Fraction of exhaled nitric oxide in healthy Chilean schoolchildren aged 8-15 years

BACKGROUND

The fraction of exhaled nitric oxide (FENO) measured using portable devices is increasingly used in the clinical setting to assess asthmatic children. However, there is little and variable information on the reference values obtained using these devices in healthy children from different populations.

METHODS

190 healthy non-smoker children (8-15 years old) were randomly selected from public schools participating in this study. The objective was to determine FENO reference values for healthy Chilean schoolchildren. Healthy individuals were identified by medical interview and parent questionnaire on the use of asthma medications, and current and past symptoms of asthma, rhinoconjunctivitis and eczema. FENO was measured at schools using a portable device with electrochemical sensor (NIO MINOX). Reference values of FENO were expressed as geometric mean and upper limit of the 95% reference interval (right-sided). The relationship of FENO with gender, age, height, body mass, and other factors was assessed by multiple regression, and the difference between groups was contrasted by ANOVA.

RESULTS

The FENO geometric mean was 15.4ppb with a 95% reference interval upper limit (right-sided), of 27.4ppb (90%CI 25.6-29.2). The 5th and 95th percentiles were 9.0ppb and 28.0ppb, respectively. Height was the only factor significantly associated to FENO (p=0.022). There was no significant difference in mean FENO regarding age, gender, weight, parent reported rhinoconjunctivitis and eczema.

CONCLUSION

This study suggests that FENO values higher than 27ppb are likely to be abnormal and would reflect airway inflammation in children as those in the present study.

Methodology to design a municipal solid waste generation and composition map: a case study

The municipal solid waste (MSW) management is an important task that local governments as well as private companies must take into account to protect human health, the environment and to preserve natural resources. To design an adequate MSW management plan the first step consists in defining the waste generation and composition patterns of the town. As these patterns depend on several socio-economic factors it is advisable to organize them previously. Moreover, the waste generation and composition patterns may vary around the town and over the time. Generally, the data are not homogeneous around the city as the number of inhabitants is not constant nor it is the economic activity. Therefore, if all the information is showed in thematic maps, the final waste management decisions can be made more efficiently. The main aim of this paper is to present a structured methodology that allows local authorities or private companies who deal with MSW to design its own MSW management plan depending on the available data. According to these data, this paper proposes two ways of action: a direct way when detailed data are available and an indirect way when there is a lack of data and it is necessary to take into account bibliographic data. In any case, the amount of information needed is considerable. This paper combines the planning methodology with the Geographic Information Systems to present the final results in thematic maps that make easier to interpret them. The proposed methodology is a previous useful tool to organize the MSW collection routes including the selective collection. To verify the methodology it has been successfully applied to a Spanish town.

Methodology to design a municipal solid waste generation and composition map: a case study

The municipal solid waste (MSW) management is an important task that local governments as well as private companies must take into account to protect human health, the environment and to preserve natural resources. To design an adequate MSW management plan the first step consist in defining the waste generation and composition patterns of the town. As these patterns depend on several socio-economic factors it is advisable to organize them previously. Moreover, the waste generation and composition patterns may vary around the town and over the time. Generally, the data are not homogeneous around the city as the number of inhabitants is not constant nor it is the economic activity. Therefore, if all the information is showed in thematic maps, the final waste management decisions can be made more efficiently. The main aim of this paper is to present a structured methodology that allows local authorities or private companies who deal with MSW to design its own MSW management plan depending on the available data. According to these data, this paper proposes two ways of action: a direct way when detailed data are available and an indirect way when there is a lack of data and it is necessary to take into account bibliographic data. In any case, the amount of information needed is considerable. This paper combines the planning methodology with the Geographic Information Systems to present the final results in thematic maps that make easier to interpret them. The proposed methodology is a previous useful tool to organize the MSW collection routes including the selective collection. To verify the methodology it has been successfully applied to a Spanish town.

Src, a potential target for overcoming trastuzumab resistance in HER2-positive breast carcinoma

BACKGROUND

Src is a non-receptor tyrosine kinase involved in signalling and crosstalk between growth-promoting pathways. We aim to investigate the relationship of active Src in response to trastuzumab of HER2-positive breast carcinomas.

METHODS

We selected 278 HER2-positive breast cancer patients with (n=154) and without (n=124) trastuzumab treatment. We performed immunohistochemistry on paraffin-embedded tissue microarrays of active Src and several proteins involved in the PI3K/Akt/mTOR pathway, PIK3CA mutational analysis and in vitro studies (SKBR3 and BT474 cancer cells). The results were correlated with clinicopathological factors and patients' outcome.

