Gliogenic LTP spreads widely in nociceptive pathways

Learning and memory formation involve long-term potentiation (LTP) of synaptic strength. A fundamental feature of LTP induction in the brain is the need for coincident pre- and postsynaptic activity. This restricts LTP expression to activated synapses only (homosynaptic LTP) and leads to its input specificity. In the spinal cord, we discovered a fundamentally different form of LTP that is induced by glial cell activation and mediated by diffusible, extracellular messengers, including d-serine and tumor necrosis factor (TNF), and that travel long distances via the cerebrospinal fluid, thereby affecting susceptible synapses at remote sites. The properties of this gliogenic LTP resolve unexplained findings of memory traces in nociceptive pathways and may underlie forms of widespread pain hypersensitivity.

Properties of spinal lamina III GABAergic neurons in naïve and in neuropathic mice

BACKGROUND

Nerve injury leads to Aβ-fibre-mediated mechanical allodynia that is in part due to an impaired GABAergic inhibition in the spinal cord dorsal horn. The properties and function of GABAergic neurons in spinal cord lamina III, an area where low-threshold mechanosensitive Aβ-fibres terminate are, however, largely unknown.

METHODS

We used transgenic mice, which express enhanced green fluorescent protein (EGFP) under control of the promoter GAD67. The morphology and neurochemical characteristics of GABAergic, EGFP-expressing neurons were characterized. We assessed active and passive membrane properties of spinal lamina III GABAergic neurons in naïve animals and animals with a chronic constriction injury (CCI) of the sciatic nerve.

RESULTS

EGFP-expressing neurons in lamina III were predominantly islet cells (47%), whereas non-EGFP-expressing neurons were largely inverted stalked cells (40%). EGFP-expressing neurons accounted for about 25% of GABAergic neurons in lamina III. Forty-four percent co-expressed glycine, 10% neuronal nitric oxide synthase and 3% co-expressed parvalbumin. We found costaining with protein kinase CβII in 42% of EGFP-expressing neurons but no expression of protein kinase Cγ. Membrane properties and excitability of EGFP-and non-EGFP-expressing neurons from naïve and neuropathic animals were indistinguishable. The most frequent firing pattern was tonic firing (naïve: 35%, neuropathic: 37%) followed by gap firing (naïve: 33%, neuropathic: 25%). Delayed, initial burst and single-spike firing patterns made up the remainder in both groups.

CONCLUSION

A change in membrane excitability or discharge pattern of this group of lamina III GABAergic neurons is unlikely the cause for mechanical allodynia in animals with CCI.

Analysis of the Relationship between Pollinosis and Date of Birth in Switzerland

BACKGROUND

The first months of life may represent a vulnerable period in the development of atopic diseases. The objective of this study was to examine the relationship between the month of birth and the development of birch and grass pollen allergy in the Swiss population.

METHODS

Data from the Swiss Study on Air Pollution and Lung Diseases in Adults(SAPALDIA) as well as the Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution and Climate (SCARPOL) were used. A logistic regression was calculated with grass and birch pollen sensitisation (positive skin prick test) or allergy (positive skin prick test and allergic symptoms) as outcome variables and the season of birth as predictor variable. The contribution of the season of birth on pollinosis was further adjusted for well-known risk factors and potential confounding variables.

RESULTS

The logistic regression revealed a significant effect of the season of birth on birch pollen sensitisation and an effect of borderline significance on birch pollen allergy, i.e. subjects born in the pollen season (March to April) showed an increased risk of being sensitised/allergic to birch pollen. The results also indicated a tendency towards an increased risk for subjects born in the grass pollen season (May to June) to develop grass pollen allergy.

CONCLUSION

Our results support the hypothesis that the first few months of life constitute a sensitive period, during which inhalative exposure to certain allergens may predispose to the subsequent development of atopic respiratory disease.

Trends in prevalence of asthma, allergic rhinitis and atopic dermatitis in 5-7-year old Swiss children from 1992 to 2001

BACKGROUND

Changing occurrence rates of asthma, allergic rhinitis and atopic dermatitis are of public health concern and require surveillance. Changes in prevalence rates of these atopic diseases were monitored during 10 years and their trend with time was determined taking into account the influence of personal and environmental risk factors.

METHODS

Four cross-sectional surveys in 5-7-year old children were performed in seven different communities in Switzerland between 1992 and 2001. Prevalence of respiratory and allergic symptoms and of affecting risk factors including parental environmental concern were assessed using a standardized parental questionnaire.

