Nasal symptoms and histopathology in a group of spray-painters

Allergic and Nonallergic Rhinitis. Classification and Pathogenesis: Part II. Nonallergic Rhinitis

Part I of this review classified and defined the causes of chronic rhinitis, describing in detail the etiology and pathophysiology of allergic rhinitis. Part II focuses on the nonallergic (non-IgE) causes of chronic rhinitis, concentrating on their clinical presentations, differential characteristics, and known or speculative pathophysiology. A comprehensive understanding of the allergic and nonallergic conditions associated with symptomatic rhinitis should aid the clinician in the appropriate diagnosis and treatment of patients with chronic rhinitis.

Effects of volatile substance abuse on the respiratory system in adolescents

Aim

Inhalant abuse is a prevalent and often overlooked form of substance abuse in adolescents. Chronic inhalant abuse can damage respiratory, cardiac, renal, hepatic, and neurologic systems. This study aims to determine the physiologic effects of inhaling solvents on the respiratory functions.

Methods

The general health status of the subjects was assessed by history taking, physical examination and a questionnaire which was designed to show the severity of respiratory symptoms. Spirometry, ventilation/perfusion scintigraphy, and high resolution computed tomography (HRCT) were performed to assess pulmonary functions and anatomy.

Results

Thirty-one male volatile substance abusers and 19 control subjects were included in the study. The mean age of onset of inhalant use was 14.6 ± 2.2 (9-18) years and duration of drug use was 3.7 ± 1.7 years. The most common respiratory symptoms in volatile substance abusers were nasal congestion (45.2%), sputum (38.7%), exercise intolerance (32.3%) and cough (22.6%). Results of spirometric studies showed 12 (41.4%) subjects with low FVC values < 80% of predicted, indicative of restrictive ventilatory pattern in the study group. Although the difference was not statistically significant, restrictive ventilatory pattern was higher in the study group. There was no statistically significant correlation between restrictive ventilatory pattern and the age of onset/duration/frequency of inhalant abuse, respiratory symptoms and scintigraphic abnormalities. Subjects who had restrictive pattern in their pulmonary function tests were more likely to have abnormal findings at HRCT (p < 0.01).

Conclusion

This study has shown a positive correlation between volatile substance abuse and the development of restrictive ventilatory pattern, but more comprehensive studies are needed for more precise conclusions.

Histopathological changes of rat larynx mucosa with exposure to chronic thinner inhalation

Objective: Histopathological changes in nasal mucosa, trachea, and pulmonary system with exposure to chronic thinner inhalation have been studied in the literature. However, the possible changes in larynx mucosa, which is a part of the upper airway tract, have not been studied yet. The aim of this study is to determine the histopathological changes of rat larynx mucosa with exposure to chronic thinner inhalation.

Study Design and Setting: Randomized trial. The study was conducted at the animal care facility of Haydarpasa Numune Education and Research Hospital.

Subjects and Methods: Fifty-one Sprague-Dawley rats were used throughout the experiment. Four groups of rats inhaled thinner in a glass cage for 2, 4, 8, and 12 weeks respectively. Seven rats inhaled only the air in the room as the control group.

Results: The comparison of inflammation and exocytosis in the control and 2 week groups revealed no significant difference ( P > 0.05), but from the beginning of 4 weeks of thinner inhalation, statistically significant differences were observed ( P < 0.05). From the beginning of 8 weeks of thinner inhalation, statistically significant differences were observed in larynx mucosa when we assessed metaplasia and cilia loss distribution among groups ( P < 0.05).

Conclusion: On the basis of histopathological evaluations, it was shown that the harmful effect of inhalation of thinner in high concentrations to larynx mucosa is similar to the effect on other organs of the respiratory system.

