Integrated biomarker responses in oysters Crassostrea gasar as an approach for assessing aquatic pollution of a Brazilian estuary.

The Laguna Estuarine System (LES), southern Brazil, suffers impacts from anthropogenic activities, releasing contaminants into the ecosystem. This study evaluated changes in biochemical and molecular biomarkers and contaminants concentrations in oysters Crassostrea gasar transplanted and kept for 1.5 and 7 days at three potentially contaminated sites (S1, S2, and S3) at LES. Metals varied spatiotemporally; S1 exhibited higher Ag and Pb concentrations, whereas Cd was present in S3. S2 was a transition site, impacted by Ag, Pb, or Cd, depending on the period. Organic contaminants concentrations were higher before transplantation, resulting in the downregulation of biotransformation genes transcripts levels. Phase II-related genes transcripts and metals showed positive correlations. Decreased levels of HSP90-like transcripts and antioxidant enzymes activity were related to increased pollutant loads. Integrated biomarker response index (IBR) analysis showed S1 and S3 as the most impacted sites after 1.5 and 7 days, respectively. Regardless of the scenario, LES contaminants pose a significant threat to aquatic biota.

Stress responses in Crassostrea gasar exposed to combined effects of acute pH changes and phenanthrene.

Ocean acidification is a result of the decrease in the pH of marine water, caused mainly by the increase in CO2 released in the atmosphere and its consequent dissolution in seawater. These changes can be dramatic for marine organisms especially for oysters Crassostrea gasar if other stressors such as xenobiotics are present. The effect of pH changes (6.5, 7.0 and 8.2) was assessed on the transcript levels of biotransformation [cytochromes P450 (CYP2AU1, CYP2-like2) and glutathione S-transferase (GSTΩ-like)] and antioxidant [superoxide dismutase (SOD-like), catalase (CAT-like) and glutathione peroxidase (GPx-like)] genes, as well as enzyme activities [superoxide dismutase, (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferases transferase (GST) and glucose-6-phosphate dehydrogenase (G6PDH)] and lipid peroxidation (MDA) in the gills of Crassostrea gasar exposed to 100 µg·L-1 of phenanthrene (PHE) for 24 and 96 h. Likewise, the PHE burdens was evaluated in whole soft tissues of exposed oysters. The accumulation of PHE in oysters was independent of pH. However, acidification promoted a significant decrease in the transcript levels of some protective genes (24 h exposure: CYP2AU1 and GSTΩ-like; 96 h exposure: CAT-like and GPx-like), which was not observed in the presence of PHE. Activities of GST, CAT and SOD enzymes increased in the oysters exposed to PHE at the control pH (8.2), but at a lower pH values, this activation was suppressed, and no changes were observed in the G6PDH activity and MDA levels. Biotransformation genes showed better responses after 24 h, and antioxidant-coding genes after 96 h, along with the activities of antioxidant enzymes (SOD, CAT), probably because biotransformation of PHE increases the generation of reactive oxygen species. The lack of change in MDA levels suggests that antioxidant modulation efficiently prevented oxidative stress. The effect of pH on the responses to PHE exposure should be taken into account before using these and any other genes as potential molecular biomarkers for PHE exposure.

Exposure to phenanthrene and depuration: Changes on gene transcription, enzymatic activity and lipid peroxidation in gill of scallops Nodipecten nodosus.

