Replicated evidence on the construct validity of the SCAG (Sandoz Clinical Assessment-Geriatric) scale

Factor analysis procedures, applied to a data bank of 1165 senile patients from 21 double-blind studies, yielded 5 factors: cognitive dysfunction (4 items), interpersonal relationships (4 items), apathy (4 items), affect (3 items) and somatic function (3 items). A retrospective review of the 1165 case histories revealed that patients fell into three distinct diagnostic classes: (a) patients whose symptoms of dementia were likely associated with multiple infarcts; (b) patients with other medical disorders such as metabolic imbalances, pulmonary diseases, etc. which may have induced dementia-like symptoms; and (c) primary degenerative dementia for patients with no evidence of other intervening causes. Factor analysis applied independently to the SCAG data of each of the three groups produced similar factor constructs, thereby suggesting that results reported with this instrument are valid across different geriatric diagnostic categories.     

Separation of Simulants of Biological Warfare Agents from Blood by a Miniaturized Dielectrophoresis Device

Separation of simulants of biological warfare agents from blood using dielectrophoresis (DEP) was demonstrated in a miniaturized DEP device. The device was fabricated by laminating five different layers (all 40 mm×40 mm) including a polycarbonate substrate, a pressure sensitive acrylic adhesive (PSA) layer, a patterned polyimide layer with a flip-chip bonded dielectrophoresis chip (DEP chip), a PSA layer with microfluidic channel, and a glass cover plate. The DEP chip consisted of repetitive interdigitated electrodes with characteristic dimension of 50 m. This device was employed to separate different simulants of biological warfare agents (BWA), namely Bacillus cereus (B. cereus), Escherichia coli (E. coli) and Listeria monocytogenes (L. monocytogenes), from blood, individually or simultaneously. PCR amplification, which was inhibited by blood components in pre-separation samples, successfully revealed bands in post-separation samples containing single or multiple BWA. Up to 97% efficiency of separation was achieved as demonstrated by culturing post-separation E. coli cells. The DEP device described here can potentially be used to reduce sample complexity for detection of infectious disease pathogens and biological warfare agents.     

Intraindividual reproducibility of nasal allergic responses to diesel exhaust particles indicates a susceptible phenotype

Previous research indicates that diesel exhaust particles (DEP) can augment allergen- driven allergic responses. In vivo nasal challenge offers a practical method to characterize variation in response to pulmonary toxicants and immunogens. We investigated the reproducibility of responses to determine whether susceptibility to DEP's adjuvant effects is intrinsic or extrinsic. Eighteen nonsmoking rhinitic volunteers with positive skin tests to ragweed were randomly assigned to allergen/placebo or allergen + DEP nasal challenge; after 30 days, the other "arm" was completed. We replicated the procedure 30 days later. Nasal washes were performed after challenge, and allergen-specific IgE and cytokines were measured by ELISA. Repeated challenge with allergen+DEP, but not allergen/placebo, produced reproducible responses for IgE, IL-4, and INF-gamma. DEPs ability to enhance allergic responses was highly reproducible within individuals and was independent from response to allergen, suggesting that susceptibility to DEPs adjuvant effects is an intrinsic trait that can be quantified using combined allergen + DEP challenges.     

Organic extract of diesel exhaust particles stimulates expression of Ia and costimulatory molecules associated with antigen presentation in rat peripheral blood monocytes but not in alveolar macrophages

We hypothesized that diesel exhaust particles (DEP) induce the activation of antigen-presenting cells (APC) in lung. The present study was designed to clarify the following about DEP: (1) whether it affects the expression of Ia and B7 molecules in alveolar macrophages (AM) as a mature cell or in peripheral blood monocytes (PBM) as an immature cell, (2) if it affects the antigen-presenting (AP) activity of PBM, (3) what component of DEP is responsible for the effects, and (4) whether the effect of DEP is related to oxidative stress. DEP was extracted with methylene chloride. Cells were exposed to whole DEP, organic extract, or residual particles for 24 h. Cell-surface molecules were measured by flow cytometry. AP activity was assessed by antigen-specific T cell proliferation. Whole DEP or organic extract significantly increased the expression of Ia and B7 molecules on PBM but not on AM. No significant effect of residual particles was observed. A low concentration of organic extract also increased the AP activity of PBM. When the induction of an antioxidative enzyme was assessed, heme oxygenase-1 protein was found to be significantly increased by exposure to whole DEP, and the organic extract was more effective than the residual particles. Furthermore, the organic extract-induced expression of Ia antigen on PBM was reduced by the addition of an antioxidative agent. These results suggest that DEP may act on immature APC and enhance their AP activity and that the action contributing to oxidative stress may be mediated by organic compounds of DEP.     