RESULTS

A total of 988 (74.1%), 1778 (79.0%), 1406 (82.6%) and 1274 (78.9%) children participated, respectively, in the 1992, 1995, 1998 and 2001 surveys. Prevalence rates of asthma and hay fever symptoms remained quite stable over time (wheeze/past year: 8.8%, 7.8%, 6.4% and 7.4%, sneezing attack during pollen season: 5.0%, 5.6%, 5.4% and 4.6%). Rates of reported atopic dermatitis symptoms (specific skin rash/past year: 4.6%, 6.5%,7.4% and 7.6%) showed an increase over time, but those of diagnosis of eczema did not show a clear pattern (18.4%, 15.7%, 14.0% and 15.2%). Stratified analysis by parental environmental concern and by parental atopy showed similar trends. Rates of atopic dermatitis symptoms showed significant increase in girls but stayed stable in boys.

CONCLUSION

Results of these four consecutive surveys suggest that the increase in prevalence of asthma and hay fever in 5-7-year old children living in Switzerland may have ceased. However, symptoms of atopic dermatitis may still be on the rise, especially among girls.

Influence of MMR-vaccinations and diseases on atopic sensitization and allergic symptoms in Swiss schoolchildren

The prevalence of asthma and allergic disease has increased in many countries. It has been proposed that vaccinations may contribute to the development of allergic disease by reducing clinical infections in infancy or through the direct IgE-inducing effects of the vaccines. Evidence for a potential role of immunizations in the development of allergic disease is scarce. Therefore the objective was to study the associations between vaccinations against measles, mumps and rubella (MMR), natural infections of these diseases and atopic sensitization to indoor and outdoor allergens and allergic symptoms in schoolchildren. The cross-sectional study including 1537 8(th) grade school children aged 13-15 years living in 10 communities across Switzerland was organized in the framework of an environmental health surveillance program within the School Health Services (Swiss Surveillance Program of Childhood Asthma and Allergies with respect to Air Pollution and Climate, SCARPOL). Main outcome measures were asthma and sneezing during pollen season assessed by parental questionnaires and atopic sensitization determined by IgE concentrations to various allergens. It was found that parents' reported history of measles or mumps was associated with a stronger immune response than two or more vaccinations against the respective infection (measles: geometric mean IgG titers (GMT) lU/ml (95% Cl) 2.8 (2.0-3.9) vs. 1.2 (1.0-1.4), mumps: GMT PE/ml (95% Cl) 16.3 (13.9-19.1) vs. 8.5 (6.1-11.7). With respect to atopic sensitization similar associations for exposure by natural MMR-infections or MMR-vaccinations were found: measles: OR (95% Cl) 1.02 (0.53-1.96) vs. 1.22 (0.69-2.16), mumps: 0.59 (0.38-0.93) vs. 0.79 (0.49-1.27), rubella: 0.93 (0.61-1.43) vs. 0.95 (0.66-1.37), respectively. Inverse relationships were found between the risk of asthma and a positive disease history or vaccination of measles 0.36 (0.14-0.91) vs. 0.45 (0.21-0.98) or a positive serum titer against measles 0.65 (0.35-1.20). From the present study can be concluded that exposure by MMR-vaccinations or natural MMR-infections in childhood does not increase the risk of sensitization to common allergens as well as to allergic respiratory diseases. MMR-vaccinations or natural MMR-infections are therefore an unlikely factor contributing to the increase in atopic disease in developed countries.

No further increase in asthma, hay fever and atopic sensitisation in adolescents living in Switzerland

Prevalence rates of childhood asthma and allergy have been on the increase for several decades. The present study investigated whether this trend continued during the 1990s in adolescents living in Switzerland. Between 1992 and 2000, the change in prevalence of specific immunoglobulin E to aeroallergens, asthma symptoms and hay fever symptoms assessed by parents' and students' answers to the International Study of Asthma and Allergies in Childhood questions was investigated using three cross-sectional surveys. In total 1,324 (74.9%), 1,668 (80.6%) and 1,250 (73.9%) adolescents participated. Prevalence rates of asthma and current asthmatic symptoms remained constant, irrespective of whether the assessment was based on parental questionnaires or the student's self-completed written or video questionnaires (students' report of current wheeze 8.8, 7.3, and 8.3%). Similarly, no further increase was observed for reported hay fever rates and allergic sensitisation rates (positive multiscreen allergy test, SX1-test: 34.6, 38.9, and 35.6%, respectively). Although time trends in the occurrence of a series of known risk factors were recorded, none of these factors had a significant impact on asthma and allergy prevalence over time. No further increase in asthma and allergy rates occurred during the 1990s in adolescents living in Switzerland. However, to adequately assess the trend a longer period of observation is needed.

