Factors predicting the outcome of allergen-specific nasal provocation test in children with grass pollen allergic rhinitis

Background

Nasal provocation testing (NPT) is a reference methodology to identify the culprit allergen in patients with allergic rhinitis. Selecting the right allergen for NPT is particularly difficult in poly-sensitized patients with seasonal allergic rhinitis (SAR). Predictors of NPT outcomes may facilitate the proper use of this test or even substitute it.

Objective

To identify predictors of grass pollen NPT outcome from an array of clinical data, e-diary outcomes, and allergy test results in poly-sensitized pediatric patients with SAR.

Methods

Poly-sensitized, SAR patients with grass pollen allergy, participating in the @IT.2020 pilot project in Rome and Pordenone (Italy), participated in a baseline (T0) visit with questionnaires, skin prick testing (SPT), and blood sampling to measure total (ImmunoCAP, TFS, Sweden) and specific IgE antibodies to grass pollen extracts and their major allergenic molecules (ESEP, Euroimmun Labordiagnostika, Germany). During the pollen season, patients filled the AllergyMonitor® e-diary app measuring their symptoms, medication intake, and allergy-related well-being via the Visual Analogue Scale (VAS). After the pollen season (T1), patients answered clinical questionnaires and underwent a nasal provocation test (NPT) with grass pollen extract.

Results

We recruited 72 patients (age 14.3 ± 2.8 years, 46 males) sensitized to grass and/or other pollens, including olive (63; 87.5%) and pellitory (49; 68.1%). Patients positive to grass pollen NPT (61; 84.7%), compared to the negative ones, had worse VAS values in the e-diary, larger SPT wheal reactions, and higher IgE levels, as well as specific activity to timothy and Bermuda grass extracts, rPhl p 5 and nCyn d 1. A positive NPT to grass pollen was predicted by an index combining the specific activity of IgE towards Phl p 5 and Cyn d 1 (AUC: 0.82; p < 0.01; best cut-off ≥7.25%, sensitivity 70.5%, specificity: 90.9%). VAS results also predicted NPT positivity, although with less precision (AUC: 0.77, p < 0.01; best cut-off ≥7, sensitivity: 60.7%, specificity: 81.8%).

Conclusions

An index combining the specific activity of IgE to rPhl p 5 and nCyn d 1 predicted with moderate sensitivity and high specificity the outcome of a grass pollen NPT in complex, poly-sensitized pediatric patients with seasonal allergic rhinitis. Further studies are needed to improve the index sensitivity and to assess its usefulness for NPT allergen selection or as an alternative to this demanding test procedure.

The impact of country-level structural stigma on loneliness and social capital in older and younger LGB individuals in 113 countries

Background

The mental health gap between sexual minorities and heterosexuals remains a pressing issue for policy makers and scholars. In past years, numerous studies from the US found support for the vast impact structural stigma on a state level can have on the lives of LGB individuals. However, most research has been conducted within a US context and research capturing structural stigma on a country level remains scarce. In the current study we aim to close this gap by examining whether country-level structural stigma can explain loneliness and social capital among sexual minorities across the world and testing whether these relationships are different for LGB individuals from different age groups.

Methods

The current study analysed a sample of over 7000 LGB people from across 113 European and non-European countries to examine the influence of country-level structural stigma on individual level loneliness and social capital.

Results

Multilevel models showed that the greater structural stigma present in a country, the lower social capital was experienced by LGB respondents (b = -0.05, 95% CI: -0.07, -0.02, p &lt; 0.001). This relationship was unaffected by respondent age. Further, multilevel models showed the following for loneliness as an outcome: The greater structural stigma present in a country, the more loneliness was experienced by LGB individuals (b = .01, 95% CI: .01, .21, p = .048). Furthermore, this relationship was moderated by respondent age (b = -.03, 95% CI: -.06, -.01, p = .01), in the sense that younger LGB people showed significantly higher levels of loneliness than older LGB people in countries with greater, but not lesser, levels of structural stigma. These effects remained robust to adjustment for demographics as well as adding country-level covariates.

Conclusions

The findings of this study demonstrate the impact structural stigma on a country level can have on LGB individuals’ loneliness and social capital, differing for older and younger individuals.

Seroprevalence and SARS-CoV-2 antibodies distribution in Portugal following mass vaccination campaign

Introduction

Information on post-infection and vaccine-induced SARS-CoV-2 seroprevalence is important for public health policies. A 3rd wave of National Serological Survey (ISN3COVID-19) was conducted to measure SARS-CoV-2 seroprevalence and characterize specific antibodies distribution in Portuguese population in September - November 2021, following a mass vaccination campaign.

Methods

ISN3COVID-19 was a cross-sectional epidemiological study that collected serum samples and questionnaire data on a sample of Portuguese residents aged 1 year or older (n = 4545). SARS-CoV-2 IgG anti-nucleoprotein and anti-spike antibody levels were measured using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence was estimated for the overall sample and stratified by age group, sex, region and self-reported chronic conditions. Medians and respective 95% confidence intervals (95%CI) were used to describe the distribution of SARS-CoV-2 antibodies in specific population subgroups.

Results

The overall seroprevalence of SARS-CoV-2 (post-infection or vaccine-induced) was 86.4% (95%CI: 85.2 to 87.6%), post-infection seroprevalence was 7.5% (95%CI: 6.6 to 8.5). Higher seroprevalence was observed among 50-59 years-old (96.5%), women (88.3%), and those with two or more self-reported chronic conditions (90.8%). Higher IgG (anti-Spike) levels were estimated for individuals vaccinated with the booster dose (median=12601.3 AU/ml; 95%CI: 4127.5 to 19089.1) and for those vaccinated with two doses of Spikevax® vaccine (median=7012.7 AU/ml, 95%CI: 5568.8 to 8456.6).

