[Nutrition in pregnancy - Practice recommendations of the Network "Healthy Start - Young Family Network"]

Nutrition, physical activity and lifestyle in pregnancy influence maternal and child health. The "Healthy start - Young Family Network" supported by the German Government with the national action plan IN FORM developed recommendations on nutrition in pregnancy. Folic acid supplements (400 µg/day) should be started before pregnancy and continue for at least the first trimester. Iodine rich foods and salt and an iodine supplement (100-150 µg/day) are recommended. Long-chain omega-3 fatty acids should be provided with ≥ 1 weekly portion of oily sea fish, or a DHA-supplement if regular fish consumption is avoided. Vitamin D supplementation is advisable unless there is regular exposure to sunlight. Iron supplements should be used based on medical history and blood testing. Vegetarian diets with nutritional supplements can provide adequate nutrition, but counselling is recommended. In contrast, a vegan diet is inadequate and requires additional micronutrient supplementation. For risk reduction of listeriosis and toxoplasmosis, raw animal foods, soft cheeses and packed fresh salads should be avoided; fresh fruit, vegetables and salad should be washed well and consumed promptly. Pregnant women should remain physically active and perform sports with moderate intensity. They should avoid alcohol, active and passive smoking. Up to 3 daily cups of coffee are considered harmless, but energy drinks should be avoided. Childhood allergy is not reduced by avoiding certain foods in pregnancy whereas oily sea fish is recommended. Health care professions should lead parents to health-promoting lifestyles. Subjects of part 1 of the article are practice recommendations on nutrition, on energy needs, micronutrient needs and body weight/weight gain in pregnancy.

Natural micro-scale heterogeneity induced solute and nanoparticle retardation in fractured crystalline rock

We studied tracer (Tritiated Water (HTO); Tritium replaces one of the stable hydrogen atoms in the H(2)O molecule) and nanoparticle (quantum dots (QD)) transport by means of column migration experiments and comparison to 3D CFD modeling. Concerning the modeling approach, a natural single fracture was scanned using micro computed tomography (μCT) serving as direct input for the model generation. The 3D simulation does not incorporate any chemical processes besides the molecular diffusion coefficient solely reflecting the impact of fracture heterogeneity on mass (solute and nanoparticles) transport. Complex fluid velocity distributions (flow channeling and flowpath heterogeneity) evolve as direct function of fracture geometry. Both experimental and simulated solute and colloidal breakthrough curves show heavy tailing (non-Fickian transport behavior), respectively. Regarding the type of quantum dots and geochemical conditions prevailing (Grimsel ground water chemistry, QD and diorite surface charge, respectively and porosity of the Äspö diorite drill core) experimental breakthrough of the quantum dots always arrives faster than the solute tracer in line with the modeling results. Besides retardation processes like sorption, filtration, straining or matrix diffusion, the results show that natural 3D fracture heterogeneity represents an important additional retardation mechanism for solutes and colloidal phases. This is clearly verified by the numerical simulations, where the 3D real natural fracture geometry and the resulting complex flow velocity distribution is the only possible process causing solute/nanoparticle retardation. Differences between the experimental results and the simulations are discussed with respect to uncertainties in the μCT measurements and experimental and simulation boundary conditions, respectively.

Electron kinetic energies from vibrationally promoted surface exoemission: evidence for a vibrational autodetachment mechanism

We report kinetic energy distributions of exoelectrons produced by collisions of highly vibrationally excited NO molecules with a low work function Cs dosed Au(111) surface. These measurements show that energy dissipation pathways involving nonadiabatic conversion of vibrational energy to electronic energy can result in electronic excitation of more than 3 eV, consistent with the available vibrational energy. We measured the dependence of the electron energy distributions on the translational and vibrational energy of the incident NO and find a clear positive correlation between final electron kinetic energy and initial vibrational excitation and a weak but observable inverse dependence of electron kinetic energy on initial translational energy. These observations are consistent with a vibrational autodetachment mechanism, where an electron is transferred to NO near its outer vibrational turning point and ejected near its inner vibrational turning point. Within the context of this model, we estimate the NO-to-surface distance for electron transfer.

