Neuroinflammation Biomarkers in the AT(N) Framework Across the Alzheimer's Disease Continuum.

In the past years, neuroinflammation has been widely investigated in Alzheimer's disease (AD). Evidence from animal, in vivo and post-mortem studies has shown that inflammatory changes are a common feature of the disease, apparently happening in response to amyloid-beta and tau accumulation. Progress in imaging and fluid biomarkers now allows for identifying surrogate markers of neuroinflammation in living individuals, which may offer unprecedented opportunities to better understand AD pathogenesis and progression. In this context, inflammatory mediators and glial proteins (mainly derived from microglial cells and astrocytes) seem to be the most promising biomarkers. Here, we discuss the biological basis of neuroinflammation in AD, revise the proposed neuroinflammation biomarkers, describe what we have learned from anti-inflammatory drug trials, and critically discuss the potential addition of these biomarkers in the AT(N) framework.

Is the polychaete, Perinereis rullieri (Pilato 1974), a reliable indicator of PCB and PAH contaminants in coastal sediments?

A field survey in a transitional environment (lagoon of Venice, Italy) and a laboratory exposure experiment were carried out to validate the use of polychaetes, Perinereis rullieri, as indicators of PCB and PAH contaminants in the sediments. Results from the field study showed that PCBs, predominantly the hexa- and hepta-chlorinated biphenyls, were promptly bioaccumulated in the tissues of P. rullieri, whereas PAH levels were generally low and fluctuating among seasons. Organisms experimentally exposed to natural polluted sediments bioaccumulated all the examined PCB congeners, whereas those exposed to the reference sediments were able to reduce them, at least to some extent. A PAH depletion was always observed, although the time variations for the single compounds differed from each other. The biomarker malondialdehyde (MDA), evaluated both in native and in treated organisms, was helpful as a supporting parameter in elucidating their oxidative stress condition, although depending on numerous natural confounding factors.

Lysosomal responses and metallothionein induction in the blue mussel Mytilus edulis from the south-west coast of Iceland.

It has recently been emphasized that high levels of inorganic and organic micropollutants (particularly organometals, POPs and PAHs) may be present in coastal waters at high latitudes, stressing the need to evaluate the effects of contaminants on marine organisms from sub-arctic zones. With this aim, specimens of the blue mussel Mytilus edulis were sampled in polluted and reference areas along the south-west coast of Iceland in July 2004. Samples were collected from the intertidal zone at three sites in Reykjavik harbour which are differently exposed to contaminants, and at three reference coastal sites, two located along the Reykjanes Peninsula and the third one on the northern part of Hvalfjordur fiord. Lipofuscin content, neutral lipid accumulation and lysosomal enlargement were evaluated in digestive cells from cryostat sections of the mussel hepatopancreas, and quantified by automated image analysis. Metallothionein induction was also determined in the same tissue. Results indicate that mussels from the inner part of Reykjavik harbour, which is the most sheltered and most influenced by extensive shipping traffic, were the worst affected, with the highest values in neutral lipids, lipofuscin and lysosomal swelling. At the other two harbour sites, mussels exhibited lower values, similar to those observed in organisms collected in Hvalfjordur fiord and in bay of Osar. Mussels from Kuagerdi had the lowest values.

Bioaccumulation and biomarker responses of trace metals and micro-organic pollutants in mussels and fish from the Lagoon of Venice, Italy.

The aims of this study were to evaluate levels and effects of trace metals (Cd, Cr, Cu, Fe, Mn, Pb, Zn), PAHs and PCBs in mussels and fish native to the Lagoon of Venice. To this end, bioaccumulation and various biomarkers of generic stress and exposure (malondialdehyde, MDA and metallothioneins, MT; ethoxyresorufin O-deethylase activity, EROD; fluorescent bile metabolites and somatic indices in fish; lysosomal membrane stability, LMS; lipofuscins, LF; neutral lipids, NL and survival-in-air, SOS in mussels) were measured in organisms seasonally collected from two differently influenced areas. In mussels, metal bioaccumulation levels at the two sites were low and fluctuated similarly, exhibiting decreasing levels in summer, like MDA and MT. Micro-organic pollutants and the probably related biological response of LMS did not show either significant site differences or seasonal trends. LF and NL revealed inconclusive patterns. The results of the survival-in-air test were quite erratic, showing that they were associated with the high variability of both natural and physiological parameters temperature, food, reproduction, and body reserve cycle. In fish, both inorganic and organic micropollutant levels were low, and differences were detected between sites only for PCBs. The pattern exhibited by micro-organic contaminants was clearly related to the reproductive cycle at both sites; a relationship with PCBs, EROD and MDA was established at the site where their levels were generally higher. Bile metabolites (3-OH benzo(a)pyrene, 1-OH pyrene) were associated with PAH contents.

