Acute coronary syndromes in the elderly: prognostic impact of anaemia

Introduction

The increase in life expectancy is a reality and cardiovascular disease incidence rises with it. The elderly are fragile patients with high prevalence of multiple comorbidities. Anaemia is one of them and, in most cases, has multifactorial causes. After an acute coronary syndrome (ACS), the thrombotic versus haemorrhagic risks in these patients are hard to balance.

Aim

The aim of this study is to evaluate prognostic impact of anaemia in the elderly after an ACS.

Methods

Retrospective analysis of consecutive patients admitted to a single Intensive Coronary Unit between 2009 and 2016 with the diagnosis of ACS. Patients younger than 80 years old were excluded. A complete blood count was collected upon admission and anaemia was defined for haemoglobin values below 12.5mg/dL. Cox regression analysis and Kaplan-Meyer curves were conducted to determine prognostic value of anaemia in this specific population. Multivariate analysis with other comorbidities and antithrombotic therapy was also performed.

Results

A total of 353 patients (median age of 84.0±6.0 years old; 52.1% males; 51.3% with anaemia) were enrolled. In cox regression analysis, anaemia predicted mortality (HR 1.614; 95% CI 1.199–2.172; P=0.002). In multivariate analysis – including gender, presence of hypertension, diabetes, chronic kidney disease and atrial fibrillation (AF) at admission, anaemia proved to be an independent predictor of mortality (HR 1.521, 95% CI 1.119–2.069, P=0.007). Adding all previous and discharge antithrombotic therapy – antiplatelet inhibition and oral anticoagulants – to the equation, anaemia maintained its prognostic value (HR 2.157; 95% CI 1.130–4.116; P=0.020). Both AF and being discharged from the hospital with ticagrelor also increased mortality risk in these patients (HR 2.188, 95% CI 1.177–4.070, P=0.13 for AF; HR 1.906, 05% CI 1.011–3.594, P=0.046 for ticagrelor at discharge).

Conclusions

After an ACS, anaemia proved to be an independent predictor of mortality in the elderly. This emphasizes the importance of its adequate aetiology investigation and treatment and careful selection of antithrombotic therapy following an ACS.

Funding Acknowledgement

Type of funding sources: None.

Lead acetate ecotoxicity in tropical soils

Lead acetate (AcPb) is an important raw material used in chemical industries worldwide. The potential toxicity of AcPb is generally attributed to the presence of Pb. However, the effect of AcPb on the environment as a whole is still poorly known. This study aimed to evaluate AcPb toxicity on three standard species of soil invertebrates and two plant species using ecotoxicology tests. Three tropical soils (Oxisol, Inceptisol, and Tropical Artificial Soil (TAS)) were contaminated with different concentrations of AcPb and one dose of K-acetate (positive control). These soils were used in tests with Eisenia andrei (earthworm), Folsomia candida (springtail), Enchytraeus crypticus (enchytraeid), Zea mays (maize), and Phaseolus vulgaris (common bean). Dose-response curves obtained in the laboratory tests were used to estimate the EC₅₀ values for each species. Among invertebrates, the highest sensitivity to AcPb was observed for E. crypticus in the TAS (EC₅₀ = 29.8 mg AcPb kg^-1), whereas for E. andrei and F. candida the highest sensitivity was observed in the Oxisol (EC₅₀ = 141.9 and 1835 mg AcPb kg^-1, respectively). Folsomia candida was the least sensitive invertebrate species to AcPb in all soils. Among plant species, Z. mays was less sensitive (EC₅₀ = 1527.5 mg AcPb kg^-1) than P. vulgaris (EC₅₀ = 560.5 mg AcPb kg^-1) in the Oxisol. The present study evidenced that the toxicity of AcPb should not be attributed uniquely to the presence of Pb, as the treatment containing uniquely Ac provoked the same toxicity as the highest dose of AcPb.

Coronary computed tomography angiography vs functional testing for stable coronary artery disease: long-term outcomes meta-analysis

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND  The emerging role of coronary computed tomography angiography (CCTA) has been acknowledged in the 2019 Guidelines of the European Society of Cardiology recommending it’s as the initial diagnostic strategy for most patients with suspected stable coronary artery disease (CAD). However, it is unclear how CCTA performs compared with the standard approach of functional testing (FT). We performed an updated meta-analysis to clarify the question, analyzing outcomes beyond one year of follow-up.

METHODS We searched PubMed for studies comparing clinical outcomes with ≥1 year of  follow-up between initial CCTA vs FT strategy in patients with suspected stable CAD. Occurrence of all-cause mortality and non-fatal acute coronary syndrome (ACS) was the combined primary outcome. Secondary outcomes included non-fatal myocardial infarction (MI), the use of longer-term investigations, revascularization procedures and new medication use.

RESULTS A total of 29,579 patients underwent either CCTA (n = 14,457) or FT (n = 15,122) and were followed for a mean of 1.75 years. CCTA was associated with a comparable all-cause mortality and non-fatal ACS to FT (2.64% vs 2.65%; risk ratio [RR], 0.97; 95% CI, 0.76-1.22). However, a 41% reduction in non-fatal MI was evident after CCTA testing (RR 0.59, 95% CI 0.41-0.83; P = 0.003). Compared with FT, patients undergoing CCTA were less likely to downstream additional testing (28.85% vs 33.86%; odds ratio [OR], 0.47, 95%CI 0.21-1.01; P = 0.05) and more prone to pursue coronary revascularization (OR 1.72; 95%CI 1.11-2.66; P = 0.01). Significant heterogeneity for invasive coronary angiography and revascularization was noted. CCTA patients had a non significant increase in new medication use, namely aspirin or statin therapy.

CONCLUSIONS In patients with suspected stable CAD, initial evaluation with CCTA was associated with a long-term 41% decrease in non-fatal MI and 53% reduction in downstream testing. Despite these differences, CCTA strategy was associated with a similar risk of long-term all-cause mortality and non-fatal ACS.

Abstract Figure.

P852 Cancer-associated thrombotic diathesis: one of your worst nightmares

A 34-year-old male patient was diagnosed with undifferentiated sarcoma of the right thigh, with lung metastasis. He underwent primary lesion resection surgery and initiated chemotherapy with both doxorubicin and ifosfamide. Though primary tumor burden was substantially reduced, secondary lesions were found to be irresponsive to drug therapy, leading to regimen switching to both gemcitabine and docetaxel. Three months later, patient started complaining of atypical chest pain and palpitations. Electrocardiography revealed very frequent supraventricular ectopic complexes, while a transthoracic echocardiogram unveiled a pulmonary vein thrombus, which extended into the left atrium. This finding, which was further characterized by cardiovascular magnetic resonance imaging, prompted anticoagulation initiation, under the form of enoxaparin 1mg/kg bid. At this time, chemotherapeutic scheme was, again, swapped, and a cycle of both doxorubicin and olaratumab was introduced. A combined episode of inferolateral ST-segment elevation myocardial infarction and peripheral arterial embolism followed shortly thereafter. Emergent invasive coronary angiogram revealed no signs of both epicardial atherosclerosis and thrombus, whereas subsequent transthoracic echocardiography showed a massive left heart thrombus, extending into the aortic valve annulus. Anti-thrombotic approach involved increasing enoxaparin dosage to 1.5mg/kg bid but no fibrinolytic therapy. Despite a rather uneventful immediate clinical course, with no electric or hemodynamic instability and no limb-threatening ischemia, lamentably, patient died two weeks later, before thrombus definitive imaging reassessment. As no autopsy was performed, it is unclear whether a cardiovascular acute event or neoplasm inexorable progression is to blame as the primary cause of death.

Thrombosis is a common, costly and potentially fatal cancer complication. Patients receiving systemic chemotherapy for advanced diseased are at higher risk. Despite major management developments in the past fifteen years, evidence still supports traditional low-molecular-weight heparins as the first-line therapy and prognosis remains dismal.

Abstract P852 Figure.