Conclusions

The SARS-CoV-2 seroprevalence was high and consistent with vaccine coverage in Portugal. Seropositivity was associated with sex, age and previous chronic conditions. The anti-SARS-CoV-2 anti-spike IgG levels varied according to vaccine brand and number of doses. These results show that monitoring seroprevalence and SARS-CoV-2 antibody distribution is of paramount importance to guide public health policies.

Key messages

• Significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign consistent with the high vaccine coverage achieved in Portugal.

• Continuous monitoring of the population‐level IgG response after vaccination remains important to guide further public health measures.

Proposal of an iELISA for Mycoplasma bovis diagnosis in dairy cattle and associated risk factors

ABSTRACT Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 μg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.

Linking health and social data in Brazil: challenges and potentials for public health research

Health research using linked routine population-based data collected for non-research purposes has increased in recent years. In Brazil, the Centre for Data and Knowledge Integration for Health (CIDACS-Fiocruz) was created in 2016 in Salvador with the objective of integrating data to answer research questions related to public health. In CIDACS, efforts are made to obtain high-quality linked data while adhering to security, ethical use and privacy issues. Efforts have been made to conduct operations with respect to implementing the appropriate structures, processes and controls over the original and integrated datasets in order to provide relevant data for research purposes. Two different cohorts have been constructed. The “100 Million Brazilian Cohort” comprises of individuals registered in a National Social Register from 2001 linked to data from different social protection programs ('exposures') and outcomes from various health-related Brazilian National databases (deaths, births, infectious diseases). The main aim is to explore the impact of social protection programs on health using natural experiment approaches. By studying the effect of social policies, they increase our possibilities to explore links between the social and economic determinants and health. The CIDACS Birth Cohort is also a population-based cohort derived from linked data, developed to investigate the relationships between prenatal and early life events on health-related outcomes for infants and children, in the context of social inequalities. The overall objective is to research the effect of obstetric and prenatal conditions on birth, growth, morbidity, and survival in a dynamic cohort. CIDACS is expected to be an important resource for researchers and policymakers interested in enhancing the evidence base pertaining to different aspects of health, as well as investigating the role of social determinants of health and the potential effects of social and environmental policies on health.

Tidal-breathing measurement of exhaled breath temperature (EBT) in schoolchildren

BACKGROUND

Non-invasive assessment of airway inflammation is particularly useful in children. The exhaled breath temperature (EBT) may reflect inflammatory vasodilation and serve to assess respiratory symptoms and therapy with inhaled corticosteroids (ICs).

AIMS

To compare EBT with other non-invasive measurements in unselected schoolchildren in relation to respiratory symptoms and IC-therapy, as well as to assess reproducibility, and potentially influencing factors.

METHODS

In 298 Italian schoolchildren, we assessed tidal-EBT, FE(NO), spirometry, skin-prick tests, questionnaires on chronic respiratory symptoms, and medication. Subjects were divided as follows: reported wheeze, respiratory symptoms other than wheeze, and without symptoms.

RESULTS

Subjects with reported wheeze (n = 30) more frequently presented atopy, respiratory symptoms, higher FE(NO), lower lung function than subjects with symptoms other than wheeze (n = 141) and those without symptoms (n = 127), but had a similar EBT. IC-treated children (5 wheeze, 9 respiratory symptoms other than wheeze, 4 without chronic symptoms) had lower median (interquartile range) EBT levels than IC-untreated children (n = 280) [EBT: 31.7 (30.1-32.5) vs. 32.6 (31.4-33.4), P = 0.027]. Duplicate EBT measurements were highly reproducible (ICC = 0.94). In a multiple linear-regression model, EBT was explained by age, weight, duration of EBT measurement, FE(NO), and ambient temperature (r = 0.63, P < 0.001).

CONCLUSION

Tidal-EBT measurements are easy to perform, reproducible, though symptom misclassification may affect the results obtained regarding the effect of IC therapy. Factors influencing EBT should be addressed in further epidemiological studies.

Comparison of the upper airways from cephalometric radiographs of children with and without finger-sucking habit

AIM

Finger-sucking in early childhood can induce morphologic changes in the oropharynx and upper airways, which could arise even in children without reported oral breathing. The aim of this study was to compare cephalometric findings in children with and without finger sucking habit with respect to oral breathing.

MATERIALS AND METHODS

Fifty-six children aged 4 to 12 years (28 with diagnosis of finger sucking and 28 controls) treated at the Port Colombia Dental Clinic underwent cephalometric radiographs, from which morphologic (n=11, whole skull), upper airways (n=10), hyoid bone (n=3) and postural (n=5) measurements were performed. The unpaired t-test was used for comparison between groups.

RESULTS

Both groups had similar age and gender distribution (7.9 yrs ± 2.9; M/F: 14/14). Patients with finger-sucking habit had a higher hard palate length from the anterior nasal spine to the posterior nasal spine (finger-sucking subjects: 50.18 mm; controls: 46.91 mm; p = 0.0001) and distance from the epiglottic vallecula to the posterior pharyngeal wall (finger-sucking subjects: 15.55 mm; controls: 13.36 mm; p = 0.0231) than control subjects. Patients with finger-sucking habits also had a shorter distance from the posterior nasal spine to the adenoids (14.91 mm vs. 17.82 mm; p = 0.0173), wider cranial-cervical angles (105.64 mm vs. 101.6 mm; p = 0.05) and lower hyoid bone positioning (14.55 mm vs. 11.82 mm; p = 0.0125) than controls.