A cluster of autosomal recessive spondylocostal dysostosis caused by three newly identified DLL3 mutations segregating in a small village

In 1982, one of us reported a cluster of eight individuals affected by spondylocostal dysostosis (SD, MIM 277300) in four nuclear families indigenous to a village from eastern Switzerland. We tested the hypothesis that the molecular basis for this cluster was segregation of a single mutation in the DLL3 gene, recently linked to SD. Marker haplotypes around the DLL3 locus contradicted this hypothesis as three different haplotypes were seen in affected individuals, but sequence analysis showed that three unreported DLL3 mutations were segregating: a duplication of 17 bp in exon 8 (c.1285-1301dup), a single-nucleotide deletion in exon 5 (c.615delC), and a R238X nonsense mutation in exon 6. Contrary to our initial assumption of a single allele segregating in this small community, three different pathogenic alleles were observed, with a putative founder mutation occurring at the homozygous state but also compounding with, and thus revealing, two other independent mutations. As all three mutations predict truncation of the DLL3 protein and loss of the membrane-attaching domain, the results confirm that autosomal recessive spondylocostal dysostosis represents the null phenotype of DLL3, with remarkable phenotypic consistency across families.

Inert gas exchange during pneumoperitoneum at incremental values of positive end-expiratory pressure

Laparoscopy is a surgical technique for a growing variety of abdominal operations. In patients undergoing this procedure, arterial blood oxygenation and hemodynamics are frequently depressed. This study evaluated the effect of different levels of positive end-expiratory pressure (PEEP) during intraperitoneal CO(2) insufflation on the lung's ventilation-perfusion distribution in a porcine model. We studied 13 anesthetized pigs with an intraperitoneal pressure of 15 cm H(2)O applied at either incremental values of PEEP (5-20 cm H(2)O, increments of 5 cm H(2)O) or a constant PEEP of 5 cm H(2)O. The effects of CO(2) pneumoperitoneum on inert gas exchange and hemodynamics were examined with the multiple inert gas elimination technique. During pneumoperitoneum, gas exchange was most augmented by 15 and 20 cm H(2)O of PEEP. Although the differences in hemodynamics between the individual settings were insignificant, 10 cm H(2)O of PEEP provided the smallest impairment of hemodynamics. We conclude that PEEP of 15 H(2)O during pneumoperitoneum resulted in a modest hemodynamic depression but significant gas exchange augmentation in our experiment.

IMPLICATIONS

Anesthetized pigs, with a pneumoperitoneum of 15 cm H(2)O, were treated either with incremental values of positive end-expiratory pressure (5-20 cm H(2)O, increments of 5 cm H(2)O) or with a constant positive end-expiratory pressure of 5 cm H(2)O. Fifteen and 20 cm H(2)O resulted in significantly improved pulmonary gas exchange compared with 5 cm H(2)O.

Effect of fluvoxamine on sufentanil antinociception and tolerance under chronic intravenous infusion in rats

Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), significantly potentiates analgesia when administered in animals together with opioids. The aim of the present study was to investigate the effects of fluvoxamine on sufentanil antinociception and tolerance. Following animal care committee approval, the effects of continuous infusions of fluvoxamine and sufentanil were studied in behavioural tests (hot-plate test, tail-flick test, catalepsy test) in Sprague-Dawley rats with a jugular vein catheter. Saline was administered as a control. The time-effect curves for continuous intravenous sufentanil indicate dose-related antinociception and rapid development of tolerance in the hot-plate and tail-flick tests. Co-administration of fluvoxamine with continuous sufentanil enhances antinociception and attenuates development of tolerance, most clearly seen in the tail-flick test. Fluvoxamine alone and saline were not effective. No animal showed catalepsy. As a side effect we observed a marked loss of body weight. The IC50 values of sufentanil binding with and without fluvoxamine addition are 0.56+/-0.17 nM and 0.3+/-0.15 nM, respectively, indicating no direct effect on the occupancy of sufentanil on the mu-receptor by this serotonin reuptake inhibitor. In conclusion, we were able to show that the combination of an opioid with an SSRI at low doses improves analgesia and decreases development of tolerance in nociceptive tests in rats. The clinical implications of these promising results in an animal model, however, await further investigation.

