Nasal symptoms and pathophysiology in farmers.

OBJECTIVES: Increased morbidity and mortality in lower airway diseases have been reported among farmers. The aim of this study was to assess upper airway problems in farmers. SUBJECTS AND METHODS: Twenty-five dairy farmers, 20 pig farmers, 21 grain farmers and 19 control subjects were studied, by use of questionnaire, skin-prick test, dynamic spirometry, nasal inspection, acoustic rhinometry (before and after a decongestant) as well as by determinations of the olfactory threshold and nasal lavage (NAL) concentrations of eosinophil cationic protein (ECP), myeloperoxidase (MPO) and albumin. RESULTS: Compared with the control group, farmers had more complaints of work-related symptoms from the lower airways, and symptoms of smell impairment, and more often had nasal polyps and hyperaemia of the nasal mucosa. They also had higher levels of MPO in NAL (especially dairy farmers and pig farmers), and a tendency to more swollen nasal mucosa and lower olfactory threshold (especially grain farmers). CONCLUSIONS: The farmers had more pathological findings in their nasal mucosa, possibly indicating effects of allergens and irritants in their work environment. More studies are needed to evaluate work environment factors causing these pathological findings in farmers.

Regional expression of the histamine H(2) receptor in adult and developing rat brain.

Histamine H(2) receptor expression was studied in adult and developing rat brain. Northern blot and in situ hybridizations indicated that histamine H(2) receptor messenger RNA expression is widespread and not limited to neurons in the adult rat brain. Prominent H(2) receptor expression in the adult brain was seen in the dentate gyrus, hippocampal subfields CA1-CA3, piriform cortex and in some diencephalic nuclei, e.g. in the suprachiasmatic nucleus and the red nucleus. Most of the adult brain nuclei displayed a very low H(2) receptor expression. Histamine H(2) receptor was also expressed during development in widespread areas of the central nervous system, coinciding with the transient production of histamine in the raphe neurons at embryonic day 15. From embryonic days 16 and 17 until birth, histamine H(2) receptor expression in the cortical plate coincided with the development and sprouting of histaminergic fibers into the cerebral cortex. The widespread and diffuse expression of histamine H(2) receptors in the adult rat brain suggests that the H(2) receptor modulates the excitability of neuron and astrocyte functions in many brain areas rather than mediating targeted cell-to-cell signals. During development, histamine H(2) receptor expression is seen in several target areas for the histaminergic fibers. This could indicate that histamine, through the H(2) receptor, regulates fetal development of the brain.

Nasal histamine reactivity in woodwork teachers.

Woodworkers exposed to wood dust have an increased frequency of rhinitis. We have previously reported such rhinitis in woodwork teachers. To test whether their nasal complaints are related to nasal hyper-reactivity, we selected 14 woodwork teachers with work-related rhinitis and 14 healthy and non-allergic control persons for nasal histamine challenge using symptom scores (0-3 scale) and acoustic rhinometry for effect evaluation. Intranasal saline followed by doubled concentrations of histamine phosphate (from 0.062 to 16 mg/ml) was given at five-minute intervals. There was no significant difference between the groups regarding symptom scores or acoustic rhinometry during the challenge. The results indicate that nasal hyperreactivity is not a prominent factor in wood-dust-related rhinitis. Other mechanisms probably prompt the nasal complaints.

Improved health after intervention in a school with moisture problems.

In a school with floor moisture problems, the personnel had complaints consistent with the sick-building syndrome (SBS). Interventive measures including the laying of a ventilated floor were undertaken to eliminate the emissions. To examine if the intervention resulted in positive health effects, 34 personnel and 336 pupils were interviewed just before the intervention and also 7 months after. Also were interviewed 21 personnel and 224 pupils at an adjacent school serving as a control. Compared with the control school, the problem school showed more complaints, more general symptoms and more symptoms from the eyes, airways and skin, both among the personnel and the pupils. In the post-intervention examinations, the excess of symptoms among the personnel had almost disappeared. Among the pupils, the frequency of eye irritation was reduced but a general improvement of the other symptoms was not as obvious. However, after adjustment for a recent common cold, atopy and stress among the pupils, only one symptom ("stuffy nose") remained significantly elevated. In conclusion, the intervention was followed by positive health effects, supporting the hypothesis that emissions from building material had contributed to the excess of symptoms. A recent common cold was highly related to the symptoms and should be considered in future SBS studies.

Wood dust from jelutong (Dyera costulata) causes contact allergy.

