Histologic changes in the eustachian tube mucosa of rats after short-term exposure to cigarette smoke

Smoking Pack Years and Eustachian Tube Dysfunction

Objective

To determine the effect of smoking history on the risk of developing obstructive eustachian tube dysfunction (OETD).

Study Design

Cross-sectional review.

Setting

National database.

Methods

Data from the National Health and Nutrition Examination Survey (1999 to present) was analyzed. OETD was defined as middle ear pressure less than -100 decapascals (daPa). Nonsmokers, current smokers, with tympanometry data were analyzed. Patients under the age of 18, with myringotomy tubes, or with a sinus problem/earache/cold in the past 24 hours were excluded. The relative risks (RRs) for developing OETD were calculated for nonsmokers versus smokers and those with greater versus less than 10, 20, and 30 pack years (py).

Results

A total of 9472 patients met inclusion criteria (54.1% female, 75.9% non-Hispanic, mean age 43, 20.3% smokers). The RR of having OETD for smokers versus nonsmokers was 1.75 [95% confidence interval, CI: 1.45-2.11]. The RR of having OETD for patients with a 10+ py was 1.97 [95% CI 1.57-2.47], 20+ py was 2.29 [95% CI 1.76-2.95], and 30 py or greater was 2.08 [95% CI 1.49-2.90].

Conclusion

In this study, smoking roughly doubled the risk of developing OETD, as represented by a single measurement of negative middle ear pressure less than -100 daPa. The definition of OETD used in this study was limited, as it did not include symptomology, and more work is needed to examine additional covariates. However, these results may guide future research to better counsel and screen patients for OETD.

Association between asthma or chronic obstructive pulmonary disease and chronic otitis media

We hypothesized that asthma/chronic obstructive pulmonary disease (COPD) might increase the risk of chronic otitis media (COM), as asthma or COPD affects other diseases. The aim of this research was to investigate whether the incidence of COM is affected by a diagnosis of asthma or COPD in patients compared to matched controls from the national health screening cohort. A COM group (n = 11,587) and a control group that was 1:4 matched for age, sex, income, and residence area (n = 46,348) were selected. The control group included participants who never received treatment for COM from Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015. The crude and adjusted odds ratios (ORs) of previous asthma/COPD before the index date for COM were analyzed using conditional logistic regression. The analyses were stratified by age, sex, income, and region of residence. The period prevalence of asthma (17.5% vs. 14.3%, p < 0.001) and COPD (6.6% vs. 5.0%, p < 0.001) were significantly higher in the COM group than in the control group. In addition, the odds of asthma and COPD were significantly higher in the COM group than in the control group. Both asthma (adjusted OR 1.23, 95% confidence interval [CI] 1.16-1.31, p < 0.001) and COPD (adjusted OR 1.23, 95% CI 1.13-1.35, p < 0.001) increased the ORs for COM. This positive association between asthma/COPD and COM indicates that asthma/COPD might increase the incidence of COM.

Effects of cigarette smoke on Haemophilus influenzae-induced otitis media in a rat model

Exposure to cigarette smoke (CS) is a factor that could delay or worsen the recovery of otitis media (OM) by causing inflammatory swelling of the Eustachian tube (ET). However, despite the suggested relationship, little is known about the association between OM and CS. Therefore, we aimed to evaluate the effects of CS on the development, progression, and recovery of OM, as well as the histological and molecular changes caused by CS exposure, by using a rat model of OM infected with non-typeable Haemophilus influenzae (NTHi). Eighty Sprague-Dawley rats with normal middle ears (MEs) were divided into four groups (n = 20 rats/group): control, CS, OM, and CS + OM. The CS and CS + OM groups were exposed to CS for 2 weeks. The inflammatory reaction to NTHi was more intense and lasted longer in the CS + OM group than in the other groups. Goblet cell proliferation and mucus secretion in the ET were more significant in the CS and CS + OM groups than in the other groups. These findings suggested that because CS directly affects the ET and ME mucosa, bacterial OM can become more severe and may resolve more slowly in the presence of CS exposure rather than in its absence.

