to substrate (LF/S) ratio, and only secondarily by operational parameters. Nitrogen losses decreased from 55-65% at low LF/S ratios (1.7-1.9 m³/t total solids (TS)) to 30-39% at high LF/S ratios (4.4-4.7 m³/t TS). Therefore, integrating the LF in the composting process at high LF/S ratios favoured nitrogen recovery and conservation. Nitrogen in the fine fraction (ranging from 27% to 48% of initial nitrogen) was governed by operational parameters, namely pH and temperature. Final compost showed low content in most heavy metals, but Zn was higher than the limits for compost use in agriculture. Zn content in the obtained compost varied from 1863 to 3269 mg/kg dm, depending on several factors. The options for obtaining better quality composts from the LF of pig manure are selecting co-substrates with low heavy metal content and using them instead of the SF of pig manure.

Carbon nanotube conditioning part 1-effect of interwall interaction on the electronic band gap of double-walled carbon nanotubes

Ab initio density functional theory simulations were used to calculate the electronic structure and the total energy of double-walled carbon nanotubes (DWCNTs). The relaxed configurations studied were uncapped, infinitely-long zigzag@zigzag double-walled carbon nanotubes. The lowest energy configuration was found to correspond to an interwall distance of 0.35 nm, except for the configurations with inner tube chiral indices (5,0), (6,0) and (7,0). The largest binding energies were found to correspond to a 0.35 nm interwall distance for all the DWCNT configurations studied, and increasing with DWCNT average diameter. In terms of the effect of the interwall interaction on the electronic band gap of DWCNTs, four regions of band gap were obtained which were termed: zero band gap, narrow band gap, small band gap, and medium band gap regions. These regions offer the possibility to first tune the electronic band gap to a region with a desired range, and further tune that choice within the region itself by varying the interwall distance. It was also found that zigzag@zigzag DWCNTs with outer tube leading chiral index n = 3k + 1 or n = 3k + 2 (k being an integer) follow, as a general trend, an inversely proportional relation of the electronic band gap with respect to the average diameter.

Engineering Antibody Reactivity for Efficient Derivatization to Generate NaV1.7 Inhibitory GpTx-1 Peptide-Antibody Conjugates

The voltage-gated sodium channel Na_V1.7 is a genetically validated pain target under investigation for the development of analgesics. A therapeutic with a less frequent dosing regimen would be of value for treating chronic pain; however functional Na_V1.7 targeting antibodies are not known. In this report, we describe Na_V1.7 inhibitory peptide-antibody conjugates as an alternate construct for potential prolonged channel blockade through chemical derivatization of engineered antibodies. We previously identified Na_V1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity. Tethering GpTx-1 peptides to antibodies bifunctionally couples FcRn-based antibody recycling attributes to the Na_V1.7 targeting function of the peptide warhead. Herein, we conjugated a GpTx-1 peptide to specific engineered cysteines in a carrier anti-2,4-dinitrophenol monoclonal antibody using polyethylene glycol linkers. The reactivity of 13 potential cysteine conjugation sites in the antibody scaffold was tuned using a model alkylating agent. Subsequent reactions with the peptide identified cysteine locations with the highest conversion to desired conjugates, which blocked Na_V1.7 currents in whole cell electrophysiology. Variations in attachment site, linker, and peptide loading established design parameters for potency optimization. Antibody conjugation led to in vivo half-life extension by 130-fold relative to a nonconjugated GpTx-1 peptide and differential biodistribution to nerve fibers in wild-type but not Na_V1.7 knockout mice. This study describes the optimization and application of antibody derivatization technology to functionally inhibit Na_V1.7 in engineered and neuronal cells.

Integrative assessment of the effects produced by Ag nanoparticles at different levels of biological complexity in Eisenia fetida maintained in two standard soils (OECD and LUFA 2.3)

There is a potential risk to increase the release of silver nanoparticles (Ag NPs) into the environment: For instance. in soils receiving sludge models estimate 0.007 mg Ag NPs kg^-1 that will annually increase due to sludge or sludge incineration residues land-disposal. Thus, the concern about the hazards of nanosilver to soils and soil invertebrates is growing. Studies performed up to now have been focused in traditional endpoints, used limit range concentrations and employed different soil types that differ in physico-chemical characteristics. Presently, effects of Ag NPs have been measured at different levels of biological complexity in Eisenia fetida, exposed for 3 and 14 d to high but sublethal (50 mg Ag NPs kg^-1) and close to modeled environmental concentrations (0.05 mg Ag NPs kg^-1). Since characteristics of the exposure matrix may limit the response of the organisms to these concentrations, experiments were carried out in OECD and LUFA soils, the most used standard soils. High concentrations of Ag NPs increased catalase activity and DNA damage in OECD soils after 14 d while in LUFA 2.3 soils produced earlier effects (weight loss, decrease in cell viability and increase in catalase activity at day 3). At day 14, LUFA 2.3 (low clay and organic matter-OM-) could have provoked starvation of earthworms, masking Ag NPs toxicity. The concentration close to modeled environmental concentrations produced effects uniquely in LUFA 2.3 soil. Accurate physico-chemical characteristics of the standard soils are crucial to assess the toxicity exerted by Ag NPs in E. fetida since low clay and OM contents can be considered toxicity enhancers.