CONCLUSION

Finger-sucking habit is associated with characteristic cephalometric changes even in children without oral breathing, especially at the hyoid bone and postural measurements.

Exhaled breath temperature in children: reproducibility and influencing factors

OBJECTIVE

This study will investigate the reproducibility and influencing factors of exhaled breath temperature measured with the tidal breathing technique in asthmatic patients and healthy children.

METHODS

Exhaled breath temperature, fractional exhaled nitric oxide, and spirometry were assessed in 124 children (63 healthy and 61 asthmatic), aged 11.2 ± 2.5 year, M/F 73/51. A modified version of the American Thoracic Society questionnaire on the child's present and past respiratory history was obtained from parents. Parents were also asked to provide detailed information on their child's medication use during the previous 4 weeks. Ear temperature, ambient temperature, and relative-ambient humidity were also recorded.

RESULTS

Exhaled breath temperature measurements were highly reproducible; the second measurement was higher than the first measurement, consistent with a test-retest situation. In 13 subjects, between-session within-day reproducibility of exhaled breath temperature was still high. Exhaled breath temperature increased with age and relative-ambient humidity. Exhaled breath temperature was comparable in healthy and asthmatic children; when adjusted for potential confounders (i.e. ambient conditions and subject characteristics), thermal values of asthmatic patients exceeded those of the healthy children by 1.1 °C. Normalized exhaled breath temperature, by subtracting ambient temperature, was lower in asthmatic patients treated with inhaled corticosteroids than in those who were corticosteroid-naive.

CONCLUSION

Measurements of exhaled breath temperature are highly reproducible, yet influenced by several factors. Corrected values, i.e. normalized exhaled breath temperature, could help us to assess the effect of therapy with inhaled corticosteroids. More studies are needed to improve the usefulness of the exhaled breath temperature measured with the tidal breathing technique in children.

Principais alterações no leite por agentes causadores de mastite no rebanho caprino dos estados de Minas Gerais e Rio de Janeiro

A mastite subclínica caprina ocasiona prejuízos econômicos em decorrência do descarte, dos gastos com medidas terapêuticas e da redução da quantidade e qualidade do leite e seus derivados. Nesse estudo, 129 amostras de leite de cabra in natura, provenientes de 11 propriedades foram avaliadas pelo teste da caneca telada, California Mastitis Test (CMT), exame bacteriológico, pesquisa de Mycoplasma spp. e pela determinação dos parâmetros físico-químicos. No teste da caneca telada e no CMT, 3,1% e 4,6% das amostras foram positivas, respectivamente. No exame bacteriológico, 57,4% das amostras foram positivas e o patógeno mais frequente foi Staphylococcus coagulase negativa com 56% das cepas resistentes à penicilina e 100% de sensíveis à gentamicina. Mycoplasma spp. não foi identificado nas amostras. O diagnóstico da mastite subclínica pelo CMT e pelo exame bacteriológico diferiu de forma significativa e não houve associação entre o número de UFC/mL obtidas no exame microbiológico e o resultado do CMT (Qui-quadrado p < 0,05). Os parâmetros físico-químicos diferiram significativamente entre os rebanhos (ANOVA, Tukey-Kramer, p < 0,05) e a gordura foi o constituinte que demonstrou maior amplitude, sendo que 63,4% dos rebanhos apresentaram os valores abaixo do exigido pela legislação brasileira. Não houve associação significativa entre a presença de mastite diagnosticada pelo exame bacteriológico e os valores obtidos para os parâmetros físico-químicos (t-Student p > 0,05). Com base nos resultados obtidos, recomenda-se a associação do exame bacteriológico quando na utilização do CMT para diagnóstico da mastite subclínica caprina.

Immune response to sublingual immunotherapy in children allergic to mites

Allergic rhinitis (AR) is characterized by Th2 polarized immune response. Specific immunotherapy modifies this arrangement restoring a physiologic Th1 profile. Sublingual immunotherapy (SLIT) is widely prescribed, but there is no early marker of response. The aim of this study is to investigate possible marker of SLIT effectiveness. Thirty children with mite allergy were studied: 15 were treated with drugs alone, 15 with SLIT and drugs on demand. The study lasted 2 years. Visual analogue scale (VAS) for symptoms and medication score were evaluated. Serum cytokines (IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, MCP-1, and TNF-alpha) were assessed by ELISA before and after 1 and 2 year SLIT. SLIT-treated children obtained a significant improvement of symptoms and a reduction of drug use, whereas children treated with a drug alone did not obtained any change. IL-10 significantly increased, whereas Th2-dependent and pro-inflammatory cytokines significantly decreased. In conclusion, the present study demonstrates that 2-year SLIT is capable of inducing immunologic hyporeactivity to mites.

Factors attributable to the level of exhaled nitric oxide in asthmatic children

Background

Asthma is a heterogeneous disease with variable symptoms especially in children. Exhaled nitric oxide (FeNO) has proved to be a marker of inflammation in the airways and has become a substantial part of clinical management of asthmatic children due to its potential to predict possible exacerbation and adjust the dose of inhalant corticosteroids.

Objectives

We analyzed potential factors that contribute to the variability of nitric oxide in various clinical and laboratory conditions.

