Functionalization of a self-assembled monolayer driven by low-energy electron exposure.

Self-assembled monolayers (SAMs) of 10-undecene-1-thiol on Au were functionalized with nitrogen-containing groups using an approach in which multilayer ammonia (NH(3)) films were deposited at low temperature onto the SAMs and subsequently exposed to 15 eV electrons. The result of this process was investigated after removal of the remaining NH(3) by annealing to room temperature using high-resolution electron energy loss spectroscopy (HREELS) and X-ray photoelectron spectroscopy (XPS). HREELS shows that the CC double bonds disappear during electron exposure, while XPS gives evidence that about 25% of the terminal double bonds of the SAM were functionalized. Also, XPS shows that a sufficiently thick NH(3) layer protects the underlying SAM from electron-induced damage. The process suggested here thus represents a particularly gentle approach to the functionalization of ultrathin molecular layers. Thermal desorption spectrometry (TDS) and electron-stimulated desorption (ESD) experiments on condensed layers of NH(3) reveal production of N(2) but show that significant amounts of the initial NH(3) as well as N(2) produced during electron exposure desorb. Hydrogen released upon formation of N(2) is held responsible for the reduction of double bonds and protection of the SAMs from damage.

Environmental risk factors for sporadic acoustic neuroma (Interphone Study Group, Germany).

The only known risk factor for sporadic acoustic neuroma is high-dose ionising radiation. Environmental exposures, such as radiofrequency electromagnetic fields and noise are under discussion, as well as an association with allergic diseases. We performed a population-based case-control study in Germany investigating these risk factors in 97 cases with acoustic neuroma, aged 30 to 69 years, and in 194 matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in multiple logistic regression models. Increased risks were found for exposure to persistent noise (OR=2.31; 95% CI 1.15-4.66), and for hay fever (OR=2.20; 95% CI 1.09-4.45), but not for ionising radiation (OR=0.91; 95 % CI 0.51-1.61) or regular mobile phone use (OR=0.67; 95% CI 0.38-1.19). The study confirms results of recently published studies, although the pathogenetic mechanisms are still unknown.

[Bedtime, television and computer habits of primary school children in Germany]. / Schlafenszeiten, Fernseh- und Computergewohnheiten von Grundschulkindern in Deutschland.

BACKGROUND: Pediatricians recommend daily sleep of at least ten hours for children aged 9 and 10 years. Sufficient sleep is necessary for maintaining the body's homeostasis, as well as for fixing memories and learning. Lack of sleep in children has been associated with a diminished school performance, reduced attention span, and obesity. Adulthood is influenced by childhood lifestyle habits. Data from 4th graders in 34 schools in Mainz and its surroundings were analysed in order to determine negative health lifestyle factors in German primary school children, such as lack of sleep and increased leisure time spent watching television and computer gaming. METHODS: Data from a cross-sectional study regarding cellular phone use in fourth-graders in Mainz were used for this analysis. Bedtime, television and computer use habits, as well as other factors were explored. A total of 1933 children from 34 schools participated by answering a questionnaire in the 2002-2003 school year (participation rate: 88%). Complete data for the secondary analysis were available from 1889 students (51% male, median age 10 years). RESULTS: Overall, 28% of the children reported going to bed after 9 pm on week nights, 16% reported watching television more than three hours daily, and 11% played computer or video games more than three hours daily. In the adjusted binary logistic regression model, being older, male, having older siblings, watching television (OR 1.82, 95% CI 1.28-2.61) and playing computer games (OR 3.23; 95% CI 2.24-4.67) for more than three hours daily, owning a mobile phone, and being in a school in the city were associated with going to bed after 9 pm. CONCLUSION: Every fourth child does not obtain a sleep duration of 10 hours, under the assumption that primary schoolchildren need to be awake at 7 am on weekdays. Lifestyle factors that may negatively influence a child's development determine their actual and future habits. Sufficient sleep and less television and computer leisure times should be assertively emphasized to parents and carers of primary school students, in order to prevent the negative consequences of lack of sleep, such as diminished school performance. Developing sex-specific prevention programs, which take into account the complex lifestyles and habits of primary schoolchildren, seems to be relevant.