[Measles, mumps and rubella: vaccination rate and seroprevalence in 8th grade students of 8 different sites in Switzerland 1995/96]

In 1987, the Swiss Federal Health Office (BAG) and the Swiss cantons launched the MMR-vaccination campaign. Within the frame of the SCARPOL Study, the vaccination status of 649, 8th class students was registered and serum samples were collected. The measles, mumps and rubella specific antibody levels were determined. The vaccination rate was 84% for measles, 74% for mumps, and 62% for rubella, 55% of these children had been vaccinated with the combined vaccine MMR. The vaccination rate for the different study areas varied from 70% to 95% for measles, 42% to 94% for mumps and 18% to 89% for rubella, 92% of the children tested seropositive for measles specific antibodies, 87% for mumps and 84% for rubella. The seroprevalence for measles, mumps and rubella was significantly higher for vaccinated than for unvaccinated children. Non-Swiss children had, without exception, a higher seroprevalence rate than Swiss children. Undergoing the disease did not influence the seroprevalence for measles, but it did so for mumps and rubella, for vaccinated and unvaccinated children alike. By analysis according to study site, we observed that sites with higher vaccination rates (e.g. Grabs in Rheintal) sometimes showed a lower seroprevalence than sites with lower vaccination rates (e.g. Langnau). This was the case for all three vaccines. This, together with other observations, shows that a booster is necessary for an adequate immunisation--as a wild virus infection or as a second vaccination.

Effect of environmental tobacco smoke exposure on respiratory symptoms in children. SCARPOL Team. Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution, Climate and Pollen

AIMS

This study determines the prevalence of exposure to environmental tobacco smoke and its relation to respiratory and allergic symptoms among schoolchildren in Switzerland.

METHODS

We studied 4470 children aged 6-14 years as part of a multicentre study (SCARPOL study--Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution, Climate and Pollen) conducted in Switzerland between 1992 and 1993. Environmental tobacco smoke exposure, maternal smoking during pregnancy and respiratory symptoms were assessed by means of a self-administered parental questionnaire.

RESULTS

Forty-seven percent of all children were exposed to environmental tobacco smoke. Sixteen percent of the mothers smoked during pregnancy. Children exposed to environmental tobacco smoke at home had an increased risk of respiratory infections (odds ratio (OR) 1.19, 95% confidence intervals (CI) 1.03, 1.37). The risk increased if they were exposed to maternal smoking (OR 1.25, CI 1.06, 1.48) and if the mother also smoked during pregnancy (OR 1.42, CI 1.14, 1.76). Wheezing (OR 1.36, CI 1.03, 1.80) and repeated coughing (OR 1.36, CI 1.14, 1.61) were only associated with maternal smoking. Children exposed to more than 20 cigarettes per day were at highest risk for respiratory problems.

CONCLUSION

Almost half of all schoolchildren in Switzerland, especially those from lower socioeconomic classes, are exposed to environmental tobacco smoke. Children with environmental tobacco smoke exposure suffer significantly more often from respiratory symptoms. Maternal smoking during pregnancy additional to current smoking further increases the risk of respiratory morbidity. These findings underline the importance of prevention strategies to reduce the prevalence of smoking and its impact on children's health.

Prevalence of hay fever and allergic sensitization in farmer's children and their peers living in the same rural community. SCARPOL team. Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution

INTRODUCTION

Lower prevalence rates of allergic diseases in rural as compared with urban populations have been interpreted as indicating an effect of air pollution. However, little is known about other factors of the rural environment which may determine the development of atopic sensitization and related diseases.

OBJECTIVE

The authors tested the hypothesis that children growing up on a farm were less likely to be sensitized to common aerollergens and to suffer from allergic diseases than children living in the same villages but in nonfarming families.

MATERIALS AND METHODS

Three age groups of schoolchildren (6-7 years, 9-11 years, 13-15 years) living in three rural communities were included in the analyses. An exhaustive questionnaire was filled in by 1620 (86.0%) parents. A blood sample was provided by 404 (69.3%) of the 13-15 year olds to determine specific IgE antibodies against six common aeroallergens.

RESULTS

Farming as parental occupation was reported for 307 children (19.0%). After adjustment for potential covariates such as family history of asthma and allergies, parental education, number of siblings, maternal smoking, pet ownership, indoor humidity and heating fuels, farming as parental occupation was significantly associated with lower rates of sneezing attacks during pollen season (adjusted OR 0.34, 95% CI 0.12-0.89) and atopic sensitization (adjusted OR 0.31, 95% CI 0.13-0.73) whereas the association with wheeze (adjusted OR 0.77 95% CI 0.38-1.58) and itchy skin rash (adjusted OR 0.86, 95% CI 0.49-1.50) was not statistically significant. The risk of atopic sensitization was lower in children from full-time farmers (adjusted OR 0.24, 95% CI 0.09-0.66) than from part-time farmers (adjusted OR 0.54, 95% CI 0.15-1.96).