Is a PBL curriculum a better nutrient medium for student-generated learning issues than a PBL island?

Problem based learning (PBL) is often introduced in curricula in form of short segments. In the literature the value of these PBL-islands is doubted. In order to gain more insight in this curricular approach, we compared student generated learning issues, from a 7-week PBL-island introduced in a traditional curriculum (PBL-I), with the gold standard of a PBL-based model-curriculum (PBL-B) existing in parallel at the same University (Ruhr-University Bochum, Germany). Both tracks use five identical PBL-cases. Thousand seven hundred and three student-generated learning issues of 252 tutorial groups (193 PBL-I and 59 PBL-B groups with six to seven students per group) were analysed in seven different categories. Results showed that overall there were no substantial differences between both curricula. PBL-B students generated more problem-related and less basic science clinical learning issues than PBL-I students, but in both groups learning issues were related to the same number of different subjects. Furthermore, students in the PBL-curriculum tend to generate little less but slightly better phrased issues. Taken together, we found no substantial evidence with respect to student-generated learning issues that could prove that students cannot work with the PBL-method, even if it is introduced later in the curriculum and last only for a short period of time.

In vivo detection of Staphylococcus aureus in biofilm on vascular prostheses using non-invasive biophotonic imaging

OBJECTIVES

Biophotonic imaging was compared to standard enumeration method both for counting Staphylococcus aureus in biofilm and bacterial susceptibility tests of different graft materials.

DESIGN

Prospective, randomized, controlled animal study.

MATERIAL AND METHODS

Five types of vascular grafts were placed subcutaneously in 35 mice and challenged with bioluminescent S. aureus. The mice were divided into equal groups as follows: group A (polyester), group B (polytetrafluoroethylene), group C and D (two types of silver acetate-coated polyester) and group E (bovine pericardium). Controls were given only the bacteria. The bioluminescence signal of S. aureus, able to predict number of viable bacteria in biofilm without any manipulation, was measured at different time points. Five days postinfection, regular cultures of adherent bacteria on grafts were obtained. Comparative analyses between bioluminescence activity and culture enumeration were performed.

RESULTS

The number of viable bacteria on silver-coated prostheses was the slightest, indicating superior bacterial resistance. The density of bacteria on polytetrafluoroethylene and polyester was comparable, with a non-significant advantage for polytetrafluoroethylene. Moreover, bioluminescence detected the number of viable S. aureus in biofilm more exactly compared to enumeration of bacteria.

CONCLUSION

Bioluminescence imaging can be considered a useful tool to characterize susceptibility of any graft material to bacterial biofilm prior to implantation.

Social, educational, and occupational predictors of total hip replacement outcome

OBJECTIVE

There is limited evidence on social, educational, and occupational factors as predictors of response to total hip replacement (THR). We aimed to analyze these factors in a large population-based setting.

METHOD

Patients of the Dresden Hip Surgery Registry were recruited and the pre and post (6 months) operative functional status was assessed using the global Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score (0-100 points). Non-response was defined a gain of <20 points in WOMAC score over a 6 months period and was analyzed with respect to six socioeconomic parameters. Multiple logistic regression modeling was applied to adjust for age, sex, BMI, co-morbidity, and preoperative functional status.

RESULTS

Data from 1007 patients (mean age 61 years, STD 13; 55% women) were included. The average preoperative WOMAC score was 45.8 which increased to 84.4 after surgery. 38.2%, 36.6%, and 25.3% of the patients attended school for 8, 9, and 12 years, respectively. 54.1% were retired, 26.9% worked full time, and 6.7% received a disability pension. A 14.8% of the patients did not achieve a gain of > or =20 points in WOMAC score and were classified as non-responders. After control for confounders, significantly increased risks of non-response were found for widowed patients compared to singles [odds ratio (OR) 4.30, 1.45-12.71], those who lived alone (OR 1.70, 1.02-2.85), and patients with a disability pension compared to those who worked full time (OR 5.81, 2.33-14.46). The risk of non-response decreased with increasing length of school education (12 vs 8 years: OR 0.49, 0.27-0.89). Compared to workers, employees (OR 0.55, 0.33-0.90) and self-employed patients (OR 0.41, 0.18-0.94) showed significantly decreased risks of non-response.

