PFAS levels and determinants of variability in exposure in European teenagers - Results from the HBM4EU aligned studies (2014-2021)

BACKGROUND

Perfluoroalkyl substances (PFAS) are man-made fluorinated chemicals, widely used in various types of consumer products, resulting in their omnipresence in human populations. The aim of this study was to describe current PFAS levels in European teenagers and to investigate the determinants of serum/plasma concentrations in this specific age group.

METHODS

PFAS concentrations were determined in serum or plasma samples from 1957 teenagers (12-18 years) from 9 European countries as part of the HBM4EU aligned studies (2014-2021). Questionnaire data were post-harmonized by each study and quality checked centrally. Only PFAS with an overall quantification frequency of at least 60% (PFOS, PFOA, PFHxS and PFNA) were included in the analyses. Sociodemographic and lifestyle factors were analysed together with food consumption frequencies to identify determinants of PFAS exposure. The variables study, sex and the highest educational level of household were included as fixed factors in the multivariable linear regression models for all PFAS and each dietary variable was added to the fixed model one by one and for each PFAS separately.

RESULTS

The European exposure values for PFAS were reported as geometric means with 95% confidence intervals (CI): PFOS [2.13 μg/L (1.63-2.78)], PFOA ([0.97 μg/L (0.75-1.26)]), PFNA [0.30 μg/L (0.19-0.45)] and PFHxS [0.41 μg/L (0.33-0.52)]. The estimated geometric mean exposure levels were significantly higher in the North and West versus the South and East of Europe. Boys had significantly higher concentrations of the four PFAS compared to girls and significantly higher PFASs concentrations were found in teenagers from households with a higher education level. Consumption of seafood and fish at least 2 times per week was significantly associated with 21% (95% CI: 12-31%) increase in PFOS concentrations and 20% (95% CI: 10-31%) increase in PFNA concentrations as compared to less frequent consumption of seafood and fish. The same trend was observed for PFOA and PFHxS but not statistically significant. Consumption of eggs at least 2 times per week was associated with 11% (95% CI: 2-22%) and 14% (95% CI: 2-27%) increase in PFOS and PFNA concentrations, respectively, as compared to less frequent consumption of eggs. Significantly higher PFOS concentrations were observed for participants consuming offal (14% (95% CI: 3-26%)), the same trend was observed for the other PFAS but not statistically significant. Local food consumption at least 2 times per week was associated with 40% (95% CI: 19-64%) increase in PFOS levels as compared to those consuming local food less frequently.

CONCLUSION

This work provides information about current levels of PFAS in European teenagers and potential dietary sources of exposure to PFAS in European teenagers. These results can be of use for targeted monitoring of PFAS in food.

Approaches to mixture risk assessment of PFASs in the European population based on human hazard and biomonitoring data

Per- and polyfluoroalkyl substances (PFASs) are a highly persistent, mobile, and bioaccumulative class of chemicals, of which emissions into the environment result in long-lasting contamination with high probability for causing adverse effects to human health and the environment. Within the European Biomonitoring Initiative HBM4EU, samples and data were collected in a harmonized way from human biomonitoring (HBM) studies in Europe to derive current exposure data across a geographic spread. We performed mixture risk assessments based on recent internal exposure data of PFASs in European teenagers generated in the HBM4EU Aligned Studies (dataset with N = 1957, sampling years 2014-2021). Mixture risk assessments were performed based on three hazard-based approaches: the Hazard Index (HI) approach, the sum value approach as used by the European Food Safety Authority (EFSA) and the Relative Potency Factor (RPF) approach. The HI approach resulted in the highest risk estimates, followed by the RPF approach and the sum value approach. The assessments indicate that PFAS exposure may result in a health risk in a considerable fraction of individuals in the HBM4EU teenager study sample, thereby confirming the conclusion drawn in the recent EFSA scientific opinion. This study underlines that HBM data are of added value in assessing the health risks of aggregate and cumulative exposure to PFASs, as such data are able to reflect exposure from different sources and via different routes.

Real-world use of mycophenolate mofetil in inflammatory bowel disease: Results from the ENEIDA registry

BACKGROUND

Studies to evaluate the use of mycophenolate mofetil (MMF) in inflammatory bowel disease (IBD) are limited after the appearance of biological treatments.

AIMS

Our primary objective was to evaluate the effectiveness and safety of MMF in IBD.

METHODS

IBD patients who had received MMF were retrieved from the ENEIDA registry. Clinical activity as per the Harvey-Bradshaw Index (HBI), partial Mayo score (pMS), physician global assessment (PGA) and C-reactive protein (CRP) were reviewed at baseline, at 3 and 6 months, and at final follow-up. Adverse events and causes of treatment discontinuation were documented.

RESULTS

A total of 83 patients were included (66 Crohn's disease, 17 ulcerative colitis), 90% of whom had previously received other immunosuppressants. In 61% of patients systemic steroids were used at initiation of MMF, and in 27.3% biological agents were co-administered with MMF. Overall clinical effectiveness was observed in 64.7% of the population. At the end of treatment, 45.6% and 19.1% of subjects showed remission and clinical response, respectively. MMF treatment was maintained for a median of 28.9 months (IQR: 20.4-37.5).

CONCLUSION

Our study suggests, in the largest cohort to date, that MMF may be an effective alternative to thiopurines and methotrexate in IBD.