RESULTS

Increased pSrc-Y416 was demonstrated in trastuzumab-resistant cells and in 37.8% of tumours that correlated positively with tumour size, necrosis, mitosis, metastasis to the central nervous system, p53 overexpression and MAPK activation but inversely with EGFR and p27. Univariate analyses showed an association of increased active Src with shorter survival in patients at early stage with HER2/hormone receptor-negative tumours treated with trastuzumab.

CONCLUSIONS

Src activation participates in trastuzumab mechanisms of resistance and indicates poor prognosis, mainly in HER2/hormone receptor-negative breast cancer. Therefore, blocking this axis may be beneficial in those patients.

Adsorption of probe molecules in pillared interlayered clays: experiment and computer simulation

In this paper we investigate the adsorption of various probe molecules in order to characterize the porous structure of a series of pillared interlayered clays (PILC). To that aim, volumetric and microcalorimetric adsorption experiments were performed on various Zr PILC samples using nitrogen, toluene, and mesitylene as probe molecules. For one of the samples, neutron scattering experiments were also performed using toluene as adsorbate. Various structural models are proposed and tested by means of a comprehensive computer simulation study, using both geometric and percolation analysis in combination with Grand Canonical Monte Carlo simulations in order to model the volumetric and microcalorimetric isotherms. On the basis of this analysis, we propose a series of structural models that aim at accounting for the adsorption experimental behavior, and make possible a microscopic interpretation of the role played by the different interactions and steric effects in the adsorption processes in these rather complex disordered microporous systems.

Efficacy of erlotinib in patients with relapsed gliobastoma multiforme who expressed EGFRVIII and PTEN determined by immunohistochemistry

Epidermal growth factor receptor gene (EGFR) alteration is a common feature in most of glioblastoma multiforme (GBM). Robust response of anti-EGFR treatments has been mostly associated with the EGFR deletion mutant variant III (EGFRvIII) and expression of PTEN. We have performed a prospective trial in order to confirm the efficacy of erlotinib treatment in patients with relapsed GBM who expressed EGFRvIII and PTEN. All patients included in the trial were required to be PTEN (+++), EGFR (+++) and EGFRvIII (+++) positives by immunohistochemistry. This new phase II trial enrolled 40 patients and was design to be stopped in case of fewer than two responses in the first 13 patients. Patient eligibility included histopathology criteria, radiological progression, more than 18 years old, Karnofsky performed status, KPS > 50, and adequate bone marrow and organ function. There was no limit to the number of prior treatments for relapses. No enzyme-inducing antiepileptic drugs were allowed. The primary endpoints were response and progression-free survival at 6 months (PFS6). Thirteen patients (6 men, 7 women) with recurrent GBM received erlotinib 150 mg/day. Median age was 53 years, median KPS was 80, and median prior treatments for relapses were 2. There was one partial response and three stable diseases (one at 18 months). PFS at 6 months was 20 %. Dose reduction for toxicity was not needed in any patient. Dermatitis was the main treatment-related toxicity, grade 1 in 8 patients and grade 2 in 5 patients. No grade 3 toxicity was observed. Median survival was 7 months (95 % IC 1.41–4.7). As conclusion, monotherapy with erlotinib in GBM relapses patients with high protein expression for PTEN (+++), EGFR (+++), and EGFRvlII (+++) showed low toxicity but minimal efficacy and the trial stopped.

What explains variation in the impacts of exotic plant invasions on the nitrogen cycle? A meta-analysis

Exotic plant invasions can notably alter the nitrogen (N) cycle of ecosystems. However, there is large variation in the magnitude and direction of their impact that remains unexplained. We present a structured meta-analysis of 100 papers, covering 113 invasive plant species with 345 cases of invasion across the globe and reporting impacts on N cycle-related metrics. We aim to explain heterogeneity of impacts by considering methodological aspects, properties of the invaded site and phylogenetic and functional characteristics of the invaders and the natives. Overall, plant invasions increased N pools and accelerated fluxes, even when excluding N-fixing invaders. The impact on N pools depended mainly on functional differences and was greater when the invasive plants and the natives differed in N-fixation ability, plant height and plant/leaf habit. Furthermore, the impact on N fluxes was related mainly to climate, being greater under warm and moist conditions. Our findings show that more functionally distant invaders occurring in mild climates are causing the strongest alterations to the N cycle.

