Lung inflammation and lack of genotoxicity in the comet and micronucleus assays of industrial multiwalled carbon nanotubes Graphistrength(©) C100 after a 90-day nose-only inhalation exposure of rats.

BACKGROUND: Graphistrength (©) C100 multiwalled carbon nanotubes (MWCNT) provide superior electrical and mechanical properties for various applications. The evaluation of the intrinsic hazard properties of Graphistrength(©) C100 is an essential step for safe use. A general feature of multiwalled carbon nanotubes after inhalation or intratracheal exposures is the induction of an inflammatory reaction in the lungs sometimes associated with local genotoxic effects. METHODS: After investigating different parameters for the aerosol generation and performing a 5-day inhalation range finding study, male and female Wistar rats were exposed nose-only for 90 days to target concentrations of 0.05, 0.25 and 5.0 mg/m(3) air of Graphistrength (©) C100 and sacrificed 24 h and 90 days after the last exposure. Broncho-alveolar lavage fluid (BALF) was also collected and analyzed for inflammatory parameters. Twenty-four hours post-exposure, chromosomal aberrations in the bone marrow cells were evaluated by the micronucleus test and DNA damages in the lung, kidney and liver cells by both the standard and the human 8-oxoguanine DNA N-glycosylase 1 (hOGG1)-modified comet assay. All studies were performed according to the OECD test guidelines. RESULTS: An inflammatory lung reaction and the release of inflammatory factors in the BALF were observed in all rats exposed to 5.0 mg/m(3), associated with changes in the differential white blood cells counts. The slight changes in BALF parameters at 0.25 mg/m(3) recovered and signs of lung clearance of the MWCNT were observed. No pathological changes were observed on the pleura. Neither increase in the number of micronucleated polychromatic erythrocytes nor increase in percent DNA damage were observed at any concentration. CONCLUSIONS: Lung inflammation characteristic of an overload with insoluble particles was observed after a 90-day exposure to 5.0 mg/m(3) of Graphistrength (©) C100. Clear signs of clearance and recovery were observed at 0.25 mg/m(3). No genotoxicity was detected locally in lung and distally in bone marrow, liver and kidney. Therefore, Graphistrength (©) C100 appears of low concern in term of local and systemic genotoxicity and a No-Observed Adverse Effect Concentration (NOAEC) of 0.25 mg/m(3) (0.28 mg/m(3) as actual concentration) was established for the repeated-dose toxicity.

Effects of fluid resuscitation with colloids vs crystalloids on mortality in critically ill patients presenting with hypovolemic shock: the CRISTAL randomized trial.

IMPORTANCE: Evidence supporting the choice of intravenous colloid vs crystalloid solutions for management of hypovolemic shock remains unclear. OBJECTIVE: To test whether use of colloids compared with crystalloids for fluid resuscitation alters mortality in patients admitted to the intensive care unit (ICU) with hypovolemic shock. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, randomized clinical trial stratified by case mix (sepsis, trauma, or hypovolemic shock without sepsis or trauma). Therapy in the Colloids Versus Crystalloids for the Resuscitation of the Critically Ill (CRISTAL) trial was open label but outcome assessment was blinded to treatment assignment. Recruitment began in February 2003 and ended in August 2012 of 2857 sequential ICU patients treated at 57 ICUs in France, Belgium, North Africa, and Canada; follow-up ended in November 2012. INTERVENTIONS: Colloids (n = 1414; gelatins, dextrans, hydroxyethyl starches, or 4% or 20% of albumin) or crystalloids (n = 1443; isotonic or hypertonic saline or Ringer lactate solution) for all fluid interventions other than fluid maintenance throughout the ICU stay. MAIN OUTCOMES AND MEASURES: The primary outcome was death within 28 days. Secondary outcomes included 90-day mortality; and days alive and not receiving renal replacement therapy, mechanical ventilation, or vasopressor therapy. RESULTS: Within 28 days, there were 359 deaths (25.4%) in colloids group vs 390 deaths (27.0%) in crystalloids group (relative risk [RR], 0.96 [95% CI, 0.88 to 1.04]; P = .26). Within 90 days, there were 434 deaths (30.7%) in colloids group vs 493 deaths (34.2%) in crystalloids group (RR, 0.92 [95% CI, 0.86 to 0.99]; P = .03). Renal replacement therapy was used in 156 (11.0%) in colloids group vs 181 (12.5%) in crystalloids group (RR, 0.93 [95% CI, 0.83 to 1.03]; P = .19). There were more days alive without mechanical ventilation in the colloids group vs the crystalloids group by 7 days (mean: 2.1 vs 1.8 days, respectively; mean difference, 0.30 [95% CI, 0.09 to 0.48] days; P = .01) and by 28 days (mean: 14.6 vs 13.5 days; mean difference, 1.10 [95% CI, 0.14 to 2.06] days; P = .01) and alive without vasopressor therapy by 7 days (mean: 5.0 vs 4.7 days; mean difference, 0.30 [95% CI, -0.03 to 0.50] days; P = .04) and by 28 days (mean: 16.2 vs 15.2 days; mean difference, 1.04 [95% CI, -0.04 to 2.10] days; P = .03). CONCLUSIONS AND RELEVANCE: Among ICU patients with hypovolemia, the use of colloids vs crystalloids did not result in a significant difference in 28-day mortality. Although 90-day mortality was lower among patients receiving colloids, this finding should be considered exploratory and requires further study before reaching conclusions about efficacy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00318942.

Effect of in utero exposure to di-(2-ethylhexyl)phthalate: distribution in the rat fetus and testosterone production by rat fetal testis in culture.