The efficiency of home composting programmes and compost quality

The efficiency of home composting programmes and the quality of the produced compost was evaluated in eight rural areas carrying out home composting programmes (up to 880 composting bins) for all household biowaste including meat and fish leftovers. Efficiency was analysed in terms of reduction of organic waste collected by the municipal services. An efficiency of 77% on average was obtained, corresponding to a composting rate of 126kg/person·year of biowaste (or 380kg/composter·year). Compost quality was determined for a total of 90 composting bins. The operation of composting bins by users was successful, as indicated by a low C/N ratio (10-15), low inappropriate materials (or physical contaminant materials, mean of 0.27±0.44% dry matter), low heavy metal content (94% of samples met required standards for agricultural use) and high nutrient content (2.1% N, 0.6% P, 2.5% K, 0.7% Mg and 3.7% Ca on average, dry matter). The high moisture (above 70% in 48% of the samples) did not compromise the compost quality. Results of this study show that home composting of household organic waste including meat and fish leftovers is a feasible practice. Home composting helps individuals and families to reduce the amount of household waste at the same time gaining a fertiliser material (compost) of excellent quality for gardens or vegetable plots.

Composting of pig manure and forest green waste amended with industrial sludge

The aim of this research was to study the composting of chestnut forest green waste (FGW) from short rotation chestnut stands amended with sludge resulting from the manufacture of Medium Density Fibreboard (MDFS) and pig manure (PM). Both FGW and MDFS presented low biodegradation potential but different characteristics in granulometry and bulk density that make its mixture of interest to achieve high composting temperatures. PM decreased the C/N ratio of the mixture and increased its moisture content (MC). Three mixtures of MDFS:FGW at volume ratios of 1:1.3 (M2), 1:2.4 (M3) and 0:1 (M4) were composted after increasing its MC to about 70% with PM. A control with food waste (OFW) and FGW (1:2.4 in volume) (M1) was run in parallel. Watering ratios reached 0.25 (M1), 1.08 (M2) 1.56 (M3) and 4.35 (M4) L PM/kg TS of added solids wastes. Treatments M2 and M3 reached a thermophilic phase shorter than M1, whilst M4 remained in the mesophilic range. After 48days of composting, temperature gradients in respect to ambient temperature were reduced, but the mineralization process continued for around 8months. Final reduction in total organic carbon reached 35-56%, depending mainly on the content in MDFS. MDFS addition to composting matrices largely reduced nitrogen losses, which range from 22% (M2) to 37% (M3) and 53% (M4). Final products had high nutrient content, low electrical conductivity and low heavy metal content which make it a valuable product for soil fertilization, right to amend in the chestnut forests and as a pillar of their sustainable management.

Integrating pretreatment and denitrification in constructed wetland systems

The aim of this work was to study the operational characteristics and the efficiency of a compact constructed wetland system for municipal wastewater treatment that integrates denitrification in the pre-treatment unit. The proposed system was simulated by two units in series with effluent recirculation, the first one being an anoxic digester, conceived as a hydrolytic up flow sludge bed for solids hydrolysis and denitrification, and the second one a sand column that simulated the operation of a vertical flow constructed wetland. The hybrid system consisted of two small columns of 4 and 10.2cm in diameter (anoxic digester and vertical flow unit, respectively). The unplanted system was operated successively with synthetic and real municipal wastewater over a period of 136days. Hydraulic loading rate ranged from 212 to 318mm/day and surface loading rate from 122 to 145g/m²·day of chemical oxygen demand and 10-15g/m²·day of total nitrogen for the overall system. The overall system reached removals of 91% to 99% for total suspended solids, chemical oxygen demand and biochemical oxygen demand whilst total nitrogen removal ranged from 43% to 61%. In addition to suspended solids removal (up to 78%), the anoxic digester provided high denitrification rates (3-12gN/m²·day) whilst the vertical flow unit provided high nitrification rates (8-15gN/m²·day). Organic matter was mainly removed in the anoxic digester (63-82% chemical oxygen demand) and used for denitrification. Final effluent concentration was lower for ammonia (7.4±2.4mgN/L on average) than for nitrate (19.8±4.4mgN/L), denitrification appearing as the limiting step in nitrogen removal in the system. CH₄ or N₂O emissions were not detected in any of the units of the system indicating very low greenhouse gas emissions.