An ecotoxicological approach to evaluate the effects of tourism impacts in the Marine Protected Area of La Maddalena (Sardinia, Italy).

In the Marine Protected Area of La Maddalena Archipelago, environmental protection rules and safeguard measures for nautical activities have helped in reducing anthropogenic pressure; however, tourism related activities remain particularly significant in summer. With the aim of evaluating their impacts, the biomarker approach using transplanted Mytilus galloprovincialis as sentinel organisms coupled with POCIS deployment was applied. Mussels, translocated to four marine areas differently impacted by tourism activities, were sampled before, during and after the tourist season. Moreover, endocrine disruptors in passive samplers POCIS and the cellular toxicity of whole POCIS extracts on mussel haemocytes were evaluated to integrate ecotoxicological information. Lysosomal biomarkers, condition index and mortality rate, as well as metals in tissues suggested an alteration of the health status of mussels transplanted to the most impacted sites. The cellular toxicity of POCIS extracts was pointed out, notwithstanding the concentrations of the examined compounds were always below the detection limits.

Field validation of autometallographical black silver deposit (BSD) extent in three bivalve species from the Lagoon of Venice, Italy (Mytilus galloprovincialis, Tapes philippinarum, Scapharca inaequivalvis) for metal bioavailability assessment.

The autometallographic approach was applied to three filter-feeder bivalves from differently polluted sites of the Lagoon of Venice. The area density (AD) values of black silver deposits (BSDs) were therefore seasonally quantified by image analysis in digestive cell lysosomes. Sediments were characterised in terms of grain size, organic content and metal concentrations (Cd, Cu, Ni, Pb, Zn). The physiological status of the bivalves was also evaluated by applying the "survival in air" test as a generic stress index. Chemical results showed that Zn contributed to the total metal load for more than 60% in sediments and for 85%-94% in mussel and clam digestive glands, respectively (data processed from published results obtained on the same samples). Regression analyses between extent of BSDs and both total metal and Zn concentrations in digestive gland followed a linear pattern in mussels and clams, but not in arks. Similarly, in mussels and clams only, BSD amount was significantly correlated with total metal concentrations in sediments according to a logarithmic model. Consequently, results obtained from autometallography can discriminate sites on the basis of their metal pollution levels, like chemical analyses on both sediments and digestive glands, evaluations being supported by the results of the physiological stress index. As a conclusion, it is suggested that autometallography in bivalves may provide overall estimates of metal fractions moving from sediments towards organisms through the ingestion of metal-enriched particles. Future work is needed to define the bioaccumulation model in arks and to clarify their possible use as metal biomonitors.

Cellular alterations in Mytilus galloprovincialis (LMK) and Tapes philippinarum (Adams and Reeve, 1850) as biomarkers of environmental stress: field studies in the Lagoon of Venice (Italy).

A long-term biomonitoring study was carried out in the Lagoon of Venice (North-East Italy) with the aim of evaluating variations in biological responses to environmental stress in estuarine bivalves. Two different species, the mussel Mytilus galloprovincialis and the clam Tapes philippinarum, both widespread in the Lagoon, were studied in several sites. Two cellular biomarkers: lysosomal membrane stability in digestive cells and thickness of digestive epithelia, were evaluated in native organisms (on a seasonal basis), and in organisms which have been transferred from a reference site to several differently influenced ones. Results indicate that, to some extent, both test and organisms were able to highlight site-specific differences, but the effects of pollution were generally more easily detected by reduction in lysosomal stability than by reduction in digestive tubule epithelium. Further findings show that the inherent variability of a number of natural parameters, particularly in the reference sites, produced less effective results when biological responses in the reference organisms were compared with the polluted ones. The assessment of the two conditions was most valuable when they referred to the 25-75% range of values comprised within the seasonal medians, recorded respectively in control and polluted sites. Impaired from steady states were most effectively distinguished when the control values were medians from two reference locations. Lately, the overall results indicate that both biomarkers are more suitably deployed through the translocation approach, revealing it to be more sensitive than traditional biomonitoring, at least in the sense that it may overcome problems related to the adaptation of native organisms to sub lethal chronic pollution levels.