Mercury levels in blood, urine and hair in a nation-wide sample of Spanish adults

Mercury (Hg) is among the top 10 environmental chemicals of major public health concern (WHO). The Minamata Convention on Mercury (United Nations Environment Program, 2017), commits signing countries to control anthropogenic mercury emissions and reduce human exposure. Human biomonitoring (HBM) programs, are the most straight-forward approaches to get information on the actual exposure levels in the population and assess over time. We report here the results of a HBM study in a nationwide cross-section of Spanish adults (18-65y) as baseline values obtained before the Minamata Convention entered into force. Subsequent follow-ups will show if the Convention has been successful. The study includes 1880 blood samples, 1704 urine samples and 577 hair samples from all Spanish regions collected and analysed under a strictly quality controlled and quality assured protocol. The EU-DEMOCOPHES project demonstrated that fish and seafood are the major sources of mercury exposure and that the Spanish as well as the Portuguese populations have higher levels than other European countries. The data from the present study confirms this pattern at national level and that inhabitants in coastal regions have higher values than from inland regions. The geometric mean (GM) for blood is 6.35 μg Hg/l, in urine is 1.11 μg Hg/l and for hair is 1.91 μg Hg/g. In an international comparison these values are not exceptional. Spanish concentrations fall into the group of Easter Mediterranean populations. Although information on gender, age, occupational sector, geographical area, sampling period and frequency of fish consumption is reported in the tables, the purpose of this paper has not been to analyse the determinants of exposure in detail but to provide baseline data for future assessments and for regional authorities.

Being Overweight Is Related to Faster Decline in Annual Glomerular Filtration Rate in Kidney Transplant

Few studies have examined the relationship between non-immunological factors and glomerular filtration rate (GFR) decline in kidney transplant. Correcting these factors in native kidneys slows the progression of chronic kidney disease. The aim of this study was to analyze the association between the control of non-immunological factors and the annual decline of GFR.

METHODS

A single-center, retrospective study was performed. We included 128 patients who received kidney transplants between 2000 and 2015, with at least 1-year post-transplant follow-up. Clinical records were reviewed. GFR was estimated by CKD-EPI. Three groups were defined according to the annual change in eGFR (ΔGFR 2016-1015): non-progressors (> -1 mL/min/1.73 m²), slow progressors (> -1 and < -5 mL/min/1.73 m²), and fast progressors (< -5 mL/min/1.73 m²). Percentage of achievement of KDIGO target was also analyzed.

RESULTS

The mean GFR was 62.5 mL/min/1.73 m². Glomerulonephritis was the most common cause of kidney failure (36%). When the fast progressor group was compared with the non-progressor group, they differed significantly in age-patients were younger (40 ± 12.3 vs 45 ± 13.1 years)-post-transplant body mass index (27.4 ± 5.6 vs 25.2 x ± 5.9 kg/m²), and serum uric acid, which was significantly higher (6.4 ± 1.7 vs 5.5 ± 1.58 mg/dL). There were no differences between the groups with regard to blood pressure, dyslipidemia, proteinuria, or venous bicarbonate. Target systolic blood pressure was achieved by 45% of patients. Biopsy-proven acute rejection was higher in the fast progression group, although this was not statistically significant (13 [24.5%] vs 8 [13.1%]).

CONCLUSIONS

High body mass index was associated with a faster decline in glomerular filtration rate in this study. Target blood pressure <140/90 mm Hg was achieved in less than 50% of cases.

A pilot study on the feasibility of European harmonized human biomonitoring: Strategies towards a common approach, challenges and opportunities

In 2004 the European Commission and Member States initiated activities towards a harmonized approach for Human Biomonitoring surveys throughout Europe. The main objective was to sustain environmental health policy by building a coherent and sustainable framework and by increasing the comparability of data across countries. A pilot study to test common guidelines for setting up surveys was considered a key step in this process. Through a bottom-up approach that included all stakeholders, a joint study protocol was elaborated. From September 2011 till February 2012, 17 European countries collected data from 1844 mother-child pairs in the frame of DEMOnstration of a study to COordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES).(1) Mercury in hair and urinary cadmium and cotinine were selected as biomarkers of exposure covered by sufficient analytical experience. Phthalate metabolites and Bisphenol A in urine were added to take into account increasing public and political awareness for emerging types of contaminants and to test less advanced markers/markers covered by less analytical experience. Extensive efforts towards chemo-analytical comparability were included. The pilot study showed that common approaches can be found in a context of considerable differences with respect to experience and expertize, socio-cultural background, economic situation and national priorities. It also evidenced that comparable Human Biomonitoring results can be obtained in such context. A European network was built, exchanging information, expertize and experiences, and providing training on all aspects of a survey. A key challenge was finding the right balance between a rigid structure allowing maximal comparability and a flexible approach increasing feasibility and capacity building. Next steps in European harmonization in Human Biomonitoring surveys include the establishment of a joint process for prioritization of substances to cover and biomarkers to develop, linking biomonitoring surveys with health examination surveys and with research, and coping with the diverse implementations of EU regulations and international guidelines with respect to ethics and privacy.

Interpreting biomarker data from the COPHES/DEMOCOPHES twin projects: Using external exposure data to understand biomarker differences among countries

In 2011 and 2012, the COPHES/DEMOCOPHES twin projects performed the first ever harmonized human biomonitoring survey in 17 European countries. In more than 1800 mother-child pairs, individual lifestyle data were collected and cadmium, cotinine and certain phthalate metabolites were measured in urine. Total mercury was determined in hair samples. While the main goal of the COPHES/DEMOCOPHES twin projects was to develop and test harmonized protocols and procedures, the goal of the current paper is to investigate whether the observed differences in biomarker values among the countries implementing DEMOCOPHES can be interpreted using information from external databases on environmental quality and lifestyle. In general, 13 countries having implemented DEMOCOPHES provided high-quality data from external sources that were relevant for interpretation purposes. However, some data were not available for reporting or were not in line with predefined specifications. Therefore, only part of the external information could be included in the statistical analyses. Nonetheless, there was a highly significant correlation between national levels of fish consumption and mercury in hair, the strength of antismoking legislation was significantly related to urinary cotinine levels, and we were able to show indications that also urinary cadmium levels were associated with environmental quality and food quality. These results again show the potential of biomonitoring data to provide added value for (the evaluation of) evidence-informed policy making.