Selective serotonine reuptake inhibitors or dual antidepressants and syndrome of inapropriate antidiuretic hormone secretion: A systematic search

Introduction

Depression is a disease with high prevalence all over the world. Selective serotonine reuptake inhibitors (SSRIs) and dual antidepressants (DA) are worldwide used to treat the different types of depressive episodes. Between the adverse events of these compounds, an unusual but potentially severe side effect is the syndrome of inapropriate antidiuretic hormone secretion (SIADH).

Results and discussion

Several cases published, and an amount of cases series have documented the association of SIADH to the use of SSRIs and DA. All SSRIs and DA are at risk of producing SIADH (fluoxetine, paroxetine, fluvoxamine, sertraline, citalopram, escitalopram, venlafaxine and duloxetine). Old age has been found as a risk factor for developing SIADH. There are not enough data to conclude that other risk factors can play a role in the development of this adverse event. Treatment should include the immediate withdrawal of the antidepressant. The introduction of other antidepressants is controversial, as SIADH has been related with all antidepressive treatments; but the risk of relapse into a depressive episode must be considered also. Between symptomatic treatments, the control of water intake and the use of low doses of loop diuretics can be recommended. Severe cases can be treated with higher doses of loop diuretics and saline hypertonic solution.

Conclusions

SIADH has been related with SSRIs and DA antidepressants and it is an infrequent but severe adverse event. Its risk must be considered when prescribing treatment with them. If this adverse event is produced, the substitution of the antidepressant should be done.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Hydrolytic anaerobic reactor and aerated constructed wetland systems for municipal wastewater treatment - HIGHWET project

The HIGHWET project combines the hydrolytic up-flow sludge bed (HUSB) anaerobic digester and constructed wetlands (CWs) with forced aeration for decreasing the footprint and improving effluent quality. The HIGHWET plant in A Coruña (NW of Spain) treating municipal wastewater consists of a HUSB and four parallel subsurface horizontal flow (HF) CWs. HF1, HF2 and HF3 units are fitted with forced aeration, while the control HF4 is not aerated. All the HF units are provided with effluent recirculation, but different heights of gravel bed (0.8 m in HF1 and HF2, and 0.5 m in HF3 and HF4) are implemented. Besides, a tobermorite-enriched material was added in the HF2 unit in order to improve phosphorus removal. The HUSB 76-89% of total suspended solids (TSS) and about 40% of chemical oxygen demand (COD) and biological oxygen demand (BOD). Aerated HF units reached above 96% of TSS, COD and BOD at a surface loading rate of 29-47 g BOD₅/m²·d. An aeration regime ranging from 5 h on/3 h off to 3 h on/5 h off was found to be adequate to optimize nitrogen removal, which ranged from 53% to 81%. Average removal rates of 3.4 ± 0.4 g total nitrogen (TN)/m²·d and 12.8 ± 3.7 g TN/m³·d were found in the aerated units, being 5.5 and 4.1 times higher than those of the non-aerated system. The tobermorite-enriched HF2 unit showed a distinct higher phosphate (60-67%) and total phosphorus (54%) removal.

Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment

Hybrid constructed wetlands (CWs) including subsurface horizontal flow (HF) and vertical flow (VF) steps look for effective nitrification and denitrification through the combination of anaerobic/anoxic and aerobic conditions. Several CW configurations including several configurations of single pass systems (HF + HF, VF + VF, VF + HF), the Bp(VF + HF) arrangement (with feeding by-pass) and the R(HF + VF) system (with effluent recirculation) were tested treating synthetic domestic wastewater. Two HF/VF area ratios (AR) were tested for the VF + HF and Bp(VF + HF) systems. In addition, a R(VF + VF) system was tested for the treatment of a high strength industrial wastewater. The percentage removal of TSS, COD and BOD5 was usually higher than 95% in all systems. The single pass systems showed TN removal below the threshold of 50% and low removal rates (0.6-1.2 g TN/m(2) d), except the VF + VF system which reached 63% and 3.5 g TN/m(2) d removal but only at high loading rates. Bp(VF + HF) systems required by-pass ratios of 40-50% and increased TN removal rates to approximately 50-60% in a sustainable manner. Removal rates depended on the AR value, increasing from 1.6 (AR 2.0) to 5.2 g TN/m(2) d (AR 0.5), both working with synthetic domestic wastewater. On real domestic wastewater the Bp (VF + HF) (AR 0.5 and 30% by-pass) reached 2.5 g TN/m(2) d removal rate. Effluent recirculation significantly improved the TN removal efficiency and rate. The R(HF + VF) system showed stable TN removals of approximately 80% at loading rates ranging from 2 to 8 g TN/m(2) d. High TN removal rates (up to 73% TN and 8.4 g TN/m(2) d) were also obtained for the R(VF + VF) system treating industrial wastewater.

