PubMed Health⌕ Search

Biomedical subjects

N E Eriksson

Publications and source records attributed to N E Eriksson.

At least 19 recordsLinked to original sources

Frequency of patients with acute asthma in relation to ozone, nitrogen dioxide, other pollutants of ambient air and meteorological observations.

OBJECTIVE: To study the association of the daily frequency of registration of patients with acute asthma at the emergency department of a central hospital in the south-west of Sweden with levels of air pollution and meteorological observations. METHODS: A retrospective longitudinal study was made of asthma patients taken from a hospital registry. This information was correlated with measurements of ozone, nitrogen dioxide, sulphur dioxide, toluene, temperature and relative humidity. Patients were from the catchment area of the Central Hospital of Halmstad containing around 120,000 inhabitants. A total of 4127 visits of patients with acute asthma to the emergency department at the Central Hospital of Halmstad were registered during a period of 1247 days from January 1990 to May 1993. The differential optical absorption spectroscopy (DOAS) technique was used to monitor levels of air pollutants over a distance of 1000 m in the central part of the town of Halmstad. Data on temperature, relative humidity, precipitation, wind speed and wind direction for the time period were supplied by the Swedish Meteorological and Hydrological Institute (SMHI). RESULTS: There were many statistically significant correlations between the levels of air pollutants and the meteorological measurements and a strong negative correlation between ozone and nitrogen dioxide. There was a statistically significant effect on asthma visits in children of low temperature and high nitrogen dioxide levels, and on asthma visits in adults of high temperature and high levels of ozone. CONCLUSIONS: There was a different reaction pattern in children and adults with asthma regarding temperature and ozone/nitrogen dioxide. The strong correlations between temperature and air pollution and between the levels of ozone and nitrogen dioxide made the true relation between asthma, air pollution and temperature hard to evaluate statistically.

Acute Disease↗

A prospective study of cancer incidence in a cohort examined for allergy.

In order to assess the association between atopy and cancer risk, a cohort of 6593 skin-prick-tested patients was established. Among atopic subjects, no overall increased cancer risk was found, but the incidence of both breast cancer (standardized incidence ratio (SIR) 2.50, 95% CI 1.01-5.16) and malignant lymphomas (SIR 4.40, 95% CI 1.20-11.3) was significantly enhanced. Atopic subjects with asthma showed a decreased overall cancer risk (SIR 0.73, 95% CI 0.27-1.60), as compared with the other asthmatic subjects (SIR 1.46, 95% CI 1.03-2.04). The cancer risk for subjects with rhinitis was near unity (SIR 1.11), irrespective of whether the subjects were atopic or not. An almost significant risk increase for cancer was observed among subjects with urticaria (SIR 1.70, 95% CI 0.99-2.80). Our results support neither the original hypothesis of an overall cancer protective effect of atopy, nor that of an opposite effect; rather, they strengthen the view that the association between atopic diseases and cancer is complex.

Adolescent↗

Allergy screening with Phadiatop and CAP Phadiatop in combination with a questionnaire in adults with asthma and rhinitis.

The efficiency of the new screening tests for atopy, Phadiatop and CAP Phadiatop, was studied by comparing their results with a clinical diagnosis of atopy in 100 consecutive adults with asthma and/or rhinitis. Further, the diagnostic efficiency of a combination of Phadiatop and a few standardized questions was studied. The Phadiatop was found to have a specificity of 0.98, and a sensitivity of 0.92 and the CAP Phadiatop a specificity of 0.94 and a sensitivity of 0.96. When the Phadiatop was combined with a few questions, a sensitivity of 1.00 was achieved. It is concluded that Phadiatop and CAP Phadiatop have a higher diagnostic precision than other hitherto used methods for screening of atopic allergy. The place of Phadiatop in a diagnostic flow chart is suggested.

Adolescent↗

The behaviour of the mean power frequency of the surface electromyogram in biceps brachii with increasing force and during fatigue. With special regard to the electrode distance.

