Cardiac Function and Serum Biomarkers throughout Staged Fontan Palliation: A Prospective Observational Study.

Fontan patients undergo multiple cardiothoracic surgeries in childhood. Following these procedures, ventricular function is temporarily decreased, and recovers over months. This is presumably related to cardiopulmonary bypass, but this is incompletely understood. Throughout the Fontan palliation, cardiac function is also affected by volume unloading. We aimed to gain insight into the biological processes related to impaired ventricular function and recovery following Fontan palliations using a panel of biomarkers. Furthermore, we described changes in ventricular function across the Fontan palliation due to volume unloading. We performed a prospective multicenter observational study in patients undergoing partial (PCPC) or total cavo-pulmonary connection (TCPC). Patients underwent assessment-including echocardiography and blood sampling-before surgery (T1), at first follow-up (T2), and 1 year after their procedures (T3). Blood samples were analyzed using a biomarker panel (OLINK CVD-III). Ninety-two biomarkers were expressed as principal components (PC) to limit multiple statistical testing. We included 32 PCPC patients aged 7.2 [5.3-10.3] months, and 28 TCPC patients aged 2.7 [2.2-3.8] years. The single ventricular longitudinal strain (SV GLS) temporarily decreased for PCPC patients at T2 (-15.1 ± 5.6 (T1) to -13.5 ± 5.2 (T2) to -17.3 ± 4.5 (T3), p < 0.047 for all differences), but not following TCPC. The serum biomarkers were expressed as 4 PCs. PC1, including biomarkers of cell-cell adhesion, was not related to any patient characteristic. PC2, including biomarkers of superoxide anion regulation, increased at T2. PC3, including biomarkers of cardiovascular development, related to the stage of Fontan palliation. PC4 was of uncertain biological or clinical significance. No PC was found that related to ventricular performance. The SV GLS was temporarily diminished following PCPC, but not following TCPC. Several biomarkers were related to post-operative stress and adaptation to the PCPC or TCPC circulation, but none were related to the outcome.

Effects of enzyme replacement therapy on cardiac function in classic infantile Pompe disease.

OBJECTIVE: Patients with classic infantile Pompe disease are born with a hypertrophic cardiomyopathy, which resolves after treatment with Enzyme replacement therapy (ERT). We aimed to assess potential deterioration of cardiac function over time using myocardial deformation analysis. METHODS: Twenty-seven patients treated with ERT were included. Cardiac function was assessed at regular time intervals (before and after start with ERT) using conventional echocardiography and myocardial deformation analysis. Separate linear mixed effect models were used to asses temporal changes within the first year and the long-term follow-up period. Echocardiograms of 103 healthy children served as controls. RESULTS: A total of 192 echocardiograms were analyzed. Median follow-up was 9.9 years (IQR: 7.5-16.3). Mean LVMI before start of ERT was increased 292.3 g/m2 (95% CI: 202.8-381.8, mean Z-score + 7.6) and normalized after 1 year of ERT 87.3 g/m2 (CI: 67.5-107.1, mean Z-score + 0.8, p < 0.001). Mean shortening fraction was within normal limits before start of ERT, up to 22 years of follow-up. Cardiac function measured by RV/LV longitudinal, and circumferential strain was diminished before start of ERT, but normalized (<-16%) within 1 year after start of ERT, and all remained within normal limits during follow-up. Only LV circumferential strain gradually worsened in Pompe patients (+0.24%/year) during follow-up compared to controls. LV longitudinal strain was diminished in Pompe patients, but did not change significantly over time compared to controls. CONCLUSION: Cardiac function, measured using myocardial deformation analysis, normalizes after start of ERT, and seems to remain stable over a median follow-up period of 9.9 years.

Longitudinal Myocardial Deformation Does Not Predict Single Ventricle Ejection Fraction Assessed by Cardiac Magnetic Resonance Imaging in Children with a Total Cavopulmonary Connection.

