Increasing the reliability of real-time electrocochleography during cochlear implantation: a standardized guideline.

PURPOSE: Electrocochleography (ECochG) measures electrical potentials generated by the inner ear in response to acoustic stimulation. Real-time (rt) recordings are increasingly used during cochlear implant (CI) surgeries to monitor the inner ear function. However, the performance of rt-ECochG is a delicate measurement procedure involving several pitfalls, which lead to inaccurate or invalid signal recordings in up to 20%. In order to use the technique routinely in CI candidates, an improvement in measurement reliability must be achieved. METHODS: In our prospective study, we systematically investigated potential pitfalls and error sources during rt-ECochG recordings. We performed experiments (i) on a head and torso simulator, (ii) on a whole-head cadaver specimen, (iii) as well as in vivo during rt-ECochG recordings in CI recipients. After analyzing experiments i-iii, a standardized measurement procedure was developed. We followed this guideline in 10 CI recipients to test the measurement reliability. RESULTS: Besides improper installation, surgical and patient-specific factors influenced the measured signal. In particular, the unattenuated presentation of the acoustic stimulus was of importance. We summarized our findings in a standardized guideline. Following this guideline, we measured successful intraoperative ECochG recordings in 9/10 patients. CONCLUSIONS: Our error analysis improved the understanding of successful rt-ECochG measurements. When following our proposed guideline, we achieved more reliable intraoperative ECochG recordings.

Transition metal-free coupling of terminal alkynes and hypervalent iodine-based alkyne-transfer reagents to access unsymmetrical 1,3-diynes.

A variety of unsymmetrical 1,3-diynes can easily be accessed in good yields under catalyst- and transition metal-free conditions by reacting terminal alkynes with hypervalent iodine-based electrophilic alkyne-transfer reagents.

Asthma and allergies: is the farming environment (still) protective in Poland? The GABRIEL Advanced Studies.

BACKGROUND: Evidence exists that a farming environment in childhood may provide protection against atopic respiratory disease. In the GABRIEL project based in Poland and Alpine regions of Germany, Austria and Switzerland, we aimed to assess whether a farming environment in childhood is protective against allergic diseases in Poland and whether specific exposures explain any protective effect. METHODS: In rural Poland, 23 331 families of schoolchildren completed a questionnaire enquiring into farming practices and allergic diseases (Phase I). A subsample (n = 2586) participated in Phase II involving a more detailed questionnaire on specific farm exposures with objective measures of atopy. RESULTS: Farming differed between Poland and the Alpine centres; in the latter, cattle farming was prevalent, whereas in Poland 18% of village farms kept ≥1 cow and 34% kept ≥1 pig. Polish children in villages had lower prevalences of asthma and hay fever than children from towns, and in the Phase II population, farm children had a reduced risk of atopy measured by IgE (aOR = 0.72, 95% CI 0.57, 0.91) and skin prick test (aOR = 0.65, 95% CI 0.50, 0.86). Early-life contact with grain was inversely related to the risk of atopy measured by IgE (aOR = 0.66, 95% CI 0.47, 0.92) and appeared to explain part of the farming effect. CONCLUSION: While farming in Poland differed from that in the Alpine areas as did the exposure-response associations, we found in communities engaged in small-scale, mixed farming, there was a protective farming effect against objective measures of atopy potentially related to contact with grain or associated farm activities.

Exposure to moulds and actinomycetes in Alpine farms: a nested environmental study of the PASTURE cohort.

Several studies have suggested that children exposed to a farm environment are protected against allergies and asthma. The present work is an environmental study nested within the PASTURE cohort and includes 97 farmers and 74 non-farmers in three regions of the Alpine Arc (Switzerland, France and Germany). The objectives were to determine and compare the fungi and actinomycetes present in farming and non-farming environments (children's bedrooms and cowsheds), and to identify the agricultural practices associated with an increase in airborne fungi and actinomycetes in cowsheds. Air samples were collected by air pump and were analysed by culture and by direct counting of spores on membranes. During their stay in bedrooms, children living on farms were exposed to significantly greater amounts of Absidia spp., Eurotium spp., Cladosporium spp., Penicillium spp. and mesophilic actinomycetes than children who did not live on farms. Depending on the season, the levels of moulds, yeasts and actinomycetes were from 14 to 82 times higher in cowsheds before feeding the cattle than in children's bedrooms, and from 12 to 464 times higher in cowsheds after feeding than in children's bedrooms. Feeding cattle in cowsheds was associated with a significant peak in airborne moulds and actinomycetes, and this peak was higher in winter than in summer. Silage distribution was associated with low amounts of moulds and actinomycetes. Other significant agricultural factors were the type of cowshed, cowshed volume, method of food distribution to cattle and use of fresh grass. An assessment of the microbiological diversity on farms and in children's rooms may help to determine the factors protecting children from asthma and atopic diseases.