CONCLUSION

Socioeconomic parameters are independent predictors of response to THR. This can help to improve the health service by identifying subgroups which need special attention in order to increase the response rate.

Differences in allergy trends between East and West Germany and possible explanations

BACKGROUND

At the time of the German reunification in 1990, manifestations of most allergic diseases were less prevalent in East than in West Germany. It was hypothesized that these East-West differences would diminish with lifestyle and pollution changes in East Germany.

OBJECTIVE

To investigate whether changes in the prevalence of asthma, hayfever, eczema or allergic sensitization in East Germany approached the levels seen in West Germany and to identify possible lifestyle or environmental factors that may influence this.

METHODS

Between 1991 and 2000, 6-year-old children from four areas in East Germany participated in an annual survey. Every 3rd year, a parallel survey was performed in four areas of West Germany. In total, 31 903 children were included. Parents completed a questionnaire regarding lifestyle factors and diagnoses and symptoms of asthma, hayfever and eczema. In sub-areas, eczema was clinically assessed by a dermatologist. Specific IgE sensitization was determined for 6121 children. Logistic regression was used to analyse differences in time trends and the influence of lifestyle and pollution changes.

RESULTS

Lifestyle and pollution changed significantly differently between East and West Germany. The trends in hayfever and in strong (specific IgE >3.5) sensitization against pollen, and particularly birch pollen, were steeper in East than in West Germany. The trend towards marked pollen sensitization was four times stronger (95% confidence interval 1.2-13.9) in East than in West Germany. Increasing numbers of only children, less single-room heating with fossil fuels and increasing importance of traffic-related pollution in East Germany partly explained these differences in time trends.

CONCLUSIONS

Hayfever and sensitization against pollen were the most sensitive allergic manifestations to changes experienced specifically in East Germany. Influences of lifestyle (single-room heating, living as a single child) were important in explaining different trend developments.

Development and evaluation of an implementation strategy for the German guideline on community-acquired pneumonia

BACKGROUND

Data of the German Competence Network for Community-Acquired Pneumonia showed a gap between the recommendations of the national guideline for management of community-acquired pneumonia (CAP) and the routine care. We developed and evaluated an implementation strategy to improve the quality of care of patients with CAP.

METHOD

A prospective, randomised, controlled trail was conducted within CAPNETZ. In four local clinical centres (LCC), the guideline was implemented by different strategies. The other four LCC served as control group. Indicators for guideline adherence comprised initial site of treatment, initial antibiotic treatment and duration of antibiotic treatment. As patient-related factors, we assessed the effect of guideline implementation on 30-day mortality and length of hospital stay.

RESULTS

Active guideline implementation yielded an increased proportion of guideline adherence to the length of antibiotic treatment in outpatients (+9.2%), the recommended antibiotic treatment (+5.6%) and duration of antibiotic treatment in inpatients (+5.0%) compared with baseline. In contrast, the proportion of patients in the control group, treated according to the guideline, decreased in the same period by 7.9%, 2.9% and 4.7%, respectively. None of these results was statistically significant. Decrease of CAP-related mortality was higher in the intervention group compared with the control group (2.9% vs 0.5%, ns).

CONCLUSION

This study showed improvements in the process of care after implementation of a guideline for treating CAP. Further strategies, such as quality improvement cycles and medical practice audits, may enhance this effect.

Identification and characterization of sorbed lutetium species on 2-line ferrihydrite by sorption data modeling, TRLFS and EXAFS

The Lu(III) sorbed species onto synthetic hydrous ferric oxide (HFO), commonly called ferrihydrite, has been identified. Characterization of the synthetic 2-line HFO shows that its synthesis is reproducible. Potentiometric titration of freshly synthesized HFO, modeled using the constant capacity model (κ1=0.5 F/m2) in the FITEQL code, yields a specific surface area S a of 360±35 m2/g (N2-BET), a site density N d of 2.86 sites/nm2 (concentration of hydroxyl groups, N s=1.71×10-3 mol sites/g HFO), and acidity constants pK a1}int=6.37 and pK a2}int=9.25.