Photodegradation studies on lacidipine in solution: basic experiments with a cis-trans reversible photoequilibrium under UV-A radiation exposure.

The photostability of Lacidipine, a dihydropyridine drug used in the treatment of mild and moderate hypertension, was studied in solutions exposed to UV-A radiations. The effects of the solvent (ethanol, acetone, dichloromethane), drug concentration and radiation wavelength on the drug photostability were evaluated. Lacidipine and its photoproducts were separated by a selective liquid chromatographic (HPLC) method, under normal phase conditions (CN-column), using n-hexane:ethanol 97:3 (v/v) as mobile phase, at a flow rate of 2.0 ml/min. The main photodegradation products were isolated and characterised and a photodegradation pathway was proposed for Lacidipine in solution. The cis-isomer and a photocyclic isomer proved to be the main photodegradation products.

Immunotoxic effects of organotin compounds in Tapes philippinarum.

One of the most harmful groups of coastal pollutants is the organotin compounds (OTCs) which have severe effects on both aquatic organisms and mammals including humans. The immunotoxic effects of OTCs were studied in the cultivated clam Tapes philippinarum by determining the immunosuppressant role on in vitro yeast phagocytosis at low doses (0.01, 0.05, 0.1 microM). The phagocytic index was significantly reduced in an irreversible non-lethal manner depending on concentration and lipophilic affinity. The order of inhibition was TBT > or = DBT > MBT for butyltins and TPTC > TPTA > or = TPTH for triphenyltins.

Field application of lysosomal destabilisation indices in the mussel Mytilus galloprovincialis: biomonitoring and transplantation in the Lagoon of Venice (north-east Italy).

A field study was carried out in the Lagoon of Venice (north-east Italy) with the aim of evaluating the potential use of lysosomal destabilisation as a biomarker of anthropogenic stress in the autochthonous mussel Mytilus galloprovincialis. Two different approaches were adopted in biomonitoring six sites in the Lagoon, evaluating indigenous populations of mussels and organisms transplanted from a reference site and checked at several points in time. Lysosomal membrane stability was investigated by means of two tests: neutral red retention assay (NRRA) for evaluating haemocyte lysosomes and lysosomal latency test (LLT) for digestive cell lysosomes. Results indicate that the lysosomal response measured in haemocytes according to NRRA is a more valuable biomarker of anthropogenic stress in the framework both of passive and active biomonitoring in marine coastal environments.

Biomarkers and trace metals in the digestive gland of indigenous and transplanted mussels, Mytilus galloprovincialis, in Venice Lagoon, Italy.

The aim of this study was to investigate the cellular and biochemical response of mussels, Mytilus galloprovincialis, transplanted from a relatively pristine site to a polluted one and vice versa in the Lagoon of Venice (northeast of Italy) and to apply auto-metallography, a rapid and sensitive histochemical technique, to determine the bio-available fraction of heavy metals accumulated in the body tissues of organisms. Animal digestive glands have been used for morphological analyses (lysosomal volume, surface and numerical density, mean epithelial thickness, mean diverticular and luminar radius), autometallographical black silver deposits quantification and biochemical assays (superoxide dismutase and catalase activity). Furthermore, heavy metal content was determined by atomic absorption spectrophotometry (AAS) using standard procedures. The overall results indicate a direct influence of the environment in the thinning of the digestive cells and in the increasing number of lysosomes in mussels from the more polluted site. These data are in agreement with the metal content in digestive cell lysosomes as determined by autometallography, whereas AAS measurements show less significant differences.

Field application of biochemical markers and a physiological index in the mussel, Mytilus galloprovincialis: transplantation and biomonitoring studies in the lagoon of Venice (NE Italy).

A number of biochemical markers and a physiological index were measured in mussels, Mytilus galloprovincialis, transplanted or native to five different contaminated sites in the lagoon of Venice. Mussels from Pellestrina, a reference site in the adjacent Adriatic Sea, were transplanted for 6 weeks to areas of the lagoon where indigenous mussels were also collected. As biochemical indices, superoxide dismutase (SOD), catalase, aldehyde dehydrogenase (ADH) and NADPH cytochrome c reductase (NADPHcred) were measured in mussel digestive gland; survival in air as a physiological index was also determined. Biomarker responses varied among sites and between indigenous and transplanted animals. Significant induction of catalase and SOD was shown in animals transplanted to the urban sites of Salute and Chioggia, respectively. In indigenous mussels, induction of SOD and NADPHcred was seen in animals from the polluted site of Treporti and the heavily contaminated industrial area of Marghera. The overall biochemical data indicate significantly higher activity for ADH in transplanted animals in comparison with indigenous ones which, in contrast, present an increase in SOD. As regard survival in air, control mussels did not seem to be healthier in comparison either with transplanted or indigenous ones, suggesting that pollution has no effect on this parameter.