Understanding the mechanism of phenanthrene (PHE) biotransformation and related cellular responses in bivalves can be an important tool to elucidate the risks of polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms. In the present study it was analyzed the transcriptional levels of 13 biotransformation genes related to cytochrome P450 (CYP), glutathione S-transferase (GST), sulfotransferase (SULT), flavin-containing monooxygenase and fatty acid-binding proteins by qPCR in gill of scallops Nodipecten nodosus exposed for 24 or 96h to 50 or 200µgL(-1) PHE (equivalent to 0.28 and 1.12µM, respectively), followed by depuration in clean water for 96h (DEP). Likewise, it was quantified the activity of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH), GST and levels of lipid peroxidation. Increased transcriptional levels of CYP2UI-like, CYP2D20-like, CYP3A11-like, GSTomega-like, SULT1B1-like genes were detected in organisms exposed to PHE for 24 or 96h. In parallel, GR and GPX activities increased after 96h exposure to 200µgL(-1) PHE and G6PDH activity increased after 24h exposure to 50µgL(-1) PHE. This enhancement of antioxidant and phase I and II biotransformation systems may be related to the 2.7 and 12.5 fold increases in PHE bioaccumulation after 96h exposure to 50 and 200µgL(-1) PHE, respectively. Interestingly, DEP caused reestablishment of GPX and GR activity, as well as to the transcript levels of all upregulated biotransformation genes (except for SULT1B1-like). Bioaccumulated PHE levels decreased 2.5-2.9 fold after depuration, although some biochemical and molecular modifications were still present. Lipid peroxidation levels remained lower in animals exposed to 200µgL(-1) PHE for 24h and DEP. These data indicate that N. nodosus is able to induce an antioxidant and biotransformation-related response to PHE exposure, counteracting its toxicity, and DEP can be an effective protocol for bivalve depuration after PHE exposure.

Differential gene transcription, biochemical responses, and cytotoxicity assessment in Pacific oyster Crassostrea gigas exposed to ibuprofen.

Pharmaceuticals, such as anti-inflammatory nonsteroidal drugs, are frequently detected in aquatic ecosystems. Studies about the effects of these substances in nontarget organisms, such as bivalves, are relevant. The aim of this study was to evaluate the effects on antioxidant status caused by ibuprofen (IBU) in oysters Crassostrea gigas exposed for 1, 4, and 7 days at concentrations 1 and 100 µg L(-1). Levels of IBU in tissues of oysters, as well as cell viability of hemocytes, were measured. The transcription of cytochrome P450 genes (CYP2AU2, CYP356A1, CYP3071A1, CYP30C1), glutathione S-transferase isoforms (GST-ω-like and GST-π-like), cyclooxygenase-like (COX-like), fatty acid binding protein-like (FABP-like), caspase-like, heat shock protein-like (HSP70-like), catalase-like (CAT-like), and the activity of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) were also evaluated in the gills of oysters. The highest levels of IBU were observed in animals exposed to 100 µg L(-1). A significant upregulation of CYP2AU1, CYP356A1, CYP3071A1, GST-ω-like, GST-π-like, COX-like, and FABP-like was observed in oysters exposed to IBU under different experimental conditions. Oysters exposed to 1 µg L(-1) for 7 days showed a significantly higher transcription of CYP2AU2, CYP356A1, CYP3071A1, GST-ω-like, and GST-π-like but lower GR activity. In conclusion, C. gigas exposed to environmentally relevant concentrations of IBU (1 µg L(-1)) exhibited increased transcription of certain genes and alterations on antioxidant and auxiliary enzymes, which could, in the the long term, cause damages to exposed organisms.

Severe hyperglycemia during gatifloxacin therapy in patients without diabetes.

OBJECTIVE: To present two cases of severe hyperglycemia in patients without diabetes who received gatifloxacin therapy. METHODS: We describe the histories, clinical findings, and hospital courses of two women in whom severe hyperglycemia developed after gatifloxacin therapy was initiated. Interacting factors that may result in severe hyperglycemia in patients without diabetes and the literature explaining the mechanism by which gatifloxacin can alter glucose metabolism are reviewed. RESULTS: Our first patient, a 46-year-old woman with end-stage renal disease, presented with a 3-day history of fever, abdominal pain, and hypotension. Admission laboratory data included a fasting plasma glucose level of 72 mg/dL and a glycosylated hemoglobin of 5.3%. She was treated with gatifloxacin for an infected ovarian cyst found on laparotomy. Her subsequent glucose values ranged from 400 to 500 mg/dL and remained high during gatifloxacin therapy. Antibiotic treatment was changed to ciprofloxacin. On outpatient follow-up, the patient's fasting plasma glucose levels had decreased to a range of 87 to 108 mg/dL. Our second patient, a 77-year-old woman with a history of chronic renal failure and congestive heart failure, was hospitalized because of dyspnea and hypotension. She was given gatifloxacin for a urinary tract infection. Her daily fasting plasma glucose value gradually increased from 100 mg/dL on admission to 694 mg/dL on the 6th hospital day. The patient required insulin therapy throughout her hospitalization, and she died on the 12th hospital day. CONCLUSION: Gatifloxacin therapy may precipitate severe hyperglycemia in patients without diabetes, especially in the elderly population, those with renal insufficiency, and those receiving multiple drugs known to alter glucose metabolism. Discontinuation of gatifloxacin treatment may result in improved glucose homeostasis.