CONCLUSION

Factors directly or indirectly related to farming as parental occupation decrease the risk of children becoming atopic and developing symptoms of allergic rhinitis.

Comparison of responses to an asthma symptom questionnaire (ISAAC core questions) completed by adolescents and their parents. SCARPOL-Team. Swiss Study on Childhood Allergy and Respiratory Symptoms with respect to Air Pollution

The primary objective of the study was to determine the impact of the identity of the respondent (parents versus adolescents) on prevalence estimates of asthma symptoms in Swiss adolescents. In addition, factors influencing agreement between parents' and adolescents' responses to the same questions were analysed. One thousand three hundred and seventy-four (78.4%) adolescents, aged 14 years, self-completed a questionnaire at school based on the International Study of Asthma and Allergy in Childhood (ISAAC) core questions on wheezing and asthma. The same questions were incorporated into a questionnaire to be completed by the parents at home. The adolescents' self-reported prevalence rates of current asthma symptoms and "asthma ever" were significantly higher than those obtained from the parental questionnaires. 856 (62.6%) parental questionnaires were filled in by parents without the help of the adolescents, 460 (37.4%) were completed by parents and adolescents and 51 (3.7%) were completed by the adolescents without the parents. Prevalence rates were higher when parents and adolescents completed the questionnaire jointly than when questionnaires were completed by parents alone. The level of agreement between parental and self-completed questionnaires was moderate to low (kappa coefficients 0.22-0.68). Agreement between parental and adolescents reports of asthma symptoms was best when questionnaires were completed jointly by parents and adolescents, when the adolescent was a girl, when a family history of asthma was recorded, when the adolescent was a non-smoker, and when the parental education was high. We conclude that the higher reporting of prevalence rates of current asthma symptoms by adolescents compared to reporting by their parents demonstrates the need to take the respondent to a questionnaire into account when comparisons are made between prevalence studies. The results also suggest that factors related to the family milieu influence symptom reporting.

Safety and characterization of the immune response engendered by two combined measles, mumps and rubella vaccines

We performed a randomized trial to compare the safety and immunogenicity of two combined measles, mumps and rubella vaccines in healthy children 14-24 months of age. Triviraten Berna Vaccine (Swiss Serum and Vaccine Institute), contains the Edmonston Zagreb 19 strain of measles virus, the Rubini mumps virus strain and the Wistar RA 27/3 rubella strain while MMR-Vax (Merck, Sharp & Dohme, West Point, PA) contains the Enders attenuated Edmonston measles strain, the Jeryl Lynn mumps strain and the Wistar RA 27/3 rubella strain. Immunization with Triviraten Berna was associated with a significantly lower incidence of swelling and redness at the injection site in addition to a reduced rate of fever compared with MMR-Vax. Seroconversion rates for the measles and rubella vaccine components were comparable in all tests used. However, seroconversion for the mumps vaccine component was test-dependent. Using an ELISA, the seroconversion rate following immunization with MMR-Vax was significantly (P < 0.01) higher than for Triviraten Berna. In contrast, nearly identical rates were obtained using an indirect immunofluorescence test. Both vaccines were equally effective at engendering antibodies capable of neutralizing wild type mumps virus. Geometric mean ELISA antibody titers against measles and mumps virus were higher following immunization with MMR-Vax while that for rubella was higher after immunization with Triviraten Berna. A small number (N = 13) of adolescents immunized either with MMR-Vax or Triviraten Berna were reimmunized with Triviraten Berna and various humoral and cellular response parameters to the measles and mumps vaccine components analyzed. While few subjects mounted a humoral antibody response to measles, most likely due to elevated baseline titers, there was a marked lymphoproliferative response. Anti-mumps virus ELISA antibody titers were higher both at baseline and after reimmunization in subjects who received MMR-Vax for primary immunization. However, there was no difference in either neutralizing titer or proliferative response in subjects primed with MMR-Vax or Triviraten Berna either before or after reimmunization.

[Acceptance of an Ethics Committee (International Review Board)]