Changes in Eustachian Tube Mucosa in Mice After Short-Term Tobacco and E-cigarette Smoke Exposure

OBJECTIVES

To evaluate histologic changes in middle ear and eustachian tube (ET) mucosa of mice after exposure to tobacco or electronic cigarette (e-cigarette) smoke. To determine whether there were any mitigating effects of middle ear application of anti-IL-13 or the epidermal growth factor receptor antagonist AG1478 on noted changes within ET mucosa.

STUDY DESIGN

Controlled animal study.

METHODS

Fifty BALB/cJ mice were randomly assigned to one of five groups: A control group with no smoke exposure, two groups exposed to tobacco smoke, and two groups exposed to e-cigarette vapor. Within the exposed groups after 4 weeks of exposure, one ear was infiltrated with a saline hydrogel and the other ear with hydrogel of either Anti-IL-13 or AG1478. After four more weeks of exposure, the animals were euthanized and the ETs were evaluated for mucosal changes.

RESULTS

Compared to control animals with no smoke exposure, there were significant decreases in the numbers of goblet cells within the ET mucosa of mice exposed to tobacco smoke and e-cigarette vapor. No significant differences in cilia, mucin, or squamous metaplasia were noted. Neither anti-IL-13 nor AG178 significantly altered goblet cell count in the ET mucosa of mice exposed to tobacco smoke; however, both agents significantly increased goblet cells within the ET mucosa of mice exposed to e-cigarette vapor.

CONCLUSION

Short-term tobacco smoke and e-cigarette vapor significantly decrease goblet cell count in mouse ET mucosa. Middle ear application of both anti-IL-13 and AG1478 resulted in an increase in goblet cell count among mice exposed to e-cigarette vapor, but not to tobacco smoke.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

The Impact of Smoking on Ossiculoplasty Outcomes

OBJECTIVES

To assess the impact of tobacco smoking on outcomes after ossiculoplasty.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary care center.

PATIENTS

Adult patients (16-88 yr of age) undergoing ossiculoplasty with cartilage tympanoplasty.

OUTCOME MEASURES

Patients were classified as smokers (TOB) or nonsmokers (TOB). Comparisons were then made between these two groups with regard to early and late audiometric outcomes, rate of cure of conductive hearing loss, rate of successful graft healing, and incidence of complications after surgery.

RESULTS

There was no significant difference between the two groups with regard to postoperative ΔPTA-ABG (change in pure-tone average air-bone gap) (-14.4 dB vs. -14.6 dB for TOB vs. TOB, respectively, p = 0.946) or final audiometric outcome (ΔPTA-ABGfinal) (-13.6 dB vs. -11.7 dB for TOB vs. TOB, respectively, p = 0.315), cure of conductive hearing loss, defined as closure of the PTA-ABG to ≤20 dB HL, at postoperative audiometry (75.0% [129/172] for the TOB group vs. 69.3% [52/75] for the TOB group, p = 0.355), late audiometry (71.4% [105/147] for the TOB group vs. 66.7% [44/66] for the TOB group, p = 0.483), or successful graft healing (99.4% in the TOB group vs. 98.7% in the TOB group, p = 0.544). However, complications were observed significantly (p = 0.0003) more often in the TOB group (34.7% [26/75]) than the TOB group (14.5% [25/172]).

CONCLUSION

Smoking is not a significant risk factor for anatomic failure of cartilage tympanic membrane graft or worsened audiometric outcome after ossiculoplasty. However, complications were significantly more common in smokers, supporting the practice of primary tympanostomy tube placement at the time of ossiculoplasty.

Impact of environmental volatile organic compounds on otitis media in children: Correlation between exposure and urinary metabolites

INTRODUCTION

Volatile organic compounds (VOCs) induce inflammatory responses. Tobacco smoke contains numerous VOCs and is a risk factor for otitis media effusion (OME); however, no previous studies have investigated the association between VOCs and OME.