Obtaining from grape pomace an enzymatic extract with anti-inflammatory properties

Grape pomace, a winemaking industry by-product, is a rich source of bioactive dietary compounds. Using proteases we have developed an enzymatic process for obtaining a water-soluble extract (GP-EE) that contains biomolecules such as peptides, carbohydrates, lipids and polyphenols in soluble form. Of especial interest is its high polyphenol content (12%), of which 77% are flavonoids and 33% are phenolic acids. The present study evaluates in vitro the potential anti-inflammatory effect of GP-EE by monitoring the expression of inflammatory molecules on N13 microglia cells stimulated with lipopolysaccharide (LPS). GP-EE decreases the mRNA levels of the inflammatory molecules studied. The molecules under study were as follows: inducible nitric oxide synthase (iNOS), tumor necrosis factor- α (TNF-α), interleukin-1β (IL-1β), the ionized calcium binding adaptor molecule-1(Iba-1) and the Toll like receptor-4 (TLR-4), as well as the iNOS protein level in LPS-stimulated microglia. Our findings suggest that, as a result of its ability to regulate excessive microglial activation, GP-EE possesses anti-inflammatory properties. Therefore, acting as a chemopreventive agent, it may be of therapeutic interest in neurodegenerative diseases involving neuroinflammation. We can, therefore, propose GP-EE as a useful natural extract and one that would be beneficial to apply in the field of functional foods.

Harmonized European human biomonitoring in small countries: Challenges, opportunities and lessons learned in Cyprus and Luxembourg from the DEMOCOPHES study

Background: To advance human biomonitoring (HBM) for policy support in Europe, a harmonized approach was developed (COPHES project, FP7 2009- 2012) and evaluated in 17 countries (DEMOCOPHES project, Life+, 2010-2012). Cyprus (CY) and Luxembourg (LU) tested the hypothesis that the COPHES European Protocol is applicable to small countries.Materials and methods: In 2011-12, the European Protocol was adopted and tested by CY and LU for the harmonized biomonitoring of 60 children and their mothers for cadmium, phthalates and cotinine in urine and for mercury in scalp hair in two sampling areas (urban, rural). Results: Both small countries achieved the preset goals for recruitment, sample collection and analysis, which allowed for the first time the assessment of children’s and mothers’ exposures to the selected chemicals in comparison with other countries. Capacity building was accomplished and communication actions were particularly effective, with both countries taking advantage of their small size to access participants, policy makers, other stakeholders and the press. Time constrains and requirements for capacity building were limiting factors. Conclusion: The COPHES European Protocol for HBM surveys is attainable in small countries. The following elements are fundamental in the design of a harmonized European HBM program, from the perspective of small countries: (a) consultation with and active involvement of the implementing countries, (b) flexibility for national decisions, while not compromising harmonization, (c) elaboration of standardized methods, procedures and documents (d) quality assurance mechanisms, (e) means of training and support.

Serum PCB levels in a representative sample of the Spanish adult population: the BIOAMBIENT.ES project

This manuscript presents the levels of six indicator polychlorinated biphenyl (PCB) congeners (IUPAC nos. 28, 52, 101, 138, 153 and 180) in the serum of 1880 individuals from a representative sample of the Spanish working population recruited between March 2009 and July 2010. Three out of the six PCBs studied (180, 153 and 138) were quantified in more than 99% of participants. PCB 180 was the highest contributor, followed by PCBs 153 and 138, with relative abundances of 42.6%, 33.2% and 24.2%, respectively. In contrast, PCBs 28 and 52 were detected in only 1% of samples, whereas PCB 101 was detectable in 6% of samples. The geometric mean (GM) for ΣPCBs138/153/180 was 135.4 ng/g lipid (95% CI: 121.3-151.2 ng/g lipid) and the 95th percentile was 482.2 ng/g lipid. Men had higher PCB blood concentrations than women (GMs 138.9 and 129.9 ng/g lipid respectively). As expected, serum PCB levels increased with age and frequency of fish consumption, particularly in those participants younger than 30 years of age. The highest levels we found were for participants from the Basque Country, whereas the lowest concentrations were found for those from the Canary Islands. The Spanish population studied herein had similar levels to those found previously in Greece and southern Italy, lower levels than those in France and central Europe, and higher PCB levels than those in the USA, Canada and New Zealand. This paper provides the first baseline information regarding PCB exposure in the Spanish adult population on a national scale. The results will allow us to establish reference levels, follow temporal trends and identify high-exposure groups, as well as monitor implementation of the Stockholm Convention in Spain.

[Spontaneous resolution of macular detachment associated with optic disc coloboma]

CASE REPORT

A 24-year-old male presented with visual acuity loss of the right eye. Examination of the right eye fundus showed a serous detachment of the posterior pole associated with optic disc coloboma. The patient refused surgical treatment. After six months an improvement in visual acuity was observed with the disappearance of macular subretinal fluid.

DISCUSSION

The macular detachment is a known complication of the optic disc coloboma. Different therapeutic options have been used, although spontaneous re-attachment may also occur as shown in this case.

Seasonal variation of pharmaceutically active compounds in surface (Tagus River) and tap water (Central Spain)

Numerous studies have shown the presence of pharmaceutically active compounds (PhACs) in different environmental compartments, for example, in surface water or wastewater ranging from nanograms per litre to micrograms per litre. Likewise, some recent studies have pointed to seasonal variability, thus indicating that PhAcs concentrations in the aquatic environment may depend on the time of year. This work intended to find out (1) whether Tagus fluvial and drinking water were polluted with different groups of PhACs and (2) if their concentrations differed between winter and summer seasons. From the 58 substances analysed, 41 were found belonging to the main therapeutic groups. Statistical differences were seen for antibacterials, antidepressants, anxiolytics, antiepileptics, and cardiovascular drugs, with higher concentrations being detected in winter than in summer. These results might indicate that the PhACs analysed in this study undergo lower environmental degradation in winter than in summer. In order to confirm these initial results, a continuous monitoring should be performed especially on those PhACs that either because of an elevated consumption or an intrinsic chemical persistence are poorly degraded during winter months due to low temperatures and solar irradiation. It is especially important to identify which of these specific PhACs are in order to recommend their substitution by equally effective and safe substances but also environmentally friendly.