Survival of children with single ventricle heart defects after the total cavopulmonary connection (TCPC) has improved, but impaired cardiac function remains a major cause of morbidity and mortality. Cardiac magnetic resonance imaging (cMRI) is the gold standard in assessing single ventricle volume and function, but high costs and limited availability hamper its routine use. A cheaper and more available alternative is echocardiography. Myocardial function can be studied in more detail using speckle tracking echocardiography (STE). The purpose of the study was to describe the association between myocardial deformation assessed by speckle tracking echocardiography (STE) and single ventricle function assessed by cMRI and to evaluate differences in myocardial deformation in children with single left and single right ventricular morphology. Cross-sectional, multicenter study in 77 children after TCPC was conducted. STE segmental and global longitudinal peak strain and systolic strain rate (SR) of the dominant ventricle were measured. Impaired SV function by cMRI was defined as ejection fraction (EF) < 45%. Mean age was 11.8 (range 9.7-14.3) years. Pearson R for cMRI EF versus global longitudinal strain and SR was - 0.25 (p = 0.06) and - 0.03 (p = 0.82), respectively. Global single ventricle longitudinal strain and SR was similar in patients after TCPC with single left and single right ventricular morphology (- 19.0 ± 3.1% vs 19.2 ± 3.2%, p = 0.94). STE myocardial deformation parameters do not correlate with single ventricle ejection fraction assessed by cMRI.

The effect of exercise training on cardiac remodelling in children and young adults with corrected tetralogy of Fallot or Fontan circulation: a randomized controlled trial.

BACKGROUND: Exercise can improve physical fitness in children and adults with congenital heart disease. We hypothesized that exercise training would not lead to adverse cardiac remodelling in this population. METHODS AND RESULTS: This multi-centre randomized controlled trial included children and young adults (10 to 25 years) with either corrected tetralogy of Fallot or Fontan circulation. The exercise-group was enrolled in a 12 week standardized aerobic dynamic exercise training program. The control-group continued their life-style and received care as usual. Both groups underwent cardiopulmonary exercise testing, cardiac magnetic resonance imaging (MRI), echocardiography and neurohormonal assessment, within 2 weeks before and 2 weeks after the intervention period. Fifty-six patients were randomized to the exercise-group and 37 to the control-group. We assessed changes between the pre- and the post-intervention period for the exercise group compared to the changes in the control-group. Peak load increased significantly in the exercise-group compared to the control-group (exercise-group 6.9 ± 11.8 W; control-group 0.8 ± 13.9 W; p=0.047). There were no adverse events linked to the study. Ventricular systolic parameters, cardiac dimensions and neurohormonal markers during follow-up did not change in patients allocated to the exercise-group and control-group. Although there were some isolated minor changes in inflow parameters, there was no consistent pattern of changes, indicating a lack of true change in the diastolic function. CONCLUSION: We demonstrated that no clinically relevant adverse cardiac remodelling occurred after 12 weeks of exercise training in patients with either corrected tetralogy of Fallot or Fontan circulation. CLINICAL TRIAL REGISTRATION: www.trialregister.nl, identification NTR2731.

Overexpression of the alpha v beta 6 integrin in cervical squamous cell carcinoma is a prognostic factor for decreased survival.

Cervical squamous cell carcinomas are composed histologically of tumour cell islands surrounded by varying amounts of tumour stroma, the amount and composition of which are influenced by local TGF-beta(1). TGF-beta(1) is secreted in an inactive complex with latency-associated peptide (LAP). Both LAP and the extracellular matrix (ECM) protein fibronectin are important ligands for the integrin receptor alpha v beta 6. While alpha v beta 6 is only weakly expressed by normal epithelia, it is up-regulated in different carcinomas where it generally reflects a more aggressive phenotype. In cervical cancer, the expression of alpha v beta 6 has not thus far been investigated. Given the ability of alpha v beta 6 both to activate TGF-beta(1) and to interact with fibronectin, we studied correlations between the expression of these components and disease parameters in a large cohort of cervical cancer specimens. We analysed alpha v beta 6 expression using immunohistochemistry in primary cervical squamous carcinomas of FIGO stage IA to IIB patients and correlated the findings with formerly investigated fibronectin and TGF-beta(1) expression and clinico-pathological parameters. alpha v beta 6 expression was also examined in cervical intra-epithelial neoplasia (CIN) and lymph node metastases. alpha v beta 6 was only weakly expressed in normal epithelium but clearly up-regulated in CIN lesions. In carcinomas, strong expression of alpha v beta 6 in tumour cells correlated with different clinico-pathological parameters and with worse overall and disease-free survival. Furthermore, alpha v beta 6 expression correlated positively with TGF-beta(1) mRNA expression as well as with fibronectin expression. Overexpression of alpha v beta 6 in cervical squamous carcinomas is an unfavourable prognostic factor. This might reflect an increased capacity of alpha v beta 6-expressing tumour cells to migrate in a fibronectin-rich ECM and/or to activate TGF-beta(1) at the tumour/stroma interface, both of which processes may contribute to cervical cancer progression.