[Allergies in adults]. / Allergien bei Erwachsenen.

Only few epidemiological studies have assessed allergic diseases in adults. In a follow-up study of the MONICA survey S3 (1994/95), which was performed 1997-1999, a total of 1,537 persons were interviewed and tested by skin prick and patch test. Furthermore data of the MONICA survey (RAST, cholesterol, food diaries) could be used. Within survey S4 (1999/2001) a total of 4,261 subjects were interviewed concerning their personal history of atopic diseases and the corresponding history of their partners. In survey S3 the prevalence of allergic sensitisation was 20.5 % for persons without formal graduation from school and 48.1 % for those with a university degree. 20.8 % reported a hypersensitivity to food and about one quarter exhibited a positive reaction in skin prick test. Atopic eczema and hay fever increased over quartiles of HDL cholesterol. Similar, allergic sensitisation (RAST) increased over quartiles of uptake of unsaturated fatty acids in men. 40 % of those who were patch tested exhibited a positive reaction, with perfume mix, nickel, thimerosal and balsam of Peru being the most prominent allergens. Inhabitants of the City of Augsburg were sensitised more often (34.0 % overall, 23.9 % pollen) than inhabitants of villages with (29.4 %, 17.0 %). Full time farmers were sensitised less frequently (22.0 %, 8.4 %). In survey S4 the lifetime prevalence of atopic diseases diagnosed by doctors was 5.1 % for atopic eczema, 6.1 % for asthma and 13.7 % for hay fever. Subjects who lived together with a partner who suffered from hay fever were affected in 19.6 % whereas 13.1 % had hay fever when the partner was not affected. Future studies will offer an unique opportunity to analyse the incidence and remission of manifestations of atopy in adults.

Epidemiology of food allergy/food intolerance in adults: associations with other manifestations of atopy.

BACKGROUND: Food allergy and food intolerance (FA/FI) are believed to be frequent medical problems; however, information from epidemiologic studies in adults is scarce. The objective was to determine the frequency of FA/FI and allergic sensitization to food in a large adult sample. Furthermore, the associations between FA/FI and other outcomes of atopy were studied. METHODS: Within a population-based, nested, case-control study, a standardized interview was performed to obtain detailed information on FA/FI and the history of atopic diseases. In addition, a skin prick test with 10 common food and nine aeroallergens was performed. RESULTS: Overall, 20.8% of the 1537 studied subjects (50.4% female, age median 50 years) reported FA/FI (women 27.5%, men 14.0%; OR 2.35, CI 1.80-3.08). Nuts, fruits, and milk most frequently led to adverse effects, and the sites of manifestation were oral (42.9%), skin (28.7%), gastrointestinal (13.0%), systemic (3.2%), and multiple (12.2%). One-quarter of the subjects (25.1%) were sensitized to at least one food allergen in the prick test, with hazelnut (17.8%), celery (14.6%), and peanut (11.1%) accounting for most of the positive reactions. The corresponding frequency estimates for the representative study base (n=4178) were 15.5% for reported adverse reactions and 16.8% for allergic sensitization. Relevant concomitant sensitization to food and aeroallergens was observed. Food-allergic subjects (positive history and sensitization to corresponding allergen) suffered significantly more often from urticaria, asthma, atopic eczema, and especially hay fever (73.1%) than controls (3.0%). Furthermore, hay fever was treated significantly more often in subjects who suffered from concomitant food allergy. CONCLUSIONS: FA/FI in adults is frequently reported and associated with other manifestations of atopy. Hay fever in conjunction with FA/FI tends to be clinically more severe since therapeutic needs are enhanced.

Epidemiology of contact allergy in adults.

