Stress-related gene expression changes in rainbow trout hepatocytes exposed to various municipal wastewater treatment influents and effluents.

The present study sought to examine the performance of six different wastewater treatment processes from 12 wastewater treatment plants using a toxicogenomic approach in rainbow trout hepatocytes. Freshly prepared rainbow trout hepatocytes were exposed to increasing concentrations of influent (untreated wastewaters) and effluent (C(18)) extracts for 48 h at 15 °C. A test battery of eight genes was selected to track changes in xenobiotic biotransformation, estrogenicity, heavy metal detoxification, and oxidative stress. The wastewaters were processed by six different treatment systems: facultative and aerated lagoons, activated sludge, biological aerated filter, biological nutrient removal, chemically assisted primary treated, and trickling filter/solids contact. Based on the chemical characteristics of the effluents, the treatment plants were generally effective in removing total suspended solids and chemical oxygen demand, but less so for ammonia and alkalinity. The 12 influents differed markedly with each other, which makes the comparison among treatment processes difficult. For the influents, both population size and flow rate influenced the increase in the following mRNA levels in exposed hepatocytes: metallothionein (MT), cytochrome P4503A4 (CYP3A4), and vitellogenin (VTG). Gene expression of glutathione S-transferase (GST) and the estrogen receptor (ER), were influenced only by population size in exposed cells to the influent extracts. The remaining genes-superoxide dismutase (SOD) and multidrug resistance transporter (MDR)-were not influenced by either population size or flow rate in exposed cells. It is noteworthy that the changes in MT, ER, and VTG in cells exposed to the effluents were significantly affected by the influents across the 12 cities examined. However, SOD, CYP1A1, CYP3A4, GST, and MDR gene expression were the least influenced by the incoming influents. The data also suggest that wastewater treatments involving biological or aeration processes had the best performance. We found that the effects of municipal effluents on gene expression depended on the population size, the initial properties of the incoming influent, and the wastewater treatment method applied. Considering that the long-term goals of wastewater treatment is to produce clean effluents for the aquatic biota and independent of the incoming influent, more research is needed in developing treatment processes to better protect aquatic life from anthropogenic contamination.

In vitro immunotoxicity of environmentally representative antibiotics to the freshwater mussel Elliptio complanata.

The separate and combined in vitro toxic effects of antibiotics (ciprofloxacin, erythromycin, novobiocin, oxytetracycline, sulfamethazole and trimethoprim) commonly found in urban wastewater effluents were assessed on the immune parameters of Elliptio complanata at environmentally relevant concentrations. The observed responses were then compared to those produced by the physicochemical-treated wastewater effluent of a major city before and after the removal of microorganisms. Most of the selected antibiotics, separately and as mixture, induced changes in immune responses. The removal of microorganisms and fine particles from the effluent increased or decreased the resulting immunotoxic effects, depending of the observed parameter. The immunotoxic effects of erythromycin, sulfamethoxazole and trimethoprim were closely associated to the antibiotic mixture and the filtered effluent. In conclusion, the data revealed that the removal of fine particles and microorganisms from municipal effluents can alter the toxic nature of the effluent that is closely associated with the cumulative effects of antibiotics.

Toxicity of silver nanoparticles to rainbow trout: a toxicogenomic approach.

Silver (Ag) nanoparticles are used as antimicrobial adjuvant in various products such as clothes and medical devices where the release of nano-Ag could contaminate the environment and harm wildlife. The purpose of this study was to examine the sublethal effects of nano-Ag and dissolved Ag on Oncorhynchus mykiss rainbow trout. Hepatic Ag contents and changes in gene expression were monitored to provide insights on bioavailability and mode of action of both forms of silver. Fish were exposed to increasing concentrations (0.06, 0.6 and 6 µg L(-1)) of nano-Ag (20 nm) and silver nitrate (AgNO(3)) for 96 h at 15°C. A gene expression analysis was performed in the liver using a DNA microarray of 207 stress-related genes followed by a quantitative polymerase chain reaction on a selection of genes for validation. The biochemical markers consisted of the determination of labile zinc, metallothioneins, DNA strand breaks, lipid peroxidation (LPO) and vitellogenin-like proteins. The analysis of total Ag in the aquarium water revealed that nano-Ag was mostly aggregated, with 1% of the total Ag being dissolved. Nevertheless, hepatic Ag content was significantly increased in exposed fish. Indeed, dissolved Ag was significantly more bioavailable than nano-Ag only at the highest concentration with 38 ± 10 and 11 ± 3 ng Ag mg(-1) proteins for dissolved and nano-Ag respectively. Exposure to both forms of Ag led to significant changes in gene expression for 13% of tested gene targets. About 12% of genes responded specifically to nano-Ag, while 10% of total gene targets responded specifically to dissolved Ag. The levels of vitellogenin-like proteins and DNA strand breaks were significantly reduced by both forms of Ag, but DNA break levels were lower with nano-Ag and could not be explained by the presence of ionic Ag. Labile zinc and the oxidized fraction of metallothioneins were increased by both forms of Ag, but LPO was significantly induced by nano-Ag only. A discriminant function analysis revealed that the responses obtained by biochemical markers and a selection of ten target genes were able to discriminate completely (100%) the effects of both forms of Ag. Exposure to nano-Ag involved genes in inflammation and dissolved Ag involved oxidative stress and protein stability. Hence, the toxicity of Ag will differ depending on the presence of Ag nanoparticles and aggregates.