DEHP is known to cause reproductive toxicity in rats, particularly during the neonatal period. Pregnant and brood rats were treated by gavage with 750 mg/kgb.w./day DEHP starting on GD14 within PND4. Two hours after (14)C-DEHP administration on GD15, GD18, GD21 and PND4, the radioactivity content was measured in the dams blood and in the liver, gonads and carcass of the offspring. The radioactivity concentration recovered in the fetuses was one or two order of magnitude lower than the concentration found in the dam plasma. A low proportion of radioactivity was present in fetal gonads, ca. 2%, 5% and 3.6% on GD18, GD21 and PND4, respectively. The effect on testosterone production of DEHP and its metabolites (MEHP, metabolites VI and IX) was assessed in fetal testis cultures using a dose-range which included the maximal exposure observed in vivo. None of the compounds affected testosterone production. Thus, DEHP and/or its metabolites appear to cross the placental barrier, reach the fetal gonads. In vitro, neither DEHP nor its main metabolites decreased the testosterone production.

Evaluation of anti-androgenic activity of di-(2-ethylhexyl)phthalate.

DEHP is a widely used platiciser in the manufacture of PVC-based materials. It is known to disrupt the reproductive tract development in male rats. We have performed the Hershberger assay with DEHP on an immature castrated rat model to check if DEHP antagonise the testosterone propionate androgenic effect on the accessory sex organs development. DEHP significantly decreased the BC/LA muscles, the prostate, and the seminal vesicles relative weights from 100, 200, and 400 mg/kg bw/day, respectively. DEHP increased the liver relative weight from 100 mg/kg bw/day. A study was also performed on MDA-MB453 cell line stably transfected with pMMTVneo-Luc with DEHP and its major metabolites (MEHP and metabolites VI and IX) to identify anti-androgenic activity. Neither DEHP nor MEHP antagonised DHT activity in the MDA-MB453 transfected cells. In contrast, metabolites VI and IX were anti-androgenic in vitro. DEHP appeared not to be a 5alpha-reductase inhibitor and acted in an independent mechanism from the testicular production in the young rat.

[Initiation into nursing care research, a tool for measuring the construction of nursing professional identity]. / L'initiation à la recherche en soins infirmiers, outil de construction de l'identité professionnelle infirmière.

This article presents some results stemming from university research work, in relation with nursing training and the construction of student nurses' professional identity. As a tool contributing in the process of this construction, Research in Nursing Care (RNS), the main subject of our research, is an element of the training program in nursing care. In a context of development of the profession, we tried to clarify the meaning of RNC as part of training but also in the fields where care is lavished as this is a work/study education program. The RNC object was discussed in historical, regulatory, and scientific contexts. Three hypotheses were raised and put to the test; the followed methodology was clarified some proposals followed the analysis of the various data corpus obtained and some reflection tracks were initiated for the trainers and assistants.

Comparative metabolism of methyl isobutyl carbinol and methyl isobutyl ketone in male rats.

Methyl isobutyl carbinol (MIBC) is an oxygenated solvent that is metabolized to methylisobutyl ketone (MIBK) and then to 4-hydroxymethyl-4-methyl-2-pentanone (HMP). Plasma levels of MIBC, MIBK and HMP were determined up to 12 h after a single oral 5 mmol/kg dose of MIBC or MIBK to male rats. The major material in the plasma in both cases was HMP, with similar areas-under-the-curve (AUC) and C(max) at 9 h after dosing. MIBK plasma levels and AUC were also comparable after MIBK or MIBC administration. MIBC AUC was only about 6% of the total material in the blood after MIBC, and insignificant after MIBK administration. No other metabolites were detected in the plasma under the analytical conditions used. The extent of metabolism of MIBC to MIBK, by comparing combined AUCs for MIBK and HMP, was at least 73%. The limited systemic toxicity data for MIBC are consistent with those for MIBK, which has been well studied. The metabolic equivalency of MIBC with MIBK indicates that MIBC will have a low potential for toxicity similar to that of MIBK, and reduces the need for additional animal studies.

Time- and dose-related effects of di-(2-ethylhexyl) phthalate and its main metabolites on the function of the rat fetal testis in vitro.

BACKGROUND: Endocrine-disrupting effects of phthalates are understood primarily from in utero exposures within the fetal rat testis. Nevertheless, their path of action, dose-response character, and cellular target(s) within the fetal testis are not known. OBJECTIVES: In this study we investigated the effects of di-(2-ethylhexyl) phthalate (DEHP), mono-(2-ethylhexyl) phthalate (MEHP), and several of their metabolites on the development of organo-cultured testes from rat fetus. METHODS: We removed testes from 14.5-day-old rat fetuses and cultured them for 1-3 days with or without DEHP, MEHP, and the metabolites. RESULTS: DEHP (10(-5) M) produced a proandrogenic effect after 3 days of culture, whereas MEHP disrupted testis morphology and function. Leydig cells were the first affected by MEHP, with a number of them being inappropriately located within some seminiferous tubules. Additionally, we found a time- and dose-dependent reduction of testosterone. By 48 hr, gonocyte proliferation had decreased, whereas apoptosis increased. Sertoli cell number was unaffected, although some cells appeared vacuolated, and production of anti-Müllerian hormone decreased in a time- and dose-dependent manner. The derived metabolite mono-(2-ethyl-5-hydroxyhexyl) phthalate was the only one to cause deleterious effects to the rat fetal testis in vitro. CONCLUSION: We hope that this in vitro method will facilitate the study of different phthalate esters and other endocrine disruptors for direct testicular effects.