Pigmented paravenous retinochoroidal atrophy with macular involvement

CASE REPORT

A 65-year-old female, with poor visual acuity in right eye since childhood, was referred to our hospital. Funduscopic examination revealed bone-spicule pigmentation and choroidal and retinal pigment epithelium atrophy along the vascular arcades, with macular involvement in right eye. The patient was diagnosed with pigmented paravenous retinochoroidal atrophy (PPRCA).

DISCUSSION

PPRCA is a rare disease, of unknown origin, characterised by retinochoroidal atrophy and retinal pigmentation along retinal veins, generally without macular involvement. Latest publications show a slow progression. No effective treatment is available.

Cytotoxicity and genotoxicity of sewage treatment plant effluents in rainbow trout cells (RTG-2)

The cytotoxicity and genotoxicity of 11 organic fractions from sewage treatment plant (STP) effluents were tested using the RTG-2 rainbow trout permanent cell line. An automated in vitro micronucleus assay developed for RTG-2 cells was used to test the genotoxicity, whereas neutral red uptake, kenacid blue protein assay and ATP content were used to evaluate cytotoxicity. The induction of micronuclei (MN) and alterations in the cell cycle were analysed in these cells by flow cytometry after exposure to the organic fractions for 72 h. More than half of the organic extracts tested demonstrated a significant increase in the MN frequency, thus indicating that most of them can be considered to be genotoxic. The extracts were analysed chemically by GC/MS. Although the most frequently detected compounds in the effluents were bisphenol A (BPA), octylphenol (OP), di-2-ethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP), as well as other possible mutagens, the concentrations cannot explain the genotoxicity of the individual chemicals, thereby suggesting a mixture effect. The results obtained support the need to apply effect-based tests to monitor complex mixtures as the most accurate means of assessing the genotoxicity of environmental samples.

Antiproliferative and immunoactivatory ability of an enzymatic extract from rice bran

The validation of natural products as source of functional foods or nutraceuticals has become an important issue in current health research. Thus, the present work has tested on MOLT-4 cells (human T cell acute lymphoblastic leukemic) the antiproliferative effect of a water-soluble enzymatic extract from rice bran (EERB). Present work shows that EERB induces cellular death in MOLT-4 cells in a dose-dependent way (0-10mg/mL) but not in non-tumoral lymphocytes. Flow cytometric analysis of MOLT-4 cells treated with EERB showed the presence of death cells by apoptosis rather than necrosis. Additionally, EERB also exerts an immunoactivatory effect on N13 microglia cells, by inducing TNF-alpha (tumour necrosis factor-α) expression, which plays a key role in the innate immune response to infection. Accordingly, we can propose EERB as a useful natural standardized extract with antiproliferative and immunoactivatory ability that would be beneficial to apply in the functional food field.

[Multifocal epithelial hyperplasia: a familial case]

Multifocal epithelial hyperplasia (MEH), or Heck disease, is a disease of the oral mucosa rarely seen in Spain. It is caused by the human papillomavirus (HPV), and is mainly associated with types 13 and 32. It appears in childhood (3-18 years) and a higher prevalence is reported in women and certain ethnic groups (American Indians and Eskimos). It consists of a benign, asymptomatic epithelial proliferation in the form of multiple papules of 3-10mm with a normal oral mucosa colour. The case involves an Ecuadorian male of 14 years, with papulous lesions in the oral mucosa with onset at 4 years of age. His 32 year-old mother had identical lesions.

CONCLUSION

We present two members of an ecuadorian family with MEH. Although it is a rare disease in Spain, we must take this disease into account, given the increase in the immigrant population in Spain.

Cytotoxic and genotoxic effect in RTG-2 cell line exposed to selected biocides used in the disinfection of cooling towers

The cytotoxic and genotoxic effects induced by trichloroisocyanuric acid, Oxone, and sodium bromide, active principles included in formulations for cleaning and disinfection of cooling towers, were studied on RTG-2 cell line. Neutral red assay was used to determine the cellular viability. Toxicity ranking based on IC(50) values found that trichloroisocyanuric acid was the most cytotoxic biocide tested followed by Oxone, whereas sodium bromide resulted in a very low cytotoxicity. DNA damage has been evaluated on RTG-2 cultures by means of an in vitro assay based on the ability of PicoGreen fluorochrome to interact preferentially with dsDNA, and the results indicated that trichloroisocyanuric acid induced DNA strand breaks at concentrations above 1.2 mg/l, equivalent to 1/50-EC(50(48)), whereas exposures to Oxone and sodium bromide did not induce DNA damage at the maximal concentrations tested (1/10-EC(50(48))). These results confirm the suitability of this method for the screening of genotoxic effects of this type of aquatic pollutants, and we suggest their use in environmental risk assessment procedures.

Biological activity of transcripts from cDNA of Pelargonium line pattern virus

A set of cDNAs of Pelargonium line pattern virus (PLPV) was assembled under the control of T7 RNA polymerase promoter and ligated into the plasmid pUC18. Transcripts synthesized in vitro from cDNA were infectious on Chenopodium quinoa according to locally induced lesions and hybridization assay. The biological activity of the viral transcripts was particularly sensitive to the short 3' terminus extensions, whereas inclusion of the 3 extra bases at the 5' terminus did not substantially affect the infectivity. Inoculation of the transcripts on plants Nicotiana benthamiana and Nicotiana clevelandii give rise to the systemic infection indistinguishable from that established by the parental isolate. This is the first report about the preparation of infectious RNA transcripts from a full-length cDNA clone of PLPV.