BACKGROUND: We aimed to determine the prevalence of contact sensitization in the general population and to investigate associations with important sociodemographic and medical characteristics. METHODS: Within a population-based nested, case-control study in Germany, we performed patch tests with 25 standard allergens in 1141 adults (50.4% female, age median 50 years). Additional information was obtained by a dermatologic examination, a standardized interview, and blood analysis. RESULTS: At least one positive reaction was exhibited by 40.0% of the subjects, with reactions most frequently observed to fragrance mix (15.9%), nickel (13.1%), thimerosal (4.7%), and balsam of Peru (3.8%). Women were sensitized more often than men (50.2% vs 29.9%, OR 2.36, CI 1.84-3.03), and this was also significant for fragrance mix, nickel, turpentine, cobalt chloride, and thimerosal. Contact sensitization was more frequent in subjects who reported adverse skin reactions (53.8% vs. 32.6%; OR 2.41, CI 1.85-3.14), and this was particularly true for sensitization to nickel (45.5% vs 8.8%, OR 8.64, CI 5.67-13.17) and fragrance mix (29.0% vs 14.0%, OR 2.51, CI 1.60-3.91) and the corresponding intolerance of fashion jewelry and fragrances. Contact sensitization decreased with increasing degree of occupational training (unskilled 45.9%, apprenticeship 40.1%, technical college 40.4%, and school of engineering 12.5%; P=0.023; trend test P=0.042). Significant associations of contact sensitization and presence of allergen-specific IgE antibodies, atopic eczema, or psoriasis were not observed. Frequency estimates for the general adult population based on these findings were 28.0% for overall contact sensitization and 11.4% for fragrance mix, 9.9% for nickel, and 3.2% for thimerosal. CONCLUSIONS: It is concluded that contact allergy is influenced by sociodemographic parameters and plays an important role in the general population.

[Global child health--interventions that work]. / Global barnehelse--tiltak som virker.

BACKGROUND: Over the last decades, better drinking water and hygiene, improved nutrition and vaccines and antibiotics have greatly reduced child mortality and morbidity. Still, 11 million children under the age of five die every year, many of them from diseases that could have been prevented or treated, given existing knowledge and technology. MATERIALS AND METHODS: On the basis of a review of recent literature, this paper discusses current strategies to reduce childhood morbidity and mortality. RESULTS: Sufficient knowledge and technology exist to further improve the health of the worlds' children. Poverty and its consequences--weak implementation and organisation of health services--is a major obstacle. INTERPRETATION: In order to improve health services in developing countries, additional resources are needed. There is also a need for better quality of service. This will require increased efforts in the field of health policy and systems research.

[The transfer of selective serotonin reuptake inhibitors to human milk]. / Overgang av selektive serotoninreopptakshemmere til morsmelk.

BACKGROUND: This article presents an overview of the excretion of the SSRIs citalopram, paroxetine, fluoxetine, fluvoxamine and sertraline in breast milk. MATERIAL AND METHODS: Published articles on selective serotonin reuptake inhibitors and excretion in breast milk were identified and reviewed. In addition, drug concentrations were measured in milk from eight women using paroxetine (n = 4), citalopram (n = 3) or fluvoxamine (n = 1). RESULTS: Data from the literature indicate that the relative dose to the infant is lowest for fluvoxamine and sertraline, somewhat higher for paroxetine and highest for citalopram and fluoxetine. Adverse effects were reported in three of the 119 breastfed infants. Our own results show minimal excretion of fluvoxamine, small excretion of paroxetine and higher excretion of citalopram into breast milk. INTERPRETATION: If treatment with a selective serotonin reuptake inhibitor is started during the postpartum period, fluoxetine should not be the first alternative. High doses of citalopram should also be used with caution. However, when the use of an SSRI is clearly indicated in a breastfeeding woman, available data generally indicate that the positive effects of breast-feeding outweigh the risks for pharmacological effects in the infant.

Promoting breastfeeding in rural Gambia: combining traditional and modern knowledge.