The work input of an institutional review board, the satisfaction or dissatisfaction of project applicants with its decisions, as well as the amount of time needed for preparatory and follow-up work for projects submitted to the board were surveyed in a questionnaire. An analysis of the status quo provided proposals for improvement, with the aim of increasing the satisfaction of all parties involved. Questionnaires were returned by 41.4% (101/244) of the specialist doctors surveyed. Of these, 42 were doctors who had submitted projects for review and whose evaluation was used for the study. The proportion of trained "clinical review doctors" was 14.3%. Analysis of work input showed that 13.5 +/- 15.2 hours were invested before submitting a project and 6.3 +/- 9.3 hours in the follow-up. Although the board's work was given a satisfactory grading with a score of 2.8 +/- 1.0, the surveyed satisfaction/importance profile showed marked deficits in many areas, primarily in organization and communication, as well as in the examination and evaluation of projects. The suggestions for improvement above all requested the introduction of a review system employing specialists from outside the institution or from other disciplines, standardization of project submission, optimization of organization and improvement in communication. In summary, the institutional review board plays an important role in clinical research. The acceptance of a review board's work, however, can only be improved when the suggestions for improvement are realized step by step. The results of this evaluation and the proposed solutions can also help other boards improve their work. At any rate, it would be desirable to take a new look in several years' time at how the proposals worked out in this study have been implemented.

Validation of a rhinitis symptom questionnaire (ISAAC core questions) in a population of Swiss school children visiting the school health services. SCARPOL-team. Swiss Study on Childhood Allergy and Respiratory Symptom with respect to Air Pollution and Climate. International Study of Asthma and Allergies in Childhood

The primary aim of the study was to assess the validity of the ISAAC core questions on rhinitis in a population of Swiss school children by comparing them to skin prick test results. Second, the positive predictive value in detecting atopy among children with rhinitis symptoms was determined. Third, agreement between parental reports of hay fever and rhinitis symptoms was evaluated, since earlier Swiss prevalence surveys had exclusively relied on reported hay fever.

MATERIAL AND METHODS

Two thousand nine hundred and fifty-four (81.2%) parents of 7, 10 and 14-year old children filled in an exhaustive questionnaire which included the ISAAC core questions on rhinitis. Two thousand one hundred and twenty children also underwent skin prick testing against six common aeroallergens (grass mixture, birch, mugwort, D. pteronyssinus, cat and dog dander). The analysis is restricted to children with both questionnaire data and skin prick test results.

RESULTS

Sensitization to any allergen was most strongly associated with reported hay fever (OR = 5.7, 95% CI 4.4-7.4), nose problems accompanied by itchy-watery eyes (OR = 4.4, 95% CI: 3.3-5.7), symptoms occurring only during pollen season (March through September) (OR = 4.9, 95% CI: 3.6-6.5) and a combination of these latter two symptoms (OR = 5.8, 95% CI: 4.1-8.1). The association was stronger for a sensitization to outdoor allergens than for indoor allergens. The specificity of the various questions was high, ranging from 77.5% to 97.6%, but the sensitivity was low (2.6% to 42.7%). The positive predictive value for atopy among children with symptoms was 63% for sneezing accompanied by itchy-watery eyes, 67% for symptoms occurring only during the pollen season and 70% for reported hay fever. However, agreement between reported rhinitis symptoms and hay fever was only moderate. About one third of the children with symptoms indicative of seasonal rhinitis did not report the label "hay fever".

CONCLUSIONS

We conclude from our analyses that the ISAAC core questions on rhinitis are highly specific and therefore useful in excluding atopy. In addition they have a high positive predictive value in detecting atopy among children with symptoms, but they are not helpful for detecting atopy in a general population of children (low sensitivity). To monitor time trends in the prevalence of allergic rhinitis in Switzerland, questions on rhinitis symptoms as well as on the diagnostic label "hay fever" have to be included in a questionnaire because they contain complementary information since under-diagnosis of allergic rhinitis is common.

Pneumothorax following nasogastric feeding tube insertion in a tracheostomized patient after bilateral lung transplantation

We report the case of a pneumothorax caused by the improper placement of a nasogastric feeding tube in a tracheostomized patient after bilateral lung transplantation. We discuss the contribution of low-pressure cuffed tracheostomy tubes to the inadvertent respiratory tract misplacement of a nasogastric feeding tube, as well as the problems of nasogastric feeding tube insertion in the sedated patient, why the previously installed closed-tube thoracostomy did not prevent the pneumothorax and possible pitfalls in confirming the proper position of the nasogastric feeding tube. In conclusions, we stress that in high risk patients a nasogastric feeding tube should only be inserted under direct vision and that a subsequent routine X-ray is mandatory for confirming proper positioning.