Neurochemical effects of benzodiazepine and morphine on freshwater mussels.

The purpose of this study was to examine the neurochemical effects of morphine, diazepam, a common benzodiazepine, and an effluent concentrate on the endemic freshwater mussel Elliptio complanata. Mussels were exposed to the drugs and to the solid-phase concentrate of a municipal effluent and left to stand at 15 degrees C for 48h. Neurochemical effects were determined by monitoring changes in dopamine, serotonin, glutamate and gamma-aminobutyric acid (GABA) levels in the visceral mass (containing the nerve ganglia) of mussels. The activities of acetylcholinesterase (AChE), dopamine and serotonin-dependent adenylyl cyclase (ADC) were also determined in the mussels. Oxidative stress was determined by tracking changes in lipid peroxidation (LPO) in the mitochondrial and post-mitochondrial fractions. The results revealed that the drugs and the effluent extract were biologically active in mussels. Morphine reduced serotonin and increased dopamine in mussel tissues while reducing AChE activity and increasing GABA levels. This suggests the induction of a relaxation state in mussels. Diazepam also reduced serotonin levels but produced no change in dopamine levels. However, dopamine-sensitive ADC activity was readily activated, indicating the potential effect on opiate signaling. Diazepam increased glutamate levels slightly, but AChE remained stable. The increase in both dopamine ADC activity and glutamate concentrations was also associated with greater oxidative stress on the mitochondrial and post-mitochondrial fractions in cells. A comparison of the global response pattern of these drugs with those of the effluent extract revealed only a relative proximity to morphine. In conclusion, the data warrant more studies on the analysis of opiates and benzodiazepines in municipal effluents to better address the potential environmental hazard of these neuroactive drug classes to aquatic organisms.

Phenotypic plasticity and the evolution of trade-offs: the quantitative genetics of resource allocation in the wing dimorphic cricket, Gryllus firmus.

In the wing dimorphic sand cricket, Gryllus firmus, there is a pronounced trade-off between flight capability and fecundity. This trade-off is found both between morphs and within the macropterous morph, in which fecundity is negatively correlated with the mass of the principle flight muscles, the dorso-longitudinal muscles (DLM). In this paper, we examine how this trade-off is affected by a reduction in food and its genetic basis. We find that the relative fitness of the two wing morphs is not changed although both fecundity and DLM mass are decreased. A quantitative genetic analysis shows that the trade-off function is genetically variable but that most of the variation occurs in the intercept rather than the slope of the function. Analysis further indicates a very high genetic correlation between environments (food ration) supporting the hypothesis of a strong functional constraint between reproduction and flight capability.

Prophylaxis of radiation-associated mucositis in conventionally treated patients with head and neck cancer: a double-blind, phase III, randomized, controlled trial evaluating the clinical efficacy of an antimicrobial lozenge using a validated mucositis scoring system.