Materials and methods

Study population consisted of 222 asthmatic children and 27 healthy control subjects. All children underwent a panel of tests: fractioned exhaled nitric oxide, exhaled carbon monoxide, asthma control test scoring, blood sampling, skin prick tests, and basic spirometry.

Results

FeNO and other investigated parameters widely changed according to clinical or laboratory characteristics of the tested children. Asthmatics showed increased levels of FeNO, exhaled carbon monoxide, total serum IgE, and higher eosinophilia. Boys had higher FeNO levels than girls. We found a significant positive correlation between FeNO levels and the percentage of blood eosinophils, %predicted of forced vital capacity, total serum IgE levels, and increasing age.

Conclusions

Various phenotypes of children's asthma are characterized by specific pattern of the results of clinical and laboratory tests. FeNO correlates with total serum IgE, blood eosinophilia, age, and some spirometric parameters with different strength. Therefore, the coexistence of atopy, concomitant allergic rhinitis/rhinoconjunctivitis, and some other parameters should be considered in critical evaluation of FeNO in the management of asthmatic children.

Pulmonary tuberculosis in adolescents: radiographic features

We studied radiographic features of pulmonary tuberculosis (PTB) described in the report forms for 907 adolescents from two Brazilian cities. A descriptive analysis showed that the most common radiographic lesions were post-primary tuberculosis (53.3%), tuberculous expansile pneumonia (27%) and primary complex with adenomegaly (1.8%). Cavitary lesions occurred in 67/243 (27.6%) patients aged 0-15 years and in 116/321 (36.1%) adolescents aged 16-19 years (P = 0.031). Most of the PTB cases had forms similar to those in adults.

Effects of a program of hospital-supervised chest physical therapy on lung function tests in children with chronic respiratory disease: 1-year follow-up

To investigate whether a hospital-supervised program of chest physical therapy improves lung function in children with chronic pulmonary diseases, twenty-four children (4 with Kartagener?s syndrome, 12 with common variable immunodeficiency, and 8 with primary ciliary dyskinesia) average age 11.2 +/- 3.2 years, were randomly assigned to a one-month hospital-supervised program of chest physical therapy (13 patients) or to a control group (11 patients) that continued unsupervised chest physical therapy at home. Lung function was assessed before the program, and one and 12 months after. At the one-month assessment, thoracic gas volume was significantly lower in the supervised group than in the controls. At the one-year assessment, forced expiratory volume in one second was significantly higher in the supervised group than in controls. A supervised program of chest physical therapy significantly improved lung function in children with chronic pulmonary diseases.

Measuring depression: comparison and integration of three scales in the GENDEP study

BACKGROUND

A number of scales are used to estimate the severity of depression. However, differences between self-report and clinician rating, multi-dimensionality and different weighting of individual symptoms in summed scores may affect the validity of measurement. In this study we examined and integrated the psychometric properties of three commonly used rating scales.

METHOD

The 17-item Hamilton Depression Rating Scale (HAMD-17), the Montgomery-Asberg Depression Rating Scale (MADRS) and the Beck Depression Inventory (BDI) were administered to 660 adult patients with unipolar depression in a multi-centre pharmacogenetic study. Item response theory (IRT) and factor analysis were used to evaluate their psychometric properties and estimate true depression severity, as well as to group items and derive factor scores.

RESULTS

The MADRS and the BDI provide internally consistent but mutually distinct estimates of depression severity. The HAMD-17 is not internally consistent and contains several items less suitable for out-patients. Factor analyses indicated a dominant depression factor. A model comprising three dimensions, namely 'observed mood and anxiety', 'cognitive' and 'neurovegetative', provided a more detailed description of depression severity.

CONCLUSIONS

The MADRS and the BDI can be recommended as complementary measures of depression severity. The three factor scores are proposed for external validation.

Non-invasive assessment of airway inflammation in ship-engine workers

Smoking is harmful for respiratory function. In young to middle-aged men the damage is insidious and difficult to demonstrate. The respiratory impairment could increase under specific stressful conditions in the professional environment. On the hypothesis that exhaled markers are useful for assessing airway susceptibility to inhaled irritants, we measured exhaled markers and lung function in smoking and non-smoking engine-driver military coastguards before and after a patrol at sea. Eighteen men, mean age 39 yrs (range 23-58 yrs), 8 smokers, underwent spirometry, exhaled and nasal nitric oxide (eNO, nNO), exhaled carbon monoxide (CO) and exhaled breath condensate (EBC) for measures of hydrogen peroxide (H2O2), leukotriene B4 (LTB4), proteins (Prots), 8-isoprostanes (8-IsoPs), nitrite (NO2-) and nitrosothiols (RS-NOs) at baseline and after an 8-hour patrol navigation on board small, high-speed diesel-powered ships. At baseline, the smokers showed higher middle flows and CO levels, lower eNO and nNO than non-smokers, but similar levels of EBC markers; geometric means (95% confidence interval), CO: 23.6 (14.5 to 38.3) vs. 3.5 (2.5 to 5.3) ppm; eNO: 7.9 (4.8 to 12.9) vs. 26.7 (15.7 to 45.5) ppb, p=0.000. After navigation, Prots, 8-IsoPs and RS-NOs (but not lung function variables or other markers) significantly increased only in smokers; baseline vs post-navigation RS-NOs: 0.27 (0.11 to 0.65) vs. 1.30 (0.58 to 2.89) micromol, p=0.012. The respiratory consequences of a stressing environment in engine-driver military coastguards who actively smoke are better assessed by measuring EBC markers than by eNO, nNO or lung function. By increasing airway inflammation from oxidative-stress, tobacco smoking appears to interact with other chemical or physical factors elicited during sea navigation. Precisely what these factors are deserves further investigation.