Evaluation of chemical sorption data reveals the presence of two different Lu surface sorbed species, dependent on pH; a monodendate species forms at low pH and a polydentate species at pH>5. Satisfactory fits to the sorption data are obtained using a combination of monodentate and bidentate surface species. The combination of species is chosen, based on extended X-ray absorption fine structure (EXAFS) results. The sorption constants obtained from these fits are pK s=-1.89(±0.1) and pK s=-1.69(±0.1) for the monodentate species ≡FeOLu(H2O)5 2+ for fits to the pH edge and to the isotherm at pH°5.9, respectively. A value of pK s=3.69(±0.01) is found for the bidentate species ≡ Fe(O)2Lu(H2O)5 + for both fits. EXAFS analysis of sorption samples prepared at 4.5<pH<8 shows that Lu is surrounded by a single first shell of 7±1 oxygen atoms, at a distance of (2.30±0.01) Â in all samples. A second coordination shell of Fe neighboring atoms at a distance of (3.38±0.01) Â is observed for sorption samples pH≥5.5. This distance is associated with the formation of a bidendate complex with bonding via edge sharing to iron octahedra. The samples prepared at pH<5.1 show no Fe shell, as expected for monodentate coordination. No evidence for surface precipitation and no noticeable difference between wet paste and dried powder samples is found.

Thermostable lipases from the extreme thermophilic anaerobic bacteria Thermoanaerobacter thermohydrosulfuricus SOL1 and Caldanaerobacter subterraneus subsp. tengcongensis

Two novel genes encoding for heat and solvent stable lipases from strictly anaerobic extreme thermophilic bacteria Thermoanaerobacter thermohydrosulfuricus (LipTth) and Caldanaerobacter subterraneus subsp. tengcongensis (LipCst) were successfully cloned and expressed in E. coli. Recombinant proteins were purified to homogeneity by heat precipitation, hydrophobic interaction, and gel filtration chromatography. Unlike the enzymes from mesophile counterparts, enzymatic activity was measured at a broad temperature and pH range, between 40 and 90°C and between pH 6.5 and 10; the half-life of the enzymes at 75°C and pH 8.0 was 48 h. Inhibition was observed with 4-(2-aminoethyl)-benzenesulfonyl fluoride hydrochloride and phenylmethylsulfonylfluorid indicating that serine and thiol groups play a role in the active site of the enzymes. Gene sequence comparisons indicated very low identity to already described lipases from mesophilic and psychrophilic microorganisms. By optimal cultivation of E. coli Tuner (DE3) cells in 2-l bioreactors, a massive production of the recombinant lipases was achieved (53–2200 U/l) Unlike known lipases, the purified robust proteins are resistant against a large number of organic solvents (up to 99%) and detergents, and show activity toward a broad range of substrates, including triacylglycerols, monoacylglycerols, esters of secondary alcohols, and p-nitrophenyl esters. Furthermore, the enzyme from T. thermohydrosulfuricus is suitable for the production of optically pure compounds since it is highly S-stereoselective toward esters of secondary alcohols. The observed E values for but-3-yn-2-ol butyrate and but-3-yn-2-ol acetate of 21 and 16, respectively, make these enzymes ideal candidates for kinetic resolution of synthetically useful compounds.

Stress-related maternal factors during pregnancy in relation to childhood eczema: results from the LISA Study

BACKGROUND

Stress has been suggested to impact the onset and exacerbation of eczema and other atopic disorders. Whether early exposure to stress-related factors might exert long-term effects remains to be clarified.

OBJECTIVE

The objective of this study was to investigate whether stress-related maternal factors during pregnancy are associated with childhood eczema during the first 6 years of life.

METHODS

Data from 3004 children from a prospective German birth cohort study (LISA) were analyzed. Information from maternity certificates and questionnaire information on unwanted pregnancy were used to evaluate stress-related maternal factors during pregnancy. Prevalence data for physician-diagnosed eczema were available up to the age of 6 years.