OBJECTIVES

We used urinary metabolites and exposure to environmental risk factors to investigate the association between VOC and polycyclic aromatic hydrocarbon exposure and recurrent OME in children.

METHODS

Children with recurrent OME who visited the Otorhinolaryngology Department of Seoul National University Hospital between November 2014 and June 2015 were prospectively enrolled in the study. Recurrent OME was defined as more than two OME episodes over a 6-month period lasting longer than 2 months. The control group consisted of children without OME in the last year. Demographic information, including age, sex, and previous medical history was obtained, and endoscopic examinations of the tympanic membrane were performed. Urinary concentrations of 1-hydroxypyrene, 2-naphthol, hippuric acid, trans, trans-muconic acid (t,t-MA), mandelic acid, phenyl glyoxylic acid, and methyl hippuric acid were analyzed using high-performance liquid chromatography/tandem mass spectroscopy. Environmental factors assessed included house type, age, renovations, the presence of furniture <6 months old, proximity to a road, and exposure to passive smoking.

RESULTS

We enrolled 11 children with OME and 39 controls. Age and sex did not differ between groups. Exposure to passive smoking was significantly more common in the OME group than in the controls (P < 0.001). Urinary concentrations of t.t.-MA were significantly higher in the OME group (126.33 μg/g cr) than in controls (52.661 μg/g cr; P = 0.003). Other metabolites including 1-hydroxypyrene, 2-naphthol, hippuric acid, mandelic acid, phenyl glyoxylic acid, and methyl hippuric acid did not demonstrated significant relation with the OME.

CONCLUSIONS

Levels of t,t-MA, a biomarker of benzene exposure, were significantly higher in the OME group than in controls. Passive smoking was significantly more common in the OME group. Our findings suggest that high t,t-MA levels which were probably originated from passive smoking and other pollutants could be indicative OME in children.

Tobacco Smoke Exposure and Eustachian Tube Disorders in US Children and Adolescents

OBJECTIVES

To describe the association between active, environmental tobacco smoke (ETS) exposure and the prevalence of eustachian tube dysfunction (ETD) in the U.S. pediatric population.

STUDY DESIGN

Cross-sectional.

SETTING

U.S. representative demographic and audiometric data from the National Health and Nutrition Examination Survey (NHANES);2005-2010.

SUBJECTS AND METHODS

The study consisted of 2,977 children aged 12-19 years. ETD was defined as middle ear pressure <100mm H20. ETS was defined as non-active smoking in individuals with serum cotinine over the limit of detection (≥0.015 ng/mL) and <10 ng/mL(N = 1559).

RESULTS

The prevalence of ETD was 6.1%. After multivariate adjustment for age, sex, body mass index, education level, ethnicity, or having a cold, sinus problem or earache during the last 24 hours, compared to unexposed children, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 12-15 in the first, second and third tertile of cotinine concentrations were, respectively, 1.38 (0.53-3.60), 0.99 (0.53-3.60) and 2.67 (1.12-6.34). Similarly, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 16-19 in the first, second and third tertile of cotinine concentrations were, respectively, 1.28 (0.48-3.41), 0.99 (0.40-2.48) and 2.86 (1.19-6.88).

CONCLUSION

These data suggest that children and adolescents exposed to high concentrations of ETS may have an increased prevalence of ETD.

Animal models of erectile dysfunction

Erectile dysfunction (ED) is a prevalent male sexual dysfunction with profound adverse effects on the physical and the psychosocial health of men and, subsequently, on their partners. The expanded use of various types of rodent models has produced some advances in the study of ED, and neurophysiological studies using various animal models have provided important insights into human sexual dysfunction. At present, animal models play a key role in exploring and screening novel drugs designed to treat ED.

Cigarette smoke promotes eosinophilic inflammation, airway remodeling, and nasal polyps in a murine polyp model

BACKGROUND

Exposure to cigarette smoking (CS) is a major risk factor for airway inflammation. However, little is known about the effects of CS exposure on eosinophilic rhinosinusitis with nasal polyps (ERSwNPs). Histopathological and molecular studies were performed to investigate its effects using a murine model of ERSwNPs.