Insecticidal activity of individual and mixed monoterpenoids of geranium essential oil against Pediculus humanus capitis (Phthiraptera: Pediculidae)

The major components of geranium (Geranium maculatum L.) oil and their mixtures were tested against female Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae). Chemical analysis by gas chromatography coupled to mass spectrometry revealed four major constituents: citronellol (38%), geraniol (16%), citronellyl formate (10.4%), and linalool (6.45%) (concentration expressed as percentage of total). Topical application demonstrated that the most potent component was citronellol and geraniol, with LD50 values 9.7 and 12.7 microg/insect, respectively. Linalool and Citronellyl formate were less toxic with LD50 values 24.7 and 38.5 microg/insect, respectively. Toxicity of these four major constituents in the same proportion as the natural oil, was greater than whole oil and each individual component. Removal of any four constituents produced a decreased in effectiveness. The absence of citronellol caused the greatest decrease in toxicity (DL50 from 2.2 to 10.9 microg/insect), leading us to conclude that this constituent is the major contributor to oil toxicity. The knowledge of the role of each constituent in the toxicity of the whole oil gives the possibility to create artificial blends of different constituents for the development of more effective control agents.

Environmental assessment of alternative municipal solid waste management strategies. A Spanish case study

The aim of this study is to compare, from an environmental point of view, different alternatives for the management of municipal solid waste generated in the town of Castellón de la Plana (Spain). This town currently produces 207 ton of waste per day and the waste management system employed today involves the collection of paper/cardboard, glass and light packaging from materials banks and of rest waste at street-side containers. The proposed alternative scenarios were based on a combination of the following elements: selective collection targets to be accomplished by the year 2015 as specified in the Spanish National Waste Plan (assuming they are reached to an extent of 50% and 100%), different collection models implemented nationally, and diverse treatments of both the separated biodegradable fraction and the rest waste to be disposed of on landfills. This resulted in 24 scenarios, whose environmental behaviour was studied by applying the life cycle assessment methodology. In accordance with the ISO 14040-44 (2006) standard, an inventory model was developed for the following stages of the waste management life cycle: pre-collection (bags and containers), collection, transport, pre-treatment (waste separation) and treatment/disposal (recycling, composting, biogasification+composting, landfill with/without energy recovery). Environmental indicators were obtained for different impact categories, which made it possible to identify the key variables in the waste management system and the scenario that offers the best environmental behaviour. Finally, a sensitivity analysis was used to test some of the assumptions made in the initial life cycle inventory model.

Outbreak of 2009 pandemic influenza A(H1N1), Los Lagos, Chile, April-June 2009

On 17 May 2009, the first two cases of 2009 pandemic influenza A(H1N1) were confirmed in the Metropolitan region (Santiago, Chile). On 6 June 2009, Chile reported 500 confirmed cases, seven severe and two fatal. Because six of the severe cases and the two deaths occurred in the region of Los Lagos in southern Chile, a retrospective study was conducted using data on emergency room visits as well as laboratory viral surveillance, during the period from 1 April to 31 May, in order to establish the date of the beginning of the outbreak. From 1 to 27 June, data were collected in real time, to establish the real magnitude of the outbreak, describe its transmission, clinical severity and secondary attack rates. Confirmed cases, their household contacts and healthcare workers were interviewed. This analysis showed that the outbreak in Los Lagos started on 28 April. By 27 June, a total of 14.559 clinical cases were identified, affecting mostly 5-19 year-olds. The effective reproduction number during the initial phase (20 days) was 1.8 (1.6-2.0). Of the 190 confirmed cases with severe acute respiratory infection, 71 (37.4%) presented a risk condition or underlying illness.

Topological considerations on microporous adsorption processes in simple models for pillared interlayered clays

The microporous structure of pillared interlayered clays is determined by their interlayer separation and the distribution of the pillars that separate their layers. The pillars provide stability to these quasi-two-dimensional high surface area materials. In this work we present a topological analysis of available and accessible volumes within various simple models of pillared interlayered clays. Each model is characterized by a distribution of pillars. Both fully ordered structures and disordered pillar distributions with either attractive or repulsive interpillar correlations are considered. Particular attention is paid to the problem of accessibility. In systems with similar degrees of porosity, even when cavities within each model might be able to host the same adsorbate molecules, their accessibility will strongly depend on the pillar distribution. The theoretical analysis presented in this work may facilitate the interpretation of experimental results, pointing out those quantities that are key to describe the texture of the porous material.