Sub-optimal breastfeeding practices still prevail in many countries, especially in traditional rural communities. Despite high breastfeeding initiation rates and long total duration of breastfeeding, exclusive breastfeeding is a rare practice. In the present study, quantitative methods were used to identify current infant feeding practices in 12 rural communities in The GAMBIA: Results indicated that delayed initiation of breastfeeding, prelacteal feeding and failure to practice exclusive breastfeeding were widespread. Qualitative data further indicated that current beliefs and practices were strongly influenced by traditional beliefs and practices. These were kept very much alive by elders, both women and men, including husbands. The results also showed an unexpected support for bottle-feeding from both male and female elders who considered it part of the modernization process. A strategy for promoting early initiation of breastfeeding, feeding of colostrum and exclusive breastfeeding for 6 months in rural communities should therefore incorporate traditional beliefs and practices into modern messages on optimal breastfeeding. Traditional beliefs and practices in the study setting that could be used in this way included knowledge from the population's acquaintance with the newborns of their livestock. It also included the traditional practice of mothers taking their very young children with them when going to work in the fields. The paper suggests such a strategy by developing a matrix to establish linkages between modern and traditional knowledge on a specific practice. Such linkages facilitate the acceptance of recommendations on infant feeding by mothers in these communities. The strategy recommends an expanded target group to include elders and husbands, as the data show that these groups are highly influential in matters regarding patterns of child feeding.

[Malnutrition and infections in children--a destructive interplay with global dimensions]. / Underernaering og infeksjoner hos barn--et destruktivt samspill med globale dimensjoner.

BACKGROUND: Seven out of ten deaths among the world's children are caused by infectious diseases. Malnutrition is a contributing cause in more than half of the children's deaths. At present, interventions against such diseases in children are the most cost-effective way of reducing the world's morbidity and mortality. MATERIAL AND METHODS: This paper discusses how nutritional status affects the immune defence, and vice versa. General protein and energy malnutrition and some specific nutrients are discussed. The paper is based on review of recent literature found in Medline, and key references in the papers identified. RESULTS: Malnutrition is the most common cause of acquired immune deficiency in children. Malnourished children are especially prone to develop persistent diarrhoea, which in turn aggravates the nutritional status. Iron deficiency may be caused or worsened by hookworm and a number of other gastrointestinal infections. There are indications that iron deficiency in itself reduces the immune defence. Vitamin A supplements have reduced the mortality of measles and other infectious diseases. Some studies have shown reduced vertical transmission of HIV when pregnant women get vitamin A supplements. Chronic diarrhoea may cause zinc deficiency which may aggravate the diarrhoea. In areas where the general population's zinc status is marginal, zinc supplementation has reduced the incidence and duration of persistent diarrhoea. INTERPRETATION: The interaction between malnutrition and common infections in children causes a considerable fraction of the global burden of disease, yet so far this is not reflected in research, which mainly targets the diseases of the rich.

[Breast feeding as family planning in a global perspective]. / Amming som familieplanlegging i globalt perspektiv.

The contraceptive effect of lactation has been recognised for a long time, but detailed knowledge concerning the size and duration of this effect, and necessary preconditions has been lacking. Research on the lactational amenorrhoea method has given new insight into these matters. A consensus statement from 1988 concluded that women are protected against a new pregnancy during the first six months post-partum, provided they practise exclusive breast-feeding and remain amenorrhoeic. Recent research indicates that supplementary feeding does not disrupt this protection, which may last even beyond six months. Breast-feeding has a contraceptive effect also after resumption of menses, but this is too uncertain to be used in systematic family planning. The lactational amenorrhoea method should become an integrated element of family planning programmes.

The struggle of weaning: factors determining breastfeeding duration in east Bhutan.

