Annular aperture arrays: study in the visible region of the electromagnetic spectrum

Baida and Van Labeke recently proposed a structure that exhibits a supertransmission of light through an array of nanometric coaxial apertures in a metallic film that has been named an annular aperture array (AAA) [Opt. Commun. 209, 17 (2002); Phys. Rev. B 67, 155314 (2003); J. Microsc. 213, 140 (2003)]. We present the first experimental study, to our knowledge, of an AAA structure in the visible region. For technological reasons, the structure under study does not produce a supertransmission of 80% as in Baida and Van Labeke [Opt. Commun. 209, 17 (2002)]. We built the nanostructure and experimentally recorded its far-field spectral response. This transmission shows only one broad band with a maximum around lambda = 700 nm, giving a maximum efficiency around 17%. A finite-difference time-domain simulation reproduces quite well the obtained transmission spectrum.

[Diffusing capacity for carbon monoxide (T(LCO)) and oxygen saturation during exercise in patients with cystic fibrosis]

OBJECTIVES

To estimate the value of diffusing capacity for carbon monoxide (T(LCO)) in patients with cystic fibrosis and to evaluate its ability to predict arterial desaturation during exercise.

METHOD

Fourty-four patients (9-30 years) with cystic fibrosis performed pulmonary function tests with measure of T(LCO) and a bicycle incremental exercise test. They represent a wide variation in disease severity: mean Shwachman score: 77.8 (range: 40-100), mean FEV1%: 72.8 (range: 17-131). This study investigated the relationship between T(LCO), lung volumes and exercise data.

RESULTS

T(LCO) remained normal for a long time in patients with cystic fibrosis: 82% of them show a normal T(LCO) (mean value: 91.3% of predicted). T(LCO) was significantly correlated with FEV(1), residual volume, maximal work load and maximum oxygen uptake. A fall in arterial oxygen saturation was uncommon in our study (five patients) and not significantly correlated with T(LCO).

CONCLUSIONS

T(LCO) is a good criter of severity of cystic fibrosis but remains unreliable to predict values above which physical activity is safe, without arterial desaturation. Exercise tests should be proposed in order to evaluate exercise adaptation of each patient and determine which factor limits maximal performance.

Comparing the clinical evolution of cystic fibrosis screened neonatally to that of cystic fibrosis diagnosed from clinical symptoms: a 10-year retrospective study in a French region (Brittany)

Until the year 2000, systematic cystic fibrosis (CF) neonatal screening was only performed in a few regions of France. The Brittany region began in 1989, but not the neighboring region of Loire-Atlantique. The present study compares the clinical evolution of both affected populations 10 years after screening was started. Although the 77 screened and 36 nonscreened children were followed in different CF centers, they were included in similar care protocols. The clinical characteristics at diagnosis and their evolution over a 10-year period of all the children affected with CF and born between January 1, 1989 and December 31, 1998, excluding those with meconium ileus, were compared. There were no significant differences in sex ratio, gestational age, anthropometric data at birth, frequency of deltaF508 homozygotes, proportion of pancreatic-insufficient patients, and mean age between the two populations. Age at diagnosis was lower in the screened group (38 days vs. 472 days, P < 10(-7)), as was the delay in supplementation with pancreatic enzymes (1.7 months vs.15.9 months, P < 10(-7)). The proportion of children who were hospitalized at least once was higher among the nonscreened than the screened patients (86% vs. 49%, P < 10(-4)). Z-scores for weight and height were significantly better in the screened population, not only in the first years of life, but also at 5 years old for height and 8 years old for weight. The Shwachman and Brasfield scores were higher among the screened children during the whole period of follow-up. No significant differences in colonization by Pseudomonas aeruginosa nor in lung function were found. Given the homogeneity in the characteristics and the follow-up of both populations, the benefits in terms of nutrition and clinical well-being of neonatal screening appear to be clear, thus confirming the advantages of its general implementation.