The prevalence of atopy in asthmatic children correlates strictly with the prevalence of atopy among nonasthmatic children

BACKGROUND

Because asthma preferentially burdens persons with atopy, atopy is simplistically considered a primary 'cause' of asthma. Yet at the population level, the percentage of asthma cases 'attributable' to atopy ranges from less than 10% to more than 60%. Seeking to understand the rationale for the variability of atopy-attributable cases of asthma, we systematically reviewed the results of our own previous epidemiological studies and several studies conducted by others in children.

METHODS

From each of the 37 random pediatric populations selected by a Medline search combining the key words 'IgE or skin tests or hypersensitivity, immediate' with 'epidemiological studies, cross-sectional, case-control, prevalence, longitudinal, epidemiology of asthma' (12 from our previous pediatric surveys and a further 25 reported from 19 studies in children), we extracted the population prevalence of asthma and atopy among asthmatic subjects and among the nonasthmatic part of the population.

RESULTS

No correlation was found between the prevalence of asthma (range 1.8-44.1%) and atopy (range 5.8-63.9%) in these 37 populations of children (r = 0.052, p = 0.761). Nevertheless, the prevalence of atopy among asthmatics strictly correlated with the prevalence of atopy in nonasthmatics (r = 0.900, p < 0.001, slope 1.364).

CONCLUSION

The prevalence of asthma and atopy varies worldwide and at various time points and independently undergoes the influence of powerful environmental factors. The almost perfect correlation we found between atopy in asthmatics and atopy in the nonasthmatic part of the childhood population shows that the prevalence of atopy in asthma depends on environmental factors that simultaneously induce atopy in asthmatic and nonasthmatic subjects.

Allergen skin weal/radioallergosorbent test relationship in childhood populations that differ in histamine skin reactivity: a multi-national survey

BACKGROUND

Histamine skin reactivity (HSR, the dimension of the skin weal elicited by histamine 10 mg/mL) is a variable that differs in children from different European countries and increases over time in the same place (Italy).

OBJECTIVE

In this epidemiologic study, we investigated to what extent differences in HSR influence the relationship between positive allergen skin prick tests (ASPTs) and serum-specific IgE concentrations.

METHODS

Between October 2001 and February 2002, 591 unselected 9-10-year-old schoolchildren drawn from five small towns in central Poland (Starachowice), central Italy (Ronciglione, Guardea) and Libya (Al-Azyzia, near the Mediterranean sea and Samno, 900 km south of the coast) were analysed for histamine, common ASPT and for serum total and specific IgE.

RESULTS

HSR differed markedly in children from the three countries (Libya>Italy>Poland) whereas serum total IgE concentrations remained the same. The prevalence of children with measurable serum specific IgE (> or = 0.35 kU) or with a positive ASPT for five common allergens was high in Italy, lower in Poland and far lower in Libya. A 3-mm ASPT weal corresponded to a serum-specific IgE concentration that was two to threefold higher in children with low HSR compared with children with high HSR (P = 0.008).

CONCLUSION

These findings suggest that HSR--a variable that differs in schoolchildren populations from the three countries studied--independently influences the results of ASPT and its influence should be considered when ASPT are assessed in international studies. The HSR differences found in the populations reported here probably reflect a complex, dynamic, environmental interaction that should be monitored in the different parts of the world.

Diffusing capacity for carbon monoxide in children with type 1 diabetes

AIMS/HYPOTHESIS

Few data are available on lung dysfunction in children with diabetes. We studied the association of pulmonary function variables (flows, volumes and alveolar capillary diffusion) with disease-related variables in children with type 1 diabetes mellitus.

METHODS

We studied 39 children with type 1 diabetes (mean age 10.9+/-2.6 years, disease duration 3.6+/-2.4 years, insulin.kg(-1).day(-1) 0.77+/-0.31) and 30 healthy control children (mean age 10.4+/-3.0 years). Pulmonary function tests included spirometry, N(2) wash-out and the single-breath diffusing capacity for carbon monoxide (DL(CO)) corrected for the alveolar volume (DL(CO)/V(A)). Glycaemic control was assessed on the basis of HbA(1)c, with HbA(1)c values of 8% or less considered to indicate good glycaemic control, and HbA(1)c values of 8% or more considered to indicate poor control.

RESULTS

Children with poor glycaemic control had comparable percentage values for predicted flows and volumes but lower DL(CO)/V(A) values than children with good glycaemic control and healthy control children (86.7+/-12.6 vs 99.8+/-18.4 and 102.0+/-15.7; p<0.05). The predicted DL(CO)/V(A) percentages correlated with HbA(1)c levels (r=-0.39, p=0.013). A multiple regression analysis (stepwise model) controlling for HbA(1)c levels and other disease-related variables (age of disease onset, disease duration, daily insulin dose/kg, sex) identified HbA(1)c levels as the sole predictor of DL(CO)/V(A) in percent.

CONCLUSIONS/INTERPRETATION

In children with type 1 diabetes, the diffusing capacity diminishes early in childhood and is associated with poor metabolic control. Although low DL(CO)/V(A) levels in these children probably reflect pulmonary microangiopathy induced by type 1 diabetes, other factors presumably influencing CO diffusion capacity measurements (e.g. a left shift in HbA(1)c resulting in high O(2) binding and low CO binding) could explain the apparent capillary and alveolar basal membrane dysfunction.