RESULTS

Maternal factors during pregnancy were positively associated with childhood eczema in terms of cumulative prevalence up to the age of 2 years (adjusted odds ratio, 1.48; 95% confidence interval, 0.95-2.30) after adjusting for potential confounders. Beyond the second year no increased risk was observed.

CONCLUSIONS

The results of this study suggest that stress-related maternal factors during pregnancy are associated with an increased risk of childhood eczema during the first 2 years of life. The impact of postnatal stress such as parental divorce or separation on this association could not be clarified. Future studies should therefore further elucidate how prenatal and postnatal stress interact and whether prenatal stress might have a programming effect. If future studies confirm the findings of this study, reducing maternal stress during pregnancy might be a possible target in the primary prevention of eczema during childhood.

The influence of colloid formation in a granite groundwater bentonite porewater mixing zone on radionuclide speciation

In the context of deep geological storage of high level nuclear waste the repository will be designed as multiple barrier system including bentonite as buffer/backfill material and the host rock formation as geological barrier. The engineered barrier (bentonite) will be in contact with the host rock formation and consequently it can be expected that bentonite porewater will mix with formation groundwater. We simulate in this study the mixing of Grimsel groundwater (glacial melt water) with synthetic Febex porewater (assuming already saturated state) in a batch-type study and investigate the formation of colloids by laser-induced breakdown detection (LIBD) and SEM-EDX as well as the changes in radionuclide (U, Th, Eu) speciation via ultrafiltration or via time-resolved laser fluorescence spectroscopy (TRLFS) analysis in the case of Cm(III). Based on PHREEQC saturation index (SI) calculations a precipitation of calcite might be expected at low Febex porewater (FPW) content (<20%), fluorite precipitation at FPW contents <60% and gibbsite precipitation at FPW contents above 10%. The colloids generated in the mixing zone aggregate when the synthetic FPW content exceeds 10%. LIBD analysis of the time-dependent colloid generation/aggregation revealed a low concentration of colloids to be stable with an estimated plateau value around 100-200 ppt and an average colloid diameter around 30 nm after 140 days reaction time at FPW admixture >10%. SEM/EDX mostly identifies Al/Si containing colloidal phases and some sulfates could be found under certain admixture ratios. TRLFS studies show that the Cm speciation is strongly influenced by colloid formation in all solutions. In the Febex pore water/GGW mixing zone with high groundwater contents (>80%) colloids are newly formed and Cm is almost quantitatively associated with most likely polysilicilic acid colloids.

Systematic review and evidence-based consensus guideline on prevention of allergy and atopic eczema of the German Network on Allergy Prevention (ABAP)

Allergies are a meaningful public-health problem. Until now no evidence-based recommendations for allergy prevention exist. An evidence based guideline for primary and secondary prevention of allergies was developed in the course of the German Network on Allergy Prevention (Aktionsbündnis Allergiepräven-tion, ABAP) with support of the German Ministry of Health. Results of the systematic evidence search and the consented recommendations are presented here. After an appropriate search strategy was developed, a systematic literature search was performed in electronic databases (Cochrane library, MEDLINE, EMBASE). Furthermore four selected journals were hand-searched and reference lists of actual reviews as well as grey literature was screened. Some 3 500 references were retrieved initially and a two-stage filter process on the relevance was applied by screening titles and abstracts and subsequently full-text papers. For the critical methodological appraisal modifications of international checklists were used. A total of 323 studies were included and evaluated. These comprised 3 Cochrane Reviews, 7 meta-analyses, 37 randomized controlled trials (RCTs) as well as 102 cohort and 174 case-control-studies. The following levels of evidence were applied: 3x1a, 21x1b, 5x2a, 59x2b, 1x3a, 45x3b, 189x4. These studies were summarized in a form of a systematic review and corresponding recommendations were formulated. The latter were consented by members of the abap steering committee in two consensus meeting where the method of a nominal group process was applied. For the first time recommendations for the prevention of allergies were developed on a high methodological standard. The content and modifications reflect the existing evidence.