[Compulsory medical certificates of early childhood: unknown epidemiology tool]

The delivery of three medical certificates has been made compulsory in 1970, the first during the first eight days of life, the second and the third respectively at 9 and 24 months. Thirty years later a survey has been conducted to evaluate the application and the efficiency of the system in 100 french departments. All the medical directors of the departmental MCH service send back the questionnaire. The number of annual birth by department is of 7,665 (mean) with extremities of 800 to 36,457. The covering of the concerned population is very good for the first certificate and increasing from 88.8% in 1992 to 94.9% in 1998; it is less good and not increasing for the CS9 (71.1%) and the CS24 (66%). The answers to each item are also variable according to the department but with an average of 86% (to refer to 650,000 annual births). The computer treatment of the certificates is increasing since ten years but 8 departments are still using manual analysis. In spite of the decentralization of MCH service each department is obliged to send to the Ministry of Health, each year, the results of 22 indicators which makes it possible to follow up the evolution of the situation of young children at the national level and to establish comparasons between departments. Simultaneously the certificates allow to guide the MCH activities, often at the canton level. The first certificate has been very useful for the study of perinatal problems and the third for the vaccination coverage. For example, some results are given and discussed (qualification of the examiner, neonatal mortality and socio-economical categories, mother âge, duration of pregnancy, birth weight, vaccination coverage...). Of course, the system is not perfect but is improving due to a better information of the medical personnel and of the families. It is still necessary to continue the research to underline the deficiencies and to correct them. Probably, in the future, the system will be extended to the registration of data obtained at the maternal school (3-4 years old) and the elementary school (5-6 years old).

[Evaluation of 47,213 infants in neonatal screening for cystic fibrosis, using pancreatitis-associated protein and immunoreactive trypsinogen assays]

OBJECTIVES

The increasing evidence of the benefits of neonatal screening for cystic fibrosis (CF) indicates that this procedure could soon be implemented throughout France. The screening strategy currently used involves the detection of infants with elevated levels of immunoreactive trypsinogen (IRT) (approximately 1% of the population), followed by the detection of CFTR gene mutations. However, genetic analysis has certain drawbacks, the most important of which being the management of heterozygotes, and in France the requirement by law of previous informed consent. In cases of CF, pancreatic alterations are already present in utero. A previous study has demonstrated the value of pancreatitis-associated protein (PAP) as a screening test for CF, and has indicated that a feasible two-stage strategy could involve the following: 1) selection of infants with elevated PAP levels; 2) in this group of infants, subsequent detection of those with elevated IRT levels for direct CF diagnosis by the sweat test thereby avoiding the use of genetic analysis. The study aim was to evaluate this strategy in a large number of neonates.

METHODS AND RESULTS

The aforementioned strategy was evaluated in a prospective study involving 47,213 infants in the Provence region of France. In infants with a PAP > 7.5 ng/mL (1.28%), 176 had an elevated IRT level > 700 ng/mL (0.37%). In this limited population sample (0.37% of the total), the sweat test diagnosed five cases of CF. A sixth case involving the monozygous twin of an infant with diagnosed CF remained undetected, probably because of a registration error. Genetic analysis confirmed the diagnosis, and also detected another case in an infant with two CFTR mutations but with a normal phenotype at 20 months of age. As the observed incidence was similar to that which had previously been reported, and as no further case was subsequently detected two years after the end of the study, this indicated that the sensitivity of this screening strategy was satisfactory. Its specificity makes the direct diagnosis of CF cases by the sweat test feasible, without further selection by genetic analysis.

CONCLUSION

The PAP/IRT technique for CF detection seems to be suitable for mass screening, without the drawbacks of genetic testing.

[Anemia and limping in a vegetarian adolescent]

A vegan diet in the child and adolescent can induce severe bone sequelae by rickets and osteomalacia and megaloblastic anemia by cobalamin deficiency.