P714 Contradicting the most basic tenet of black holes: light can, indeed, escape

A 69-year-old man with history of non-insulin-treated type 2 diabetes mellitus, arterial hypertension and mixed dyslipidemia presented to the emergency department with chest pain lasting for four days. Immediate twelve-lead electrocardiogram unveiled an inferior ST-segment elevation myocardial infarction (STEMI), prompting emergent coronary angiography, which, in turn, revealed two-vessel disease, specifically proximal ramus intermedius 60-70% stenosis and proximal right coronary artery acute occlusion. Culprit lesion was successfully managed with balloon angioplasty and a single drug-eluting stent implantation. Still, clinical course was noticeable for deterioration, under the form of cardiogenic shock, which required invasive ventilation and intravenous vasopressor support with norepinephrine. Despite biventricular systolic function relative preservation, transthoracic echocardiography disclosed inferior akinesis, right ventricle dilation, mild circumferential pericardial effusion and, particularly, a 2.3cm posteroinferior ventricular septal defect (VSD), in the setting of a 4.4cm2 pseudoaneurism, resulting in left-to-right shunting, quantified through maximal/mean trans-VSD pressure gradients of 84/44mmHg. Further imaging with transesophageal echocardiography and cardiac computed tomography angiography allowing the conception of a 3D-printed model was performed. Surgical correction of the defect followed, achieving partial anatomic success, namely with residual shunting, as of a left ventricular systolic pressure of 80mmHg and a right ventricular systolic pressure of 25mmHg. Patient survived, recovered and got discharged three weeks later. At one-year follow-up, he was hospitalized for acute decompensated heart failure (hemodynamic profile C) twice, with medication non-adherence reported as the main precipitating factor. In addition to a significant remaining left-to-right shunt (maximal velocity 3m/s), adverse cardiac remodeling was recognized, featuring left ventricular ejection fraction of 30-35%, severe functional mitral regurgitation, severe postcapillary pulmonary hypertension and de novo left bundle branch block (QRS duration of 197ms). Having been deemed clinically unsuitable for another surgical correction, patient underwent percutaneous VSD closure with both AmplatzerTM septal and muscular VSD occluders, with a suboptimal result. He is now on New York Heart Association class III heart failure and on the waiting list for both MitraClip and cardiac resynchronization therapy implantation.

Reflecting numerous breakthroughs in the management of acute myocardial infarction, incidence of mechanical complications is on the decline. Nevertheless, when they occur, morbidity and mortality remain high. Acquired ventricular septal defects are no exception, demanding the best care from a tertiary hospital heart team.

Abstract P714 Figure.

5034Is stroke an issue after transcatheter mitral valve repair? A systematic review and meta-analysis

Background

Transcatheter mitral valve repair (TMVR) is a minimally invasive therapeutic procedure used as an alternative to surgery for mitral valve regurgitation in high risk patients. This technique creates a double orifice area, which might be comparable to a mitral prosthesis or mitral stenosis. So far, no strict antithrombotic therapy has been recommended and different post-procedure protocols are being currently applied.

Objectives

To assess stroke rate after TMVR, comparing it with surgical mitral valve repair (SMVR) and optimal medical treatment (OMT).

Methods

We systematically searched PubMed, Embase and Cochrane databases, in December 2018, for both interventional or observational studies comparing TMVR with SMVR and/or OMT in the treatment of severe mitral regurgitation. Only studies including data on post-procedure stroke incidence were selected. Two authors independently screened articles for inclusion, risk of bias and data extraction. Random-effects meta-analysis for TMVR, SMVR and OMT were performed. Due to the low number of pooled events, a cumulative meta-analysis was subsequently implemented. The meta-analysis was registered on the Prospero database.

Results

15 studies were selected for qualitative analysis and, among these, 10 were included in the quantitative analyses (7 of TMVR vs. SMVR and 3 of TMVR vs. OMT), providing a total of 1881 patients. TMVR patients were older and had higher surgical risk scores than SMVR patients. Groups were homogeneous regarding previous atrial fibrillation rate (pooled OR 1.45 [0.82–2.55]), whereas post-procedure de novo atrial fibrillation was more frequent in SMVR when compared with TMVR (pooled OR 0.20 [0.06–0.7]). Although the pooled stroke rate was numerically lower in the TMVR group, there was no statistically difference in the stroke incidence between TMVR and SMVR (pooled OR 0.49 [0.17, 1.42], p=0.19, I2= 0%) – Panel A. On the other hand, cumulative meta-analysis was able to show a significantly lower stroke rate in TMVR, when compared to SMVR (OR 0.4 [0.40, 0.67], p<0.05). As for TMVR vs. OMT, no difference in stroke rate was identified (pooled OR 1.09 [0.60, 1.97], p=0.79, I2=0%) – Panel B.

Forest Plots – Stroke incidence

Conclusions

Post-procedure TMVR stroke rate was similar to that of patients managed with OMT only. For the same outcome, results favored TMVR when compared with SMVR, which might be related to its lower incidence of post-procedure de novo atrial fibrillation. These findings may prove insightful to future recommendations regarding the conundrum of the best antithrombotic strategy, particularly for patients with atrial fibrillation.

P1589Thiazides and skin cancer risk: should we be worried?

Introduction

Diuretic thiazides represent a first-line therapeutic option for arterial hypertension. However, this drug class is regarded as having photosensitizing properties, and, as such, may act as a carcinogen, by triggering phototoxic reactions. Whether or not its long-term use increases skin malignancy risk remains unclear.

Purpose

To examine a possible association between thiazide usage and the risk of skin cancer, namely basal cell carcinoma, squamous cell carcinoma and malignant melanoma.

Methods

MEDLINE, EMBASE, Cochrane Library and Google Scholar databases were comprehensively searched, from inception to the first of February of 2019, for observational studies mentioning thiazide diuretic usage and incidence or prevalence of cutaneous basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Literature review, study selection and appraisal, including methodological quality assessment, and data extraction were independently led by two investigators. Meta-analysis was conducted using generic inverse variance outcome and, due to heterogeneity of the original studies, a random effects model. Confounder-adjusted summary relative risk (RR), with 95% confidence interval (CI), was pooled.

Results

Ten studies met eligibility criteria. Of these, six had a case-control design and the remaining were cohort studies. Overall, 7,079,530 patients were included; 125,946 were diagnosed with basal cell carcinoma, 21,775 with squamous cell carcinoma and 31,191 with malignant melanoma. One study encompassed only squamous cell carcinoma of the lip. In five articles, individual thiazides employed were not addressed, whereas three embraced solely hydrochlorothiazide and other two exclusively bendroflumethiazide. Thiazides were found to be associated with increased risk of basal cell carcinoma (six studies, RR=1.05, 95% CI=1.01–1.10, p=0.02, i2=62%), squamous cell carcinoma (seven studies, RR=1.35, 95% CI=1.05–1.74, p=0.02, i2=92%) and malignant melanoma (six studies, RR=1.17, 95% CI 1.11–1.23, p<0.ehz748.03491, i2=0%).

Conclusion

Risk of all three major forms of skin malignancy is heightened in thiazide diuretic users. Increased awareness and education, especially for those who are at high risk and under the form of intense solar irradiation avoidance, are warranted for both patients and healthcare providers.

P6447Prediabetes versus diabetes mellitus in acute coronary syndrome patients: two sides of the same coin

Background

Prediabetic patients are at increased risk of composite cardiovascular (CV) events and all-cause mortality. The impact of prediabetes diagnosis in the context of an acute coronary syndrome (ACS) remains to be determined.

Purpose

To assess the differences on long-term mortality between well controlled diabetic and prediabetic patients admitted with non-ST elevation ACS.

Methods

352 non-ST elevation ACS patients admitted to a single coronary care unit between 2009 and 2016 were included. Clinical, laboratorial and echocardiographic data were evaluated. Two groups were created based on the diabetic status and HBA1c level: Group A (prediabetic patients, HBA1c between 5.7–6.4%) N=229; Group B (diabetic patients, HBA1c ≤7%) N=123. The primary endpoint was long-term all-cause mortality. Kaplan-Meyer survival curves and Cox regression were done. The mean time of follow up was 48±30 months.