The present study aims to investigate: a) the relationship between force and mean power frequency of the EMG, and b) how the distance between surface electrodes influences the mean power frequency. The study consisted of three parts: 1) a gradually increasing contraction upto 100% MVC, 2) contractions performed at 5 different levels from 20% upto 100% MVC with rest in between, and 3) an endurance test at 30% MVC. Nine healthy women participated. The elbow was flexed 90 degrees and EMG signals were obtained from the biceps brachii. The surface electrodes were placed so that electrode distances of 10 mm, 20 mm and 30 mm were obtained. The mean power frequency increased upto 60% MVC. Above 60% MVC no change in mean power frequency occurred. No differences in the mean power frequency with respect to the electrode distances existed at each force level. No significant differences were found at each contraction level between the gradually increasing contraction and the stepwise increasing contractions. The mean power frequency decreased linearly during the endurance test without any differences with respect to the electrode distances. It is concluded that the different electrode distances do not affect the mean power frequency-force relationship or the decrease in mean power frequency during fatigue. It is proposed that the increase in mean power frequency, on group level, can be used as an indicator of motor unit recruitment. However, this proposal was found to be complicated when individual analyses were made.

Adult↗

Immunological specificity of chloramine-T-induced IgE antibodies in serum from a sensitized worker.

A procedure for the preparation of chloramine-T (CT) conjugates used to assay IgE antibodies was developed using response surface methodology and serum from a subject occupationally exposed to the substance. The conjugates, synthesized by reacting CT with human serum albumin (HSA) and other protein carriers, were used as antigens in a radio-allergosorbent test (RAST). Human serum albumin was found to be a suitable carrier, although other protein carriers also gave specific IgE-binding of a similar extent. The CT-HSA conjugates used in the RAST were characterized by high performance liquid chromatography, electrophoresis, immunodiffusion and ammonium sulphate precipitation. However, no strong correlation was seen between the ability of the conjugates to bind IgE and their physical or immuno-chemical properties. The hapten and carrier specificity of CT-induced IgE antibodies in the subject's serum were studied by direct RAST and RAST inhibition. No existence of new antigenic determinants related to the carrier could be demonstrated. Although HSA as a carrier was altered immunochemically by CT, the IgE antibodies were found to be specific to hapten only. Chloramine-T-specific IgG antibodies could not be demonstrated in the subject's serum.

Adult↗

Hypersensitivity to larvae of chironomids (non-biting midges). Cross-sensitization with crustaceans.

In 2,368 consecutive adult patients with asthma and/or rhinitis the incidence of positive skin prick test (SPT) with a chironomid extract (CHIR) (produced from "red feather mosquito larvae" used as fish food) was 14% (26% in atopics and 4% in non-atopics). RAST with chironomid was positive in 4% of 110 consecutive sera (8% in atopic sera). Significant correlations were found between RAST and SPT results with chironomid and between SPT results with CHIR and with various crustaceans. Correlations were also found reciprocally among SPT results with different crustaceans and between some crustaceans and moluscs (clam and oyster) as well as among RAST results with chironomid, shrimp and crab. Inhibition experiments showed that chironomid extracts inhibited RAST with shrimp, and vice versa. It is concluded that Chironomidae might be allergens of clinical importance in asthma and rhinitis in Sweden, that cross-allergy exists between chironomids and shrimp and that cross-allergy also might occur among chironomids, crustaceans and molluscs.

Animals↗

Total IgE influences the relationship between skin test and RAST.

Positive correlations were found between total IgE, skin prick test (SPT) and RAST results with tree pollen allergens. The relationship between SPT and RAST was influenced by the level of total IgE. At each level of atopy, defined according to the strength of SPT, patients with high total IgE had higher RAST values than patients with low total IgE.

Adolescent↗

Changes in the surface electromyogram during increasing isometric shoulder forward flexions.