Role of p38 and inducible nitric oxide synthase in the in vivo dopaminergic cells' degeneration induced by inflammatory processes after lipopolysaccharide injection

Accumulating evidences suggest that neuroinflammation is involved in the progressive death of dopaminergic neurons in Parkinson's disease. Several studies have shown that intranigral injection of lipopolysaccharide induces inflammation in the substantia nigra leading to death of tyrosine hydroxylase-positive cells. To better understand how the inflammatory response gives rise to neurotoxicity we induced inflammation in substantia nigra by injecting lipopolysaccharide. The damage of substantia nigra dopaminergic neurons was evaluated by immunohistochemistry, reverse transcription-PCR and Western blot analysis of tyrosine hydroxylase. In parallel, activation of microglial cells, a hallmark of inflammation in CNS, was revealed by immunohistochemistry. Similarly the expression of molecules involved in the inflammatory response and apoptotic pathway was also tested, such as cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), inducible nitric oxide synthase and caspase-11. Tyrosine hydroxylase expression (both mRNA and protein) started to decrease around 3 days post-injection. At the mRNA level, our results showed that the cytokines expression peaked shortly (3-6 h) after lipopolysaccharide injection, followed by the induction of inducible nitric oxide synthase and caspase-11 (14 h). However, inducible nitric oxide synthase protein peaked at 24 h and lasted for 14 days. The lipopolysaccharide-induced loss of substantia nigra dopaminergic neurons was partially inhibited by co-injection of lipopolysaccharide with S-methylisothiourea, an inducible nitric oxide synthase inhibitor. Co-injections of lipopolysaccharide with SB203580, a p38 MAP kinase inhibitor, reduced inducible nitric oxide synthase and caspase-11 mRNA expression, and also rescued dopaminergic neurons in substantia nigra. In summary, this is the first report to describe in vivo the temporal profile of the expression of these inflammatory mediators and proteins involved in dopaminergic neuronal death after intranigral injection of lipopolysaccharide. Moreover data strongly support that lipopolysaccharide-induced dopaminergic cellular death in substantia nigra could be mediated, at least in part, by the p38 signal pathway leading to activation of inducible nitric oxide synthase and caspase-11.

[Conclusions of the III SENPE Debate Forum on specialized nutritional support: ethical issues]

Conclusions of the III SENPE-Abbott Debate Forum on several ethical issues of specialized nutritional support in hospitalized patients and outpatients. An insight in the principle of equity is given depending on geographical location, in its indications both as a primary therapy and palliative care, and in informed consent.

Genotoxic effects of selected biocides on RTG-2 fish cells by means of a modified Fast Micromethod Assay

A sensitive in vitro assay for detecting DNA damage in RTG-2 cells culture is described. This assay employs a dye, PicoGreen double stranded DNA (dsDNA) quantitation reagent, which becomes intensely fluorescent upon binding nucleic acids. The assay includes a simple and rapid 50-min sample lysis in the presence of EDTA, SDS, and high urea concentration at pH 10, followed by time-dependent DNA denaturation at pH 11.6 after NaOH addition. The time course and the extent of DNA denaturation are followed in a microplate fluorescence reader at room temperature for less than 1h. Comparative studies between suspension and fixed RTG-2 cells indicated that it is possible to apply this methodology in both cases with good results. Neutral red assay was used for to determine the cellular viability when RTG-2 cultures were exposed to tetrakis(hydroxymethyl) phosphonium chloride (THPC) and benzalkonium chloride (BC), as biocides used in the disinfection of cooling towers. The results obtained by neutral red assay indicate IC(50(48)) values of 0.017 (0.011-0.028) and 2.71 (1.91-3.86) mg/L for tetrakis(hydroxymethyl) phosphonium chloride and benzalkonium chloride, respectively. DNA damage has been evaluated for both disinfectants in RTG-2 culture, by exposure to 1/10-, 1/25-, 1/50-, and 1/100-IC(50(48)) value, and the results obtained indicate a strain scission factor (SSF) of 0.126+/-0.014, 0.181+/-0.014, 0.217+/-0.013, and 0.245+/-0.013 in cell suspensions, and 0.077+/-0.019, 0.107+/-0.014, 0.151+/-0.014, and 0.202+/-0.015 in attached cells for tetrakis(hydroxymethyl) phosphonium chloride; while the SSF values for benzalkonium chloride are 0.023+/-0.009, 0.033+/-0.017, 0.068+/-0.012, and 0.088+/-0.015 in cell suspensions, and 0.033+/-0.010, 0.044+/-0.011, 0.080+/-0.009, and 0.093+/-0.010 in attached cells. Thus, the assay proposed in this study has made it possible to show DNA damage in RTG-2 cells when exposed to 0.2(1/100 IC(50(48))) and 300(1/10 IC(50(48))) Hg/L of tetrakis(hydroxymethyl) phosphonium chloride and benzalkonium chloride, respectively. The results obtained indicate that the Fast Micromethod Assay, applied on RTG-2 cell line cultures, is a fast and sensitive method for the early DNA damage detection in the aquatic environment.

[Mechanisms of hypertension in obesity]

Obesity is a chronic disease, considered to be an important risk factor in the development of coronary disease, hypertension, renal insufficiency and failure. Obesity contributes to hypertension by mechanisms such as: insulinic resistance and hyperinsulinaemia, increase of adrenergic activity and of concentrations of aldosterone, retention of sodium and water and increase of cardiac wear, alteration of the endothelial function, through molecules such as leptin and adiponectin and genetic factors. Many paths of research remain open. The angiotensin-converting-enzyme inhibitors (ACEI) and/or the angiotensin II receptor antagonists (ARA II) are first choice medicines because of their beneficial effect on insulinic resistance and sympathetic activity.

Complete nucleotide sequence and genome organization of Pelargonium line pattern virus and its relationship with the family Tombusviridae

The complete nucleotide sequence of Pelargonium line pattern virus (PLPV) has been determined. The PLPV genomic RNA comprises 3884 nt and contains six open reading frames (ORFs) potentially encoding proteins of 27 (p27), 13 (p13), 87 (p87), 7 (p7), 6 (p6), and 37 kDa (p37), respectively. The arrangement of these ORFs on the PLPV genome closely resembles that of members of the genus Carmovirus in the family Tombusviridae and, moreover, most of the putative PLPV gene products showed high identity with proteins of this viral group. However, several striking differences were noticed. Carmoviruses generate two subgenomic RNAs whereas PLPV produces a single one. In addition, only p7 showed similarity with movement proteins of carmoviruses whereas p6 (as p13) has no viral (or other) homologs. This protein might be expressed from a non-canonical start codon or, alternatively, through a −1 frameshift (FS) mechanism. Both, the production of one subgenomic RNA and the likely involvement of a −1 FS for expression of an internal ORF parallel the translation strategies reported for the unique species of the genus Panicovirus, belonging also to the family Tombusviridae. Overall, the results support the placement of PLPV in this family although its peculiar characteristics preclude its direct assignment to any of the current genera.