[Pathophysiology of the obesity hypoventilation syndrome]

The obesity hypoventilation syndrome (OHS) is defined by extreme overweight (BMI 30 kg/m2), daytime hypoventilation (PaCO2 > 45 mm Hg, the absence of other known causes of hypoventilation) and sleep-related breathing disorders. Obesity impairs breathing due to a restrictive ventilatory disorder, reduction of the capacity of respiratory muscles and diminishment of the ventilatory response. The restriction cannot serve as the only explanation of OHS because body weight or compliance on the one hand and hypoventilation on the other hand only correlate weakly. Obesity increases the work of breathing by greater body mass with its increased oxygen demand, impaired diaphragmatic mobility, upper airway obstruction, and oxygen desaturation which result in an inadequacy of oxygen demand and supply. The adjustment of the chemoreceptors can avoid the overload on the capacity of the respiratory muscles, at least in a number of patients or in the course of the disease. This disproportion results in hypercapnia. Furthermore, the level of leptin is an important factor in the pathophysiology of OHS. The blood level of leptin correlates with the body fat mass in humans. However, there seems to be a relative leptin deficiency in the brain in overweight humans. Therefore, in contrast to animals, leptin cannot sufficiently increase ventilation in man to avoid hypercapnia.

Predictivity of allergic sensitization (RAST) for the onset of allergic diseases in adults

BACKGROUND

Specific IgE antibodies are often detected without any clinical manifestation of allergies. We aimed to analyse the predictivity of allergic sensitization for incident symptoms of allergic diseases in adults during a 10-year follow-up.

METHODS

In 1994/95 specific IgE antibodies against five common inhalant allergens (grass pollen, birch pollen, house dust mite, cat dander and Cladosporium) were diagnosed by radioallergosorbent test in 4178 adults aged 25-74 years. A subset of 2656 participants could be re-evaluated in 2004/05. Information on socio-economic factors and medical history, including data on atopic diseases, was assessed by a combination of a personal interview and a self-administered questionnaire. Logistic regression models were applied to study associations between allergic sensitization and incident allergic diseases.

RESULTS

Allergic sensitization was an important predictor for incident hay fever (OR 7.95, CI 95% 4.64-13.62) and asthma (OR 1.82, CI 95% 1.29-2.57). Specific IgE antibodies were mainly related to outdoor allergens (grass and birch pollen) for hay fever and indoor allergens (mite and cat dander) for asthma, while for atopic dermatitis no specific IgE antibodies were identified as major predictors.

CONCLUSIONS

Allergic sensitization not only covers clinically apparent allergies, but indicates a prognostic factor for later allergies, even in adulthood.

Allergic sensitization to cat in childhood as major predictor of incident respiratory allergy in young adults

BACKGROUND

Little is known on the predictive value of sensitization to specific aeroallergens in children with respect to asthma and hay fever incidence in young adulthood. We followed the incidence of asthma and hay fever in children (mean age 11 years) over 9 years, and analyzed the predictive value of sensitization to five common aeroallergens.

METHODS

Three consecutive surveys were conducted in East German school children. Specific IgE antibodies to birch and timothy grass pollen, house dust mite, cat, and cladosporium were measured. In 1207 out of the 2453 children, the 9-year incidence of asthma and hay fever was assessed by reported doctors' diagnoses. For sensitization, diagnostic parameters were determined and logistic regression analyses controlled for relevant confounders.

RESULTS

A total of 176/78 incident hay fever/asthma cases occurred equaling a cumulative incidence of 1.93/0.86% per year. Incident asthma was associated with previous sensitization to cat [risk ratio (RR) 3.49, 1.57-7.74] and grass pollen (RR 1.79, 1.01-3.19), whereas incident hay fever was associated with each allergen, with grass pollen (RR 6.00, 4.04-8.90) and cat (RR 5.36, 2.87-9.99) exhibiting the strongest associations. When mutually adjusting for all allergens, sensitization to cat remained significantly associated with asthma and hay fever. The latter was also associated with sensitization to grass pollen. The highest positive predictive values for asthma and hay fever were obtained for cat sensitization (10/49 = 20.4% and 23/49 = 46.9%).