This paper presents the qualitative part of a project in a traditional community in East Bhutan, which, among other items, investigates the effects on child health of breastfeeding, weaning and subsequent pregnancy of the mother. Quantitative data from the project have shown that children who are weaned during a subsequent pregnancy of the mother have a reduced weight gain and an increased incidence of infectious diseases during weaning, while this is not so for children weaned from non-pregnant mothers. In-depth interviews with 35 women with experience from breastfeeding were carried out in the local language in order to obtain qualitative data regarding the processes underlying the mothers decisions during weaning. Breastfeeding was found to fulfil a valuable social function in addition to its biological and emotional properties. The breastfed child had an undebatable "right of access" to the mother's care, not only her breast, whenever it wanted. This child also assumed a status in the family in which both its vulnerability, its special needs and its value were clearly recognized. The mothers expressed a basic motivation to breastfeed "as long as possible". There were, however, important limitations as to how this was manifested in the practical weaning process. If the mother was pregnant at the time of weaning, these limitations tended to be mother-centred. Most of the women had experienced tenderness of the breasts and a reduced milk production from the start of the next pregnancy. It was believed that the breast milk of a pregnant woman could "rot" and cause disease in the child. In spite of this belief, concurrent breastfeeding and pregnancy were common, but a pregnant mother whose breastfed child got ill, e.g. with diarrhoea, would immediately stop breastfeeding. The child would thereby abruptly loose the most important protection against the negative effects of the disease, when this protection was most needed. Concurrent pregnancy and lactation are common in many areas of the poor world. This has important consequences for the health of mothers and children, and has only recently been given the attention it derserves.

Child growth during weaning depends on whether mother is pregnant again.

Few longitudinal studies are available which relate data on breastfeeding and growth of the last-born child to data on the mother's subsequent pregnancy. The purpose of the present prospective study from Bhutan was to compare growth rate of children weaned during a subsequent pregnancy, with those of children weaned at the same age, but from non-pregnant mothers. Measurements of weight of 113 children and interviews with their mothers were done monthly through 32 months during the children's first 3 years of life. The period of overlap between lactation and pregnancy had a median duration of 5 months, and increased with an average of one week for each month reduction in the subsequent birth interval (P< 0.01). Children who stopped breastfeeding during their mothers' subsequent pregnancy showed a reduced growth rate during the last months before termination of breastfeeding when compared to children weaned at the same age, but from non-pregnant mothers (P = 0.04), and when compared to children who continued breastfeeding (P = 0.06).

Frequent diarrhoeas in early childhood have sustained effects on the height, weight and head circumference of children in East Bhutan.

Episodes of diarrhoea and nutritional status of 113 children in East Bhutan were recorded monthly from 7 to 36 months of age. A re-examination was carried out 20 months later. The load of diarrhoeal diseases in early childhood was negatively associated with the parameters of children's long-term nutritional status 20 months later. Also, when early nutritional status and socioeconomic factors are included in the model, the diarrhoea variable explains a significant part of the variation in height for age (p = 0.04, delta R2 = 0.035), weight for age (p = 0.03, delta R2 = 0.030) and head circumference (p = 0.0007, delta R2 = 0.077). This is not so for the variation in weight for height or mid-upper arm circumference (p > 0.1, delta R2 < 0.005). Stunting is widespread in the area, and the effects of diarrhoea on nutritional status are more likely to be sustained in settings where dietary intake is marginal.

Subsequent pregnancy affects morbidity of previous child.

A prospective study of 113 children in rural Bhutan registered their morbidity and weight and their mothers' subsequent pregnancies, monthly for 32 months during the children's first 3 years of life. Children whose mothers had a subsequent birth interval of 18-30 months had an incidence of diarrhoea during the subsequent pregnancy 50% higher than their matched cohort whose mothers did not become pregnant (p = 0.02). The relative risk for diarrhoea calculated from pooled child months was 1.51. Children whose mothers became pregnant also tended to have a higher incidence of skin infections. Children, whose mothers were pregnant when they terminated breastfeeding, experienced an increased incidence of diarrhoea around weaning (p = 0.01). Children weaned at the same age from non-pregnant mothers did not show increased morbidity. This study, for the first time, relates observations of children's morbidity directly in time to the occurrence of the mother's subsequent pregnancy, and provides evidence of a causal relationship between a moderately short subsequent birth interval and a concurrent increase in morbidity for the study child.

Breast feeding and seasonal determinants of child growth in weight in east Bhutan.