[Childhood asthma]

The concept of chronicity in asthma, as emphasized by recent definitions of the disease, rests on the major characteristics of inflammatory response of the airways and progressive development of irreversible structural and functional alterations, or so-called airway remodeling. In childhood, however, such characteristics as chronicity and irreversibility are debatable. Various clinical phenotypes with variable degrees of severity of persistence are found in children. Furthermore, many patients with a history of recurrent wheezing in early infancy do not develop asthma later in life. The prevalence of asthma, especially in its mild forms, has increased markedly in recent years. Although the trend has stabilized in Italy, it continues to rise in other Western countries. Our research has shown that increased cutaneous response to histamine determines a major prevalence of positive skin tests. The rise in clinical forms of the disease accompanied by gastrointestinal symptoms is partly attributable to the dietary intake of food and beverages processed from environmentally engineered products. The features of the new forms of asthma demand accurate clinical and functional assessment. In addition to pulmonary function tests, determinations for eosinophils and inflammation markers in the blood and sputum, noninvasive methods have recently become available to assess airway inflammation. Among these, particularly useful studies include test for nitric oxide in exhaled air, along with tests for other markers of allergic inflammation and oxidative stress in the droplets of the exhaled air. Because in paediatric age, prolonged use of inhaled steroids increase the risk of growth impairment, asthma therapy should be guided by clinical criteria and examinations, rather than by rigid treatment guidelines. Moreover, to secure successful treatment, the parents and the child as well should be involved in monitoring the course of the disease.

Immediate skin reactivity to histamine and to allergens in cohorts of 9-year-old schoolchildren studied 16 years apart

BACKGROUND

Differing or increasing prevalence of positive allergen skin-prick tests observed in Europe could at least in part be explained by population changes in histamine skin reactivity. These changes would also alter the relationship between positive allergen skin-prick tests and serum IgE.

OBJECTIVE

To assess changes in histamine reactivity, allergen skin-prick tests and serum IgE in our geographical setting.

METHODS

We compared the outcome of two epidemiological surveys conducted 16 years apart in unselected 9-year-old schoolchildren (170 in 1983 and 176 in 1999) from a semi-rural region in central Italy. Outcome measures were skin-prick tests with two histamine concentrations (10 and 1 mg/mL) and 11 locally relevant allergens; serum total and specific IgE for positive allergens.

RESULTS

The two histamine concentrations induced significantly larger mean weal diameters in 1999 than in 1983 (10 mg/mL: 5.28+/-0.82 mm vs. 3.25+/-0.97 mm; P<0.001). Whereas the prevalence of subjects with at least one positive allergen-induced weal reaction (>or=3 mm) increased over the 16 years (from 15.3% in 1983 to 25.6% in 1999), the prevalence of positive skin-prick tests, expressed as the allergen/ histamine weal ratio, remained almost unchanged. A given allergen weal diameter yielded less total (P<0.05 by Student's t-test for cumulative weals <8 mm) and specific (P<0.01 by Student's t-test for weals <3 mm, P<0.05 by Kruskal-Wallis test) serum IgE in 1999 than in 1983.

CONCLUSIONS

Although the causes and mechanisms remain unclear, the increased histamine skin reactivity over time is associated with an increase in positive allergen skin-prick tests. In the presence of increased tissue and organ susceptibility to histamine, minute amounts of specific IgE could have important biological consequences.

Exhaled nitric oxide in asthmatic and non-asthmatic children: influence of type of allergen sensitization and exposure to tobacco smoke

Asthmatic bronchial inflammation is associated with increased nitric oxide concentrations in exhaled air (eNO). Recent data suggest that this effect arises from atopy. Our aim in this study was to find out whether atopy and sensitization to particular allergens influences eNO levels. A total of 213 subjects (41 asthmatics and 172 controls) (96 boys and 117 girls, 7.3-14 years of age) were studied. Parents completed a questionnaire that sought information on their children's respiratory symptoms and exposure to tobacco smoke. Subjects underwent skin-prick tests for the following common allergens: Dermatophagoides pteronyssinus (Dpt), cat fur, Aspergillus fumigatus, Alternaria tenuis, mixed grass, mixed tree pollen, Parietaria officinalis, egg, and cow's milk. eNO was collected in 1-l mylar bags (exhaled pressure 10 cmH2O, flow 58 ml/s) and analyzed by using chemiluminescence. Atopic and non-atopic children without a history of chronic respiratory symptoms had a similar geometric mean eNO (atopics, n = 28, 11.2 p.p.b.; non-atopics, n = 96, 10.0 p.p.b.; mean ratio 1.1, 95% confidence interval [CI]: 0.7-1.6). Conversely, atopic asthmatic subjects had significantly higher eNO values than non-atopic asthmatic subjects (atopics, n = 25, 24.8 p.p.b.; non-atopics, n = 16, 11.4 p.p.b.; mean ratio 2.2, 95% CI: 1.2-3.9, p= 0.000). In children with rhinitis alone (n = 15) and those with lower respiratory symptoms other than asthma (n = 33), eNO increased slightly, but not significantly, with atopy. eNO levels correlated significantly with Dpt wheal size (r = 0.51) as well with the wheal size for cat, mixed grass, and Parietaria officinalis (r = 0.30-0.29), and with the sum of all wheals (r = 0.47) (p= 0.000). Subjects sensitized only for Dpt (but not those subjects sensitized only for grass pollen or other allergens) showed significantly higher eNO levels than non-atopic subjects (16.4 p.p.b. vs. 10.2 p.p.b., mean ratio 1.6, 95% CI: 1.1-2.3, p= 0.002). In asthmatic subjects, Dpt sensitization markedly increased eNO levels (Dpt-sensitized subjects: 28.0 p.p.b.; Dpt-unsensitized subjects: 12.2 p.p.b.; mean ratio 2.3, 95% CI: 1.5-3.5, p= 0.000). Non-asthmatic Dpt-sensitized subjects also had significantly higher eNO values than non-asthmatic, non-Dpt-sensitized subjects (14.2 p.p.b. vs. 10.1 p.p.b.; mean ratio 1.4, 95% CI: 1.1-1.9, p= 0.008). No difference was found between eNO levels in asthmatic subjects and control subjects exposed or unexposed to tobacco smoke. In conclusion, eNO concentrations are high in atopic asthmatic children and particularly high in atopic asthmatics who are sensitized to house-dust mite allergen.