Exhaled nitric oxide in 4-year-old children: relationship with asthma and atopy.

Airway inflammation is an early feature of asthma. Early detection and anti-inflammatory treatment may have important therapeutic impact. Exhaled nitric oxide is a noninvasive marker of airway inflammation. The current study investigated the association between exhaled nitric oxide and asthma, wheezing phenotypes, atopy and blood eosinophilia in a large group of 4-yr-old children from the general population. All children participated in the Prevention and Incidence of Asthma and Mite Allergy study, a birth cohort study of high-risk (atopic mother) and low-risk children in the Netherlands. Nitric oxide levels were successfully determined in 429 children. Although there was overlap in the distribution of values of children with and without asthma or atopy, mean values were higher in children with atopy or doctor's diagnosed asthma (geometric mean (ppb) 9.4 and 10.0, respectively) as compared to those without (7.7 and 7.9). Values were highest in atopic symptomatic children. Values were not associated with wheezing phenotype or blood eosinophilia. This study is one of the few large-scale epidemiological studies among 4-yr-old children from the general population showing that children with symptoms of asthma and atopy have higher levels of exhaled nitric oxide than those without.

Age- and infection-related maturation of the nasal immune response in 0-2-year-old children.

BACKGROUND: The hygiene hypothesis suggests that exposure to micro-organisms influences development of the immune system in children. METHODS: In this study, we examined nasal immune responses in the first 2 years of life in relation to age of children and the number of viral infections they have experienced. Nasal brushes were taken during rhinovirus- (n = 20) or respiratory syncytial virus (RSV)-induced (n = 7) upper respiratory tract infections (URTI), and of controls (n = 40). RESULTS: The number of macrophages were higher during URTI and increased with age. The number of T lymphocytes increased with age in controls and were higher during URTI at all ages. We found an age-related decrease in the number of interleukin (IL)-4- and IL-10-positive cells in controls, while the number of IL-12-positive cells remained unchanged. Changes in T lymphocyte and IL-4 cell number were stronger related to the age of the child than to the number of respiratory infections, while the opposite was true for macrophages. CONCLUSIONS: In infants, we found an infection- and age-related increase respectively for nasal macrophages and T lymphocytes during URTI. Furthermore, the number of IL-4- and IL-10-positive cells decreased with age. Whether this maturation reflects a natural age-related maturation, the degree of exposure to respiratory infections, or possibly both, could not be resolved and needs further study.

Reduced nasal IL-10 and enhanced TNFalpha responses during rhinovirus and RSV-induced upper respiratory tract infection in atopic and non-atopic infants.

Rhinovirus and respiratory syncytial virus (RSV) are the most prevalent inducers of upper respiratory tract infections (URTI) in infants and may stimulate immune maturation. To estimate the amount of immune stimulation, nasal immune responses were examined during rhinovirus and RSV-induced URTI in infants. Nasal brush samples were taken from infants (2-26 months; 57% atopic family) with rhinovirus-induced URTI (N=20), with RSV-induced URTI (N=7), and with rhinovirus-induced rhinitis (N=11), from children with asymptomatic rhinovirus infection (N=7) and from eight non-infected children. Numbers of nasal brush cells positive for Th1-, Th2-, regulatory and proinflammatory cytokines were measured by immunohistochemistry or by measuring protein levels using a cytometric bead array analysis. During rhinovirus and RSV-induced URTI, fewer regulatory cytokine IL-10 positive cells were found compared to non-infected children. This fall was accompanied by an increase in levels of the Th1 cytokine TNFalpha. IL-10 responses were inversely related to TNFalpha responses. No enhanced responses were observed for IFNgamma, IL-12 and IL-18. Cytokine responses were comparable in children with rhinovirus-induced URTI and in children with rhinitis, while responses in asymptomatic rhinovirus-infected children were located between those for symptomatic and asymptomatic rhinovirus-infected children. Cytokine responses did not depend on the age of the child or atopy in the family. In conclusion, reduced nasal IL-10 responses during URTI in infants could facilitate the induction of a TNFalpha response. TNFalpha in turn could replace the immature production of IL-12, IL-18 and IFNgamma during URTI to induce an effective clearance of the viral infection and which could stimulate the maturation of Th1 cytokine production in infancy.