High levels of grass pollen inside European dairy farms: a role for the allergy-protective effects of environment?

BACKGROUND: There is evidence of an allergy protective effect in children raised on farm. It has been assumed that microbial exposure may confer this protection. However in farm, little attention has been given to the pollen level and to concomitant microbiological exposure, and indoor pollen concentrations have never been precisely quantified. METHODS: The kinetics of pollen in dairy farms have been studied in a pilot study (n = 9), and exposure in a sub-sample of the ongoing European birth cohort PASTURE (n = 106). Measurements of viable microorganisms and pollen were performed in air samples. To identify factors that modulate the pollen concentration multivariate regression analyses were run. RESULTS: Indoor pollen (95% of Poaceae fragments and grains) were significantly higher in winter than in summer (P = 0.001) and ranged between 858 to 11 265 counts/m(3) during feeding in winter, thus exceeding typical outdoor levels during the pollen season. Geometric mean in French farms was significantly higher than in German and Swiss farms (7 534, 992 and 1 079 count/m(3), respectively). The presence of a ventilation system and loose housing systems significantly reduced indoor pollen levels. This pollen concentration rise after feeding was accompanied by an increase in fungal and actinomycetal levels, whereas the concentration of bacteria was not associated with feeding. CONCLUSIONS: Farmers and their children who attend cowsheds during the feeding sessions are exposed perennially to high pollen concentrations. It might be speculated that the combined permanent exposure to microbes from livestock and grass pollen may initiate tolerance in children living on a farm.

Regulation of calreticulin gene expression by calcium.

We have isolated and characterized a 12-kb mouse genomic DNA fragment containing the entire calreticulin gene and 2.14 kb of the promoter region. The mouse calreticulin gene consists of nine exons and eight introns, and it spans 4.2 kb of genomic DNA. A 1.8-kb fragment of the calreticulin promoter was subcloned into a reporter gene plasmid containing chloramphenicol acetyltransferase. This construct was then used in transient and stable transfection of NIH/ 3T3 cells. Treatment of transfected cells either with the Ca2+ ionophore A23187, or with the ER Ca2+-ATPase inhibitor thapsigargin, resulted in a five- to sevenfold increase of the expression of chloramphenicol acetyltransferase protein. Transactivation of the calreticulin promoter was also increased by fourfold in NIH/3T3 cells treated with bradykinin, a hormone that induces Ca2+ release from the intracellular Ca2+ stores. Analysis of the promoter deletion constructs revealed that A23187- and thapsigargin-responsive regions are confined to two regions (-115 to -260 and -685 to -1,763) in the calreticulin promoter that contain the CCAAT nucleotide sequences. Northern blot analysis of cells treated with A23187, or with thapsigargin, revealed a fivefold increase in calreticulin mRNA levels. Thapsigargin also induced a fourfold increase in calreticulun protein levels. Importantly, we show by nuclear run-on transcription analysis that calreticulin gene transcription is increased in NIH/3T3 cells treated with A23187 and thapsigargin in vivo. This increase in gene expression required over 4 h of continuous incubation with the drugs and was also sensitive to treatment with cycloheximide, suggesting that it is dependent on protein synthesis. Changes in the concentration of extracellular and cytoplasmic Ca2+ did not affect the increased expression of the calreticulin gene. These studies suggest that stress response to the depletion of intracellular Ca2+ stores induces expression of the calreticulin gene in vitro and in vivo.

Efficient electrotransformation of Enterococcus hirae with a new Enterococcus-Escherichia coli shuttle vector.