Results

The groups were similar regarding demographics, CV risk factors, ACS type, heart failure diagnosis, peak troponin I, left ventricular (LV) systolic function, multivessel disease and treatment option (PCI, CABG or OMT). On the contrary, well controlled diabetic patients had a higher prevalence of chronic kidney disease (CKD) (27.9% vs 39.0%, P<0.05), hypertension (82.5% vs 91.9%, P<0.05), higher body mass index (BMI) (23±4 vs 24±4 kg/m2, P<0.05) and previous coronary artery disease (37.1% vs 51.2%, P<0.05). 95 patients met the primary outcome. Kaplan-Meyer curves showed a tendency to decreased survival in the diabetic group (72.8% vs 66.4%, Log Rank P=0.09 – Figure 1). After adjustment for age, CKD, BMI (6 categories), heart failure diagnosis, peak troponin I and LV systolic function, controlled diabetes was not associated with increased death (HR 1.40, 95% CI 0.87–2.26). In this model, only age (HR 1.05, 95% CI 1.02–1.08), peak troponin (HR 1.01, 95% CI 1.00–1.01) and moderate to severely impaired LV function (HR 2.00, 95% CI 1.12–3.56) remained associated with the outcome.

Conclusion

In the context of an ACS, prediabetics should be regarded as a high-risk group. This study raises the provocative question that prediabetics and diabetics patients should be approached in similar ways in terms of risk stratification and therapeutic options after an ACS. In these patients, age, peak troponin and impaired LV function appear to be the main contributors to decreased survival.

P5499Coronary angioplasty for octogenarian acute coronary syndrome patients? Is it worth it?

Background

As the population ages, doctors are being challenged by the decision to offer intervention treatment in increasingly older and fragile patients. The comorbidity burden and performance status should be considered when making the decision.

Purpose

To assess the impact of optimal medical therapy (OMT) versus percutaneous coronary intervention (PCI) in non-ST elevation acute coronary syndrome (ACS) patients older than 80 years.

Methods

182 patients older than 80 years old admitted to a single coronary care unit with a diagnosis of non-ST elevation ACS, who survived hospital stay were included. Clinical, laboratorial and echocardiographic data were evaluated. Two groups were created: Group A (OMT group) N=83; Group B (PCI group) N=99. The primary endpoint was long-term all-cause mortality. Kaplan-Meyer curves and Cox regression were conducted to evaluate the impact of OMT versus PCI on the primary endpoint. The mean time of follow-up was 37±29 months.

Results

Groups were homogenous regarding gender, cardiovascular risk factors, heart failure diagnosis, left ventricular (LV) systolic function and peak troponin I. OMT group patients were older (85.1±3.7 vs 82.7±3.2 years old, P<0.01), had a higher prevalence of chronic kidney disease (CKD) (61.4% vs 46.5%, P<0.05), a lower haemoglobin (Hb) level (12.0±1.9 vs 12.6±1.7 g/dL, P<0.05) and were less likely to receive double antiplatelet therapy at discharge (80.8% vs 100%, P<0.001). 84 patients met the primary outcome. Kaplan-Meyer curves showed increased survival in the PCI group (36.5% vs 59.3%, Log Rank P<0.001 – Figure 1). Nevertheless, PCI was not associated with long-term mortality (HR 1.05, 95% CI 0.98–1.12) in a model adjusted for age, CKD, peak troponin, LV systolic function and Hb level. Only Hb (HR 0.81, 95% CI 0.73–0.93), peak troponin (HR 1.01, 95% CI 1.00–1.01) and LV function (slightly impaired [HR 1.89, 95% CI 1.03–3,48] and moderate/severely impaired [HR 1.96, 95% CI 1.14–3.36]) remained associated with the outcome.

Conclusion

Increased survival in older patients receiving PCI after a non-ST elevation ACS may be ascribed to the selection of patients with less comorbidities. This reinforces the idea it may be applied in well-fit patients regardless of age. In our elderly population, lower Hb level, peak troponin and impaired LV systolic function appear to be the main contributors to decreased survival, irrespective of intervention.

Salinization effects on coastal ecosystems: a terrestrial model ecosystem approach

In coastal areas, intrusion/irrigation with seawater can threaten biodiversity along with crop yields, and the leaching of salts from areas affected by these processes can increase the salinity of water bodies nearby. The aims of this study were to evaluate the effects of salinization on coastal soil ecosystems due to saline intrusion/irrigation. Terrestrial model ecosystems were used to simulate two soil salinization scenarios: (i) seawater intrusion and irrigation with distilled water and (ii) seawater intrusion and irrigation with saline water. Three sampling periods were established: T0-after acclimation period; T1-salinization effects; and T2-populations' recovery. In each sampling period, the abundance of nematodes, enchytraeids, springtails, mites and earthworms, and plant biomass were measured. Immediate negative effects on enchytraeid abundance were detected, especially at the higher level of saltwater via intrusion+irrigation. Eight weeks after the cessation of saline irrigation, the abundance of enchytraeids fully recovered, and some delayed effects were observed in earthworm abundance and plant biomass, especially at the higher soil conductivity level. The observed low capacity of soil to retain salts suggests that, particularly at high soil conductivities, nearby freshwater bodies can also be endangered. Under saline conditions similar to the ones assayed, survival of some soil communities can be threatened, leading to the loss of biodiversity.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.

Efeito do Método de Produção de Cárie Artificial E Diferentes Biomateriais na Resistência da União Resina/Dentina

O objetivo foi avaliar o efeito da aplicação de 0,2% de NaF-NF, MI Paste™-MP e Curodont™ Repair-CR na resistência da união (µTBS) da dentina desmineralizada por diferentes métodos (MD): químicoMQ (gel ácido em 37 ºC por 48h) e biológicoMB (biofilme de S. mutans), sobre a µTBS resina/dentina. Blocos de dentina média obtidos de 3os molares hígidos foram distribuídos em 9 grupos (n6): G1-Dentina hígida-DH; G2-Dentina desmineralizada/MQ-DDQ; G3-DDQ+NF; G4-DDQ+MP; G5-DDQ+CR; G6--Dentina desmineralizada/MB-DDB; G7-DDB+NF; G8-DDB+MP; G9-DDB+CR. Blocos de compósito Filtek™ Z350XT (4mm) foram construídos sobre a dentina com Adper™ Single Bond 2 e os conjuntos armazenados por 24h a 37ºC em água. Palitos  (1mm área de secção) foram obtidos e submetidos ao teste de µTBS (1,0mm/min 500N). Os dados foram submetidos à ANOVA fatorial e teste de Tukey, e Dunnett (a5%). Houve interação significativa dos dados de µTBS, entre os fatores (MDxTratamento) (p<0,01); G4(45,25±8,83), G5(46,42±12,03) e G8(47,95±6,69) apresentaram os maiores valores, não diferindo entre si (p<0,05); G2(21,96±5,92) e G6(22,89±2,68) apresentaram os menores valores e não diferiram entre si (p>0,05). Houve influência do MD entre G3(33,43±10,42) e G7(26,94±6,70), e G5(46,42±12,03) e G9(42,07±7,83) (p<0,05). Teste de Dunnett mostrou diferença entre G1(43,32±4,35) e G2, G3, G6, G7 e G8 (p<0,05). Tipo de falha: a maioria dos grupos apresentaram falha do tipo adesiva e mista. Dependendo do método artificial de produção de cárie o tratamento remineralizador pode alterar a µTBS.Palavras-chave: Dentina. Remineralização Dentária. Resistência à Tração.