Early stress response of human nasal respiratory epithelia after exposure to 1-methoxypropanol-2

To evaluate the impact of 1-methoxypropanol-2 (MEP) for the stimulation of an inflammatory response in human respiratory mucosa, we exposed 22 primary cell cultures of nasal respiratory epithelia of healthy individuals to MEP concentrations at the level of the German MAK-value (100 ppm) and to the 10-fold concentration (1000 ppm). After 4 and 24h we analyzed the transcription of TNF-alpha, IL-1beta, IL-6, IL-8, MCP-1, GMCSF, Cox-1 and Cox-2 by quantitative PCR as well as the release of the respective cytokines by ELISA. At both MEP concentrations we observed a significant increase of TNF-alpha-, IL-1beta-, IL-6- and Cox-2-transcripts after 4h. After 24h cytokine transcription of TNF-alpha, IL-1beta and IL-6 was normalized, but Cox-2 remained elevated. On the protein level IL-1beta as well as granulocyte macrophages colony stimulating factor (GM-CSF) were decreased after 4h or 24h and uniquely IL-8 levels were increased after 4h. Our data suggest that MEP induces the transcription of genes encoding proinflammatory cytokines and mediators but largely not translation of those. Considering these in vitro data, existing exposure limits seem to be safe with respect to inflammatory responses of the upper respiratory tract. However, the effects of long-term exposures to MEP should be watched closely.

mRNA-induction and cytokine release during in vitro exposure of human nasal respiratory epithelia to methyl methacrylate

BACKGROUND

Methyl methacrylate (MMA) has been reported to cause histopathological changes in rodent nasal epithelium after inhalation challenges. Data in humans are lacking.

METHODS

In this in vitro design 22 primary cell cultures taken from inferior turbinate tissue of healthy individuals were exposed to MMA concentrations of 50 ppm (German MAK-value) and 200 ppm. mRNA expression and cytokine release of inflammatory mediators were quantified after 4h and after 24h. Controls were exposed to synthetic air. Q-PCR analysis was performed for TNF-alpha, IL-1beta, IL-6, IL-8, MCP-1, GMCSF, Cox-1 and Cox-2. ELISA assays were performed from culture supernatants for TNF-alpha, IL-1beta, IL-6, IL-8, MCP-1 and GMCSF.

RESULTS

Acute inductions of mRNA after 4h were observed for TNF-alpha, IL-1beta, IL-6, IL-8 and MCP-1 at 50 ppm. ELISA analysis of the described parameters did not reveal any significant upregulations at both concentrations after both 4h and 24h.

CONCLUSIONS

The obtained data suggest that exposure of human respiratory epithelia in vitro to 50 ppm and to 200 ppm of MMA does not induce lasting upregulation of the inflammatory mediators measured in this study. The exposure limit of 50 ppm appears safe following these results obtained from human respiratory epithelia.

Effect of Air Pollution on Olfactory Function in Residents of Mexico City

To our knowledge there has been no study of the effect of everyday air pollution on olfactory function. It was therefore the aim of this study to compare the olfactory performance of long-term residents of Mexico City, an environment with high air pollution, with the olfactory performance of residents of the Mexican state of Tlaxcala, a region geographically similar to Mexico City but with low air pollution. Healthy volunteers [82 Mexico City subjects (MEX), 86 Tlaxcala subjects (TLX)] 20-63 years of age and balanced for age and gender between the two localities were tested for the perception of the odors of everyday beverages presented in squeeze bottles. When tested with ascending concentrations of stimuli in a three-way oddball paradigm, residents of Tlaxcala detected the odors of instant coffee and of an orange drink at significantly lower concentrations than residents of Mexico City. They also performed significantly better in discriminating between the two similar-smelling Mexican beverages horchata and atole in an oddball test. Significant differences between the two populations in overall olfactory performance were apparent in three of the four age classes (20- to 29-, 30- to 39-, and 40- to 49-year-old subjects) but not in the 50-63 years age class. About 10% of MEX subjects compared to about 2% of TLX subjects were judged to have poor olfactory function; all were from the older age classes (mean age: 48.6 years). Thus, air pollution in Mexico City appears to have a substantial impact on olfactory function even in young and middle-aged residents.