Isolation and characterization of RNA of Entamoeba histolytica

RNAs were isolated from Entamoeba histolytica with a high salt sodium dodecylsulfate-diethylpyrocarbonate technique. Majority species of 25 S, 17 S and 4 S RNAs were detected after sucrose gradient centrifugation. An additional 5 S RNA was detected by polyacrylamide gel electrophoresis. The molecular weights of these RNAs as determined by completely denaturing polyacrylamide gel electrophoresis were 1.31 X 10(6) (25 S), 0.803 X 10(6) (17 S), 4.0 X 10(4) (5 S) and 2.5 X 10(4) (4 S). The 25 S RNA was labile and dissociated under mild denaturing conditions (between 37 degrees C and 55 degrees C) into 17 S and 16 S RNAs with molecular weights of 0.700 X 10(6) and 0.614 X 10(6), respectively; under completely denaturing conditions an additional 5.8 S RNA with a molecular weight of 4.8 X 10(4) was detected. Evidence is presented which suggests that the lability of the 25 S RNA is the result of an in vivo cleavage rather than one which is generated during RNA isolation.     

Lack of transient receptor potential melastatin 8 activation by phthalate esters that enhance contact hypersensitivity in mice

We studied the involvement of sensory neurons in skin sensitization to allergens using a mouse model in which the T-helper type 2 response is essential. Skin sensitization to fluorescein isothiocyanate (FITC) has been shown to be enhanced by several phthalate esters, including dibutyl phthalate (DBP). For different types of phthalate esters, we found a correlation between the ability of transient receptor potential (TRP) A1 activation and that of enhancing skin sensitization. A TRPA1-specific antagonist, HC-030031, was shown to suppress skin sensitization in the presence of DBP. However, since phthalate esters also activate TRPV1, phthalate esters could activate other types of TRP channels non-selectively. Furthermore, sensitization to FITC is also enhanced by menthol, which activates TRPA1 and TRPM8. Here we established an in vitro system for measuring TRPM8 activation. The selectivity for TRPM8 was established by the fact that two TRPM8 agonists (menthol and icilin) induced calcium mobilization, whereas agonists of TRPA1 and TRPV1 did not. We demonstrated that phthalate esters do not activate TRPM8. TRPA1-antagonist HC-030031 did not inhibit TRPM8 activation induced by menthol or icilin. These results show that phthalate esters activate TRPA1 and TRPV1 with selectivity. TRPM8 activation is not likely to be involved in the sensitization to FITC.     

Mechanistic link between diesel exhaust particles and respiratory reflexes

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Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis

Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO₂) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO₂ on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO₂ and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO₂ induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO₂ and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO₂, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP + CeO₂ were significantly larger than CeO₂ or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP + CeO₂ reflects the combination of DEP-exposure plus CeO₂-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO₂ induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO₂ in the combined exposure. Using CeO₂ as diesel fuel catalyst may cause health concerns.     

Physical activity and cardiovascular risk factors in Spanish children aged 11-13 years

Introduction and objectives

The prevalence of childhood obesity has increased in recent decades. The aim was to determine whether a 3-month intervention on daily physical activity at school could affect body weight and cardiovascular risk factors associated with childhood obesity.

Methods

A total of 137 children (12[1] years old) volunteered to participate in an observational cross-sectional study. Children were allowed to join one of the following groups: a) sedentary group (2 h/week of physical education at school); b) active group (2 h/week of physical education at school plus 3 h/week extra physical activity), and c) sports group (2 h/week of physical education at school plus 5 h/week extra physical activity). Anthropometric characteristics, blood pressure, physical condition (estimated by the Course-Navette test), and biochemical parameters related with cardiovascular risk factors were determined.

Results

Body weight, body mass index, waist circumference, sum of skinfold thickness, body fat percentage, and fat mass index of children were decreased with high physical activity level, whereas body water content significantly increased with activity. Parameters related with cardiovascular risk —triglycerides, insulin, systolic blood pressure, and homeostatic model assessment index— presented lower values in the sports group. Maximal oxygen uptake and maximum heart rate (Course Navette test) progressively increased with activity. Children participating in a total of 7 h/week of physical activity presented significantly lower odds ratio of having high levels of the following cardiovascular risk factors: waist circumference, fat mass index, and homeostatic model assessment index.

Conclusions

Physical activity is important for metabolic health in children. Children with higher levels of physical activity presented better anthropometric and biochemical profiles.Full English text available from:www.revespcardiol.org     

Phthalate-induced oxidative stress and association with asthma-related airway inflammation in adolescents

Background

In Belgium, around 8.5% of the children have asthmatic symptoms. Increased asthma risk in children has been reported in relation to exposure to phthalate plasticizers but the underlying mechanisms are largely unknown.