Prevalence of pulmonary hypertension and its association with respiratory disturbances in obese patients living at moderately high altitude

OBJECTIVE

To determine the point prevalence of pulmonary hypertension (PH) and its relationship with respiratory disturbances in obese patients living at moderate altitude.

SUBJECTS

A total of 57 obese patients comprised the final sample and consisted of 34 women and 23 men, with a mean age of 42.7+/-12.1 ys and a mean body mass index (BMI) 47.1+/-10.6 kg/m(2) (range from 30.1 to 76.1). The mean living altitude was 2248.7 m, range 2100-2400 m above sea level.

MEASUREMENTS

Doppler echocardiography, pulmonary function tests, arterial blood gas analysis, and polysomnography were performed.

RESULTS

Data showed that 96.5% of the studied sample had daytime PH defined as calculated systolic pulmonary artery pressure (PSAP) >30 mmHg (mean PSAP=50, s.d.=13 mmHg). The severity of diurnal PH was found to be related to the presence of alveolar hypoventilation and BMI. The main risk factor for severity of diurnal PH was hypoventilation with a significant odds ratio (OR) 7.96, 95% CI 1.35-46.84, BMI was (OR 1.12, 95% CI 1.02-1.25) and apnea/hypopnea index was not a predictor of pulmonary hypertension severity (OR 0.99, 95% CI 0.97-1.02).

CONCLUSION

We concluded that prevalence of diurnal PH is high in obese patients living at moderate altitude, and that hypoventilation is the main risk factor associated with the severity of pulmonary hypertension.

The degenerative effect of a single intranigral injection of LPS on the dopaminergic system is prevented by dexamethasone, and not mimicked by rh-TNF-alpha, IL-1beta and IFN-gamma

It is becoming widely accepted that the inflammatory response is involved in neurodegenerative disease. In this context, we have developed an animal model of dopaminergic system degeneration by the intranigral injection of lipopolysaccharide (LPS), a potent inductor of inflammation. To address the importance of the inflammatory response in the LPS-induced degeneration of nigral dopaminergic neurones, we carried out two different kinds of studies: (i) the possible protective effect of an anti-inflammatory compound, and (ii) the effect of the intranigral injection of inflammatory cytokines (TNF-alpha, IL-1beta and IFN-gamma) on dopaminergic neurones viability. Present results show that dexamethasone, a potent anti-inflammatory drug that interferes with many of the features characterizing pro-inflammatory glial activation, prevented the loss of catecholamine content, Tyrosine hydroxylase (TH) activity and TH immunostaining induced by LPS-injection and also the bulk activation of microglia/macrophages. Surprisingly, injection of the pro-inflammatory cytokines failed to reproduce the LPS effect. Taken together, our results suggest that inflammatory response is implicated in LPS-induced neurodegeneration. This damage may be due, at least in part, to a cascade of events independent of that described for TNF-alpha/IL-1 beta/IFN-gamma.

Detection of cytogenetic alterations and blood cell changes in natural populations of carp

A field study was conducted to investigate the appearance of alterations in the peripheral blood cells of wild populations of fish. Two aspects were evaluated: the appearance of cytogenetic effects, measured as increases on micronuclei frequencies, and the appearance of haematological effects by checking changes in the relative proportion of the different blood cell types. For this purpose common carp (Cyprinus carpio) were caught from four areas along a Spanish river. Three areas were located under the influence of chemical industries and/or a nuclear power plant. The fourth was a clean reference area. Flow cytometry was used to quantify the appearance of micronuclei on the same day of sampling and also after two and twelve months. The alterations in the relative proportion of cell types were counted in blood smears stained with Giemsa. Increases in micronuclei frequencies were observed in fish living in supposedly polluted areas. Alterations of the relative proportions of blood cells were manifested as an increase in white blood cells and as a decrease in red blood cells vs. control area. Since accidental spills have not been reported over this period of time, the alterations observed could suggest that fish are suffering chronic effects due to low level contamination associated with the sampled areas.

Long-lasting induction of brain-derived neurotrophic factor is restricted to resistant cell populations in an animal model of status epilepticus

We have recently characterized an animal model of status epilepticus induced by a single intraseptal injection of kainate. Under these conditions, there is a delayed expanding apoptotic hippocampal and amygdalar cell death. In order to further characterize this animal model, we have performed a detailed time-course analysis of the appearance of cell death, brain-derived neurotrophic factor messenger RNA expression and astroglial and microglial response in different brain areas related to the limbic system. We found a long-lasting delayed apoptotic cell death in the hippocampal formation, amygdala, medial thalamus, dorsal endopiriform nucleus and multiple cortical areas from two to 21 days post-injection. There was a spatiotemporal correlation between the appearance of cell death and induction of brain-derived neurotrophic factor messenger RNA expression in the areas studied, and interestingly this induction was found in non-degenerating cells. We conclude that our animal model of status epilepticus exhibits remarkable features of recurrent seizure activity and provides evidence for a neuroprotective role of brain-derived neurotrophic factor against seizure-induced apoptotic cell death.

Protein precipitation In Vitro as a measure of chemical-induced cytotoxicity: an EDIT sub-programme

As a priority area of the Evaluation-Guided Development of In Vitro Toxicity and Toxicokinetic Tests (EDIT) programme, an in vitro protein precipitation (PP) assay was used on the 50 reference chemicals of the Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) project, to confirm and extend the MEIC results. Dose-response curves were generated for only 30 of the chemicals, and the concentrations causing 10% (EC10) and 50% (EC50) protein precipitation versus the positive control were chosen as endpoints. The number of chemicals with a positive response increased to 46 when a new endpoint, the minimum effect concentration (MEC) that induces protein precipitation with respect to the negative control, was used. When the results were correlated with in vitro cytotoxicity in human cell lines, a similarly good correlation was found between the various endpoints of the PP assay at 5 hours and the 24-hour IC50 average cytotoxicity in human cell lines, even though the number of chemicals included in the correlation was larger for the MEC. Using the prediction error, the endpoint that gave the best correlation between the PP assay and human cell cytotoxicity was once more found to be the 5-hour MEC, and this was chosen for the PP assay. The sensitivity of the PP assay is lower than that of the in vitro cell-line cytotoxicity assay, possibly due to its shorter exposure period and because precipitation is the ultimate event in the sequence of a protein disturbance. It is expected that earlier denaturation steps would give better sensitivity. However, this simple, inexpensive and rapid assay could be useful in the early stages of testing chemicals.