CASE REPORT

A 15-year-old adolescent was hospitalized because of lameness and pallor. The lameness was explained by femoral epiphysiolysis caused by rickets with severe hypocalcemia. The pallor, jaundice and splenomegalia were due to cobalamin-deficiency megaloblastic anemia. A prolonged supplemental diet with calcium, vitamins D and B12 as well as orthopedic treatment stabilized the bone lesions. The megaloblastic anemia was cured by parenteral cobalamin. The adolescent and his brother were victims of a diet imposed by a cult and a lack of care due to their parents refusing that a vegan diet was the cause of the deficient pathology. Penal proceedings led to the incarceration of the parents and to the placement of the children.

COMMENTS

Deficiencies in calcium and vitamins D and B12 may be severe in a child's development with a vegan diet. This case report reveals the social and legal problems of an inappropriate diet in infancy imposed by parents who are followers of a fundamentalist church. Beyond the management of children in cults, health professionals have to prevent, screen and supplement the deficient diet.

[Does neonatal screening of cystic fibrosis affect outcome? Comparative study of two cohorts in Britanny and Loire-Atlantique with follow-up after ten years]

Neonatal screening for cystic fibrosis was started in Brittany in 1989 but not in the adjacent department of Loire-Atlantique. This study compares the outcome from the children of both populations nine years after the beginning of the screening. Those children were seen in different centers but with the same following guidelines.

POPULATION AND METHODS

All children with cystic fibrosis born between 01/01/89 and 31/12/97 in Brittany and the Loire-Atlantique, excluding the meconium ileus, were compared for their initial characteristics and their outcome after nine years of follow-up.

RESULTS

There was no significant difference between both populations for sex ratio, gestational age, birth biometry, percentage of homozygotes delta F508, and mean age of children. Age at diagnosis was lower in Brittany (37 vs 372 days, P < 10(-7)), as was the delay for starting pancreatic supplementation (1.5 vs 14.3 months, P < 10(-7)). Percentage of children hospitalized at least once was higher in Loire-Atlantique (84.4 vs 40.3%, P < 10(-4)). There was no significant difference for colonization with Pseudomonas aeruginosa. Z-scores for weight and height were better in Brittany, as were Shwachman's and Brasfield's scores.

CONCLUSION

The homogeneity of both populations and their follow-up points out that even if the numbers of children are small and the study is retrospective, some benefits of neonatal screening appear, which are already found in other countries where it is partly practiced. This leads us recommend its general use in our populations, which should be associated with the follow-up of the screened children in cystic fibrosis centers to achieve the most of its benefits.

Microbiologic contamination study of nebulizers after aerosol therapy in patients with cystic fibrosis

BACKGROUND

To evaluate the contamination of delivery systems after an aerosol therapy session in patients with cystic fibrosis who have chronic Pseudomonas aeruginosa infection.

METHODS

Fifty-three patients with cystic fibrosis were enrolled in the study from March 1996 to June 1997. All patients were age 7 years or older and had P aeruginosa infection. They also had been treated with recombinant deoxyribonuclease and were capable of producing sputum for culture.

RESULTS

Nine devices were excluded for the study. A total of 44 nebulizers were included: 37 from patients with P aeruginosa colonization with a count of 10(6) colony-forming units/mL or more and 7 with a count of between 10(5) colony-forming units/mL and 10(6) colony-forming units/mL.

CONCLUSION

This study demonstrates that in the absence of cleaning, nebulizers of patients with cystic fibrosis who are infected with P aeruginosa are likely to be contaminated by a pathogenic flora.

Neonatal screening for cystic fibrosis in Brittany, France: assessment of 10 years' experience and impact on prenatal diagnosis

BACKGROUND

Neonatal screening for cystic fibrosis has been a subject of debate over the past few years. This study assesses 10 years of neonatal screening in Brittany, France, and examines its impact on prenatal screening of subsequent pregnancies in couples with an affected child.

METHODS

The study included all the neonates screened for cystic fibrosis in Brittany from Jan 1, 1989, to Dec 31, 1998. The screening consisted of an immunoreactive trypsinogen assay from dried blood spots, plus, from 1993, mutation analysis. Data were collected on incidence of cystic fibrosis, and genotypic and biochemical characteristics. The use of prenatal screening of subsequent pregnancies in affected families was also investigated.