Off-line exhaled nitric oxide measurements in children

The concentration of exhaled nitric oxide (eNO) is a useful marker of asthmatic bronchial inflammation. eNO can now be measured away from the laboratory (off-line), even in children. Short exhalation maneuvers (8 sec) and small samples (1 L) of exhaled gas are probably sufficient in children, but more information is needed about the effect of different measurement conditions. As a preliminary step before conducting epidemiological studies in schoolchildren, we investigated the effects of expiratory flow, dead space, and expiratory time on eNO concentrations collected in 1-L mylar collection bags. We studied 101 cooperative subjects (62 males) aged 5-18 years (30 healthy volunteers, 51 asthmatics, and 20 children with various other respiratory diseases) in our pulmonary function laboratory. On-line and off-line eNO were compared in a single session, and analyzed with a Sievers NOA 280 nitric oxide analyzer. For both methods of collecting expired gas, subjects did a single exhalation without breath-holding against an expiratory pressure 10 cm H(2)O. We investigated the effects of expiratory flow, dead space, and exhalation time on eNO; we also compared on-line and off-line eNO measurements, and the repeatability of both techniques at a given flow rate. Expiratory flows of 58 mL/sec provided more reproducible data than lower flows (coefficient of repeatability 1.1 ppb for 58 mL/sec vs. 2.8 for 27 mL/sec vs. 5.7 for 18 mL/sec). eNO concentrations were about 25% higher in off-line than in on-line recordings if the initial 250 mL of exhaled gas were not eliminated, and 37% higher if exhalation lasted longer (16 sec vs. 8 sec). Eliminating 250 mL of dead space and shortening the filling time to 8 sec yielded off-line eNO values close to those on-line (geometric mean off-line eNO 14.4 ppb, 95% confidence interval: 12.2-17.0) vs. on-line eNO 13.8 ppb (95% confidence interval: 11.6-16.5). On-line and off-line results were highly correlated (r = 0.996, P = 0.000) and had similar coefficients of variation (on-line eNO 2.6%, off-line 2.8%). Neither agreement nor repeatability of eNO measurements were affected by disease status or baseline FEV(1) (% predicted values). Once standardized, the off-line eNO technique using 1-L gas collection bags will provide results similar to those recorded on-line.

Is the increase in childhood asthma coming to an end? Findings from three surveys of schoolchildren in Rome, Italy

Time trends in the prevalence of asthma, family history of asthma and atopy in Roman schoolchildren were assessed. The study population consisted of all children (aged 6-14 yrs) attending two primary schools in Rome, situated in urban areas that differed markedly in socioeconomic conditions and environmental pollution. Three questionnaire-based surveys were conducted in 1974, 1992 and 1998 in 2,259, 1,229 and 1,139 children. The prevalence of asthma in males and females increased significantly during 1974-1992 and remained stable from 1992-1998. In age groups born in the subsequent 4-yr periods it increased almost linearly, for children born from 1962-1965 to 1982-1985 (4.4%-12.5%), and remained remarkably stable in children born after 1985. Because the prevalence of asthma had a steeper trend in males than in females (approximately 0.55% x yr(-1) versus 0.25% x yr(-1)), the male:female asthma ratio increased (1:38 in 1974; 1:84 in 1992 and 1:62 in 1998). No single environmental factor, including area of residence, seemed to influence the prevalence of asthma. Family history of asthma and atopy also increased steadily (0.72% x yr(-1) and 0.30% x yr(-1) respectively) more than doubling during the 24-yr study period. The strong relationship between asthma and a family history of atopy not only persisted but also strengthened over time (23.3% of asthmatic children belonged to families with atopic illnesses in 1974 but 44.2% in 1998). The environmental factors that might explain the almost three-fold rise in childhood asthma between 1974 and 1992 remain unknown but the genetic background of the disease has presumably remained unchanged since the early 1970s. The fact that the prevalence of asthma increased no further during the past 6 yrs suggests that the progressive induction of asthma symptoms in genetically predisposed subjects is a self-limiting process that has probably come to an end in the authors' study area.

Changes over 13 years in skin reactivity to histamine in cohorts of children aged 9-13 years

BACKGROUND

Several studies report substantial differences in the prevalence of skin test reactivity to allergens in children from adjacent geographic areas; others report an increased prevalence over time. To find out whether these differences depend on variations in skin reactivity to histamine, we determined the time trend of histamine wheal sizes in successive cohorts of unselected children living in the same area (Viterbo, Italy).

METHODS

We conducted three epidemiologic surveys, each including children aged 9 and 13 years. The 1983-7 study investigated 170 children (150 were tested twice); the 1992 study, 158 children; and the 1996 study, 208 children.