Biochemical and histochemical responses to environmental contaminants in clam, Tapes philippinarum, transplanted to different polluted areas of Venice Lagoon, Italy.

In this study the clam, Tapes philippinarum, a filter-feeding bivalve living in soft bottoms, was used to investigate the water/sediment pollution in Venice Lagoon (Venice, Italy), a heavily urbanised and industrialised area. To this end, clams collected from indigenous populations in a clean farming area (Val Dogà) were transplanted into a relatively low contaminated site (Palude della Rosa) and in a heavily polluted area (Porto Marghera), for 5 weeks. A range of possible induced stress indices were measured, on the basis of potential toxicity mechanisms, including specific enzymatic activities [Bap hydroxylase and NADPH cytochrome c reductase, superoxide dismutase, catalase, glutathione peroxidase and propionaldehyde dehydrogenase (PDH)] and general cellular responses (lysosomal latency). Moreover, chemical analyses (polychlorinated biphenyls, polycyclic aromatic hydrocarbon, DDTs) were carried out on sediments and animal tissues at the beginning and end of the transplantation experiments. The chemical results show an active bio-accumulation activity from sediment in clams translocated to the most polluted area. Correspondingly, biological data indicate marked effects on PDH activity and latency in T. philippinarum from the same site. In contrast, no similar pattern has been observed in the other considered indices, possibly due to antagonistic effects of the complex contaminant mixture present in the environment.

A preliminary investigation on nanohorn toxicity in marine mussels and polychaetes.

Single walled carbon nanohorns (SWCNHs) are a black nanoscale spherical aggregate of cylindrical tubes of graphitic carbon which differ from nanotubes in their "horn-like" shape. Their peculiar structure makes them one of the best electronconductors at a nanoscale level. Although not commercially exploited, their rapid environmental diffusion is expected to rise significantly in the next few years. Therefore, we appraised the ecotoxicology of SWCNH powders by taking into account the ecological role of the two species that were deployed in exposure experiments: polychaetes, Hediste diversicolor, and mussels, Mytilus galloprovincialis. Adult mussels and polychaetes were exposed to three SWCNH concentrations: 1, 5, and 10 mg L(-1) and acute effects were measured after 24 and 48 h. Sub-lethal effects were estimated at level of physiological functions such as digestion in mussels (i.e. variations in lysosomal parameters and lipofuscin content) and the antioxidant system in both species (i.e. glutathione peroxidase activity and malondialdehyde content). SWCNH suspension in sea water was also characterised, highlighting the formation of aggregates the size of which was related to SWCNH concentrations and their resident time in the medium. The results showed that SWCNH affected the oxidative and lysosomal systems on the hepatopancreas and led to lysosomal alterations on haemocytes in mussels. The biological responses were less clear in polychaetes. This preliminary investigation highlighted the need of focusing future research efforts on possible physiological impairments caused by long-term exposure to SWCNHs in marine species.

Assessing the significance of Ruditapes philippinarum as a sentinel for sediment pollution: bioaccumulation and biomarker responses.

The present study assessed whether the bivalve Ruditapes philippinarum may be appropriately deployed as a bioindicator in monitoring transitional environments, in terms of bioaccumulation potential and biomarker responses. The concentrations of trace metals, PAHs and PCBs were determined in sediments and clam tissue, and biomarkers were estimated at various levels of biological complexity (i.e. metallothioneins, lipofuscins, survival-in-air and reburrowing behaviour). Sediments and clams were collected biannually in 2004 and 2005 at eight sites within Venice lagoon, which were influenced differently by natural and anthropogenic impacts. Results highlighted that the broad variations of pollutant concentrations in sediments were not consistent either with the body residuals or with the biomarker responses. Consequently, on the basis of the observed weak responsiveness and sensitivity to anthropogenic stressors we suggest a more cautious use for R. philippinarum as sentinel organism, at least in estuarine sediments in the north Adriatic transitional areas.