Respiratory health effects related to occupational spray painting and welding

OBJECTIVE

We sought to study respiratory symptoms among automobile assembly workers.

METHODS

In a cross-sectional study, we compared rates of respiratory symptoms and of physician-diagnosed asthma and COPD in painters and welders to those in assembly workers.

RESULTS

Respiratory symptom reporting was significantly increased among welders (odds ratio [OR] = 1.79-2.61) compared with painters or assembly workers, after age, race, and smoking adjustment in multiple logistic regression analyses. Welders also reported significantly more improvement in symptoms on weekends or vacation. However, no significant elevations in adjusted ORs were observed for physician-diagnosed asthma or chronic obstructive pulmonary disease for welders. In contrast, significantly more painters had physician-diagnosed chronic obstructive pulmonary disease (OR = 3.73, 95% confidence interval = 1.27, 11.0).

CONCLUSIONS

Welders and painters in this plant appeared to have increased risk of respiratory health effects compared with assembly workers.

The dilemma of occupational rhinitis: management options

Occupational rhinitis is a common heterogeneous group of inflammatory conditions in the nose, caused by exposure to airborne irritants and sensitizers in the occupational environment. The mechanism can be allergic, neurogenic or toxic. Data from several epidemiologic studies indicate that animal dander, organic dusts, latex and chemicals can cause occupational rhinitis, but because of methodological problems as well as weaknesses in the definition of occupational rhinitis, occupational exposure is probably an underestimated cause of rhinitis. The effect of rhinitis on the mental aspects of quality of life and substantial costs due to loss of productivity make it important to diagnose and treat occupational rhinitis. Diagnosis relies on a history of exposure, skin prick testing and, if possible, nasal provoacation. Avoidance of exposure, protective measures at the workplace and medical treatment, with agents such as second generation antihistamines and nasal corticosteroids, can make it possible to avoid progress of the disease from rhinitis to asthma. The efficacies of montelukast, a leukotrienne receptor antagonist, and omalizumab, an anti-immunoglobulin E monoclonal antibody in the treatment of occupational rhinitis are yet to be evaluated

The use of noncancer endpoints as a basis for establishing a reference concentration for formaldehyde

Published studies involving formaldehyde were selected for quality and relevance for determining whether noncancer endpoints could be used to derive a reference concentration for formaldehyde. Chamber studies provided the highest quality data for determining the presence of eye, nose, or throat irritation at a known level of formaldehyde. Some individuals begin to sense irritation at about 0.5 ppm, 5-20% report eye irritation at 0.5 to 1 ppm, and greater certainty for sensory irritation appears at 1 ppm or greater. These levels of formaldehyde do not appear to impact asthmatics even though these individuals are thought to be more sensitive to irritants. Mild, reversible changes in pulmonary function (forced expiratory volume at 1 s and midexpiratory flow) can occur in sensitized individuals at levels approaching 2 ppm. Studies in the manufacturing setting, while confounded by multiple exposures, provide useful information for setting boundaries for sensory irritation or changes in pulmonary function. Community surveys do not provide the specificity nor sensitivity needed to establish a reference concentration. Histological studies of the nasal mucosa suffer significant methodological and technological shortcomings in addition to issues commonly associated with the design of residential and workplace studies. Based on the review of chamber, community, and workplace studies of human exposures to formaldehyde, it is not possible to identify a specific no observed adverse effect level or lowest observed adverse effect level for formaldehyde. Ranges of exposures associated with acute sensory irritation can be derived and do include sensitive subpopulations. However, given the quality and variability of the data, human studies alone, especially those involving sensory irritation, are not adequate to serve as a reference concentration for estimating risk, or lack thereof, for a lifetime of exposure to formaldehyde. Alternative approaches, such as modeling cellular changes observed in animal studies, may be more useful for quantitative risk assessment of noncancer endpoints and should be used as an adjunct to interpreting human sensory studies.