PURPOSE: Mucositis occurs in almost all patients treated with radiotherapy for head and neck cancer. The aim of this multicenter, double-blind, prospective, randomized trial was to evaluate the clinical efficacy of an economically viable antimicrobial lozenge (bacitracin, clotrimazole, and gentamicin [BcoG]) in the alleviation of radiation-induced mucositis in patients with head and neck cancer. PATIENTS AND METHODS: One hundred thirty-seven eligible patients were randomized to treatment with either antimicrobial lozenge (69 patients) or placebo lozenge (68 patients). The primary end point of the study was the time to development of severe mucositis from the start of radiotherapy. Secondary end points included severity and duration of mucositis, pain measurement, radiation therapy interruption, and quality of life. Mucositis was scored using a validated mucositis scoring system. RESULTS: Toxicity profiles were similar between the two arms of the study. The median time to development of severe mucositis from the start of radiotherapy was 3.61 weeks on BCoG and 3.96 weeks on placebo (P =.61). There were no statistically significant differences between the arms in the extent of severe mucositis as measured by physician, in oral toxicities as recorded by patients, or in radiotherapy delays. CONCLUSION: This study was conducted on the basis of a pilot study that demonstrated the BCoG lozenge to be tolerable and microbiologically efficacious. A validated mucositis scoring system was used. However, in this group of patients treated with conventional radiotherapy, the lozenge did not impact significantly on the severity of mucositis. Whether such a lozenge would be beneficial in treatment situations where rate of severe mucositis is higher (ie, in patients treated with unconventional fractionation or with concomitant chemotherapy) is unknown.

Foundation for change built on four cornerstones.

Clear purpose and balanced goals, sponsorship and leadership, user-friendly processes, and commitment and capability are four key elements necessary to bring about effective change in organizations. The ability to change effectively and efficiently is an absolute necessity for health care organizations in today's marketplace. To best build employee support for change, leaders must use a combination of education, persuasion, rewards, recognition, participation, and conversation.

Learn how to aid organizational change.

Key points. Change agents are members of the organization through whom the organization figures out how to improve itself. Change agents can provide the focused attention that is required to develop "organizational horsepower." Change agents should be selected from the very best people in the organization. Change agents can come from all areas and all levels of the organization.

Delivery of trifluridine to human cornea and aqueous using collagen shields.

PURPOSE: We investigated the ability of collagen shields to deliver trifluridine (trifluorothymidine [TFT]) to human cornea and aqueous humor. METHODS: 24-hour porcine collagen shields were soaked in commercially prepared TFT (Viroptic). Patients undergoing penetrating keratoplasty wore a pre-soaked collagen shield for at least 30 minutes preoperatively. Control patients received drops of TFT only. Cornea and aqueous samples were obtained. TFT levels were measured using high performance liquid chromatography. RESULTS: Among the four patients with intact corneal epithelium, TFT was detected in only one patient (0.13 microgram/g in the aqueous). In seven patients with poor epithelium, corneal levels ranged from 0 to 635.34 micrograms/g, and aqueous levels ranged from 0.06 to 11.17 micrograms/g. CONCLUSIONS: Collagen shields do not enhance delivery of TFT to corneas with intact epithelium. In corneas with poor epithelium, drug penetration was higher but variable. The role of collagen shields as a drug delivery system for the treatment of herpes simplex keratitis remains to be determined.

[Prevention of second primary cancer with vitamin supplementation in patients treated for head and neck cancers]. / Prévention des seconds cancers primaires par supplémentation vitaminique chez les patients traités pour un cancer ORL.

Second primary cancers often occur in head and neck cancer patients successfully treated by radiation therapy. Experimental and epidemiological data suggest that these second primaries might be prevented by antioxidant vitamins, in particular beta-carotene and alpha-tocopherol. A randomized double-blind clinical trial is being conducted in Canada to determine whether vitamin supplementation with beta-carotene (30 mg/d) and alpha-tocopherol (400 IU/d) reduces the incidence of second primaries in head and neck cancer patients treated by radiation therapy.

[Incidence and risk factors of second primary cancers in patients treated for primary pharyngeal cancer]. / Incidence et facteurs de risque de seconds cancers primaires chez les patients traités pour un premier cancer du pharynx.

About 13% of patients treated for a pharyngeal cancer suffer from a second primary cancer. Excessive consumptions of tobacco and/or alcohol are recognized as risk factors of second primary cancers in these patients. Epidemiologic studies suggest that antioxidant vitamins could have a protective effect on the occurrence of second primary cancers; however, this hypothesis should be confirmed by randomized clinical trials. A better knowledge of the risk factors of second primary cancers in patients with a pharyngeal cancer could help reducing the occurrence of second primary cancers and improving the follow-up of these patients.

Impact of magnetic resonance imaging and computed tomography on the staging of laryngeal cancer.