Risk factors for atopic dermatitis in infants at high risk of allergy: the PIAMA study.

BACKGROUND: It has been suggested that the period immediately after birth is a sensitive period for the development of atopic disease. OBJECTIVE: We investigated whether birth characteristics and environmental factors are associated with the development of atopic dermatitis in the first year of life. METHODS: Seventy-six children with and 228 without atopic dermatitis, all children of mothers with respiratory allergy or asthma (PIAMA birth cohort study) were included in the study. Atopic dermatitis was defined as a positive history of an itchy skin condition with at least two of the following characteristics: visible dermatitis, history of outer arms/leg involvement, or general dry skin. Multiple logistic regression analysis was performed to study the independent effects of various risk factors. RESULTS: A birth weight >/=4000 g compared to 3000-4000 g was a significant risk factor for atopic dermatitis (odds ratio (OR)=2.4; 95% CI: 1.1-5.1) as was day care attendance (OR=2.9; 95% CI: 1.5-5.9). Exclusive breastfeeding in the first 3 months was negatively associated with atopic dermatitis (OR=0.6; 95% CI: 0.3-1.2), especially with visible dermatitis (OR=0.4; 95% CI: 0.2-1.0). Gender, gestational age, the presence of siblings or pets, and parental smoking were not significantly associated with atopic dermatitis. CONCLUSION: This study shows that a high birth weight and day care attendance increase the risk of atopic dermatitis in the first year of life, while exclusive breastfeeding is a protective factor when dermatitis is found on inspection.

Short and long term variability of the interrupter technique under field and standardised conditions in 3-6 year old children.

BACKGROUND: The short and long term variability of the interrupter technique was assessed to determine whether interrupter resistance is a stable individual characteristic over time. The effect of field and standardised measurement conditions on the within-subject variability of the interrupter technique was also examined. METHODS: The interrupter technique was studied under field and standardised conditions in children aged 3-6 years. Under field conditions, five investigators performed the measurements using two different measurement devices in random sequence. Both short term (20-30 minutes) and long term variability (median 38 days) were assessed in 32 children. Under standardised conditions, a single investigator conducted all measurements using a single device; the repeated measurements were conducted at the same time of day in a familiar quiet classroom. Long term variability (median 11 days) was estimated in 15 children. Within-subject standard deviations were estimated by analysis of variance with adjustment for the effects of different investigators and measurement devices on within-subject variability under field conditions. RESULTS: Under field conditions within-subject standard deviations for short and long term variability were 0.10 kPa/l/s (adjusted 0.10 kPa/l/s) and 0.13 kPa/l/s (adjusted 0.14 kPa/l/s), respectively. Under standardised conditions the within-subject standard deviation for long term variability was 0.10 kPa/l/s. CONCLUSIONS: Measurement of interrupter resistance under field conditions only slightly increased the within-subject variability compared with standardised conditions. The results indicate that interrupter resistance is a stable individual characteristic over a period of some weeks.

Moderate local and systemic respiratory syncytial virus-specific T-cell responses upon mild or subclinical RSV infection.