Efeito da Aplicação de MI Paste™ e Diferentes Sistemas Adesivos na μTBS da Dentina Desmineralizada

O objetivo do presente estudo foi avaliar o efeito de MI Paste™ e dois sistemas adesivos (Adper™ Single Bond 2-SB e Clearfil™ SE Bond-CSE) na resistência de união à microtração (µTBS) da dentina desmineralizada. 36 blocos de dentina média obtidos foram distribuídos em 6 grupos (n6): G1 - Dentina Hígida/SB - DH/SB G2 - DH/CSE - DH/CSE G3–Dentina Desmineralizada/SB - DD/ SB G4–DD/CSE G5-DD+MI Paste™-MP/SB - DD+MP/SB e G6–DD+MP/CSE. Blocos de compósito FiltekTM Z350XT (4mm) foram construídos sobre a dentina com SB ou CSE e os conjuntos armazenados por 24h a 37 ºC em água. Palitos (1mm área de secção) foram obtidos e submetidos ao teste de µTBS (1,0mm/min 500N). Os dados foram submetidos à ANOVA e teste de Tukey, e Dunnett (a5%). Os tipos de fraturas foram avaliados por MEV. Houve interação significativa dos dados de µTBS, entre os fatores (Adesivo/Substrato) (p<0,01). DD+MP/SB (45,25) e DD+MP/CSE (48,10) apresentaram os maiores valores de µTBS (p<0.05)   do que os demais grupos e não diferiram entre si (p>0,05). DH/SB (40,8) mostraram maiores valores de µTBS do que DH/CSE (32,9) (p<0.05). Não houve diferença estatisticamente significativa entre DD/SB (26,4) e DD/CSE (25,4) (p>0,05). A maioria das falhas foi do tipo adesiva/mista. O tratamento da dentina desmineralizada com MI Paste™ mostrou uma alternativa favorável aos procedimentos adesivos a curto prazo, independente do adesivo utilizado.Palavras-chave: dentina. Remineralização Dentária. Resistência à Tração.

Toxicity of the bionematicide 1,4-naphthoquinone on non-target soil organisms

The main goal of the present study was to evaluate the ecotoxicological effects of 1,4-naphthoquinone (1,4-NTQ), a natural-origin compound presenting nematicidal activity, that can be obtained from walnut husk, in plants and soil invertebrates, including non-target soil nematode communities. This research was part of an ongoing project that aims to develop environmentally-friendly nematicides obtained from agricultural residues. The battery of ISO tests included emergence and growth of corn (Zea mays) and rape (Brassica napus); avoidance with the earthworm Eisenia andrei and the collembolan Folsomia candida; and reproduction with the previous species plus the enchytraeid Enchytraeus crypticus. A novel soil nematode community assay was also performed. ISO tests and nematode assays were conducted using a natural uncontaminated soil that was spiked with a range of 1,4-NTQ concentrations. Toxicity of 1,4-NTQ was found for all test-species and the most sensitive were F. candida and E. andrei. After 7 days of exposure to 1,4-NTQ, nematode abundance decreased along the concentration gradient, and a partial recovery was observed after 14 days (1,4-NTQ <48 mg kg^-1 soil). The number of nematode families consistently decreased in both periods. Overall, results indicate that a 1,4-NTQ concentration of <20 mg kg^-1 could be environmentally safe but preliminary data suggest that it might be ineffective for the target-nematodes, root-knot nematodes, Meloidogyne spp., and root-lesion nematodes, Pratylenchus spp. In addition, if higher dosages of 1,4-NTQ bionematicide are necessary, the potential recovery of non-target organisms under real field scenarios also needs to be assessed.

Recycling organic wastes to agricultural land as a way to improve its quality: A field study to evaluate benefits and risks

A field study was established to assess the effects of a sewage sludge (SS), a mixed municipal solid waste compost (MMSWC) and a compost produced from agricultural wastes (AWC), in a Vertisol, using Lolium multiflorum L. The amendments were applied for two consecutive years: 6, 12 and 24t dry matter ha^-1 for SS, and the amendment doses for MMSWC and AWC were calculated to deliver the same amount of organic matter (OM) per unit area. The amendments had significant beneficial effects on some soil properties (e.g. soil OM, N_Kjeldahl, extractable P and K), and on plant productivity parameters (e.g. biomass yield, chlorophyll, foliar area). For instance, soil OM increased from 0.78% to 1.71, 2.48 and 2.51%, after two consecutive years of application of 24t dry matter ha^-1 of SS, MMSWC and AWC, respectively, while the plant biomass obtained increased from 7.75tha^-1 to 152.41, 78.14 and 29.26tha^-1, for the same amendments. On the plant, effects were more pronounced for SS than for both compost applications, a consequence of its higher capacity to provide N to the plant in a readily available form. However, after two years of application, the effects on soil properties were more noticeable for both composts, as their OM is more resistant to mineralization, which endures their beneficial effects on soil. Cadmium, Cr, Ni and Pb pseudo-total concentrations, were not affected significantly by the application of the organic wastes to soil, in all tested doses, neither their extractability by 0.01M CaCl₂. On the contrary, Cu and Zn pseudo-total concentrations increased significantly in the second year of the experiment, following the application of the higher rate of MMSWC and AWC, although their extractability remained very low (<0.5% of their pseudo-total fraction). Trace elements concentrations in the aboveground plant material were lower than their maximum tolerable levels for cattle, used as an indicator of risk of their entry into the human food chain. Despite these results, it is interesting to note that the SS promoted a significant increase in the foliar concentrations of Cu, Ni and Zn that did not happen in composts application, which can be explained by the reduction of the soil pH, as a consequence of SS degradation in soil. Concluding, if this type of organic wastes were to be used in a single application, the rate could be as high as 12 or even 24tha^-1, however, if they are to be applied in an annual basis, the application rates should be lowered to assure their safe application (e.g. to 6tha^-1). Moreover, it is advisable to use more stable and mature organic wastes, which have longer lasting positive effects on soil characteristics.

Effects of NaCl and seawater induced salinity on survival and reproduction of three soil invertebrate species

The increase of global mean temperature is raising serious concerns worldwide due to its potential negative effects such as droughts and melting of glaciers and ice caps leading to sea level rise. Expected impacts on soil compartment include floodings, seawater intrusions and use of saltwater for irrigation, with unknown effects on soil ecosystems and their inhabitants. The present study aimed at evaluating the effects of salinisation on soil ecosystems due to sea level rise. The reproduction and mortality of three standard soil invertebrate species (Folsomia candida, Enchytraeus crypticus, Hypoaspis aculeifer) in standard artificial OECD soil spiked with serial dilutions of seawater/gradient of NaCl were evaluated according to standard guidelines. An increased sensitivity was observed in the following order: H. aculeifer≪E. crypticus≈F. candida consistent with the different exposure pathways: springtails and enchytraeids are exposed by ingestion and contact while mites are mainly exposed by ingestion due to a continuous and thick exoskeleton. Although small differences were observed in the calculated effect electrical conductivity values, seawater and NaCl induced the same overall effects (with a difference in the enchytraeid tests where a higher sensitivity was found in relation to NaCl). The adverse effects described in the present study are observed on soils not considered saline. Therefore, the actual limit to define saline soils (4000 μS cm(-1)) does not reflect the existing knowledge when considering soil fauna.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A5 mutations and clinical characterization of 22 families

Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.

Functional and structural parameters to assess the ecological status of a metal contaminated area in the tropics

Ecological parameters (soil invertebrates, microbial activity, and plant community) were assessed in a metal contaminated site in an abandoned lead smelter and non-contaminated reference sites, as part of an ecological risk assessment (ERA). Vegetation cover inside the smelter area was lower and presented a more homogenous species composition than outside. A more simplified and less abundant vegetation community within the smelter area also simplified the habitat conditions, which in addition to metal toxicity, impaired the soil microbial and faunal communities. A significant reduction in the feeding activity was observed within the smelter area. Also a significant change in community composition of surface dwelling invertebrates was observed at those sites when compared to sites outside the smelter area. Moreover, basal respiration, microbial biomass C, dehydrogenase and phosphatase activity also decreased in several of these points under the smelter area. As a result, a significant impairment of organic material decomposition in the most contaminated sites was observed. Metal contamination affected the ecological status of the site, leading to a risk for ecosystem functioning and provisioning of ecosystem services like organic matter decomposition and nutrient cycling, even 17 years after the end of smelting activities. Regarding the sensitivity of the ecological parameters assessed, most were able to distinguish sites within the smelter area boundaries from those outside. However, only bait lamina (feeding activity), basal respiration and microbial biomass carbon presented high capacity to distinguish the level of soil contamination, since they were significantly correlated with metal loadings, and thus are promising candidates to be integrated in the Ecological Line of Evidence of an ERA.