METHODS

Mice were assigned to one of the following four groups (n = 8 for each group): control group, CS exposure (CS group), ERSwNP (ERS group), and ERSwNPs exposed to CS (ERS + CS group). Histopathological changes were investigated using various stains, including hematoxylin and eosin for inflammation and polyp-like lesions, Sirius red for eosinophils, toluidine blue for mast cells, Alcian blue for goblet cells, and Masson's trichrome stain for collagen fibers. mRNA expression of cytokines from nasal mucosae was measured. Serum IgE and systemic cytokine levels were measured by enzyme-linked immunosorbent assays. The expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF) 1-alpha was evaluated by immunohistochemical staining.

RESULTS

The ERS + CS group showed more severe symptoms, increased the number of polyp-like lesions, infiltration of eosinophils, goblet cell hyperplasia, and subepithelial fibrosis, compared with the ERS group. Additionally, mRNA expressions of IL-4 and IL-17A were up-regulated in ERS + CS group and higher levels of IL-4, IL-6, IL-17A, and interferon gamma from splenocytes were observed significantly in the ERS + CS group compared with the ERS group. In the ERSwNP murine model, exposure to CS enhanced the expression of VEGF and HIF-1-alpha in nasal epithelial cells.

CONCLUSION

Chronic exposure to CS aggravated eosinophilic inflammation and promoted airway remodeling and nasal polyp formation in a murine model of ERSwNPs. The underlying mechanism might involve up-regulated expression of VEGF and HIF-1-alpha.

Effect of side-stream smoking on random-pattern skin flap survival in rats

The secondhand exposure to cigarette smoke is being considered evil, and damage caused by this passive exposure has been proven by several studies. To investigate the effects of sidestream smoke exposure on random-pattern skin flap survival, 20 female rats were separated into 2 groups: group A (n = 10) was exposed 6 weeks to the smoke from the burning cigarette (passive smoking) and group B (n = 10) was the control group. After 6 weeks of exposition, a dorsal McFarlane flap of 4 × 10 cm was performed in all rats. Two weeks after this procedure, the ratio of necrotic and total areas was calculated using computer programs. The median area of necrosis in group A was 29.5%, significantly higher than that in group B with 17.5% (P < 0.024). In conclusion, this study suggests increased risk of random-pattern skin flap necrosis after sidestream exposure to cigarette smoke.

Estudo comparativo das medidas de imitância acústicas em tabagistas e não tabagistas

OBJETIVO: realizar um estudo comparativo das medidas de imitância acústica em tabagistas e não tabagistas, visando identificar a ocorrência de um comportamento específico na população tabagista.MÉTODOS: em uma amostra 80 indivíduos, 40 tabagistas e 40 não tabagistas, foram obtidos o volume do meato acústico externo, a admitância, a pressão de pico e o gradiente.RESULTADOS: os resultados mostraram que pressão de pico apresentou diferença significante entre os grupos, revelando-se mais negativa no grupo dos tabagistas, tanto para a orelha direita (p=0,004) quanto para a esquerda (p=0,011). Nas demais medidas investigadas não foram verificadas diferenças estatísticas.CONCLUSÃO: Desta forma, o presente estudo conclui que a pressão do pico do timpanograma é uma medida imitanciométrica capaz de diferenciar tabagistas e não tabagistas, sendo que nos tabagistas a pressão mostra-se significantemente mais negativa.

Cartilage tympanoplasty in smokers

OBJECTIVES

We compared the outcomes of cartilage tympanoplasty in nonsmokers and smokers.

METHODS

We performed a retrospective chart review of patients who underwent cartilage tympanoplasty in a tertiary academic medical center from 1991 to 2010. There were 129 operations in 118 patients; 84 operations were performed in nonsmokers and 45 operations were performed in smokers. The primary outcome measure was the tympanic membrane graft take rate at the interval and most recent follow-up visits. Secondary measures included recurrence, the need for revision surgery, and hearing outcomes.