When using electromyographic techniques in the evaluation of muscular load it is necessary to determine the mathematical relationship between the torque and the amplitude of the electromyographic signal. Isometric gradually increasing contractions up to 100% MVC can then be used. Often more than linear increases for the amplitude (RMS)--force regression have been reported. The present study was designed to test whether changes in power spectral density function take place during a gradually increasing isometric contraction (duration 10 s). Twenty-two clinically healthy females performed an increasing isometric shoulder forward flexion for 10 s using an isokinetic dynamometer. Electromyographic activity was measured in trapezius, deltoid, infraspinatus and biceps brachii using surface electrodes. Mean torque values were determined together with mean power frequency (MPF) and root mean square values (RMS) from the EMG signals for each 256 ms period. The RMS-torque regressions showed higher regression coefficients during the 6th to 9th sec than during the first 5 s. No significant correlation existed between MPF for the four muscles and the torque. A gradual decrease in MPF was generally found from the 6th s. It is concluded that this decrease in power spectral density function might have contributed to the significantly higher regression coefficient for the RMS torque regression at the high output part of the gradually increasing isometric contraction.

Adult↗

Surface EMG recordings during maximum static shoulder forward flexion in different positions.

This study investigated how position in the range of motion influences the power spectral density function during static shoulder forward flexion. 23 healthy females (20-30 years) volunteered as subjects. They performed maximum static shoulder forward flexions in three positions: 45, 65 and 90 degrees of shoulder flexion. An isokinetic dynamometer was used and the subjects were seated in a specially constructed chair to enable adequate fixation. The elbow was extended and the hand pronated. Electromyographic (EMG) signals (using surface electrodes) were obtained from the descending part of the right trapezius, the anterior portion of the right deltoid, the right infraspinatus and the common belly of the right biceps brachii. The four EMG-signals and the torque and shoulder angle were analyzed by computer. For each 256 ms, mean power frequency, root mean square value and mean torque were calculated. At each of the three positions four 256 ms periods were analyzed and the data are presented as their means. In the trapezius and the biceps brachii the mean power frequency did not change between the three positions. Deltoid and infraspinatus had significantly higher mean power frequencies at 90 degrees than at 45 degrees of flexion. Different factors behind the change in mean power frequency are discussed. The need to standardize the range of motion when studying dynamic fatiguing contractions is emphasised.

Adult↗

Biological equilibration of allergen preparations: methodological aspects and reproducibility.

A method for biological equilibration (BE) of allergen reference preparations using the skin-prick test (SPT) method and histamine HCl 10 mg/ml as reference substance (reference method), was evaluated. The precision was low for weals less than 10 mm2. The slope (log weal area/log concentration) of allergen and histamine did not vary significantly between investigators and allergens. The median slopes were 0.39 (n = 384) and 0.34 (n = 397), for allergen and histamine, respectively (P less than 0.01). The concentration of allergen eliciting a weal of the same size as that of histamine HCl 1 mg/ml (Chl) in the median sensitive patient, 1000 Biological Units/ml (BU/ml), did not vary significantly between clinics/geographical regions (grasses, mites and moulds). As BE is repeatable between regions, BUs estimated by this method are generally valid. A high correlation (r = 0.91, P less than 0.001) was found between the median Chl as estimated with histamine 1 and 10 mg/ml as reference substance, respectively. Thus, this reference method for BE is valid. The precision of the SPT method with histamine HCl 1 mg/ml is not as good as with 10 mg/ml, which is therefore recommended as the reference concentration.

Adolescent↗

Selection of patients for biological standardization as exemplified by standardization of mugwort, goosefoot and English plantain pollen allergen extracts/preparations.