CONCLUSIONS

Childhood sensitization to cat and grass pollen predicts the incidence of asthma and hay fever in young adulthood. The predictive capacity differs by allergen and manifestation of atopy.

Determinants of influenza and pneumococcal vaccination in elderly people: a systematic review

OBJECTIVES

Despite strong national and international recommendations on immunization practices, rates for influenza (IV) and pneumococcal vaccinations (PV) are low. We aimed to review international immunization rates and to analyze attitudes and beliefs regarding IV and PV.

STUDY DESIGN

Systematic review.

METHOD

The MEDLINE database search comprised articles from 1966 to October 2005. Fourteen surveys evaluating a total number of 49292 participants in nine different countries were included into the analysis.

RESULTS

Vaccination rates among risk groups do vary significantly between different countries, reaching highest rates in the USA (IV, 82%; PV, 71%) and lowest in former West-Germany for IV (37%) and in Israel for PV (20%). Recommendations by doctors play a central role in promoting IV and PV. The main reason for not being vaccinated was lack of information.

CONCLUSION

Specific strategies targeted at groups are needed to increase the knowledge of IV and PV, and thereby decrease incidences of acute lung diseases.

[Daytime ventilatory efficiency in obstructive sleep apnea syndrome--influence of CPAP-therapy]

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a nocturnal breathing disorder with possibly negative consequences on daytime control of ventilatory drive. We therefore investigated ventilatory efficiency, defined as the ventilatory equivalent for CO2 (VaE/VaCO2), in patients with OSAS during exercise before and under treatment with continuous positive airway pressure (CPAP).

PATIENTS AND METHODS

In 21 patients with untreated OSAS, ventilatory efficiency, described as the slope (DeltaVaE vs. VaCO2) and the lowest ratio (VaE/VaCO2 min) of the ventilatory equivalent for CO2, was determined below the anaerobic threshold using spiroergometry. A follow-up after at least 6 months of CPAP therapy was performed in 16 of these patients and in 5 CPAP-neglecting patients with OSAS, who served as controls.

RESULTS

In 21 patients with untreated OSAS, DeltaVaE vs. VaCO2 was significantly and VaE/VaCO2 min non-significantly lower, revealing better ventilatory efficiency, compared to normal values. In 16 patients, ventilatory efficiency did not change after on average 305.7 +/- 104.8 nights of CPAP-therapy, compared to 5 controls.

CONCLUSIONS

OSAS is not associated with a disturbed ventilatory efficiency during exercise. Long-term CPAP-therapy does not change ventilatory efficiency during exercise in patients with OSAS. The improved ventilatory efficiency during exercise compared to normal controls may be due to differences concerning anthropometric data (e. g., obesity, hypertension) and cardiopulmonary exercise-test (45 degrees lying position).

Further evidence for a somatic KRAS mutation in a pilocytic astrocytoma

Astrocytomas are the most common brain tumors of childhood. However, knowledge of the molecular etiology of astrocytomas WHO grade I and II is limited. Germline mutations in the Ras-guanosine triphosphatase-activating protein, neurofibromin, in individuals with neurofibromatosis type I predispose to pilocytic astrocytomas. This association suggests that constitutive activation of the Ras signaling pathway plays a fundamental role in astrocytoma development. We screened 25 WHO I and II astrocytomas for mutations of PTPN11, NRAS, KRAS, and HRAS genes and identified the somatic G12A KRAS mutation in one pilocytic astrocytoma. These data suggest that Ras is rarely mutated in these tumors. Analyzed astrocytomas without mutations in Ras or neurofibromin may harbor mutations in other proteins of this pathway leading to hyperactive Ras signaling.

[Giving up pets--organic milk--eliminating mold. What preventive measures are reliable?]

Data gained from studies show that allergies are aggravated by passive smoking and a room climate that fosters the growth of mold. On the other hand, a certain degree of protection is provided by breastfeeding, hypoallergenic infant formulas, the banning of cats or pet rodents from a household with risk children, and the appropriate stimulation of the young child's immune system. Vaccinations recommended by the STIKO (National Board for Immunization) should also be given to children at risk of developing an allergy, since they are more likely to have a preventive rather than an allergy-promoting effect.