[Complete response to tyrosine kinase inhibitors in metastatic renal cancer. Report of four cases]

OBJECTIVSE

To describe the complete responses in our patients with metastatic renal cancer treated with tyrosine kinase inhibitors.

MATERIAL AND METHODS

Between June 2007 and December 2014 we treated in our department 43 patients with metastatic renal cancer with antiangiogenic drugs.

RESULTS

9.3% (4/43) of the patients treated with antiangiogenic drugs obtained complete response according to RECIST 1.1 criteria. In 3 of the 4 patients, complete response was obtained during the first-line treatment with sunitinib at doses of 50 mgr/day in a 4/2 scheme and the remaining patient obtained it with second line axitinib at doses of 10 mgr/day.

CONCLUSIONS

Tyrosine kinase inhibitors can induce complete responses in patients with metastatic renal cancer. Discontinuation of treatment with tyrosine kinase inhibitors after a complete response may be an option.

Nanoparticle size and combined toxicity of TiO2 and DSLS (surfactant) contribute to lysosomal responses in digestive cells of mussels exposed to TiO2 nanoparticles

The aim of this investigation was to understand the bioaccumulation, cell and tissue distribution and biological effects of disodium laureth sulfosuccinate (DSLS)-stabilised TiO2 nanoparticles (NPs) in marine mussels, Mytilus galloprovincialis. Mussels were exposed in vivo to 0.1, 1 and 10 mg Ti/L either as TiO2 NPs (60 and 180 nm) or bulk TiO2, as well as to DSLS alone. A significant Ti accumulation was observed in mussels exposed to TiO2 NPs, which were localised in endosomes, lysosomes and residual bodies of digestive cells, and in the lumen of digestive tubules, as demonstrated by ultrastructural observations and electron probe X-ray microanalysis. TiO2 NPs of 60 nm were internalised within digestive cell lysosomes to a higher extent than TiO2 NPs of 180 nm, as confirmed by the quantification of black silver deposits after autometallography. The latter were localised mainly forming large aggregates in the lumen of the gut. Consequently, lysosomal membrane stability (LMS) was significantly reduced upon exposure to both TiO2 NPs although more markedly after exposure to TiO2-60 NPs. Exposure to bulk TiO2 and to DSLS also affected the stability of the lysosomal membrane. Thus, effects on the lysosomal membrane depended on the nanoparticle size and on the combined biological effects of TiO2 and DSLS.

Methane and carbon dioxide emissions from constructed wetlands receiving anaerobically pretreated sewage

The aim of this research was to determine methane and carbon dioxide emissions from a hybrid constructed wetland (CW) treating anaerobically pre-treated sewage. The CW was constituted of two horizontal flow (free water surface followed by a subsurface) units. A long-term study was carried out as both CW units were monitored for three campaigns in Period 1 (0.9-1.5years after start-up), and four campaigns in Period 2 (4.5-5.8years after start-up). The closed chamber method with collecting surfaces of 1810cm(2) was used. For this system, variability due to position in the transverse section of CW, plant presence or absence and recommended sampling period was determined. Overall methane emissions ranged from 96 to 966mgCH4m(-2) d(-1), depending on several factors as the operation time, the season of the year and the position in the system. Methane emissions increased from 267±188mgCH4m(-2)d(-1) during the second year of operation to 543±161mgCH4m(-2)d(-1) in the sixth year of operation. Methane emissions were related to the age of the CW and the season of the year, being high in spring and becoming lower from spring to winter. Total CO2 emissions ranged mostly from 3500 to 5800mgCO2m(-2)d(-1) during the sixth year of operation, while nitrous oxide emissions were below the detection limit of the method.

Physico-chemical and biological characteristics of compost from decentralised composting programmes

Composts that originated from small-scale composting programmes including home, community and canteen waste composters were studied. Heavy metals concentration indicated compliance with current regulations for conventional and organic agriculture. Compost from canteen waste showed high organic matter content (74% VS), while community (44 ± 20% VS) and home composts (31 ± 16% VS) had moderate levels. N content increased from home compost (1.3 ± 0.9% dm) to community (2.0 ± 0.9%) and canteen compost (2.5-3.0%) while P content ranged from 0.4% to 0.6% dm. C/N, absorbance E4/E6 and N-NH4(+)/N-NO3(-) ratios as well as respiration index indicated well-stabilized final products. Culturable bacterial and fungal cfu linkage to composting dynamics were identified and higher diversity of invertebrates was found in the smaller scale static systems. With similar process evolution indicators to industrial systems, overall results support the sustainability of these small-scale, self-managed composting systems.