RESULTS

In both age groups, the mean diameter of the wheal induced by histamine skin prick tests (10 mg/ml) increased significantly over time (9-year-olds: 3.25 mm in 1983, 4.68 in 1992, and 5.89 in 1996; 13-year-olds: 3.89 mm in 1987, 5.18 in 1992, and 6.50 in 1996) (P < 0.001 between subsequent studies). The distribution of the wheal diameters for both ages showed a trend to a right shift in the three successive studies (P < 0.001). The dose-response curves for three histamine concentrations (0.2, 1, and 10 mg/ml) had significantly steeper slopes in 1996 than in 1983-7 (P < 0.001).

CONCLUSION

The marked time-related increase in the size of the histamine wheals could help to explain the trend toward an increased prevalence of positive allergen skin test reactions reported during the past years. The causes of increased skin reactivity to histamine remain conjectural.

Phoresy of a louse (Mallophaga: Philopteridae) on a mosquito from Cali, Colombia

A case of phoresy of a female Sturnidoecus sp. on the wing of a female Culex nigripalpus in Cali, Valle is presented. The phenomenon in southwestern Colombia is discussed.

Lutzomyia sand flies (Diptera: Psychodidae) from middle and lower Putumayo Department, Colombia, with new records to the country

A total of 4,840 phlebotomine sand flies from 54 localities in Putumayo department (=state), in the Colombian Amazon region, were collected in Shannon traps, CDC light traps, resting places and from human baits. At least 42 Lutzomyia species were registered for the first time to the department. Psychodopygus and Nyssomyia were the subgenera with the greatest number of taxa, the most common species being L. (N.) yuilli and L. (N.) pajoti. They were sympatric in a wide zone of Putumayo, indicating that they should be treated as full species (new status). Among the anthropophilic sand flies, L. gomezi and L. yuilli were found in intradomiciliar, peridomestic, urban or forest habitats. L. richardwardi, L. claustrei, L. nocticola and L. micropyga are reported for the first time in the Colombian Amazon basin. L. pajoti, L. sipani and L. yucumensis are new records for Colombia.

Comparative physiology and biochemistry of rat and rabbit urinary bladder

OBJECTIVE

To compare directly the biochemistry and contractile responses of rat and rabbit bladder to different stimuli. Materials and methods Sexually mature male New Zealand White rabbits and Sprague Dawley rats were compared. Each bladder was excised while the animal was anaesthetized; longitudinal bladder strips were cut and then mounted in an organ bath. Tension (2 g) was placed on all strips and each underwent field stimulation (FS) for a total of 20 s at 1-32 Hz, 1 ms and 80 V and was exposed to carbachol (100 micromol/L), ATP (2 mmol/L) and KCl (120 mmol/L). The tension was monitored continually using a polygraph and data stored digitally in a computer. The responses to each stimulus were determined as the maximum tension generated, maximum rate of tension generation and duration to a maximum response. The Ca2+- ATPase activity of the rat and rabbit bladder was determined. Bladder pressures were then predicted from the strip data using Laplace's law and compared with published values.

RESULTS

Contractile responses (per unit tissue mass) of rat bladder strips were significantly greater than those of rabbit bladder strips at all frequencies of FS and to carbachol, KCl and ATP. The rate of contractile force generated by rat bladder strips in response to all stimuli were significantly greater than that generated by rabbit strips. Rabbit bladder strips took significantly longer to generate maximum tension than did rat bladder strips in response to pharmacological stimuli. In response to FS, rat strips took significantly longer than rabbit strips to generate maximum tension. Although the predicted rat bladder pressures were significantly greater than those for rabbit, the predicted pressures for both the rat and rabbit were significantly lower than the pressure responses of the isolated whole bladder model. The contractile data correlated well with the Ca2+-ATPase activity data; rat bladder had seven times the enzyme activity of rabbit bladder.

CONCLUSION

Per unit mass, rat bladder is capable of generating more than five times the tension of rabbit bladder. Similarly, the rate of tension generation by rat bladder is three to five times greater than that by rabbit bladder. The duration to maximum tension generated in response to FS compared with pharmacological stimuli was affected by the inherent difference in the rate of contractile response to electrical activation compared with agents which diffuse through tissue, and by the difference in size between rat and rabbit bladder smooth muscle cells.

Evaluation of cognitive and psychomotor effects of nisoldipine or placebo in healthy volunteers

The purpose of this study was to compare the cognitive and psychomotor effects of the calcium antagonist nisoldipine with placebo in healthy volunteers over the three-week period of this randomised, double-blind, parallel group trial. Thirty volunteers received either a twice-daily dose of 10 mg nisoldipine or placebo. Psychometric testing and measurement of blood pressure and heart rate were carried out on days 0, 7, 14 and 21. Psychometric testing included: Critical Flicker Fusion (CFF), Choice Reaction Time (CRT), Digit Span (DS), Digit Symbol Substitution Test (DSST), and Letter Cancellation (LC). No significant treatment effects were found. CFF performance improved for both groups during the first week. In the CRT task, significant improvements were observed on days 14 and 21, relative to baseline, for total and motor reaction time. Similar improvements over time were found on the LC and DSST tasks. There were no significant differences between the active treatment and placebo for heart rate and systolic/diastolic blood pressure and nisoldipine was well tolerated. The results of this study indicate that nisoldipine does not have any cognition enhancing properties but, unlike some calcium antagonists, it does not markedly impair CNS activity. Copyright 2000 John Wiley & Sons, Ltd.