Respiratory syncytial virus (RSV) infections are a major cause of severe respiratory disease in infants. It has been shown that there is an increased frequency of childhood wheezing in ex-bronchiolitic preteen children. This was postulated to be mediated by a vigorous virus-specific Th2 response influencing the further development of the immune system. Little is known about the possible role of the immune response to clinically mild RSV infections in this respect. We have studied the RSV-specific cellular immune response in infants with a laboratory-confirmed RSV upper respiratory tract infection (URTI; n = 13, mean age 12 months, range 2-22 months) in comparison with infants with non-RSV mediated URTI (n = 9, mean age 9.3 months, range 4-18 months) or infants with severe RSV bronchiolitis (n = 11, mean age 2.3 months, range 1-6 months). RSV-specific cytokine-producing cells were enumerated using the ELISPOT method in peripheral blood mononuclear cells and nasal brush T-cells, collected during the acute and convalescent phase of the infection. Mixed Th1 (IFN-gamma) and Th2 (IL-4 and IL-13) responses were detected in all three groups. Frequencies of RSV-specific T-cells were lower in both URTI groups than in the RSV bronchiolitis group, and not significantly different between the RSV URTI and the non-RSV URTI group. The absence of vigorous virus-specific Th2 responses upon mild RSV infection does not support the hypothesis that these infections influence the development of the immune system and that they predispose for the development of atopic disease.

Mattress encasings and mite allergen levels in the Prevention and Incidence of Asthma and Mite Allergy study.

BACKGROUND: Reduction of allergen exposure from birth may reduce sensitization and subsequent allergic disease. OBJECTIVE: To measure the influence of mite allergen-impermeable mattress encasings and cotton placebo encasings on the amount of dust and mite allergen in beds. METHODS: A total of 810 children with allergic mothers took part in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Allergen-impermeable and placebo mattress encasings were applied to the childrens' and the parents' beds before birth. Dust samples were taken from the beds of children and their parents before birth and 3 and 12 months after birth. Extracts of dust samples were analysed for mite allergens (Der p 1 and Der f 1). RESULTS: Active mattress encasings were significantly more effective in reducing dust and mite allergen levels than placebo encasings. Mite allergen levels were low in general and the treatment effect was modest. Twelve months after birth, mattresses with active mattress encasings had about half the amount of Der 1 (Der p 1 + Der f 1)/m2, compared to mattresses with placebo encasings, for the child's and the parental mattress. CONCLUSION: This study shows that mite-impermeable mattress encasings have a significant but modest effect on dust and mite allergen levels of mattresses with low initial mite allergen levels, compared to placebo.

Early respiratory and skin symptoms in relation to ethnic background: the importance of socioeconomic status; the PIAMA study.

AIMS: To evaluate ethnic differences in the prevalence of respiratory and skin symptoms in the first two years of life. METHODS: A total of 4146 children participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Parents completed questionnaires on respiratory and skin symptoms, ethnic background, and other potential confounders during pregnancy, and at 3 months, 1 year, and 2 years of age. RESULTS: In the first year, "non-Dutch" children (compared with "Dutch" children) had a higher prevalence of runny nose with itchy/watery eyes (11.0% versus 5.0%). In the second year, a higher prevalence of wheeze at least once (26.7% versus 18.5%), night cough without a cold (24.6% versus 15.5%), runny nose without a cold (34.1% versus 21.3%), and runny nose with itchy/watery eyes (13.7% versus 4.6%) was found. Adjustment for various confounders, especially adjustment for socioeconomic factors, reduced most associations between ethnicity and respiratory symptoms. Only runny nose with itchy/watery eyes in the second year of life was independently associated with non-Dutch ethnicity (adjusted odds ratio 2.89, 95% CI 1.3-6.4). CONCLUSIONS: Non-Dutch children more often had respiratory symptoms in the first two years of life than Dutch children. This could largely be explained by differences in socioeconomic status. Follow up of the cohort will determine whether this higher prevalence of respiratory symptoms in children with non-Dutch ethnicity represents an increased risk of developing allergic disease rather than non-specific or infection related respiratory symptoms.

Respiratory infections in infants: interaction of parental allergy, child care, and siblings-- The PIAMA study.