The predictive and prognostic value of serum CA 125 kinetics and CA 125 nadir during paclitaxel/platinum based chemotherapy in patients with advanced ovarian carcinoma

e16534

Background: The tumor marker CA 125 is an accurate and reliable marker for monitoring the response to treatment and detecting early relapse in epithelial ovarian cancer (EOC). The aim of this retrospective study is to analyze the predictive and prognostic value of CA 125 kinetics and the implications of the different levels of CA 125 within the normal range after chemotherapy (CT). Methods: Between 1996 and 2008, 127 patients (pts) were treated with standard CT regimen for FIGO stage IIb-IV EOC. Median age was 64 years (24–87). Tumors were classified: 70 (55%) serous, 24 (19%) poorly differentiated, 14 (11%) endometrioid and 19 (15%) clear cell carcinoma. FIGO stage: 12 (9%) II; 95 (75%) III; and 20 (16%) IV. Tumor grade: 1 (1%) G1; 11 (9%) G2; and 115 (90%) G3. Residual disease after initial surgery: 52 (41%) optimal <2cm and 39 (31%) suboptimal. After surgery, 117 (92%) of the pts received a median of 6 cycles/patient with platinum based (cisplatin or carboplatin) CT in combination with paclitaxel. Median follow-up was 31 months. 93 (73%) pts achieved levels <35 U/ml after CT. Survival analyses for disease-free survival (DFS) and overall survival (OS) used univariate (Kaplan-Meier) and multivariate (Cox) model. Results: For 127 stage IIb-IV pts, 88 (69%) relapsed and 60 (47%) died from EOC. The median DFS for 3 groups 1, 2 and 3, was 34, 20, 14 months, respectively (p < 0.0001). The median OS for 3 groups was 7.5, 3 and 3 years, respectively (p < 0.0001). Pre-CT Ca 125 (p < 0.002), and time to negativization (p < 0.043) all had a univariate prognostic value for DFS and OS. In Cox models, FIGO stage (p < 0.0001) and nadir concentration (p < 0.0001) were the most powerful prognostic factors for DFS and OS. We found no differences in DFS and OS related to time to nadir. Conclusions: Serum CA 125 kinetics during early CT has a strong predictive and prognostic relevance for patients with advanced EOC. Within normal range, the differences between CA 125 levels could add prognostic information, stratify pts according to the risk of progression and would be a useful tool when performing consolidation CT in future clinical trials.

No significant financial relationships to disclose.

Microtubule-regulatory phosphoproteins and NER system are involved in platinum and paclitaxel-based chemotherapy resistance in ovarian cancer

5567

Background: The treatment of ovarian cancer is hindered by intrinsic resistance to platinum and paclitaxel-based chemotherapy (CT). Nucleotide excision repair system plays a central role in DNA repair and is related with resistance to platinum compounds. Excision repair cross-complementation 1 (ERCC1) and 3 (ERCC3) genes confer a differential sensitivity to CT. OP18/stathmin and mDIA are involved in regulation of microtubules dynamics and may represent a mechanism of resistance to paclitaxel. Both mechanisms have been recently investigated in ovarian cancer (OC). Methods: Formalin and paraffin-embedded tissues obtained from 33 patients with advanced OC were retrospectively collected to investigate ERCC1, ERCC3, OP18, and mDIA mRNA levels by quantitative RT- PCR. All patients received a median of 6 cycles platinum based CT in combination with taxanes. Median age was 62 years. Tumors were classified: 52% serous, 9% endometrioid, 27% clear cell, and 12% poorly differentiated carcinomas. FIGO stage: 4 (12%) stage II, 19 (58%) stage III, and 10 (30%) stage IV. 12 chemoresistant tumors (time to recurrence (TTR) < 6 months) and 21 chemosensitive tumors (TTR = 6 months) were analyzed. Median follow-up was 31 months. Results: An increase in mRNA levels was consistently observed in the chemoresistent group: 1.9-fold increased in ERCC1 and 1.6-fold increased in ERCC3. Both genes exhibited comparable expression levels. Statistically significant differences on ERCC1 and ERCC3 mRNA levels were encountered when chemoresistant and chemosensitive tumors were compared (p=0.01 and p= 0.03, respectively). Statistically differences on OP18 mRNA levels were found when chemoresistant and chemosensitive tumors were compared (p=0.05). No differences in mDIA mRNA levels were encountered. Conclusions: Our results suggest that determination of ERCC1-ERCC3 before chemotherapy is potentially useful to predict the effectiveness of platinum-based therapy. Microtubule drug resistance in OC may be associated with altered OP18/stathmin expression. Novel treatment approaches based on molecular markers could be useful predictors of response and could identify targets for therapeutic strategies. Further studies are required.