In the present study, an Enterococcus-Escherichia coli shuttle vector, pC3, was constructed that allows efficient transformation by electroporation of Enterococcus hirae ATCC9790. 5 x 10(6) transformants per microgram of plasmid DNA were obtained, using a commercial capacitor discharge device with an improved circuitry and a home-made electrode assembly, delivering pulses of 24 kV/cm across the cell suspension. The transformants were stable without selective pressure and plasmid DNA reisolated from transformed cells displayed no alterations in restriction enzyme analysis. Chromosomal DNA from E coli or E hirae, carried by pC3, was stably maintained in E hirae, making cloning and genetic manipulation in this organism feasible.

Mechanism of action of ketanserin: studies on cardiovascular reactivity in essential and diabetes-associated hypertension.

Ketanserin is a selective serotonin-S2 receptor antagonist with alpha 1-adrenoceptor inhibiting activity. The relative contribution of the latter mechanism to antihypertensive efficacy was studied in a group comprising eight normal subjects, 10 patients with essential hypertension and eight diabetics with arterial hypertension. Ketanserin treatment administered over a period of 8 weeks, decreased arterial pressure in patients with essential hypertension and, to a lesser extent, in diabetics, but not in normal subjects. In all three groups, exchangeable sodium, blood volume, the activity of the adrenergic and renin-angiotensin-aldosterone systems and the pressor responsiveness to norepinephrine (NE) or angiotensin II (Ang II) were unaltered, while the pressor reactivity to phenylephrine showed a significant decrease in normal subjects only. This suggests that the antihypertensive mechanism of ketanserin does not involve a modification of the physiological relationship between endogenous noradrenergic and pressor reactivity to NE. Moreover, ketanserin does not interfere with Ang II-dependent mechanisms.

Irreversibility of cyclosporine-induced renal function impairment in heart transplant recipients.

The use of cyclosporine therapy for heart transplant recipients has been associated with a significant improvement of graft survival. Renal function impairment is a frequent finding in patients chronically treated with cyclosporine. The purpose of this prospective randomized study was to establish renal function in a group of heart transplant recipients receiving chronic cyclosporine treatment and to test the hypothesis of reversibility of cyclosporine-induced nephropathy by late reduction of cyclosporine. A total of 28 patients who underwent operation at least 18 months before this study began were randomly assigned to either group A (n = 14), in which the whole-blood polyclonal cyclosporine target trough level was reduced from 400 to 600 micrograms/L to 200 to 400 micrograms/L, and group B (n = 14), in which the level was maintained at 400 to 600 micrograms/L. Renal and cardiac function were assessed by paraaminohippuric acid, inulin and lithium clearances and heart catheterization, respectively, at entry and 4 months later. Cellular rejection in the transplanted heart was monitored by at least four endomyocardial biopsies every 14 days with the histologic Texas scale (grading: 0 to 10). In heart recipients renal blood flow (592 +/- 202 ml/min/1.73 m2) and glomerular-filtration rate (74 +/- 33 ml/min/1.73 m2) were significantly lower (p < 0.01), and mean arterial blood pressure (109 +/- 13 mm Hg) and renal vascular resistance (22.4 +/- 9 mm Hg/dl/min/1.73 m2) were significantly higher than the corresponding values in normal controls (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Orthotopic heart transplantation: an efficient treatment in a young boy with doxorubicin-induced cardiomyopathy.

We present the case of a boy who underwent orthotopic heart transplantation at the age of 14 years because of doxorubicin-induced cardiomyopathy 9 years after treatment of a Wilms tumor of the left kidney. Three years after heart transplantation the patient enjoys a normal daily life. Invasive studies show normal cardiac hemodynamic results and in spite of previous nephrectomy and long-term cyclosporine treatment, renal function is only slightly impaired. So far no secondary neoplasia has occurred under chronic immunosuppression.

ChoICE PT wire for recanalization of chronically occluded coronary arteries: multiple wires in one?