DNA fingerprint comparison of rainbow trout and RTG-2 cell line using random amplified polymorphic DNA

The detection of genotoxic effects using in vitro cell systems can be extremely useful in risk assessment procedures. However, care should be taken in the extrapolation of in vitro results since, amongst other factors, established cell lines may deviate from the genetic characteristics of their species. In this work, the genetic similarities between the RTG-2 cell line and rainbow trout individuals (Oncorhynchus mykiss) from several fish farms have been studied by the RAPD technique. Results show a significant analogy in the band patterns obtained for both systems, up to 73% of the bands composing the fingerprint of the RTG-2 cell line were found in all the individuals analysed. The inter-population similarity index (Lynch, 1990), considering the RTG-2 cell line as a population, gives a value of 0.931 between both systems. The dendrogram constructed from all the individuals, considering the RTG-2 cell line as just another individual of a single population, showed that the genetic structure of the cell line was not different from those of the other individuals tested. The strong genetic similarity of both systems, together with the previously proven capability of the RAPD technique to detect genetic alterations caused in vitro by genotoxic agents, can be very useful in genetic ecotoxicological studies.

[Factorial and discriminant analyses of neuropsychological variables in familial and sporadic late onset Alzheimer disease]

INTRODUCTION

Prevalence of late onset Alzheimer's disease (LOAD) both familial and sporadic is increasing with the raising proportion of third-age population. There are evidences either supporting or rejecting the existence of differences in the behavior of neuropsychological variables between familial and sporadic cases of LOAD.

OBJECTIVE

To identify neuropsychological variables discriminating between familial and sporadic cases of LOAD, in order to detect clinical manifestations that may provide information on the pathological process of the neurodegenerative process.

PATIENTS AND METHODS

Using sequential sampling, we selected individuals affected by LOAD according to the criteria of the DSM-IV and NINCS-ADRDA. The following neuropsychological protocol was used: CERAD, Wisconsin, Phonological Fluency, Rey's Figure, Raven, A Cancellation Test, WAIS (Arithmetic); also used were: Global Deterioration Scale, Functional Assessment Staging of Reisberg (FAST), Barthel and Yesavage. Parametrical and non-parametrical univariate, factorial (principal components) and discriminant analyses were performed. In total, 52 patients were analyzed (average age: 74.8 years; mean age at onset of the disease: 69 years; time of disease's evolution: 5.7 years; average of educational level: 6.4 years).

RESULTS

No significant statistical differences were found in clinical or neuropsychological variables between familial and sporadic cases of LOAD. Additionally, neither variables nor models were detected discriminating significantly between them.

CONCLUSION

Familial and sporadic cases of LOAD present the same clinical and neuropsychological phenotype which makes very probable that sporadic cases are low penetrance familial ones.

The single intranigral injection of LPS as a new model for studying the selective effects of inflammatory reactions on dopaminergic system

We have injected lipopolysaccharide (LPS) into the nigrostriatal pathway of rats in order to address the role of inflammation in Parkinson's disease (PD). LPS induced a strong macrophage/microglial reaction in Substantia nigra (SN), with a characteristic clustering of macrophage cells around blood-vessels. The SN was far more sensitive than the striatum to the inflammatory stimulus. Moreover, only the dopaminergic neurons of the SN were affected, with no detectable damage to either the GABAergic or the serotoninergic neurons. The damage to the DA neurons in the SN was permanent, as observed 1 year postinjection. Unlike the direct death of dopaminergic neurons caused by agents as MPP(+) or 6-OHDA, LPS seems to cause indirect death due to inflammatory reaction. Therefore, we suggest that the injection of a single dose of LPS within the SN is an interesting model for studying the selective effects of inflammatory reaction on dopaminergic system and also potentially useful for studying PD.

The endogenous amine 1-methyl-1,2,3,4- tetrahydroisoquinoline prevents the inhibition of complex I of the respiratory chain produced by MPP(+)

The endogenous monoamine 1-methyl-1,2,3,4-tetrahydroisoquinoline has been shown to prevent the neurotoxic effect of MPP(+) and other endogenous neurotoxins, which produce a parkinsonian-like syndrome in humans. We have tested its potential protective effect in vivo by measuring the protection of 1-methyl-1,2,3,4-tetrahydroisoquinoline in the neurotoxicity elicited by MPP(+) in rat striatum by tyrosine hydroxylase immunocytochemistry. Because we know that cellular damage caused by MPP(+) is primarily the result of mitochondrial respiratory inhibition at the complex I level, we have extended the study further to understand this protective mechanism. We found that the inhibitory effect on the mitochondrial respiration rate induced by MPP(+) in isolated rat liver mitochondria and striatal synaptosomes was prevented by addition of 1-methyl-1,2,3,4-tetrahydroisoquinoline. This compound has no antioxidant capacity; therefore, this property is not involved in its protective effect. Thus, we postulate that the preventive effect that 1-methyl-1,2,3,4-tetrahydroisoquinoline has on mitochondrial inhibition for MPP(+) could be due to a "shielding effect," protecting the energetic machinery, thus preventing energetic failure. These results suggest that this endogenous amine may protect against the effect of several parkinsonism-inducing compounds that are associated with progressive impairment of the mitochondrial function.