Respiratory health and long-term exposure to air pollutants in Swiss schoolchildren. SCARPOL Team. Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution, Climate and Pollen

The impact of long-term exposure to air pollution on respiratory and allergic symptoms and illnesses was assessed in a cross-sectional study of schoolchildren (ages 6 to 15 yr, n = 4,470) living in 10 different communities in Switzerland. Air pollution measurements (particulate matter less than 10 microns in diameter [PM10], nitrogen dioxide [NO2], sulfur dioxide [SO2], and ozone) and meteorologic data were collected in each community. Reported symptom rates of chronic cough, nocturnal dry cough, and bronchitis, adjusted for individual risk factors, were positively associated with PM10, NO2, and SO2. The strongest relationship was observed for PM10 (adjusted odds ratios for chronic cough, nocturnal dry cough, and bronchitis between the most and the least polluted community for PM10 were 3.07 [95% CI: 1.62 to 5.81], 2.88 [95% CI: 1.69 to 4.89], and 2.17 [95% CI: 1.21 to 4.89], respectively). The high correlation between the average concentrations of the pollutants makes the assessment of the relative importance of each pollutant difficult. No association between long-term exposure to air pollution and classic asthmatic and allergic symptoms and illnesses was found. There was some indication that frequency of fog is a risk factor of chronic cough and bronchitis, independent of air pollution. In conclusion, this study provides further evidence that rates of respiratory illnesses and symptoms among children augment with increasing levels of air pollution even in countries like Switzerland with moderate average air pollution concentrations.

[Allergies in agriculture]

Thanks to enormous progress in industrial medicine, life expectancy of workers in dust-polluted (dust-burdened) jobs has massively improved; however, farmers, gained too little interest of industrial medicine so far and thus show one of the highest mortality rates from pulmonary diseases. Today the farmer's exposure to dust and respective allergens is often extremely high; however, the composition of the inhaled dust varies extremely, depending on the type of work. Particularly organic dusts are inhaled that are known as common and frequent allergy inducers in the normal population. In spite of the increased exposure to the common airborne allergens, children of farmers rarely develop allergies, obviously due to an increased tolerance to common allergens. The high mortality rate from pulmonary diseases, including asthma, in farmers seems therefore less a question of profession-specific allergens than of decompensated adaptation phenomena. Thus an optimized dust prevention seems important. Dermatologic diseases: Farmers are exposed to many irritative and potentially sensitizing contact allergens including those from natural sources (plants) and diverse fungicides, pesticides as well as chemicals used in mechanical professions. The risk of phototoxic and photoallergic reactions is increased by profession-related exposure to sun. This also concerns related reactions to medical drugs. The best preventive measure for contact sensitization is an optimized skin protection, particularly of the hands.

[Mumps: efficacy of booster immunization]

10 children aged 15 years, who presented with anti-mumps antibodies of < 3 PEI (Paul Ehrlich Institute) despite documented mumps vaccination in the past, were boosted with Triviraten Berna (Rubini mumps strain) and the antibody response was assessed after 7, 28 and 90 days. All 5 children boosted with the same vaccine (Rubini mumps strain) had a titer rise as early as day 7 persisting for 3 months. The 4 children primed with the Jeryl Lynn mumps strain showed a primary immune response, i.e. a rise of the antibody titer after 28 days only, which did not persist well. The child originally primed with the Urabe mumps strain did not show any significant immune response on day 28, which means a negative result. Children apparently susceptible to mumps cannot be differentiated from immune children by measurement of antibody titers. Reexposure to the homologous vaccine virus elicited a persisting immune response: however, revaccination with a heterologous vaccine virus elicited an immune response directed against different antigenic epitopes, followed by limited persistence of circulating antibodies. The efficacy of a second dose of mumps vaccine was demonstrated in 9/10 children. Only by using a two-dose immunization schedule is it possible to effectively avoid the occasionally serious complications of this viral infection, as has been achieved in Finland.

[Why do farmers die more often from lung diseases?]

During the period 1988-1992 deaths from lung diseases were more frequent among the farming population according to Swiss mortality data. The age-standardized proportional mortality rate (PMR) is 127 for all the lung diseases (ICD-8 460-519), 140 for bronchitis and asthma (ICD-8 490-493), 137 for asthma alone (ICD-8 493) and 841 for pneumoconiosis due to organic dust (ICD-8 516.1 + .2). Stock-farmers showed a mortality pattern for chronic obstructive pulmonary disease opposite to that of vegetable farmers and wine-growers. This increased mortality among farmers is paradoxical in the light of the more frequent tolerance for aeroallergens among the children of farmers, the conservative style of housing and living as well as received ideas about working in natural and therefore healthy air. Insufficient knowledge of the multifactorial risks of natural pathogenic organic substances and of dangerous work are just as important for the pathogenesis of these diseases and deaths as the changed social and cultural values with the consequences on insurance policy. These factors affect optimal prophylaxis (limitation of air pollution, safety measures, job change and measures in order to achieve adequate social security).

