Pulmonary Inflammation and Cell Death in Mice After Acute Exposure to Air Particulate Matter From an Industrial Region of Buenos Aires

Epidemiological studies have shown that air particulate matter (PM) can increase respiratory morbidity and mortality being the lungs the main target organ to PM body entrance. Even more, several in vivo and in vitro studies have shown that air PM has a wide toxicity spectra depending among other parameters, on its size, morphology, and chemical composition. The Reconquista River is the second most polluted river from Buenos Aires, and people living around its basin are constantly exposed to its contaminated water, soil and air. However, the air PM from the Reconquista River (RR-PMa) has not been characterized, and its biological impact on lung has yet not been assessed. Therefore, the present investigation was undertaken to study (1) RR-PMa morphochemical characteristic and (2) RR-PMa lung acute effects after intranasal instillation exposure through the analysis of three end points: oxidative stress, inflammation, and apoptosis. A single acute exposure of RR-PMa (1 mg/kg body weight) after 24 h caused significant (p < 0.05) enrichment in bronchoalveolar total cell number and polymorphonuclear (PNM) fraction, superoxide anion generation, production of pro-inflammatory cytokines TNF-α and IL-6, and induction of apoptosis. It was also observed that in lung homogenates, none of the antioxidant enzymes assayed showed differences between exposed RR-PMa and control mice. These data demonstrate that air PM from the Reconquista River induce lung oxidative stress, inflammation, and cell death therefore represents a potential hazard to human health.     

Efficacy of Single and Combined Antibiotic Treatments of Anthrax in Rabbits

Respiratory anthrax is a fatal disease in the absence of early treatment with antibiotics. Rabbits are highly susceptible to infection with Bacillus anthracis spores by intranasal instillation, succumbing within 2 to 4 days postinfection. This study aims to test the efficiency of antibiotic therapy to treat systemic anthrax in this relevant animal model. Delaying the initiation of antibiotic administration to more than 24 h postinfection resulted in animals with systemic anthrax in various degrees of bacteremia and toxemia. As the onset of symptoms in humans was reported to start on days 1 to 7 postexposure, delaying the initiation of treatment by 24 to 48 h (time frame for mass distribution of antibiotics) may result in sick populations. We evaluated the efficacy of antibiotic administration as a function of bacteremia levels at the time of treatment initiation. Here we compare the efficacy of treatment with clarithromycin, amoxicillin-clavulanic acid (Augmentin), imipenem, vancomycin, rifampin, and linezolid to the previously reported efficacy of doxycycline and ciprofloxacin. We demonstrate that treatment with amoxicillin-clavulanic acid, imipenem, vancomycin, and linezolid were as effective as doxycycline and ciprofloxacin, curing rabbits exhibiting bacteremia levels of up to 10⁵ CFU/ml. Clarithromycin and rifampin were shown to be effective only as a postexposure prophylactic treatment but failed to treat the systemic (bacteremic) phase of anthrax. Furthermore, we evaluate the contribution of combined treatment of clindamycin and ciprofloxacin, which demonstrated improvement in efficacy compared to ciprofloxacin alone.     

Using the concept of family strengths to enhance nursing care

This article was written to help nurses better understand the family strengths framework and encourage them to incorporate family strengths into the nursing care they give. In times of stress or crisis for families, nurses can use the conceptual framework of family strengths as a mechanism to promote strong, healthy relationships. The family strengths perspective identifies and builds on positive attributes in family functioning. Family strengths qualities are (a) commitment, (b) appreciation and affection, (c) positive communication, (d) time together, (e) a sense of spiritual well-being, and (f) the ability to cope with stress and crisis. With the family strengths approach, nurses help families define their visions and hopes for the future instead of looking at what factors contribute to family problems. Family strengths assessment can be used in nursing practice, nursing education, and everyday life.     

The DNT-EST: A predictive embryonic stem cell-based assay for developmental neurotoxicity testing in vitro

As the developing brain is exquisitely vulnerable to chemical disturbances, testing for developmental neurotoxicity of a substance is an important aspect of characterizing its tissue specific toxicity. Mouse embryonic stem cells (mESCs) can be differentiated toward a neural phenotype, and this can be used as a model for early brain development. We developed a new in vitro assay using mESCs to predict adverse effects of chemicals and other compounds on neural development – the so-called DNT-EST. After treatment of differentiating stem cells for 48 h or 72 h, at two key developmental stages endpoint for neural differentiation, viability, and proliferation were assessed. As a reference, we similarly treated undifferentiated stem cells 2 days after plating for 48 h or 72 h in parallel to the differentiating stem cells. Here, we show that chemical testing of a training set comprising nine substances (six substances of known developmental toxicity and three without specific developmental neurotoxicity) enabled a mathematical prediction model to be formulated that provided 100% predictivity and accuracy for the given substances, including in leave-one-out cross-validation. The described test method can be performed within two weeks, including data analysis, and provides a prediction of the developmental neurotoxicity potency of a substance.     

Differential contribution of Bacillus anthracis toxins to pathogenicity in two animal models

The virulence of Bacillus anthracis, the causative agent of anthrax, stems from its antiphagocytic capsule, encoded by pXO2, and the tripartite toxins encoded by pXO1. The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play major roles in pathogenicity. We tested this assumption by a systematic study of mutants with combined deletions of the pag, lef, and cya genes, encoding protective antigen (PA), lethal factor (LF), and edema factor (EF), respectively. The resulting seven mutants (single, double, and triple) were evaluated following subcutaneous (s.c.) and intranasal (i.n.) inoculation in rabbits and guinea pigs. In the rabbit model, virulence is completely dependent on the presence of PA. Any mutant bearing a pag deletion behaved like a pXO1-cured mutant, exhibiting complete loss of virulence with attenuation indices of over 2,500,000 or 1,250 in the s.c. or i.n. route of infection, respectively. In marked contrast, in guinea pigs, deletion of pag or even of all three toxin components resulted in relatively moderate attenuation, whereas the pXO1-cured bacteria showed complete attenuation. The results indicate that a pXO1-encoded factor(s), other than the toxins, has a major contribution to the virulence mechanism of B. anthracis in the guinea pig model. These unexpected toxin-dependent and toxin-independent manifestations of pathogenicity in different animal models emphasize the importance and need for a comprehensive evaluation of B. anthracis virulence in general and in particular for the design of relevant next-generation anthrax vaccines.     

Simulated clinical experience: nursing students' perceptions and the educators' role

Simulation with high-fidelity technology is an innovative and effective teaching strategy to address increasing student enrollment, faculty shortages, and limited clinical sites. This interactive learning method allows the educator to focus on desired content and teach multiple objectives. This study examines students' perceptions of a preterm labor simulated clinical experience as a method of instruction, emphasizing the importance of the educators' role in promoting positive student outcomes.     

North American Indigenous adolescent substance use

Objectives

To investigate growth in problem drinking and monthly marijuana use among North American Indigenous adolescents from the upper Midwest and Canada.

Methods

Panel data from a community-based participatory research project includes responses from 619 adolescents residing on or near 7 different reservations/reserves. All respondents were members of the same Indigenous cultural group.

Results

Rates of problem drinking and monthly marijuana use increased steadily across the adolescent years, with fastest growth occurring in early adolescence (before age 15). In general, female participants reported higher rates of substance use prior to age 15; however, male reports of use surpassed those of females in later adolescence.

Conclusions

Results of this study highlight the importance of early adolescent substance use prevention efforts and the possible utility of gender responsive programming.