No significant financial relationships to disclose.

The International Study of Wheezing in Infants: questionnaire validation

BACKGROUND

There are no internationally validated questionnaires to investigate the prevalence of infant wheezing. This study was undertaken to validate a questionnaire for the International Study on the Prevalence of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL).

MATERIAL AND METHODS

Construct and criterion validity were tested for the question 'Has your baby had wheezing or whistling in the chest during his/her first 12 months of life?'. Construct validity (i.e. the ability of parents and doctors to refer to the same symptoms with the same words) was tested in a sample of 50 wheezing and 50 non-wheezy infants 12-15 months of age in each of 10 centres from 6 different Spanish- or Portuguese-speaking countries. Criterion validity (i.e. the ability of parents to correctly detect the symptom in the general population) was evaluated in 2 samples (Santiago, Chile and Cartagena, Spain) of 50 wheezing and 50 non-wheezing infants (according to parents) of the same age, randomly selected from the general population, who were later blindly diagnosed by a paediatric pulmonologist.

RESULTS

Construct validity was very high (kappa test: 0.98-1) in all centres. According to Youden's index, criterion validity was good both in Cartagena (75.5%) and in Santiago (67.0%). Adding questions about asthma medication did not improve diagnosis accuracy.

CONCLUSIONS

The EISL questionnaire significantly distinguished wheezy infants from healthy ones. This questionnaire has a strong validity and can be employed in large international multicentre studies on wheezing during infancy.

Nonendodontic periapical lesions: a retrospective study in Chile

AIM

To determine the frequency with which the histopathological diagnosis of periapical lesions contributes to a change in the clinical diagnosis.

METHODOLOGY

Cases having a clinical diagnosis of disease resulting from dental pulp necrosis were selected from the database of the Oral Pathology Reference Institute between 1975 and 2005. Cases with different histopathological diagnoses were determined and information about age and gender of the patient, location of associated tooth, pulp status and the histopathological diagnosis were recorded. The percentage of nonendodontic periapical lesions was then determined.

RESULTS

In the 30-year period, 32,423 [corrected] biopsy specimens were received. Overall 4006 (9.13%) had a clinical diagnosis of pulpal necrosis with associated pathosis in the periradicular area. Within this group, 26 cases (0.65%) had a histopathological diagnosis of nonendodontic pathology. Keratocystic odontogenic tumour was the most frequent nonendodontic lesion (11 cases) in the periradicular region followed by central giant cell granuloma (three cases), chronic sinusitis (three cases) and one case each of the following lesions: nasopalatine duct cyst, lateral periodontal cyst, calcifying cystic odontogenic tumour, ameloblastic fibroma, squamous odontogenic tumour, cemental dysplasia, haemangioma, foreign body cell granuloma and amalgam tattoo.

CONCLUSIONS

The histopathological study of periapical pathosis can occasionally reveal nonendodontic lesions. Odontogenic tumours made up the largest group.

[Diagnosis of caseous lymphadenitis in sheep from Patagonia]

Caseous lymphadenitis (CLA) is a chronic bacterial, infectious and contagious disease caused by Corynebacterium pseudotuberculosis. It affects sheep and results in abscesses of the lymph nodes in subcutaneous tissue, as well as in internal organs such as lungs, liver and kidneys. Differential diagnosis of the disease is based on the isolation and biochemical identification of the etiological agent. The purpose of this study was to characterize the bacteria isolated from typical CLA lesions in sheep from Patagonia, Argentina, at metabolic and genetic levels. Macroscopic observations show a fibrous membrane containing caseous necrotic tissue. Histopathological analysis shows an eosinophilic necrotic area surrounded by epitheloid cells and polymorphonuclear infiltration. Other analyses performed such as microscopic observations, in vitro culture, biochemical tests and 16s rDNA sequencing confirmed diagnosis of caseous lymphadenitis due to C. pseudotuberculosis.