This retrospective study quantitatively assessed the effects of magnetic resonance imaging (MRI) and computed tomography (CT) on the staging of laryngeal cancer. A blind comparison between CT and MRI was made in a group of previously untreated patients with squamous cell carcinomas of the larynx. From June 1992 to November 1993, 29 patients were eligible for study. Of these, 14 patients (48%) had supraglottic lesions, 11 patients (40%) had glottic lesions and 4 patients (14%) had both. No subglottic lesions were seen. The data suggest that clinical staging of laryngeal tumors is inadequate. MRI proved superior to CT for staging tumors, especially those confined to the supraglottis. Nevertheless, clinically staged T1 or T2 lesions could be adequately assessed by CT alone. Findings also indicate that MRI should be reserved for T3 or T4 clinically staged lesions. Furthermore, most nodal disease can be staged by CT.

Comparison of anthropometric measures of men with HIV: asymptomatic, symptomatic, and AIDS.

OBJECTIVE: Anthropometric measures were performed to determine differences in estimated fat mass, lean body mass, and body weight among three groups of men infected with human immunodeficiency virus (HIV). DESIGN: This study was cross-sectional. SETTING: Local centers of community services and support groups for persons infected with HIV in the province of Quebec, Canada. SUBJECTS: Thirty-seven HIV-positive men were recruited; 11 were asymptomatic (T helper cells [CD4+ count] > 400 cells/mm3), 8 were symptomatic (CD4+ < 400 cells/mm3), and 17 were clinically stable but met the criteria of the Centers for Disease Control and Prevention for acquired immunodeficiency syndrome (AIDS). MAIN OUTCOME MEASURES: Self-reported usual weight, actual weight, body mass index, midarm circumference, and triceps and subscapular skinfolds were recorded. From those we derived the percentage of body fat, the midarm muscle, and fat areas. Daily energy and protein intakes were determined from a 7-day food record. Clinical signs and symptoms were assessed by a structured questionnaire. STATISTICAL ANALYSES PERFORMED: For statistical comparisons, analysis of variance was used, with P < .05 being significant. RESULTS: We found a trend toward a decrease in body weight and in the fat mass indicators as the disease progressed. Lower energy intakes were observed among symptomatic and AIDS groups. The number of nutrition-related clinical signs and symptoms experienced by each individual correlated with the magnitude of weight loss (P < .0004, r = -.69). APPLICATIONS: The findings suggest that anthropometric measures can be used in routine clinical practice to assess changes in body weight and in estimated fat mass among men infected with HIV. Symptoms and energy intakes should be assessed to identify subjects at high risk of greater weight loss.

Epidemiological evidence of an interaction between calcium and sodium intake impacting on blood pressure. A Montréal study.

Nutritional calcium and sodium are considered to be important regulators of blood pressure. This study was performed on 182 randomly selected Canadians from Montréal to test the relative contribution of these ions to systolic and diastolic blood pressure, as well as their interaction with other demographic indices. Multiple analysis of the total study population revealed that 28% (P less than .001) of systolic blood pressure was predicted by gender sodium, and calcium interaction (P = .003), weight, and the additive effect of age and weight. The same characteristics contributed to 37% (P less than .001) of diastolic blood pressure with an additional contribution of alcohol intake. Analysis by terciles of sodium and calcium intake indicated that the positive effect of sodium on blood pressure occurred only in subjects given a low calcium diet, whereas blood pressure was lowest in the tercile of both high calcium and sodium intake. The impact of the sodium and calcium interaction on blood pressure represented as much as a 10 mm Hg decrement of systolic blood pressure with 400 mg calcium/1000 kcal intake at the highest level of sodium consumption and a 6 mm Hg decrease for diastolic blood pressure. In subjects without a family history of hypertension, the same indices contributed up to 53% of systolic and 55% of diastolic blood pressure with a synergetic effect of sodium and calcium, indicating that blood pressure was lowest in subjects given a high calcium and sodium diet. For subjects with a family history of hypertension, there was no significant impact of sodium, whereas calcium intake contributed negatively to both systolic and diastolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions among calcium, sodium, and alcohol intake as determinants of blood pressure.

It has been reported that calcium intake may effectively modulate the expression of hypertension affected by sodium. The present study extends our previous analysis of this calcium-sodium interaction, additionally demonstrating that calcium, sodium, and alcohol intake further contribute to both systolic and diastolic blood pressures in normotensive subjects. Calcium intake was related to lower blood pressure over all ranges of sodium and alcohol intake, and alcohol intake contributed positively and significantly to both systolic and diastolic blood pressures. However, sodium was associated with increased blood pressure only at low calcium intake, particularly in subjects who consumed large amounts of alcohol. This study points to a significant interaction among sodium, calcium, and alcohol intake as determinants of blood pressure, which, together with gender and weight, contribute to 31% of systolic blood pressure and with the addition of age to 36% of the variance in diastolic blood pressure.