Jelutong is the wood from Dyera costulata growing in south-east Asia. It is soft and easy to work and is used in, e.g., model workshops in car factories. It has also been much used in woodwork teaching in Swedish comprehensive schools. To estimate the prevalence of contact allergy to jelutong, 84 woodwork teachers and 110 consecutive dermatitis patients were patch tested with extract from wood dust of jelutong. 16/84 (19%) teachers had positive reactions. When they were tested with a dilution series, positive reactions were obtained for 6 mg and down to 0.3 mg of the extracted material. Half the test-positive teachers had skin symptoms that might be related to exposure to jelutong 4/110 dermatitis patients at the clinic also had positive reactions, and possible exposure to jelutong was traced in 3 of them. 3 other dermatitis patients had flare-up reactions after about 2 weeks, indicating patch-test sensitization. To investigate the sensitizing capacity of the extract, the cumulative contact enhancement test was performed in guinea pigs. This confirmed that the extracted material was sensitizing, and a clear dose-response relationship was found. The schools will be recommended to use safer wood alternatives in woodwork teaching.

Skin symptoms and contact allergy in woodwork teachers.

To estimate the occurrence of skin symptoms and the prevalence of contact allergy to occupational allergens, 84 male woodwork teachers were interviewed, clinically examined and patch tested. The tests included a supplemented European standard series and acetone extracts of wood dust of pine, spruce, juniper and birch. In addition, 10 colophony-allergic volunteers were tested with dilution series of wood dust extracts. Major colophony compounds in the dust extracts were analyzed with gas chromatography. We found a high 1-year period prevalence of generally mild hand eczema: 19%. Contact allergy was diagnosed to several allergens in the working environment, e.g., benzisothiazolin-3-one, nickel, formaldehyde and colophony. A clear relationship between patch test reactions to colophony and to coniferous woods, especially pine, was found. Exposure to wood dust at work caused dermatitis in a colophony-sensitized teacher.

Work related impairment of nasal function in Swedish woodwork teachers.

OBJECTIVE: To study the relation between exposure and nasal function in woodwork teachers. METHODS: 39 selected woodwork teachers employed full time and 32 control subjects (other school personnel) were examined at the beginning and at the end of a working week with symptom rating, nose and throat inspection, rhinomanometry, nasal mucociliary clearance test, and a smell identification test. During one working day of the same week climate, dust and terpene concentrations were measured in all 39 schools. RESULTS: The ventilation rate was highest in rooms with mechanical ventilation. Range of total dust (personally sampled) was 0.12-1.18 mg/m3, respirable dust 0.02-0.21 mg/m3, and terpenes (area sampled) 0.02-6.8 mg/m3. In contrast to the control subjects, the woodwork teachers had more nasal symptoms on the Thursday afternoon than on the Monday morning, especially those working in rooms without mechanical ventilation. Their mucociliary clearance worsened during the week (mean increase 4 min, P < 0.001). A small impairment of olfactory function was also found, but their rhinomanometric values did not change significantly. Nasal symptoms correlated weakly with the percentage of respirable dust in the total dust. Otherwise there were no significant dose-effect relations between measured dust or terpene concentrations and nasal tests. CONCLUSIONS: The woodwork teachers had mainly reversible nasal complaints, impaired nasal mucociliary clearance and olfactory function related to the work environment, with dust concentrations below the Swedish threshold limit value of 2 mg/m3.

Serial nasal peak expiratory flow measurements in woodwork teachers.

Serial nasal peak expiratory flow rate (PEFRN) recordings and symptom ratings were used on 39 woodwork teachers exposed mainly to wood dust and on 31 control subjects (other school personnel) during a working week. The objective was to study whether the peak flow method is useful for the assessment of work-related nasal obstructive symptoms. By comparison with the controls, the woodwork teachers reported a higher level of nasal blockage, with a pattern of gradual increase during the working week, over which period the PEFRN deteriorated gradually. The method is considered useful for detecting work-related nasal obstruction in groups with exposure to airborne irritants and can be recommended for such purposes. But because of the great variability of peak flow values, many measurements on a great number of individuals must be performed.

Response of guanosine tetraphosphate to glucose fluctuations in fed-batch cultivations of Escherichia coli.

A rapid transient increase of guanosine 3'-diphosphate 5'-diphosphate (ppGpp) in Escherichia coli was found in response to short-term glucose fluctuations that may occur in large-scale fed-batch cultivations. The concentration of ppGpp was measured in laboratory-scale glucose limited fed-batch cultivations. Starvation zones were imitated by using an intermittent feeding scheme or a two-compartment reactor system. The cellular concentration of ppGpp per biomass increased from 80 nmol to 300-600 nmol per g cell dry weight within only 1 min after consumption of the residual glucose in dependence on the test system, which is much faster than earlier described in literature. Readdition of glucose caused immediate reduction of the ppGpp to the basic level which did not differ in cultivations with simulated starvation zones from control cultivations. Possible physiological consequences by an enhanced stringent response in cultivations with limited mass transfer have to be considered.

Inflammatory markers in nasal lavage fluid from Industrial Arts teachers.