[Immunological-allergological reactions with changed environmental conditions]

Is the increased incidence of allergic diseases a by-product of technologic development? Can this hypothesis be supported by measurable alterations in immunoreactivity? Continuous sero-epidemiologic monitoring since 1983 in children from Grabs prove a statistically significant increase in allergic sensitization, in particular against grass pollen. An etiologic link between the increased prevalence of hay fever and growing volume of motor vehicle traffic is suggested by: 1. the temporal correlation: Prevalence of hay fever has increased simultaneously with the raise of emission of photo-oxidants. High ozone and pollen immissions do also coincide over the course of the day. 2. pathophysiology: Ozone prolongs and intensifies exposure to allergens by reducing bronchociliary clearance and increasing permeability for inhaled antigens. Children from farmers exhibit a lower morbidity for hay fever in spite of a more intense exposure to both photo-oxidants and grass pollen. They show that not only exposure but also adaptive mechanisms may be important in assessing correlations with aerial pollutants.

[Significance of fecal streptococci in the detection of bacteriologic contamination of drinking water]

Because of their increased environmental resistance faecal streptococci are a good indicator of a contamination dating back a long time. Under the new Federal German Drinking Water Regulations, examination of faecal streptococci is not mandatory. On the basis of 190 samples of water from natural springs it was shown that, if the water was examined only in respect of E. coli and coliform bacteria there were no objections in 22% of water that was faecally contaminated, so that such water escaped detection. Hence, it is advisable to perform the faecal streptococci test in water that is frequently or potentially infected with bacteria.

[Costovertebral dysplasia. A receptor defect of sclerotome development?]

8 subjects with costovertebral dysplasia in 4 interrelated families are described. The cases occurred from 1949 to 1978 and all showed the analogous generalized malformation of the vertebrae and ribs. One child with concomitant chromosomal anomaly (Down's syndrome) died at the age of 7 days. Follow-up in the 7 cases shows no decrease in life expectancy or any other malformation, and in particular non bronchopneumonial complications. Case reports and comparisons of the prevalence of neural tube defects in this isolated population and in Switzerland rule out increased risk of neural tube defects for costovertebral dysplasia. The pedigree of kindred over 8 generations is consistent with autosomal recessive inheritance. As the cause of the malformation a possible receptor defect of the mesodermal sclerotomes is discussed.

[Trampers in India - Description of a population (author's transl)]

50 trampers in India and Sri Lanka were studied in a semistructured interview by a questionnaire for socio-demographic data, for their medical and psychiatric history and their drug-experience. The MPI (Eysenck) and SSS (Zuckermann) were applied as tests for describing personality. Most of the trampers are around 25 years, stem from medium economical strata, have an education of high school or university. Nearly all of them are experienced drug-users (mainly hashish), most of them for long time without increase of intake and without bodily or mental or social deterioration. In the MPI the score for extraversion and neuroticism is within the (English) norm rage. Female probands showed a higher score of neuroticism than males. The total score in the SSS was significantly higher than in the standard population, mainly due to significantly elevated scores in the scale for disinhibition and boredom susceptibility.

Magnetic relaxation analysis of dynamic processes in macromolecules in the pico- to microsecond range

A formalism based on the theory of Markov processes and suitable for the analysis of multiple internal motions in macromolecules is presented. Computer calculations of specific motional models for (13)C nuclear magnetic resonance (NMR) relaxation, treated as special cases of the proposed formalism, demonstrate the potential of this approach for discriminating between different motional models on the basis of NMR relaxation data.

The phosphoenolpyruvate-dependent phosphotransferase system of Staphylococcus aureus. 3. 1H and 31P nuclear-magnetic-resonance studies on the phosphocarrier protein HPr; tyrosine titration and denaturation studies

The phosphocarrier protein HPr has been investigated by proton nuclear magnetic resonance (NMR) at 270 MHz in order to evaluate structural properties of the whole molecule and its active site. The titration behaviour of the three tyrosines of the HPr protein was analysed by monitoring the chemical shifts of the aromatic proton resonances of these residues as a function of pH. It was found that the HPr protein contains a lot of slowly exchanging NH backbone protons which suggested a relatively rigid secondary structure of the protein molecule itself although it contains no disulfide bridges. The HPr protein shows a sharp reversible denaturation behaviour at alkaline pH values. Between pH 10.8 and 11.1 two C-2 proton resonance peaks for the single histidine residue could be observed together with abrupt changes in the aromatic and aliphatic absorption region of the HPr protein which are due to chemical exchange processes. The NMR spectrum of the HPr protein is only changed a little upon raising the temperature from 14 degrees C to 70 degrees C. At 76 degrees C all resonances in the spectrum broaden and almost disappear. This process is irreversible.