OBJECTIVE: To investigate the association between contacts with other children and the development of respiratory infections in the first year of life in children with or without genetic predisposition for allergy. METHODS: Children (n = 4146) who participate in a prospective birth cohort study (Prevention and Incidence of Asthma and Mite Allergy study) were investigated. Questionnaires were used to obtain information on doctor-diagnosed upper respiratory tract infection (URTI) and lower respiratory tract infection (LRTI), child care attendance, having siblings, family history of allergic disease, and various potential confounders. RESULTS: Child care attendance in the first year of life was associated with doctor-diagnosed URTI (adjusted odds ratio [AOR]: 2.7; 95% confidence interval [CI]: 2.1-3.4 for large child care facility vs no child care) and doctor-diagnosed LRTI (AOR: 5.6; 95% CI: 3.9-7.9). Having siblings was associated with doctor-diagnosed LRTI (AOR: 2.6; 95% CI: 2.0-3.4). In addition, children who have allergic parents and attend child care or have older siblings have a higher risk of developing doctor-diagnosed LRTI than do children who have nonallergic parents. CONCLUSIONS: Child care attendance or having siblings increases the risk of developing doctor-diagnosed LRTI in the first year of life to a greater extent in allergy-prone children than in children who are not allergy prone.

Definition of respiratory symptoms and disease in early childhood in large prospective birth cohort studies that predict the development of asthma.

We have reviewed the prospective value of early respiratory symptoms for determining the risk of development of asthma later in life by using data from studies based on the general population, hospital population, and general practices. Although "wheezing" in infancy generally has a good prognosis, it is an important risk factor for the development of asthma later in life. The prognostic value of "coughing" and "shortness of breath" in infancy for the later development of asthma is less clear. Despite the fact that no internationally accepted criteria for the definition of asthma in early childhood are available, many studies have been performed on this topic. We also investigated the outcome variables that were used to describe respiratory symptoms and disease in early childhood in the publications of nine large prospective birth cohort studies on the development of asthma. From seven of these studies, we reviewed the original questionnaires. We found that various studies used different outcome variables, but the data actually collected were similar. This is an important observation because it implies that comparisons between studies can be markedly improved by data sharing among investigators.

Are children at high familial risk of developing allergy born into a low risk environment? The PIAMA Birth Cohort Study. Prevention and Incidence of Asthma and Mite Allergy.

BACKGROUND: A family history of allergy, reflecting genetic risk factors, increases the risk of developing allergic diseases, but environmental factors, especially those present in early life, also contribute to the actual development of allergic phenomena. OBJECTIVE: To identify differences in lifestyle between allergic and non-allergic parents, which may influence the prevalence of environmental risk factors in their homes. METHODS: Data were collected in a Dutch birth cohort study by postal questionnaire about 2 months before and 3 months after the birth of the child. RESULTS: Of the 3147 infants in the study 1910 (61%) had two non-allergic parents, of 315 infants (10%) only the mother was allergic, of 787 infants (25%) only the father was allergic and 135 (4%) infants had two allergic parents. If both parents were allergic, 53% reported that allergy was taken into consideration when they furnished their home and significantly more of their homes were free of cats and free of cigarette smoke; adjusted odds ratio's for two allergic parents vs. two non-allergic parents were 0.30 (confidence interval (CI) 0.17-0.50) for the presence of cats and 0.46 (CI 0.27-0.75) for smoking in the home. Parental allergy was also associated with having a smooth floor in the baby's bedroom and with postponement of the introduction of fruits and vegetables until the age of 26 weeks. The presence of dogs at home, the prevalence of mothers' smoking during pregnancy and the decision to breast feed were unrelated to parental allergy. CONCLUSION: We conclude that studies on the relationship between allergy in parents and allergy in their offspring should always consider the home environment as a potential confounder. For allergy prevention our results imply that among allergic parents there is awareness and willingness to take measures that reduce exposure to indoor allergens.

Distinction between HLA class I-positive and -negative cervical tumor subpopulations by multiparameter DNA flow cytometry.