Percutaneous transluminal coronary angioplasty (PTCA) of chronic total occlusions may be technically difficult and the success rate is limited despite increasing operator experience and improvements in PTCA hardware. The number of guidewires required to cross totally occluded lesions is higher than that for stenotic lesions. The ChoICE polymer-tip (PT) wire (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) is a relatively new stainless-steel core wire with a hydrophilic-coated polyurethane tip. Though never described in the literature, we found that the distal 4 cm of the wire can be cut and reshaped according to the operator's needs. Thus, instead of reshaping a kinked tip or using another new wire, the former being time-consuming and the latter expensive, one can simply cut off the kinked tip and start again with a "new wire." As the tip is resected, the wire becomes progressively more "intermediate-like" and "standard-like." We report our experience with the ChoICE PT wire in 50 consecutive cases of chronic total occlusions. The cumulative crossing success rates were 13/50 (26%) before any resections, 24/50 (48%) after 1 resection, 41/50 (82%) after 2 resections and 42/50 (84%) after 3 resections. There were no perforations, deaths, myocardial infarctions or need for bypass surgery. Our findings suggest that successful recanalization of chronic total occlusions can be achieved with a high success rate using the ChoICE PT wire. A strategy of progressively resecting the more floppy and kinked distal end can provide multiple uses from a single wire, optimizing recanalization success and obviating the need for additional wires.

[Toxoplasmosis in the heart transplant patient]. / Die Toxoplasmose beim herztransplantierten Patienten.

Toxoplasmosis is a well-known problem under immunosuppressive conditions in cardiac transplant patients. In our series 12% of the patients (8 of 65) had clinical and/or serological signs of active toxoplasmosis. Due to its serious prognosis once the clinical process has started we favor a generous diagnostic interpretation of the serological results and a broad indication to drug therapy.

[Graft rejection reaction and immunosuppression following heart transplantation]. / Abstossungsreaktion und Immunosuppression nach Herztransplantation.

Acute rejection is the most important factor influencing mortality after heart transplant. Acute rejection occurs at least once in over 95% of the patients in the early phase after heart transplant. In the vast majority of episodes of acute rejection clinical symptoms are absent. The regular performance of endomyocardial biopsy after heart transplant allows histological diagnosis of rejection episodes as well as follow-up control of rejection treatment. This overview points to the major problems regarding acute rejection and immunosuppressive regimen in heart transplant recipients.

[Cytomegalovirus (CMV) infection: a frequent and life-threatening complication in heart transplant patients]. / Zytomegalievirus-(CMV-) Infektion: eine häufige und bedrohliche Komplikation bei Herztransplantationspatienten.

We investigated the clinical relevance of cytomegalovirus infection in our heart transplant recipients (n = 48). There was a high incidence of CMV-infection in patients where IgG positive donor versus IgG negative recipient was present. A total of 5/8 patients (= 62.5%) showed severe clinical CMV-infection with pneumonitis, colitis or tonsillitis besides general malaise, requiring long hospital treatment (2 to 24 weeks). CMV-infection is a frequent and threatening complication in patients after heart transplant (HTPL). We discuss the various managements in diagnosis, prophylaxis and treatment.

Using static and dynamic canonical correlation coefficients as quantitative EEG markers for Alzheimer's disease severity.

We analyzed the relation between Alzheimer's disease (AD) severity as measured by Mini-Mental State Examination (MMSE) scores and quantitative electroencephalographic (qEEG) markers that were derived from canonical correlation analysis. This allowed an investigation of EEG synchrony between groups of EEG channels. In this study, we applied the data from 79 participants in the multi-centric cohort study PRODEM-Austria with probable AD. Following a homogeneous protocol, the EEG was recorded both in resting state and during a cognitive task. A quadratic regression model was used to describe the relation between MMSE and the qEEG synchrony markers. This relation was most significant in the δ and θ frequency bands in resting state, and between left-hemispheric central, temporal and parietal channel groups during the cognitive task. Here, the MMSE explained up to 40% of the qEEG marker's variation. QEEG markers showed an ambiguous trend, i.e. an increase of EEG synchrony in the initial stage of AD (MMSE>20) and a decrease in later stages. This effect could be caused by compensatory brain mechanisms. We conclude that the proposed qEEG markers are closely related to AD severity. Despite the ambiguous trend and the resulting diagnostic ambiguity, the qEEG markers could provide aid in the diagnostics of early-stage AD.

Environmental determinants of atopic eczema phenotypes in relation to asthma and atopic sensitization.