Exposure to wood dust can cause allergic and nonallergic rhinitis. Inflammatory markers [cells, albumin, tryptase, and eosinophil cationic protein (ECP)] were examined in nasal lavage fluid (NAL) sampled from 24 Industrial Arts (IA) teachers exposed to wood dust and other irritants and from 24 control subjects. The IA teachers had more nasal complaints but they did not differ significantly from the controls regarding ECP concentration (median 4.1 and 4.7 micrograms/L, respectively), albumin concentration (median 30.7 and 20.7 g/L), and percentage of neutrophils (median 56 and 34) in NAL. Tryptase was not detected. No marked inflammation was thus found, but the albumin concentration was higher in subjects reporting nasal stuffiness. In the IA teachers, a relationship between the percentage of neutrophils and the number of classes during the working week was found (Spearman's rank correlation coefficient 0.53, p < 0.01) indicating a possibility of wood-dust-related inflammatory effects on the nasal mucosa.

IgE-mediated allergy to wood dusts probably does not explain the high prevalence of respiratory symptoms among Swedish woodwork teachers.

A previous study revealed an increased occurrence of work-related respiratory complaints among Swedish woodwork teachers. For determination of whether an IgE-mediated mechanism was the cause of the symptoms, 127 woodwork teachers and 111 reference subjects (other school personnel) in Stockholm gave serum for analysis of total IgE, Phadiatop, and RAST to extract of sawdust from five commonly used Scandinavian woods (pine, birch, juniper, alder, and linden). The total serum-IgE level was similar in the woodwork teachers (geometric mean 35, range < 2-1700 kU/l) and the reference group (34, < 2-860 kU/l), and the frequency of positive Phadiatop was equal (29.9% and 31.5%, respectively). RAST was positive only in three cases, two reference subjects (birch and pine) and one woodwork teacher (alder). Hence, no correlation between exposure and sensitization to wood dust was found, and the results do not support the assumption that the complaints related to exposure to dusts from the examined Scandinavian woods are IgE mediated.

Work-related respiratory problems in industrial arts teachers.

Because of reports of respiratory complaints in Swedish industrial arts (IA) teachers, a cross-sectional study was performed on 130 IA teachers in Stockholm to study the relationship between the work environment and health, and especially the aforementioned complaints. One hundred and twelve other school employees served as control subjects. Sex, age, and smoking habit distribution were similar in the two groups. All subjects answered a questionnaire about their health problems, and the IA teachers answered questions about their work environment. The work environment consisted of many old and neglected workshops (hereafter called shops). Compared to the control subjects, the IA teachers had more complaints in respect of the skin, eyes, nose, throat, and lower airways--including chronic bronchitis (OR 12.4, 95% confidence interval 2.95-110.5). A higher occurrence of symptoms existed in shops with bad ventilation and dust-spreading machines and in shops where dust-spreading cleanup methods were used. A suspected interaction between smoking and work environment was noted for some symptoms, especially impaired smell and chronic bronchitis. In conclusion, several factors in the work environment were identified as risk factors for health. Identification of these risk factors should result in a program to reduce the health problems in the work environment.

Nasal peak-flow-rate recording is useful in detecting allergic nasal reactions--a case report.

Serial nasal peak-expiratory-flow-rate recordings have been used to detect changes in nasal patency. A hospital nurse with allergy to latex showed a marked decrease in nasal flow when exposed to latex gloves in a challenge test and in her work environment. We propose using the method as a diagnostic tool for allergic rhinitis in occupational and other exposure situations in which nasal blockage is a prominent symptom.

Nasal peak flow rate records in work related nasal blockage.

Eleven patients, who had symptoms of blocking nose in relation to exposure to airway irritants in their work environment, and 11 control subjects recorded nasal and bronchial peak expiratory flow rates (PEFRN and PEFRB) during a working week. In contrast to the control subjects the patients demonstrated a pattern of gradual decrease in PEFRN during the working week with restitution during the subsequent weekend and a different day rhythm in PEFRN during working days from days off. The changes in PEFRB were similar but less pronounced. The results indicate that the symptoms of nasal blockage can be visualized by following the PEFRN during a working week and that the changes in PEFRN may have a relationship to different environmental exposures.

Impeded lung function in moulders and coremakers handling furan resin sand.

A total of 39 moulders and coremakers exposed to furan resin sand and 27 unexposed local controls were examined by lung-function tests before and after a work shift. In all, 28 of the subjects exposed to furan resin sand and the control group were evaluated by dynamic spirometry and nitrogen washout. The remaining 11 subjects exposed to furan resin sand were studied using both static and dynamic spirometry and the CO single-breath technique. The time-weighted average exposure to furfuryl alcohol was about 7 mg/m3, with peak values exceeding the present Swedish short-term exposure limit (40 mg/m3). The exposure to respirable dust and formaldehyde as time-weighted over the shift was less than 2 mg/m3 and 0.4 mg/m3, respectively, in all groups. During the work shift studied, the 28 exposed subjects had more complaints of airway symptoms than did the controls, showing an average decrease of 0.21 in forced vital capacity but no fall in any other lung-function variable. The remaining 11 exposed subjects demonstrated a post-shift decrease in total lung capacity. The results indicate an acute restrictiveness induced by exposure to furan resin sand, but the underlying mechanism is unclear. Chronic impairment of lung function was not observed.