Epithelial atypia and squamous metaplasia in nasal polyps

Fifteen routine nasal polypectomy specimens submitted to our laboratory over an eight-month period were noted to show marked atypia within areas of squamous metaplasia to a degree suggestive of dysplasia. Reviewing the literature revealed little published work in this area, especially recently. Further nasal polyp cases from this, and a similar previous time period, were re-examined, and possible causes for these changes discussed.

Respiratory effects of organic solvent exposure

Organic solvents are widely used in industrial processes and found in many common household products. Exposures to solvents are common in both idustrialized and industrializing countries. While organic solvents exposure is well known to produce central nervous system toxicity, hepatic, renal and dermatologic injury, the respiratory effects of solvent exposure are poorly documented. Several recent population-based epidemiologic studies have found an independent association of occupational solvent exposure with respiratory symptoms, impaired pulmonary function or respiratory disease, but interpretation of these studies is limited by self-reported exposure data. Animal studies have demonstrated adverse effects in both the conducting and the respiratory airways, although often at very high exposure levels. Human chamber studies have most consistently reported irritation of the eyes, nose and throat without evidence of airway hyper-responsiveness. Case series have observed obstructive and restrictive effects in patients with high level inhalational exposures to solvents, particularly formaldehyde, but occupational epidemiologic studies have not consistently demonstrated changes in pulmonary function. Finally, mortality studied have not found increased mortality rates from respiratory disease in occupations associated with solvent use. In general, solvents have been demonstrated to cause mucosal irritation of the eyes and upper airways, but studies of pulmonary impairment following exposure have been limited and inconsistent. Solvent-mediated respiratory toxicity is biologically plausible, but further research is needed to better characterize exposures and to elucidate the specific mechanisms associated with injury.

Occupational rhinitis--possible mechanisms of pathogenesis

Occupational rhinitis has been a prescribed industrial disease in the UK since 1907. It has only relatively recently received significant attention from otorhinolaryngologists although numerous studies have been performed in the past by occupational and industrial health physicians. At the present time the precise mechanisms of pathogenesis are unclear and would appear to be multiple. Recently interest has arisen because of compensation claims. Diagnosis made on the basis of the clinical history is subject to two problems: firstly, there is difficulty in differentiating between occupational and nonoccupational rhinitis, and secondly, clinical histories can easily be feigned. Physical signs would be a more reliable indicator of occupational damage to the nasal mucosa if they differ from the signs normally found in allergic or vasomotor rhinitis. In a series of 100 shipyard workers dry atrophic nasal mucosa was found in 66 and septal ulceration in two. From their clinical histories 78 individuals complained of nasal obstruction, 28 of epistaxis, 42 of hyposmia, 10 of anosmia and 90 of rhinorrhoea. Possible pathogenesis is described.

Pollution: the nose and sinuses

The nose and sinuses are constantly exposed to the huge quantities of gases needed to maintain life. Not only is the human nose well-equipped to warm and humidify this inhaled air, but it is also uniquely able to clean much of it. Any material other than physiologic amounts of oxygen, nitrogen, carbon dioxide, and water that accompanies the airstream can be considered a pollutant, and this pollutant could potentially injure the individual. The following discussion will review the defense mechanisms that allow the nose and sinuses to protect the lower airways. The effects of pollutants on the respiratory mucosa will then be described, including some recent trends in those effects. These trends include specific population consequences of indoor and outdoor air pollution, and changes in risk for individuals in several occupations. Throughout these discussions, specific areas that would benefit from further research will be mentioned.