Pesticide application to agricultural fields: effects on the reproduction and avoidance behaviour of Folsomia candida and Eisenia andrei

The objective of this work was to assess the impact of pesticide application to non-target soil organisms simulating what happens following pesticide application in agricultural fields and thus obtaining higher realism on results obtained. For that purpose, three commercial formulations containing the insecticides chlorpyrifos and endosulfan and the herbicide glyphosate were applied to a Mediterranean agricultural field. The soil was collected after spraying and dilution series were prepared with untreated soil to determine the impact of the pesticides on the avoidance behaviour and reproduction of the earthworm Eisenia andrei and the collembolan Folsomia candida. A significant avoidance was observed at the recommended field dose in case of endosulfan by earthworms (60 %) and in case of chlorpyrifos by collembolans (64 %). In addition, both insecticides affected the number of juveniles produced by the earthworms (EC(50) were below the recommended field dose). Glyphosate did not seem to affect either earthworms or collembolans in the recommended field dose. Folsomia candida was more sensitive to pesticide application than Eisenia andrei, what was corroborated by the EC(50) and LC(50) values. In conclusion, insecticides may affect the structure of the soil community by reducing the survival of collembolans and the reproductive capacity of collembolans and earthworms.

Short-term changes of metal availability in soil. Part I: comparing sludge-amended with metal-spiked soils

Sewage sludge application to soils is regulated by its total metal content. However, the real risk of metals is determined by the fraction that is biologically available. The available fraction is highly related to the strength of metal binding by the matrix, which is a dynamic process. The evaluation of the fate of metals in time can contribute increased accuracy of ecological risk assessment. Aiming to evaluate short-term changes in metal availability when metals were applied to soil directly (metal-spiked) or by way of an organic matrix (sludge-amended), a laboratory experiment was performed using open microcosms filled with agricultural soil. A concentration gradient of industrial sludge (11, 15, 55, and 75 t/ha) that was contaminated predominantly with chromium, copper, nickel, and zinc, or soil freshly spiked with the same concentrations of these metals, were applied on top of the agricultural soil. After 0, 3, 6, and 12 weeks, total (HNO(3) 69 %) and 0.01 M CaCl(2)-extractable metal concentrations in soil and metal content in the percolates were measured. Results demonstrated that comparison between sludge-amended and metal-spiked soils may give important information about the role of sludge matrix on metal mobility and availability in soil. In sludge-amended soils, extractable-metal concentrations were independent of the sludge concentration and did not change over time. In metal-spiked soils, metal extractability decreased with time due to ageing and transport of metals to deeper layers. In general, the sludge matrix increased the adsorption of metals, thus decreasing their mobility in soils.

Boric acid as reference substance: pros, cons and standardization

Boric acid (BA) has been successfully used as reference substance in some standard test guidelines. Due to the fact that previously selected reference substances present a significant risk to human health and/or are banned for environmental reasons, BA is being discussed for broader adoption in OECD or ISO guidelines. To provide input on BA data and contribute to the discussion on its suitability as a reference substance, in the present study BA was tested with two standard soil organisms, Enchytraeus albidus and Folsomia candida, in terms of survival, reproduction and avoidance. Additionally, published data on other organisms was analysed to derive the most sensitive soil dwelling invertebrate (hazard concentration-HC5). Results showed that BA affected the tested organisms, being two times more toxic for collembolans (LC50 = 96; EC50 = 54 mg/kg) than for enchytraeids (LC50 = 325; EC50 = 104 mg/kg). No avoidance behaviour occurred despite the fact that BA affects earthworms. Actually, it is the recommended reference substance for the earthworm avoidance test. Clearly, the suitable performance of BA in one species should not be generalized to other species. Absolute toxicity is not an important criterion for the selection of a reference substance, but it has been proposed that effects should occur within a reasonable range, i.e. <1,000 mg/kg. We could confirm, compiling previous data that for most soil invertebrates, the EC50 is expected to be below 1,000 mg/kg. From these data it could be derived that the most sensitive soil dwelling invertebrate (HC5, 50%) is likely to be affected (EC10) at 28 (8-53) mg H(3)BO(3)/Kg, equivalent to 4.6 (1.4-8.7) mg boron/kg.

Toxicity to Eisenia andrei and Folsomia candida of a metal mixture applied to soil directly or via an organic matrix

Regulatory limits for chemicals and ecological risk assessment are usually based on the effects of single compounds, not taking into account mixture effects. The ecotoxicity of metal-contaminated sludge may, however, not only be due to its metal content. Both the sludge matrix and the presence of other toxicants may mitigate or promote metal toxicity. To test this assumption, the toxicity of soils recently amended with an industrial sludge predominantly contaminated with chromium, copper, nickel, and zinc and soils freshly spiked with the same mixture of metals was evaluated through earthworm (Eisenia andrei) and collembolan (Folsomia candida) reproduction tests. The sludge was less toxic than the spiked metal mixture for E. andrei but more toxic for F. candida. Results obtained for the earthworms suggest a decrease in metal bioavailability promoted by the high organic matter content of the sludge. The higher toxicity of the sludge for F. candida was probably due to the additive toxic effect of other pollutants.

Are great tits (Parus major) inhabiting the vicinity of a pulp mill healthy? Impacts on physiology and breeding performance

The evaluation of pollution effects on wildlife provides biologically meaningful information concerning environmental quality and possible impacts on populations and can be used as an early warning of environmental change. We aimed to assess the potential effects of exposure to atmospheric pollution from pulp mill emissions on the morphology, physiology, and reproductive performance of the great tit (Parus major). Great tits from a population inhabiting the vicinity of a pulp mill had significantly higher feather mercury levels and were physiologically distinct from other birds not under the direct influence of the pollution source. This distinction, due to significantly higher levels of red blood cell-glutathione peroxidase antioxidant activity, in birds from the vicinity of the pulp mill, was observed both in autumn and winter and was repeatable between years. No detectable effects were observed on breeding performance or nestling morphology and physiology. The effects of pollution in this study seem to be related to increased levels of oxidative stress.

Ammonia volatilization in soil treated with tannery sludge

The utilization of tannery sludge in agricultural areas can be an alternative for its disposal and recycling. Despite this procedure may cause the loss of nitrogen by ammonia volatilization, there is no information about this process in tropical soils. For two years a field experiment was carried out in Rolândia (Paraná State, Brazil), to evaluate the amount of NH(3) volatilization due to tannery sludge application on agricultural soil. The doses of total N applied varied from zero to 1200 kg ha(-1), maintained at the surface for 89 days, as usual in this region. The alkalinity of the tannery sludge used was equivalent to between 262 and 361 g CaCO(3) per kg. Michaelis-Menten equation was adequate to estimate NH(3)-N volatilization kinetics. The relation between total nitrogen applied as tannery sludge and the potentially volatilized NH(3)-N, calculated by the chemical-kinetics equation resulted in an average determination coefficient of 0.87 (P>0.01). In this period, the amount of volatilized NH(3) was more intense during the first 30 days; the time to reach half of the maximum NH(3) volatilization (K(m)) was 13 an 9 days for the first and second experiments, respectively. The total loss as ammonia in the whole period corresponded in average to 17.5% of the total N applied and to 35% of the NH(4)(+)-N present in the sludge. If tannery sludge is to be surface applied to supply N for crops, the amounts lost as NH(3) must be taken into consideration.