An ecotoxicological approach for the Boka Kotorska Bay (south-eastern Adriatic Sea): first evaluation of lysosomal responses and metallothionein induction in mussels.

Mytilus galloprovincialis was used as a biomonitoring organism in Boka Kotorska Bay, a coastal transitional ecosystem in south-western Montenegro. Native mussels were collected in June 2008 at four sites thought to be differently impacted. Biological effects were investigated analysing both generic and specific biomarkers at cellular level (metallothionein content, lysosomal membrane stability, lipofuscin and neutral lipid accumulation, lysosomal structural changes). Trace element levels in mussels were quite low, only Cu and Zn exhibiting slight increases in the two sampling sites of Tivat Bay, the first one in front of a small working dockyard and the other in the water area of a former Naval dockyard. Mussels collected from these sites exhibited the highest values in neutral lipid and lysosomal volume density and the lowest neutral red retention times. Metallothionein content was always low, reflecting the minor body burden of the trace elements and suggesting a non-relevant environmental induction.

A study to determine the pharmacokinetics and inflammatory fluid penetration of two doses of a solid formulation of the hexetil prodrug of a trinem, sanfetrinem (GV 104326).

The trinem sanfetrinem (GV 104326) was administered as the oral hexetil prodrug GV 118819X in two dose levels to six healthy volunteers. A single dose equivalent to 125 mg of sanfetrinem was administered, followed 6 weeks later by a single dose equivalent to 500 mg of sanfetrinem. The concentrations of the drug in plasma, cantharidin-induced inflammatory fluid, and urine were measured with a microbiological assay. The stability of sanfetrinem was studied in serum and inflammatory fluid. The mean peak concentrations in plasma of 0.77 and 2.47 microg/ml were attained at 1.1 and 2.0 h after the 125- and 500-mg doses, respectively. Mean peak concentrations in inflammatory exudate of 0.26 and 0.86 microg/ml were attained at 2.80 and 2.67 h after the 125- and 500-mg doses, respectively. The mean terminal elimination half-lives in plasma were 1.33 and 1.97 h for the 125- and 500-mg doses, respectively. The half-lives in the inflammatory fluid were 1.66 and 1.74 h for the 125- and 500-mg doses, respectively. The overall penetration of the drug into the inflammatory fluid was 51.4 and 47.0% for the 125- and 500-mg doses, respectively. Mean urine recovery was greater following 500 mg (24.15%) than after 125 mg (18.4%) of sanfetrinem. Sanfetrinem was relatively unstable in the inflammatory exudate in vitro (half-life, 5.5 h), and this could explain the poor penetration of the drug in the inflammatory exudate observed in this study.

The effects of lacidipine on the steady/state plasma concentrations of simvastatin in healthy subjects.

AIMS: Lacidipine, a long acting 2, 4-dihydropyridine calcium channel antagonist is frequently administered with cholesterol lowering agents, particularly in elderly populations. The effects of lacidipine on the pharmacokinetics of simvastatin were investigated, since they share the CYP3A4 pathway for metabolism. METHODS: The study was an open, randomised, two-way crossover design, with at least 7 days washout. Eighteen healthy subjects received simvastatin, 40 mg once daily, alone and together with lacidipine, 4 mg once daily, for 8 days. The pharmacokinetics of simvastatin were studied on the eighth day. Analysis was made of total simvastatin acid concentrations (naive simvastatin acid plus that derived from alkaline hydrolysis of the lactone). RESULTS: Lacidipine increased the maximum concentration of simvastatin (Cmax) by approximately 70% (P=0.016) and the area under the plasma concentration-time curve AUC(0,24 h) by approximately 35% (P=0.001). The mean Cmax and AUC(0,24 h) of simvastatin (95% confidence interval) when given alone were 8.76 (6.72-11.41) ng ml(-1) and 60.36 (47.15-77.28) ng ml(-1) h. During treatment with lacidipine they were, respectively, 14.89 (10.77-20.58) ng ml(-1) and 80.96 (64.62-101.44) ng ml(-1) h. No significant differences were observed in either time to peak concentration (tmax was 1.0 h for simvastatin alone and 1.5 h for the combination) or in the half-life (t1/2,z was 8.5 h in both cases). The combination was safe and well tolerated. CONCLUSIONS: The observed increased exposure to simvastatin 40 mg following coadministration of lacidipine is unlikely to be of clinical relevance.