BACKGROUND: There is still uncertainty about the determinants of atopic eczema (AE). To explain the heterogeneity of the disease, different phenotypes of AE have been suggested. METHODS: The cross-sectional PARSIFAL study included 14 893 school-age children of farmers or children attending Steiner schools and their respective reference groups. A detailed questionnaire was completed, and house dust was collected for the measurement of endotoxin and glucans. Atopic sensitization was defined by allergen-specific IgE levels in the serum. RESULTS: In multivariate analyses, helping with haying was the only variable related to a farming environment having a consistent inverse association with both current symptoms and a doctor's diagnosis of AE [aOR = 0.65 (95% CI: 0.46-0.93) and 0.73 (0.51-1.05)], respectively. Severe lower respiratory tract infections (LRTI) in the first 2 years of life and usage of antibiotics ever were found to be positively related only to asthma-associated AE, whereas the effect of LRTI on AE without asthma had an opposite effect. Levels of beta(1-->3)-glucans in mattress dust were inversely related to a doctor's diagnosis of asthma-associated AE [aOR = 0.75 (0.57-0.98)], and endotoxin levels to current symptoms of asthma-associated AE [aOR = 0.73 (0.57-0.94)]. CONCLUSIONS: The analyses of the PARSIFAL study revealed two different phenotypes of AE, depending on the association with asthma and wheezing ever. With regard to the hygiene hypothesis, help with haying, exposure to beta(1-->3)-glucans and endotoxin were found to be inversely associated with the AE phenotype associated with asthma and wheezing.

Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe.

BACKGROUND: Dietary interventions as a means for atopy prevention attract great interest. Some studies in rural environments claimed an inverse association between consumption of farm-produced dairy products and the prevalence of allergic diseases, but current evidence is controversial. OBJECTIVE: To investigate whether consumption of farm-produced products is associated with a lower prevalence of asthma and allergy when compared with shop-purchased products. METHODS: Cross sectional multi-centre study (PARSIFAL) including 14,893 children aged 5-13 years from five European countries (2823 from farm families and 4606 attending Steiner Schools as well as 5440 farm reference and 2024 Steiner reference children). A detailed questionnaire including a dietary component was completed and allergen-specific IgE was measured in serum. RESULTS: Farm milk consumption ever in life showed a statistically significant inverse association with asthma: covariate adjusted odds ratio (aOR) 0.74 [95% confidence interval (CI) 0.61-0.88], rhinoconjunctivitis: aOR 0.56 (0.43-0.73) and sensitization to pollen and the food mix fx5 (cut-off level of >or=3.5 kU/L): aOR 0.67 (0.47-0.96) and aOR 0.42 (0.19-0.92), respectively, and sensitization to horse dander: aOR 0.50 (95% CI 0.28-0.87). The associations were observed in all four subpopulations and independent of farm-related co-exposures. Other farm-produced products were not independently related to any allergy-related health outcome. CONCLUSION: Our results indicate that consumption of farm milk may offer protection against asthma and allergy. A deepened understanding of the relevant protective components of farm milk and a better insight into the biological mechanisms underlying this association are warranted as a basis for the development of a safe product for prevention.

Exposure to microbial components and allergens in population studies: a comparison of two house dust collection methods applied by participants and fieldworkers.

Dust collection by study participants instead of fieldworkers would be a practical and cost-effective alternative in large-scale population studies estimating exposure to indoor allergens and microbial agents. We aimed to compare dust weights and biological agent levels in house dust samples taken by study participants with nylon socks, with those in samples taken by fieldworkers using the sampling nozzle of the Allergology Laboratory Copenhagen (ALK). In homes of 216 children, parents and fieldworkers collected house dust within the same year. Dust samples were analyzed for levels of allergens, endotoxin, (1-->3)-beta-D-glucans and fungal extracellular polysaccharides (EPS). Socks appeared to yield less dust from mattresses at relatively low dust amounts and more dust at high dust amounts than ALK samples. Correlations between the methods ranged from 0.47-0.64 for microbial agents and 0.64-0.87 for mite and pet allergens. Cat allergen levels were two-fold lower and endotoxin levels three-fold higher in socks than in ALK samples. Levels of allergens and microbial agents in sock samples taken by study participants are moderately to highly correlated to levels in ALK samples taken by fieldworkers. Absolute levels may differ, probably because of differences in the method rather than in the person who performed the sampling. Practical Implications Dust collection by participants is a reliable and practical option for allergen and microbial agent exposure assessment. Absolute levels of biological agents are not (always) comparable between studies using different dust collection methods, even when expressed per gram dust, because of potential differences in particle-size constitution of the collected dust.