The use of alternative systems for the ecotoxicological screening of complex mixtures on fish populations

This paper presents the results of the use of alternative systems in a screening study of four complex mixtures. The following tests were performed: in vitro induction of micronuclei in a rainbow trout-derived cell line by flow cytometry, and hatching percentage, time of hatching and teratogenic alterations on the embryolarval development on medaka fish eggs. The results obtained with the proposed tests in this study allows an increase in the information level in a short period of time (2 weeks), using very low sample volumes (< 100 ml). Inclusion of chronic and specific effects (genotoxicity and teratogenicity) allows the selection of the most sensitive endpoint to increase security factors in the ecotoxicological assessment of complex mixtures, so that detailed studies can be focused only on those samples which require further research.

Flow cytometric detection of micronuclei and cell cycle alterations in fish-derived cells after exposure to three model genotoxic agents: mitomycin C, vincristine sulfate and benzo(a)pyrene

The measurement of cytogenetic alterations in vitro is considered an initial step in the risk assessment procedures for genotoxic agents. The concern about genotoxic pollutants in natural fish population makes the use of fish-derived cells an useful tool for these purposes. The technological improvements in well-established cytogenetic endpoints, such as micronuclei (MN) estimations by means of flow cytometry, have been proposed in the later years using mammalian cells. In this work, we test the capability of flow cytometry to evaluate MN induction and cell cycle alterations in an established fish cell line (RTG-2) using three agent-inductor models at different concentrations and exposure periods. For mitomycin C, an inverse relationship between length of exposure period and concentrations was observed. A dose-response relationship was observed after exposing RTG-2 cells to vincristine sulfate and benzo(a)pyrene. As this study shows, RTG-2 cells respond to clastogenic and aneugenic effects of the tested chemicals through the induction of MN at similar doses to mammalian cells and without the addition of exogenous metabolic activity. The possibility to check cell cycle alterations, in the same sample, gives the opportunity to evaluate early signals of cytotoxicity. The use of flow cytometry improves the assay by means of its speed and objectivity, which makes the assay very useful for genotoxicity assessment of aquatic chemicals.

Detection of mitomycin C-induced genetic damage in fish cells by use of RAPD

Concern about genetic alterations in fish populations arising from anthropogenic activities has led to the adaptation and/or development of new tests and techniques that shed light on these alterations. The high number and the reduced size of chromosomes and the long cell cycle associated with most fish species preclude the use of most accepted genotoxicity assays. The purpose of this work was to study the capability of the randomly amplified polymorphic DNA technique to show genotoxic effects induced by chemicals in fish cells. To do that we studied the effect of 0.5 microg/ml mitomycin C (MMC) on an established rainbow trout cell line (RTG-2). To increase the sensitivity of detecting altered copies of DNA and to avoid the presence of false positives and a lack of reproducibility, the amounts of DNA template and primer present in amplification reactions were studied and optimized after comparison between the control and exposed fingerprints for 4, 6 and 8 h. Results show that 5 ng of DNA template and 4 pM chosen primer were optimum to show differences between control and exposed cells and to obtain reproducible results. The results obtained, after optimum conditions were established, show that this system could be useful for the assessment of DNA alterations in in vitro genotoxicity studies.

Effects of aging on the various steps of protein synthesis: fragmentation of elongation factor 2

The possible mechanism responsible for the in vivo protein synthesis decline during aging was studied. In order to determine the effect of aging on the various steps of protein synthesis, we determined the ribosomal state of aggregation and the time of assembly and release of polypeptide chains in the process of protein synthesis in rat liver. The results suggest that elongation is the most sensitive step to aging. A molecular study of the Elongation Factor 2 (EF-2), the main protein involved in the elongation step, shows that this protein has a higher content of carbonyl groups and is less active in old rats. In addition, the molecular mass analysis of EF-2 shows that this protein becomes fragmented in old rats. A similar pattern of fragmentation is found in 3-month-old rats suffering oxidative stress, in that the decline in protein synthesis is similar to that found in old rats. These data suggest that: i) oxidative stress seems to be involved in the modifications of EF-2 observed during aging, and ii) the observed modifications (oxidation and fragmentation) of EF-2 could account for the decline in protein synthesis in old animals.

Sublethal effects of repeated intraperitoneal cadmium injections on rainbow trout (Oncorhynchus mykiss)

Acute and chronic effects of cadmium have been widely described for different aquatic organisms and exposure routes. However, there is clearly a lack of information on the potential of cadmium to cause genotoxic effects. This work presents genotoxic and nongenotoxic parameters analyzed in cadmium-exposed rainbow trout. The assessment was performed for sublethal levels after long-term exposure using six intraperitoneal injections of 0.5 mg/kg (Day 1), 1 mg/kg (Days 3, 7 and 11), and 2 mg/kg (Days 15 and 19) to allow precise estimation of the dose. Cadmium accumulation in target tissues, essential metal mobilization by cadmium at the subcellular and tissue levels, and induction of metallothioneins were selected as exposure and effect parameters. Induction of micronuclei and variation in DNA content (expressed as variation coefficient in the G1 phase of the cell cycle) in blood cells, determined by flow cytometry, were selected as biomarkers for genotoxic effects. Cadmium accumulation, induction of metallothioneins, and mobilization of essential metals at the subcellular level were observed in different organs in response to cadmium exposure. The highest metallothionein induction was observed in liver, reaching 270+/-90 nmol/g wet tissue in treated fish versus 2.68+/-1.1 nmol/g wet tissue in controls. The highest cadmium accumulation was also observed in the liver (27.8+/-9.5 microgram Cd/g wet wt in treated animals versus 1.0+/-1.7 in the control group). However, no genotoxic effects were observed in blood cells. The frequency of micronuclei was 0.012+/-0.008 for the control group and 0.013+/-0.021 for treated animals. The variation coefficient of G1-phase nuclei was 3.61+/-0.66 and 3.22+/-0.29 for control and cadmium-exposed groups, respectively. Thus, it is concluded that under the experimental conditions employed here, treatment of rainbow trout with cadmium chloride at doses that produce significant toxicological alterations at the tissue and subcellular levels does not provoke observable alterations in the genotoxic parameters considered in this study.