The biological activity of a partly purified, biochemically/immunochemically characterized mugwort pollen allergen preparation and crude pollen extracts of mugwort, goosefoot and English plantain was determined by means of skin prick test (SPT). The patient inclusion criteria with mugwort were a well-defined positive clinical history and a positive SPT. Symptoms related to goosefoot/English plantain pollens are difficult to define, as these weeds flower during the grass pollen season. Thus patients tested with these allergens did not fulfill the most important inclusion criterion for so-called biological standardization. To elicit a wheal of the same size as that produced by histamine 1 mg/ml required 100 to 10,000 times more material from these weeds, than from mugwort and other pollen allergen extracts investigated earlier. One thousand Biological Units/ml (BU/ml) corresponded to 8.3 micrograms dry weight (dw/ml) of the crude and 1.8 micrograms dw/ml of the purified mugwort pollen allergen preparation. Only 7/22 goosefoot-and English plantain-tested patients were positive at conjunctival or nasal challenge. All three weeds showed a similar composition with 5-10 allergens by CIE/CRIE analysis and 10-13 by immunoblotting analysis. One dominating allergen (approx. 15,000 d), could be identified for each weed species by protein gel blot after separation by SDS g-PAGE. There was no other explanation for the difference in biological activity than the criteria of selection. If there is no obvious clinical history, which is the main patient inclusion criterion in biological standardization, then additional criteria should be used.

Adolescent↗

Allergy screening in asthma and allergic rhinitis. Which allergens should be used?

To detect atopy by a screening method employing skin prick testing with a limited number of allergens, the test results of 939 patients with allergic airways diseases were analysed. It was found that an allergen panel consisting of cat, timothy and house dust mite could detect 85% of atopic patients with asthma and/or rhinitis. For subgroups of patients the results were even more favourable. Thus 98% of atopic patients with seasonal allergic rhinitis were detected by an allergen panel consisting of timothy, birch and mugwort. It is concluded that screening methods using only three of four allergens could be used for detecting atopy in patients with airways diseases. The method should be most valuable for in vitro tests used in combination with standardized questionnaires.

Adult↗

Tree pollen allergy. III. Cross reactions based on results from skin prick tests and the RAST in hay fever patients. A multi-centre study.

872 adult hay fever patients were investigated with skin tests, using 20 different tree pollen allergens, and Phadebas RAST, using eight different tree pollen allergens. Correlation between test results with the different allergens were studied employing the Spearman's correlation coefficient (Rho). Most combinations showed statistically significant correlations. The highest values of Rho (0.8-0.9) were found for pollen from combinations of trees belonging to the families Betulaceae, Corylaceae and Fagaceae (birch, alder, hazel, beech and oak). High values were also found between pollens from aspen and sallow (belonging to Salicaceae). With several of the trees a high degree of pollen cross sensitization was found, even with trees from a different plant family. Since most of the patients were allergic to birch pollen, some of the reactions to other pollens could be due to allergens shared by birch. To exclude this possibility, a separate analysis was performed for patients having no birch pollen allergy. Even in these patients evidence of cross sensitization was found. It is concluded that cross reactions are common among tree pollens and are most pronounced within botanical families.

Adult↗

Flowers and other trigger factors in asthma and rhinitis--an inquiry study.

Six hundred and eighty adult patients with asthma and/or rhinitis were questioned about symptoms elicited by 46 different flowers and 10 common non-specific environmental trigger factors listed in a questionnaire. Flowers or birch twigs were reported to elicit symptoms in 79% of the patients, somewhat more often in rhinitis than in asthma patients, and caused symptoms as often in non-atopics as in atopics. Birch twig and marguerite most frequently induced symptoms, followed by strongly smelling flowers such as hyacinth, lilac, and lily of the valley. Unspecific irritants caused symptoms in 98% of the asthmatics and in 67% of patients with rhinitis. Tobacco smoke and perfumes were the most important troublemakers. A significant positive correlation was found for elicitation of symptoms from flowers and from certain non-specific irritants. It is concluded that non-specific hyperreactivity as well as reaginic hypersensitivity are the mechanisms involved when birch twigs and flowers elicit symptoms.

Adult↗