RESULTS

Nonsmokers and smokers had comparable long-term rates of intact eardrums (90.6% versus 92.9%; p = 0.99). There was a trend toward a higher rate of recurrent or persistent disease requiring further operation for smokers (13.3% versus 4.7%; p = 0.09). Both groups had improvement in pure tone averages (12.1 dB in nonsmokers and 12.8 dB in smokers) and air-bone gaps (9.6 dB in nonsmokers and 5.1 dB in smokers), although the rates were not statistically significantly different from each other. The rates of success of cartilage tympanoplasty in smokers appear superior to previously published rates of noncartilage tympanoplasty.

CONCLUSIONS

Cartilage tympanoplasty has success rates and postoperative audiological measures that are comparable between smokers and nonsmokers. In smokers, cartilage grafting is superior to noncartilage grafting and is recommended for any patient who smokes and is undergoing tympanoplasty.

Effects of smoking on plasma testosterone level and erectile function in rats

INTRODUCTION

There have been several conflicting reports of the effects of smoking on plasma testosterone levels and erectile function in clinical and animal studies.

AIM

This study was conducted to determine the actual effects of smoking on plasma testosterone levels and erectile function in rat-smoking models.

METHODS

For the exposure to cigarette smoke, the rats in a cage had a constant influx of smoke using a specially constructed device. Twenty-four Sprague Dawley (SD) rats for the acute cigarette exposure were allocated randomly into two groups: an experimental group and a control group. Thirty-six SD rats for the chronic cigarette smoke exposure were randomly divided into three groups: a control group and two experimental groups.

MAIN OUTCOME MEASURES

After exposure to smoking, the rats were subjected to electrical field stimulation of the cavernosal nerve to assess the erectile function, and blood was collected to measure the levels of plasma thiocyanate, testosterone, luteinizing hormone, and follicle-stimulating hormone. The histological changes of testes and corpora cavernosum (CC) were examined.

RESULTS

In the smoking groups, the thiocyanate levels were significantly higher than in the control group. Also, the mean arterial pressure (MAP) was significantly higher in the smoking groups, but the corpora cavernosal filling rate and maximal intracavernosal pressure/MAP were significantly lower than in the control group. The testosterone levels of experimental groups were significantly lower than those of control group, and the testosterone and thiocyanate levels were significantly correlated with erectile function components in chronic smoking groups. There was no significant histological change in the testes; however, in the CC, there was an increase in collagen fibers and decrease in smooth muscle and sinusoidal space in chronic smoking groups.

CONCLUSION

The results suggest that both the vasoconstrictor effects of smoking and the decrease in testosterone levels after chronic smoking had some effects on erectile function in rats.

Histologic changes in the auditory tube mucosa of rats after long-term exposure to cigarette smoke

PURPOSE

The aim of the study was to investigate the effect of cigarette smoke on the auditory tube and middle ear mucosa after long-term exposure (4 and 6 months).

MATERIALS AND METHODS

Fifteen rats were divided into 3 groups. The experimental groups were exposed to cigarette in a smoking chamber for 4 and 6 months (n = 5 each). A control group (n = 5) was placed in the same chamber without exposure to cigarette smoke. Histologic changes of the auditory tube mucosa were observed through light and electron microscopes. Histologic changes of the middle ear mucosa were also observed through light microscopes.

RESULTS

The histologic changes consisted of a proliferation of goblet cells and an increase of mucus secretion in auditory tube. Squamous metaplasia was paradoxically decreased according to the duration of exposure in auditory tube. The number of goblet cell was gradually increased according to the duration of exposure in the auditory tube and middle ear.

CONCLUSIONS

Long-term passive smoke directly affects the auditory tube and middle ear mucosa. Histologic changes of auditory tube mucosa consisted of goblet cell proliferation and excessive mucus secretion.