Gingival crevicular fluid levels of interleukin-1beta and glycemic control in patients with chronic periodontitis and type 2 diabetes.

BACKGROUND: Patients with diabetes have increased incidence and severity of periodontal disease not accounted for by differences in the subgingival microbial infection. Poor glycemic control has been consistently associated with periodontal disease severity. Also, recent evidence suggests that hyperglycemia may induce inflammatory cytokine production. Few studies, however, have examined local biochemical measures of periodontal inflammation in patients with type 2 diabetes. The aim of this study was to determine whether glycemic control was related to gingival crevicular fluid (GCF) levels of interleukin-1beta (IL-1beta). METHODS: GCF samples were collected from 45 patients with type 2 diabetes and untreated chronic periodontitis. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and attachment level (AL) were recorded at six sites per tooth. IL-1beta levels were determined from individual GCF samples by enzyme-linked immunoabsorbent assay (ELISA). Individual site and mean patient values were calculated. Glycated hemoglobin (HbA1c) levels were measured from anticoagulated whole blood using an automated affinity chromatography system. Serum glucose was also determined. RESULTS: Clinical periodontal measures (PD, AL, BOP) and measures of glycemic control (HbA1c, random glucose) were significantly correlated with GCF IL-1beta. Patients with greater than 8% HbA1c had significantly higher mean GCF IL-1beta levels than patients with less than 8% HbA1c. In a multivariate model adjusting for age, gender, PD, AL, BOP, and PI, HbA1c and random glucose were independent predictors of high GCF IL-1beta. CONCLUSIONS: Poor glycemic control is associated with elevated GCF IL-1beta. These data are consistent with the hypothesis that hyperglycemia contributes to an heightened inflammatory response, and suggests a mechanism to account for the association between poor glycemic control and periodontal destruction.

Validation of healthcare administrative data for the diagnosis of epilepsy.

BACKGROUND: Administrative databases have become an important tool to monitor diseases. Patients with epilepsy could be traced using disease-specific codes and prescriptions, but formal validation is required to obtain an accurate case definition. The aim of the study was to correlate administrative data on epilepsy with an independent source of patients with epilepsy in a district of Lombardy, Northern Italy, from 2000 to 2008. METHODS: Data of nearly 320 600 inhabitants in the district of Lecco collected from the Drug Administrative Database of the Lombardy Region were analysed. Among them were included patients who fulfilled the International Classification of Diseases 9 (ICD-9) codes and/or the disease-specific exemption code for epilepsy and those who had at least one EEG record and took antiepileptic drugs (AEDs) as monotherapy or in variable combinations. To ascertain epilepsy cases, 11 general practitioners (GPs) with 15 728 affiliates were contacted. Multiple versions of the diagnostic algorithm were developed using different logistic regression models and all combinations of the four independent variables. RESULTS: Among the GP affiliates, 71 (4.5/1000) had a gold standard diagnosis of epilepsy. The best and most conservative algorithm included EEG and selected treatment schedules and identified 61/71 patients with epilepsy (sensitivity 85.9%, CI 76.0% to 92.2%) and 15 623/15 657 patients without epilepsy (specificity 99.8%,CI 99.7% to 99.8%). The positive and negative predictive values were 64.2% and 99.9%. Sensitivity (86.7%) and the positive predictive value (68.4%) increased only slightly when patients with single seizures were included. CONCLUSIONS: A diagnostic algorithm including EEG and selected treatment schedules is only moderately sensitive for the detection of epilepsy and seizures. These findings apply only to the Northern Italian scenario.