Langerhans cells and subsets of lymphocytes in the nasal mucosa

Langerhans cells and different lymphocytes were studied in the nasal mucosa of 39 woodwork teachers and a control group of 14 healthy subjects. Ten of the woodwork teachers were sensitized as determined by skin prick test. A panel of different monoclonal antibodies was applied on the frozen nasal mucosal specimens. Intraepithelial CD1-positive dendritic cells were found in all specimens. However, there was no difference between the number of these Langerhans cells found in the study group and the number found in the controls. In every specimen the intraepithelial lymphocyte population was dominated by T lymphocytes, and there were relatively few B cells. Similarly the ratio between CD4- and CD8-positive lymphocytes in the study group and the controls was the same. In all specimens there was a dominance of T suppressor/cytotoxic cells compared with T helper/inducer cells. The study confirms that Langerhans cells are present in normal nasal surface epithelium, and suggests that there is no basic difference in the number of Langerhans cells between healthy persons, persons with nasal complaints, and persons with nasal allergy. The dominance of T lymphocytes in the epithelium may indicate the existence of a local cell-mediated immunity other than that associated with the regulation of IgE.

Occupational exposure to formaldehyde and histopathological changes in the nasal mucosa

To study the cytotoxic effect of formaldehyde on the human nasal mucosa 75 men with occupational exposure to formaldehyde or to formaldehyde and wood dust, were examined, looking particularly at early signs of irritative effects and histopathological changes in the nasal mucosa. All men underwent a medical examination and a nasal biopsy specimen was examined by a pathologist and graded from 0-8 according to the morphological changes. A high frequency of nasal symptoms, mostly a running nose and crusting, was related to exposure to formaldehyde. Only three men had a normal mucosa; the remainder had loss of cilia and goblet cell hyperplasia (11%) and squamous metaplasia (78%); in six cases (8%) there was a mild dysplasia. The histological grading showed a significantly higher score when compared with unexposed contents (2.9 v 1.8). There was no dose response relation, no malignancies, and no difference in the histological score between those exposed to formaldehyde or to formaldehyde and wood dust.

Nonolfactory surface epithelium of the nasal cavity of the bonnet monkey: a morphologic and morphometric study of the transitional and respiratory epithelium

The purpose of the present study was to characterize ultrastructurally the nonolfactory nasal epithelium of a nonhuman primate, the bonnet monkey. Nasal cavities from eight subadult bonnet monkeys were processed for light microscopy, and scanning and transmission electron microscopy. Nonolfactory epithelium covered the majority of the nasal cavity and consisted of squamous (SE), transitional (TE), and respiratory epithelium (RE). Stratified SE covered septal and lateral walls of the nasal vestibule, while ciliated pseudostratified RE covered most of the remaining nasal cavity. Stratified, nonciliated TE was present between SE and RE in the anterior nasal cavity. This epithelium was distinct from the other epithelial populations in abundance and types of cells present. TE was composed of lumenal nonciliated cuboidal cells, goblet cells, small mucous granule (SMG) cells, and basal cells, while RE contained ciliated cells, goblet cells, SMG cells, basal cells, and cells with intracytoplasmic lumina lined by cilia and microvilli. TE and RE contained similar numbers of total epithelial cells and basal cells per millimeter of basal lamina. TE was composed of more SMG cells but fewer goblet cells compared to RE. We conclude that nonolfactory nasal epithelium in the bonnet monkey is complex with distinct regional epithelial populations which must be recognized before pathologic changes within this tissue can be assessed adequately.

Nasal cuboidal metaplasia with dysplasia. Precursor to adenocarcinoma in wood-dust-exposed workers?

The histological study of the non-tumours nasal mucosa in 22 wood-workers with ethmoidal adenocarcinoma was carried out and special attention was paid to the presence of cuboidal metaplasia with or without dysplasia. The workers had been exposed to wood dust for an average of 38 years (range 18 to 55 years). In 19 cases cuboidal metaplasia was found and 16 of these also had dysplasia. In 10 cases there was a transitional zone with dysplastic cuboidal epithelium in continuity with the tumour. In 5 cases there was squamous metaplasia. The results indicate cuboidal metaplasia with dysplasia being a possible precursor to nasal adenocarcinoma in workers exposed to wood dust, similar to the findings of squamous metaplasia and squamous cell carcinoma in nickel workers.