The use of Collembola avoidance tests to characterize sewage sludges as soil amendments

The ecotoxicological characterization of sewage sludge takes into account the additive, antagonistic and synergistic effects that occur as a result of multi-chemical interactions. Such an evaluation therefore is essential to complement the chemical analysis that, although required by law, is clearly insufficient. Using a tiered approach in the toxic evaluation of sewage sludge allows for characterization of toxicity in a timely manner. According to the literature, reproduction tests with Folsomia candida are suitable tools for the toxic assessment of organic sludges. Therefore, the inclusion of Collembola avoidance tests at a screening level (low tier), and acting as a trigger for longer-period tests (high tier; e.g. reproduction test), may provide a successful strategy, and may complement the currently proposed test battery. To evaluate the use of both avoidance and reproduction tests with collembolans in such a tiered approach, three sewage sludges (urban, olive and electroplating industries) were mixed in with a field-collected soil at different concentrations. Avoidance and reproduction tests were performed with the soil-sludge mixtures after 0, 4 and 12 weeks of incubation. The tests detected no toxicity in soil-sludge mixtures of urban and olive sludges at any incubation period. Mixtures with sludge from the electroplating industry induced toxicity only in the avoidance tests with freshly prepared and 4-week incubated samples. These results demonstrate the ability of Collembola avoidance tests to assess sewage sludge toxicity over time and its potential for hazardous sludge characterization at low tier levels.

Evaluating a bioremediation tool for atrazine contaminated soils in open soil microcosms: the effectiveness of bioaugmentation and biostimulation approaches

A previously developed potential cleanup tool for atrazine contaminated soils was evaluated in larger open soil microcosms for optimization under more realistic conditions, using a natural crop soil spiked with an atrazine commercial formulation (Atrazerba FL). The doses used were 20x or 200x higher than the recommended dose (RD) for an agricultural application, mimicking over-use or spill situations. Pseudomonas sp. strain ADP was used for bioaugmentation (around 10(7) or 10(8) viable cells g(-1) of soil) and citrate for biostimulation (up to 4.8 mg g(-1) of soil). Bioremediation treatments providing fastest and higher atrazine biodegradation proved to differ according to the initial level of soil contamination. For 20x RD of Atrazerba FL, a unique inoculation with Pseudomonas sp. ADP (9 +/- 1 x 10(7) CFU g(-1)) resulted in rapid atrazine removal (99% of the initial 7.2 +/- 1.6 microg g(-1) after 8d), independent of citrate. For 200x RD, an inoculation with the atrazine-degrading bacteria (8.5 +/- 0.5 x 10(7) CFU g(-1)) supplemented with citrate amendment (2.4 mg g(-1)) resulted in improved biodegradation (87%) compared with bioaugmentation alone (79%), even though 7.8 +/- 2.1 microg of atrazine g(-1) still remained in the soil after 1 wk. However, the same amount of inoculum, distributed over three successive inoculations and combined with citrate, increased Pseudomonas sp. ADP survival and atrazine biodegradation (to 98%, in 1 wk). We suggest that this bioremediation tool may be valuable for efficient removal of atrazine from contaminated field soils thus minimizing atrazine and its chlorinated derivatives from reaching water compartments.

Biological testing of a digested sewage sludge and derived composts

Aiming to evaluate a possible loss of soil habitat function after amendment with organic wastes, a digested sewage sludge and derived composts produced with green residues, where biologically tested in the laboratory using soil animals (Eisenia andrei and Folsomia candida) and plants (Brassica rapa and Avena sativa). Each waste was tested mimicking a field application of 6ton/ha or 12ton/ha. Avoidance tests did not reveal any impact of sludge and composts to soil biota. Germination and growth tests showed that application of composts were beneficial for both plants. Composts did not affect earthworm's mass increase or reproduction, but the highest sludge amendment revealed negative effects on both parameters. Only the amendment of composts at the highest dose originated an impairment of springtails reproductive output. We suggest that bioassays using different test species may be an additional tool to evaluate effects of amendment of organic wastes in soil. Biological tests are sensitive to pollutants at low concentrations and to interactions undetected by routine chemical analysis.

[Drowning: tematic review and casuistic analysis in the Intensive Care Medicine Service of University Hospital of Coimbra (1989-2002)]

Drowning is a major cause of accidental deaths, especially in childrens. In this review (part one) the definition, epidemiology, pathophysiology and treatments (with an enphasis on the ressuscitation) are discussed. From 1989 to 2002 part two) we recorded the clinical course of the 19 patients vitims of submersion admited to our ICU. We conclued that the majority of patients are young (mean = 37,3 years), mortality is high (26%), but the complete recovery is possible (63%). The cardio-respiratory arrest or Glasgow Coma Scale < or = 5 were related with poor prognosis, only with 3 survivors (1 without sequels). Trauma associated lesions were observed only in one patient.

Assimilation efficiency and toxicokinetics of 14C-lindane in the terrestrial isopod Porcellionides pruinosus: the role of isopods in degradation of persistent soil pollutants

An achievable way to evaluate the bioavailability of a certain toxic in the environment is to measure the concentration inside soil organisms. Non-target saprotrophic organisms like isopods are often exposed to agrochemicals or other kind of persistent chemicals. In this study the isopod Porcellionides pruinosus was exposed to a constant concentration of Lindane (gamma-HCH) via food. Using toxicokinetic models the bioaccumulation and fate of the pesticide by isopods was assessed and compared with previous studies, where an unexpected decrease in gamma-HCH concentration was observed. Animal body burdens showed higher values, and a lower assimilation rate constant, although the elimination rate constant was twice the value previously observed. It was also observed that a significant amount of gamma-HCH had an unknown fate. To discover its possible destiny, a factorial experiment was carried out using two types of CO2 traps and contaminated leaves in the presence and absence of isopods. It was concluded that isopod activity might have been responsible for a more rapid biotransformation of gamma-HCH in leaves, since the amount of the pesticide is reduced in their presence.

Bioavailability and toxicokinetics of (14)C-lindane (gamma-HCH) in the enchytraeid Enchytraeus albidus in two soil types: the aging effect

Enchytraeids are important members of the soil fauna living in the true soil layer instead of the humus like most earthworms, resulting in a different interaction with chemicals in soil. It is well known that the detectable concentration of contaminants in the soil cannot fully predict a biological effect; therefore bioaccumulation studies are of great importance. In this study the bioaccumulation pattern of the pesticide lindane ([(14)C]gamma-HCH) in Enchytraeus albidus was analyzed in two different soil types, an artificial Organisation for Economic Co-operation and Development (OECD) soil and a natural agricultural soil. The effect of aging on bioaccumulation and bioavailability was also analyzed. Aging experiments consisted of having the same procedures at different times after soil contamination: Immediately after contamination and 1, 2, 4, 6, and 10 months after that. Major differences occurred within the first month. Considering the overall data (10 months), it is possible to observe that in OECD soil there is a correlation between concentration in soil and in the organisms, but that was not observed for the natural soil. The decrease patterns for concentration in soil and in watery soil extracts were different: monophasic behavior occurred in OECD soil, and a biphasic pattern was measured in natural soil. It was observed that the bioavailable ( i.e., water-extractable) fraction of lindane in the natural soil decreased faster than the total soil concentration. In natural soil the decrease of concentration appeared faster than in OECD soil; this may be related to the lower amount of organic matter content.

Effect of endosulfan and parathion on energy reserves and physiological parameters of the terrestrial isopod Porcellio dilatatus

The in vivo effects of parathion and endosulfan on the isopod Porcellio dilatatus were investigated. Feeding parameters (food consumption and assimilation rates), growth, and energy reserves (glycogen, lipid, and protein contents) of pesticide-exposed isopods were compared with those of control animals. Isopods were exposed to a wide range of concentrations of parathion or endosulfan (0.1, 1, 10, 25, 50, 100, 250, and 500 microg/g of food) for 21 days. The route of uptake of the pesticides was through the diet (alder leaves). Results revealed that parathion induces a significant depression of glycogen, lipid, and protein contents. However, no significant effect was observed on either feeding parameters or growth. Animals fed endosulfan-contaminated food had smaller amounts of glycogen and lipid than control animals, while protein levels were similar in all treatments. Endosulfan also induced a significant decrease in food consumption and assimilation rates at the highest concentrations tested. Growth rate was also significantly affected by endosulfan. These results suggest that the isopod P. dilatatus is a suitable species for use in toxicity tests and that energy reserves could be used as effect criteria in both laboratory and field studies.