FINDINGS

Of the 343,756 neonates screened, 118 children with cystic fibrosis were identified, giving an incidence of one in 2913. All mutated alleles were characterised: 34 different mutations resulting in 36 genotypes were detected. The introduction of DNA analysis into the protocol greatly reduced the recall rate and increased the sensitivity of the test. The mean cost of the screening programme was US$2.32 per screened child. 39 (34%) of the families identified by neonatal screening opted for subsequent prenatal diagnosis at least once. 12 couples would have benefited from this procedure while their first child was still symptom-free. 42 healthy children were born, and 18 pregnancies were terminated (therapeutic abortion rate of 100%).

INTERPRETATION

We have shown the feasibility of neonatal screening for cystic fibrosis in Brittany. Through the detection of a large range of mutations, neonatal screening provides the opportunity for more reliable prenatal diagnosis and cascade screening. The neonatal screening programme described here could provide a good model for other countries intending to initiate such a scheme.

[Adult care centers for patients with cystic fibrosis: prerequisites and practical organization. Cystic Fibrosis Care Centers of Rennes and Lille]

In the past 40 years there has been an increase in the median age of survival of patients with cystic fibrosis (CF), attributed to advances in the diagnosis and treatment of patients with this disease. This progress was also due to the level of care provided by pediatricians and now by adult physicians in CF care centers. They centralize and integrate knowledge and skills of pulmonary medicine, gastroenterology, nutrition, nursing, respiratory therapy, social work, and genetics to provide specialized care to patients with CF from childhood to adulthood. They are also expected to develop teaching and research, particularly the development of new life-extending therapies. The continuity of care of this multisystemic disease is best carried out through a close collaboration between the patient's primary care physician or pulmonologist and the specialized staff of the CF care center.

Blood concentrations of pancreatitis associated protein in neonates: relevance to neonatal screening for cystic fibrosis

AIM

To determine whether pancreatitis associated protein (PAP) is a marker for cystic fibrosis which could be used in neonatal screening for the disease.

METHODS

PAP was assayed on screening cards from 202,807 neonates. Babies with PAP > or = 15 ng/ml, or > or = 11.5 ng/ml and immunoreactive trypsinogen (IRT) > or = 700 ng/ml were recalled for clinical examination, sweat testing, and cystic fibrosis transmembrane regulator (CFTR) gene analysis.

RESULTS

Median PAP value was 2.8 ng/ml. Forty four cases of cystic fibrosis were recorded. Recalled neonates (n = 398) included only 11 carriers. A receiver operating characteristic curve analysis showed that PAP above 8.0 ng/ml would select 0.76% of babies, including all those with cystic fibrosis, except for one with meconium ileus and two with mild CFTR mutations. Screening 27,146 babies with both PAP and IRT showed that only 0.12% had PAP > 8.0 ng/ml and IRT > 700 ng/ml, including all cases of cystic fibrosis.

CONCLUSION

PAP is increased in most neonates with cystic fibrosis and could be used for CF screening. Its combination with IRT looks promising.

Prevalence of the C282Y mutation in Brittany: penetrance of genetic hemochromatosis?

Hemochromatosis (GH) is an inborn error of iron metabolism, characterized by progressive iron loading that, if untreated, causes high morbidity and death. The gene responsible for the disease (HFE), located 4.5 megabases telomeric to the HLA-A locus, encodes a protein homologous to class I MHC molecules. A main mutation, C282Y, has been identified within the gene. Although hemochromatosis is considered as the most frequent inherited disease in the populations of Northern European origin, its prevalence in Brittany had not been evaluated yet. In this issue we report the C282Y mutation frequency in a cohort of 1000 newborns from maternity hospitals of the four breton départements. The homozygote frequency was 5/1000 and heterozygote frequency was 12%; such high frequencies raise the question of the penetrance of the disease and the relevance of systematic genotypic screening for hemochromatosis.