In a prospective study of 113 children in rural Bhutan, morbidity, nutritional status and feeding practices were recorded monthly over a period of 32 months. This information was related to seasonal variations in rainfall. Diarrhoea had a negative impact on growth, as measured in monthly intervals, during the second and third years of life, reducing daily weight gain by 4.4 +/- 2.0 g (p<0.0001). this impact was largest during the monsoon season. For respiratory tract infections the value was 2.6 +/- 1.7 g (p<0.01). Growth in weight was lowest during the monsoon period (p<0.0001). Continued breast feeding was associated with an odds ration for diarrhoea of 0.51 (95% CI 0.34-0.78), and for respiratory tract infections of 0.63 (95% CI 0.40, 0.99). Growth in weight was less reduced during the monsoon season for children who were breast fed (2.5 +/- 1.7 g/day) than for those not breast fed (7.5 +/- 3.5 g/day) (p<0.01). We conclude that breast feeding is of particular importance throughout the warm and rainy season.

Premature weaning in east Bhutan: only if mother is pregnant again.

The relationship between breast-feeding and subsequent pregnancy in East Bhutan is examined, against the background of local attitudes to family planning. Ninety-eight mothers who had given birth 30-36 months earlier were interviewed. Semisolid supplementary feeding was introduced at a median age of 3 months. Median total duration of breast-feeding was 28 months, and day and night breast-feeding on demand was continued throughout. Median duration of postpartum amenorrhoea was 12 months, and was associated with the timing of the introduction of supplementary foods. There was a significant association between the occurrence of a subsequent pregnancy and early termination of breast-feeding. The relationships between breast-feeding pattern and pregnancy interval are complex, and their relative influence changes with time. During the first year postpartum, infertility during lactational amenorrhoea is important. During the second year there is a strong negative effect on lactation from the next pregnancy. The only important reason for ceasing to breast-feed within 2 years seems to be a new pregnancy.

PIP: Breast feeding and subsequent pregnancy was investigated against the background of local attitudes to family planning. There were 113 index children born during the period of April-September 1990 in villages in Wamrong subdistrict in East Bhutan. 99 children remained in the sample, including one pair of twins. The 98 women who were their mothers were interviewed during March and April 1993. 7 children died during the study period, leaving 92 children whose average age was 32.7 months. The mean duration of breast feeding was 26.8 months. Breast feeding was halted for 61 children (66%). The median age of the child was 3 months at the time of introduction of semisolid supplementary food in the form of porridge made of rice flour in 61% of cases. 51 (82%) of these 61 children were fed at night; thus breast feeding remained on demand as long as it was practiced. The estimated mean duration of breast feeding for women who became pregnant again was 22.0 +or- 1.7 months and for those who did not it was 32.9 +or- 1.8 months (p 0.001). There was an inverse association between the birth to birth interval and duration of breast feeding in pregnancy. Those with an interval of less than 2 years had a mean duration of breast feeding in pregnancy of 5.2 months, while those with an interval of more than 2 years had a mean duration of 4.3 months. The median duration of postpartum amenorrhea was 12 months. 59 women who had lactational amenorrhea for 12 months or more did not become pregnant during the first year postpartum, while 9 women with amenorrhea for less than 12 months became pregnant (p 0.001). 51 women became pregnant when they were still breast feeding, which they stopped at 4.8 months. The actual birth interval averaged 25 months and the desired average was 40.6 months (p 0.001). A new pregnancy seemed to be the only important reason for stopping breast feeding within 2 years.

Subsequent pregnancy affects nutritional status of previous child: a study from Bhutan.

In a rural area of Bhutan, anthropometric measurements of 113 children and interviews with their mothers were carried out monthly for 32 months. The purpose of the study was to investigate the effect of a mother's subsequent pregnancy on growth in weight of her last-born child. The children whose mothers had a subsequent birth interval of 18-30 months were matched for date of birth with children whose mothers did not become pregnant. Growth of the children during the subsequent pregnancy was compared with growth during the same period of children whose mothers were not pregnant. A statistically significant reduction of 28% was found (p < 0.05), which was most pronounced in early pregnancy. A similar trend was found for change in mid-upper-arm circumference (p < 0.05). The study provides evidence of a causal relationship between a moderate subsequent pregnancy interval and a concurrent reduction in growth rate for the previous child.