Optimization of culture conditions of Porcellio dilatatus (Crustacea: Isopoda) for laboratory test development

This paper describes the experimental results for optimizing isopod culture conditions for terrestrial ecotoxicity testing. The influence of animal density and food quality on growth and reproduction of Porcellio dilatatus was investigated. Results indicate that density influences isopod performance in a significant way, with low-density cultures having a higher growth rate and better reproductive output than medium- or high-density cultures. Alder leaves, as a soft nitrogen-rich species, were found to be the best-quality diet; when compared with two other food mixtures, alder leaves induced the best results, particularly in terms of breeding success. Guidance regarding culture conditions of isopod species, especially in terms of culture density and diet, is given.

Novel bioassay based on acetylcholinesterase and lactate dehydrogenase activities to evaluate the toxicity of chemicals to soil isopods

This study developed a bioassay with the isopod Porcellio dilatatus based on the activity of the enzymes acetylcholinesterase (AChE) and lactate dehydrogenase (LDH). The in vivo effects of the insecticides parathion-ethyl and endosulfan-sulfate on AChE and LDH activities of P. dilatatus under laboratory conditions were investigated. The route of uptake of the pesticides was through the food (alder leaves). Isopods were exposed to a wide range of concentrations of parathion or endosulfan (0.1, 1, 10, 25, 50, 100, 250, and 500 microg/g of food) for 21 days. After this period, the activity of AChE and LDH was determined. Parathion induced significant depression of both AChE and LDH activities. Animals fed with endosulfan-contaminated food exhibited lower LDH activities than control animals, while AChE activity was similar in all treatments. The results of the present investigation suggest that the isopod. P. dilatatus is a suitable species for use in toxicity tests and indicate that the enzymes AChE and LDH could be used as effect criteria both in laboratory and in field studies with this species.

Histological effects of iron accumulation on mice liver and spleen after administration of a metallic solution

Special attention has been focused on the toxicity of some metallic species released from implanted materials, which accumulate in vital organs over long periods of time. A set of experiments with mice was designed to investigate the individual effects caused by iron in the liver and spleen. Histological features of these organs were evaluated and slight morphological changes were observed during the treatment time suggesting a negative correlation with the duration of the iron treatment. In addition, to associate the histological changes in the organs with iron accumulation an electrochemical method, adsorptive stripping voltammetry, was chosen to quantify the iron levels in these mentioned organs. The accuracy of the proposed method was checked by atomic absorption spectrometry. Both organs showed elevated concentrations of iron, nearly twofold, 7 days after iron administration compared to control organs.

Individual study of chromium in the stainless steel implants degradation: an experimental study in mice

To study the accumulation and the histological effects in mice organs caused by hexavalent chromium, one of the corrosion products released from AISI 316L stainless steel implants, mice groups were subcutaneously injected with a metallic solution of chromium during a certain period of time. Similar injections were made with HBSS (Hank's Balanced Salt Solution) in other groups to be used as controls. The levels of chromium found in the liver, kidney and spleen of the control and the treated animals were obtained by atomic absorption spectrometry (AAS) and were compared to those obtained by AdSV (adsorptive stripping voltammetry) to test the accuracy of the results. During the experimental period, the liver and spleen showed a progressive and significant accumulation of chromium whereas in the kidney the significant accumulation found after the first week practically remained unchanged during the four weeks. Apparently, the histological analysis of these tissues did not evidence any relevant morphological alteration induced by the chromium accumulations during the four weeks of treatment.

In vitro osteoblastic differentiation of human bone marrow cells in the presence of metal ions

For periods up to 21 days human bone marrow was cultured in control conditions that favor the proliferation and differentiation of osteoblastic cells. The effect of AISI 316L corrosion products and the corresponding major separate metal ions (Fe, Cr, and Ni) were studied in three different phases of the culture period in order to investigate the effects of metal ions in cell populations representative of osteoblastic cells in different stages of differentiation. Toxicity consequences of the presence of metal ions in bone marrow cultures were evaluated by biochemical parameters (enzymatic reduction of MTT, alkaline phosphatase activity, and total protein content), histochemical assays (identification of ALP-positive cells and Ca and phosphates deposits), and observation of the cultures by light and scanning electron microscopy. Culture media were analyzed for total and ionized Ca and P and also for metal ions (Fe, Cr, and Ni). The presence of AISI 316L corrosion products and Ni salt in bone marrow cultures during the first and second weeks of culture significantly disturbs the normal behavior of these cultures, interfering in the lag phase and exponential phase of cell growth and ALP expression. However, the presence of these species during the third week of culture, when expression of osteoblastic functions occurs (mineralization process), did not result in any detectable effect. Fe salt also disturbs the behavior of bone marrow cell cultures when present during the lag phase and proliferation phase, and a somewhat compromised response between the normal pattern (control cultures) and intense inhibition (AISI 316L corrosion products and Ni salt-added cultures) was observed. Fe did not affect the progression of the mineralization phase. Osteogenic cultures exposed to Cr salt (Cr3+) presented a pattern similar to the controls, indicating that this element does not interfere, in the concentration studied, in the osteoblastic differentiation of bone marrow cells. Quantification of metal ions in the culture media showed that Cr (originated from AISI 316L corrosion products but from not Cr3+ salt) and Ni (originated from AISI 316L corrosion products and Ni salt) appear to be retained by the bone marrow cultures.

Decreased consumption of Ca and P during in vitro biomineralization and biologically induced deposition of Ni and Cr in presence of stainless steel corrosion products

The purpose of this study was to investigate the effects of 316L stainless steel (SS) corrosion products on the in vitro biomineralization process, because tissue necrosis, bone loss, impaired bone mineralization, and loosening of orthopedic implants are associated with ions and debris resulting from biodegradation. Rat bone marrow cells were cultured in experimental conditions that favored the proliferation and differentiation of osteoblastic cells and were exposed to SS corrosion products obtained by electrochemical means for periods ranging from 1 to 21 days. Quantification of total and ionized Ca and P, as well as Fe, Cr, and Ni, ions in the culture media of control and metal added cultures during the incubation period was performed to study the influence of corrosion products on the Ca and P consumption that occurs during the mineralization process. Control cultures and metal effects on cultures were evaluated concerning DNA content, enzymatic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and alkaline phosphatase (ALP) activity. Histochemical detection of ALP, Ca, and phosphate deposition, and examination of the cultures by scanning and transmission electron microscopy (SEM and TEM) were also performed. The presence of SS corrosion products resulted in impairment of the normal behavior of rat bone marrow cultures. Levels of Cr and Ni in the medium of cultures exposed to 316L SS corrosion products decreased throughout the incubation period, suggesting a regular deposition of these species; these results were supported by TEM observation of the cultures. Cultures exposed to the corrosion products presented lower DNA content, MTT reduction, and ALP activity and failed to form mineralized areas. These cultures showed negative staining on histochemical reactions for the identification of calcium and phosphate deposition and SEM and TEM examination did not show mineral globular structures or mineralization foci, respectively, which is characteristic of cultures grown in control conditions. These results suggest that metal ions associated with 316L SS are toxic to osteogenic cells, affecting their proliferation and differentiation.