BACKGROUND: The study of the molecular-genetic basis of heterogeneity of HLA class I expression in solid tumors is hampered by the lack of reliable rapid cell-by-cell isolation techniques. Hence, we studied the applicability of a flow cytometric approach (Corver et al.: Cytometry 2000;39;96-107). METHODS: Cells were isolated from five fresh cervical tumors and simultaneously stained for CD45 or vimentin (fluorescein isothiocyanate fluorescence), Keratin (R-phycoerythrin fluorescence), HLA class I (APC fluorescence), and DNA (propidium iodide fluorescence). A dual-laser flow cytometer was used for fluorescence analysis. Tissue sections from the corresponding tumors were stained for HLA class I antigens, keratin, vimentin, or CD45. RESULTS: Flow cytometry enabled the simultaneous measurement of normal stromal cells (vimentin positive), inflammatory cells (CD45 positive), epithelial cells (keratin positive), and DNA content readily. Normal stromal/inflammatory cells served as intrinsic HLA class I-positive as well as DNA-diploid references. Good DNA histogram quality was obtained (average coefficient of variation < 4%). Intratumor keratin positive subpopulations differing in HLA class I expression as well as DNA content could be clearly identified. Losses of allele-specific HLA class I expression found by immunohistochemistry were also detected by flow cytometry. CONCLUSIONS: We conclude that multiparameter DNA flow cytometry is a powerful tool to study loss of HLA class I expression in human cervical tumors. The method enables flow-sorting of discrete tumor and normal cell subpopulations for further molecular genetic analysis.

Using nicotine measurements and parental reports to assess indoor air: the PIAMA birth cohort study. Prevention and Incidence of Asthma and Mite Allergy.

We used two methods to collect data on indoor smoking exposure of 3-month-old infants. First, parents of approximately 100 children completed a questionnaire. We then measured nicotine in the air of the living rooms in smoking and non-smoking households with a passive sampler for a period of 2 weeks, several months after the questionnaire had been completed. Smoking habits reported in the questionnaire generally with reported number of cigarettes smoked during the measurement weeks, and with nicotine concentrations in the air. These results suggest that exposure classification based on questionnaire data is likely to be reasonably valid.

Cartilaginous airway wall dimensions and airway resistance in cystic fibrosis lungs.

It is not clear how airway pathology relates to the severity of airflow obstruction and increased bronchial responsiveness in cystic fibrosis (CF) patients. The aim of this study was to measure the airway dimensions of CF patients and to estimate the importance of these dimensions to airway resistance using a computational model. Airway dimensions were measured in lungs obtained from CF patients who had undergone lung transplantation (n=12), lobectomy (n=1), or autopsy (n=4). These dimensions were compared to those of airways from lobectomy specimens from 72 patients with various degrees of chronic obstructive pulmonary disease (COPD). The airway dimensions of the CF and COPD patients were introduced into a computational model to study their effect on airway resistance. The inner wall and smooth muscle areas of peripheral CF airways were increased 3.3- and 4.3-fold respectively compared to those of COPD airways. The epithelium was 53% greater in height in peripheral CF airways. The sensitivity and maximal plateau resistance of the computed dose/response curves were substantially increased in the CF patients compared to COPD patients. The changes in airway dimensions of cystic fibrosis patients probably contribute to the severe airflow obstruction, and to increased bronchial responsiveness, in these patients.

Multiple genetic alterations cause frequent and heterogeneous human histocompatibility leukocyte antigen class I loss in cervical cancer.

The nature and frequency of human histocompatibility leukocyte antigen (HLA) class I loss mechanisms in primary cancers are largely unknown. We used flow cytometry and molecular analyses to concurrently assess allele-specific HLA phenotypes and genotypes in subpopulations from 30 freshly isolated cervical tumor cell suspensions.Tumor-associated HLA class I alterations were present in 90% of the lesions tested, comprising four altered pheno/genotype categories: (a) HLA-A or -B allelic loss (17%), mostly associated with gene mutations; (b) HLA haplotype loss, associated with loss of heterozygosity at 6p (50%). This category included cases with additional loss of a (third) HLA-A or -B allele due to mutation, as well as one case with an HLA class I-negative tumor cell subpopulation, caused by a beta2-microglobulin gene mutation; (c) Total HLA class I antigen loss and retention of heterozygosity (ROH) at 6p (10%); and (d) B locus or HLA-A/B downregulation associated with ROH and/or allelic imbalance at 6p (10%). Normal HLA phenotypes and ROH at 6p were observed in 10% of the cases. One case could not be classified (3%). Altered HLA class I antigen expression occurs in most cervical cancers, is diverse, and is mainly caused by genetic changes. Combined with widespread tumor heterogeneity, these changes have profound implications for natural immunity and T cell-based immunotherapy in cervical cancer.