Chromium determination in osteoblast-like cell culture medium by catalytic cathodic stripping voltammetry with a mercury microelectrode

A catalytic cathodic stripping voltammetric procedure for the determination of total chromium in osteoblast-like cell culture medium using a mercury film microelectrode (MFM) was optimised. The method is based on the pre-concentration of the Cr(III)-diethylenetriaminepentaacetic acid (DTPA) complex by adsorption at the potential of-1.00 V (vs. Ag/AgC1) in the presence of 10 x 10(-3) mol/L DTPA, 0.70 mol/L sodium nitrate, 0.04 mol/L sodium acetate and 1.0 x 10(-3) mol/L potassium permanganate at pH 5.9-6.0. The limit of detection obtained for a 40 s collection time was 2.80 x 10(-10) mol/L of chromium. The results achieved by stripping voltammetry using the MFM were compared to those obtained by atomic absorption spectrometry (AAS) to ensure the reliability of the electrochemical method. This procedure proved to be an alternative to AAS and valuable in biocompatibility studies performed in vitro using osteoblast-like cells.

Effects of AISI 316L corrosion products in in vitro bone formation

Rat bone marrow cells were cultured in experimental conditions that favour the proliferation and differentiation of osteoblastic cells (i.e., 2.52 x 10(-4) mol l(-1) ascorbic acid, 10(-2) mol l(-1) beta-glycerophosphate and 10(-8) mol l(-1) dexamethasone) in the absence and in the presence of stainless-steel corrosion products, for a period of 18 days. An AISI 316L stainless-steel slurry (SS) was obtained by electrochemical means and the concentrations of the major metal ions, determined by atomic absorption spectrometry, were 8.78 x 10(-3) mol l(-1) of Fe, 4.31 x 10(-3) mol l(-1) of Cr and 2.56 x 10(-3) mol l(-1) of Ni. Bone marrow cells were exposed to 0.01, 0.1 and 1% of the SS and at the end of the incubation period, control and treated cultures were evaluated by histochemical assays for the identification of the presence of alkaline phosphatase and also calcium and phosphate deposition. Cultures were further observed by scanning electron microscopy. Levels of total and ionised calcium and phosphorus in the culture media collected from control and metal exposed cell cultures were also quantified. Histochemical staining showed that control cultures presented a strong reaction for the presence of alkaline phosphatase and exhibited formation of calcium and phosphates deposits. The presence of 0.01% SS caused no detectable biological effects in these cultures, 0.1% SS impaired osteoblastic behaviour and, 1% SS resulted in cell death. In the absence of bone cells, levels of total and ionised calcium and phosphorus in the control and metal added culture medium were similar throughout the incubation period. A significant decrease in the levels of ionised calcium and phosphorus were observed in the culture medium of control cultures and also in cultures exposed to 0.01% SS after two weeks of incubation, an event related with the formation of mineral calcium phosphate deposits in these cultures. In cultures grown in the presence of 0.1 and 1% SS corrosion products, levels of calcium and phosphorus were similar to those observed in the absence of cells. Results showed that stainless-steel corrosion products above certain concentrations may disturb the normal behaviour of osteoblast-like rat bone marrow cell cultures.

Evaluation of nickel toxicity on liver, spleen, and kidney of mice after administration of high-dose metal ion

The toxic effects caused by nickel (Ni) per si were explored by performing in vivo studies on mice following subcutaneous administration of a metallic solution of nickel at 1, 2, 3, and 4 weeks to evaluate the side effects of this metal ion when released from stainless steel implants. Other groups were similarly injected with HBSS and used as controls. Accumulation of Ni ions on liver, spleen, and kidney was assessed by an electrochemical method, adsorptive stripping voltammetry (AdSV) using microelectrodes, and atomic absorption spectrometry (AAS). Alterations of those organs induced by Ni ions were studied, showing that several histological changes had been induced. Chemical analysis and histological features indicate that Ni is partially accumulated in the study organs.

Adsorptive stripping measurements of iron accumulation in mice kidney using microelectrodes and histological features

The toxic effects caused by iron in kidney was performed on experimental studies with mice following administration of a metallic solution of this species to simulate the iron corrosion products of a metallic implant. To quantify the total levels of iron present in this organ, an electrochemical method was chosen based on the application of square wave voltammetry using adsorptive collection of iron-catechol on a mercury film microelectrode (MFM). The optimal working conditions to produce a very stable and reproducible iron peak in the digested kidney samples were found to be pH = 7.2 provided by 8.0 mmol/L PIPES buffer, catechol concentration of 3.0 x 10(-4) mol/L, deposition potential -1.80 V and deposition time 20 s. These results were compared with those obtained by atomic absorption spectrometry (AAS) indicating a good performance of the electrochemical method used. The analytical results show an increase of iron concentration with treatment time, which indicates that this metal ion is partially accumulated in the kidney. This accumulation induces with time some morphological alterations as evidenced by the histological analysis.

In vitro biomineralization by osteoblast-like cells. I. Retardation of tissue mineralization by metal salts

The cytocompatibility of stainless steel 316L (SS 316L) corrosion products was investigated with particular focus on the dose- and time-effect of electrochemically dissolved SS and the corresponding separate metal ions on osteogenic bone marrow derived cells. Type AISI 316L stainless steel (Fe 63.9%, Cr 18.0%, Ni 12.5%, Mo 2.8%, Si 1.2%, Mn 1.6% and C 0.025%, weight for weight) was anodically dissolved in Hank's Balanced Salt Solution (HBSS) and diluted to the following concentrations: 500 microg ml(-1) of Fe, 122 microg ml(-1) of Cr and 101 microg ml(-1) of Ni, as estimated by atomic absorption spectrometry. Similarly, salt solutions containing 50 microg ml(-1) of Fe (FeCl3 x 6H2O), 122 microg ml(-1) of Cr (CrCl3 x 6H2O) or 101 microg ml(-1) of Ni (NiNO3) were prepared. All solutions were diluted 1:10(3), 1:10(4) and 1:10(5) and their effects on cell proliferation and function of rabbit bone marrow cells were studied up to 28 days of culture. Bone marrow cells (second subculture) were cultured in alpha-Minimal Essential Medium (alpha-MEM) supplemented with 10% fetal bovine serum 10(-8) mol l(-1) dexamethasone, 2.52 x 10(-4) mol l(-1) ascorbic acid and 10(-2) mol l(-1) beta-glycerophosphate. The osteoblast response to the presence of metal ions was evaluated by biochemical assays (enzymatic reduction of MTT for evaluation of cell viability/proliferation, and estimation of alkaline phosphatase (ALP) activity) and histochemical assays (identification of ALP positive cells and calcium and phosphates deposits). Results suggest a decrease in the expression of the osteoblast phenotype in the presence of ion and alloy solutions. Stainless steel corrosion products elicited slight effects but the corresponding metal ions produced pronounced effects on the osteoblast phenotype, namely an alteration in the levels and temporal expression of ALP and lower and retarded tissue mineralization ability.

In vitro biomineralization by osteoblast-like cells. II. Characterization of cellular culture supernatants

The quantification of total calcium, phosphorus, iron, chromium and nickel in cell culture medium by electrochemical or spectroscopic means may require digestion of samples. Nevertheless, when pH adjustment is performed for values higher than about 6.5, the formation of two phases occurs: a white precipitate and a clear solution. Analysing both phases using microelectrodes, atomic absorption spectrometry (AAS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray dispersive (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) analysis, it was observed that iron, chromium and nickel are not co-precipitating with the white solid phase. If quantification of calcium, phosphorus and magnesium is intended, a ten-fold dilution at least, must be performed to avoid most of these elements going into the precipitate. This knowledge is crucial if a mineralization study is going to be made.

Acromesomelic dwarfism: a new variation

The rate skeletal disorder, acromesomelic dwarfism, is characterized by short stature and short limbs. Bone dysplasia is evident. We report two cases of a variation of this disorder in a Portuguese woman and her son. The clinical features of these two cases differ from those of cases previously reported in the literature.

Use of microelectrodes as electrochemical sensors of metal ions released from biomaterials

In vitro studies to determine Fe3+ levels in mice liver samples were performed using platinum microelectrodes and atomic absorption spectrophotometry. Microelectrodes have been shown to be useful for quantitative analysis of metal ions released during the biodegradation process that occurs on implanted metallic biomaterials.