Effect of Cigarette Smoke on Wound Healing of the Septal Mucosa of the Rat

The rat as an animal model in chronic wound research: An update

The increasing global prevalence of chronic wounds underscores the growing importance of developing effective animal models for their study. This review offers a critical evaluation of the strengths and limitations of rat models frequently employed in chronic wound research and proposes potential improvements. It explores these models in the context of key comorbidities, including diabetes, venous and arterial insufficiency, pressure-induced blood flow obstruction, and infections. Additionally, the review examines important wound factors including age, sex, smoking, and the impact of anesthetic and analgesic drugs, acknowledging their substantial effects on research outcomes. A thorough understanding of these variables is crucial for refining animal models and can provide valuable insights for future research endeavors.

The Effect of Rosmarinic Acid on Wound Healing of Nasal Mucosa in the Rats

BACKGROUND

The nose can be damaged by environmental pollutants and foreign bodies, as well as a result of trauma, infection or surgical interventions. Proper healing of the damaged nasal mucosa is important for health.

OBJECTIVE

There is no study in the literature investigating the effects of rosmarinic acid on mucosal healing. The aim of this study was to investigate the effect of rosmarinic acid on nasal mucosal healing.

METHODS

21 male, adult Spraque Dawley albino rats were divided into three groups as the control group, the local treatment group in which rosmarinic acid was applied locally to the nasal mucosa, and the systemic treatment group in which rosmarinic acid was injected intraperitoneally. The wound area was obtained by creating a trauma area by inserting a 10 mm interdental brush through the right nasal nostril into the right nasal cavities of all animals. For the following 15 days, the treatment agent was applied as indicated once a day and on the 15th day the animals were decapitated and tissue samples taken from the nasal mucosa were prepared for histopathological examination. The preparations were examined in terms of cellular hyperplasia, goblet cell hypertrophy and degeneration, leukocyte infiltration, cilia loss and degeneration, edema and vascular dilatation, and they have been classified into four categories as mild (+), moderate (++), severe (+++) and very severe (++++).

RESULTS

There was a significant difference between the groups in terms of all parameters evaluated, and there is a decrease in the intensity of the parameters with transition from the control group to the local group and from there to the systemic group.

CONCLUSION

Systemic rosmarinic acid administration showed an enhancing effect on the healing of experimentally induced nasal mucosal injury due to its possible anti-inflammatory effect.

Protective Effect of Alpha-Lipoic Acid against Liver Damage Induced by Cigarette Smoke: An in vivo Study

Background:

Long-term cigarette smoking damages the liver tissue. Alpha-lipoic acid (ALA) is used as a therapeutic agent in a number of conditions and is known to have ameliorative effects against oxidative stress in the liver.

Objective:

To investigate the ameliorative effects of ALA on cigarette smoke (CS)-induced oxidative liver damage by examining histopathological, immunohistopathological changes and biochemical parameters in an animal model.

Materials and Methods:

Twenty-eight female Sprague–Dawley rats were randomly divided into three groups. In the control group (n = 8), rats were exposed to fresh air twice a day and given 0.1 ml of saline by gavage once a day for 8 weeks. In the smoking group (n = 10), rats were exposed to CS for 1 h in the morning and afternoon and given 0.1 ml of saline by gavage once a day for 8 weeks. In the smoking + ALA group (n = 10), CS exposure was same as the smoking group in addition to 100 mg/kg of ALA per day for 8 weeks through gavage. Oxidative damage in the liver tissue was determined by evaluating malondialdehyde (MDA), catalase (CAT) and superoxide dismutase (SOD) levels. Aspartate aminotransferase (AST), alanine aminotransaminase (ALT), alkaline phosphatase (ALP), direct bilirubin and total bilirubin levels were measured in the blood. Histopathological and immunohistochemical examinations were performed.

Results:

MDA (P = 0.011), AST (P = 0.018) and total bilirubin levels (P < 0.001) were increased, while CAT activity (P = 0.009) and the efficiency of SOD (P = 0.010) were decreased in the smoking group compared with the control group. CAT activity was increased (P = 0.017) and AST (P = 0.018) and total bilirubin levels (P < 0.001) were decreased in ALA-treated group compared with the smoking group. We observed vascular dilatation and hemorrhagic areas in the smoking group. TNF-α expression was increased in the smoking group compared with the control group. However, TNF-α expression was high in some preparations in the ALA-treated group.

Conclusions:

ALA can enhance antioxidant activity, but studies with different doses of ALA are required to determine the extent of its hepatoprotective effect.

General Complications after Endoscopic Sinus Surgery in Smokers: A 2005-2016 NSQIP Analysis

BACKGROUND

Exposure to cigarette smoke has been associated with a higher incidence of postoperative complications across a variety of surgical specialties. However, it is unclear if smoking increases this risk after endoscopic sinus surgery (ESS). Because complication rates after ESS are relatively low, a large national database allows for a statistically meaningful study of this topic.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) dataset from 2005 to 2016 was analyzed. Patients who underwent ESS were identified. Thirty-day postoperative complication rates between smokers and nonsmokers were compared. Complications included infection, thromboembolic events, reintubation, readmission, acute renal failure, and cardiovascular events.

RESULTS

921 patients who underwent ESS were identified. 182 (20%) were smokers and 739 (80%) were nonsmokers. 609 patients underwent outpatient ESS, while 312 patients underwent inpatient ESS. A total of 12 patients experienced postoperative surgical site infections involving the deeper tissues beyond the wound (organ/space SSI). On univariate analysis, smoking was associated with a higher incidence of organ/space SSI (P = .0067) and pulmonary embolism (P = .0321) after ESS. On multivariate logistic regression, smoking was associated with increased odds (4.495, 1.11- 8.17, P = .0347) of organ/space SSI after ESS.

CONCLUSIONS

This study demonstrates an association between exposure to cigarette smoke and potentially serious surgical site infections in the 30-day postoperative period after ESS. Our findings may help when counseling smokers who are considering ESS. Further study is required to understand the nature of these infections and ways to prevent them.Level of Evidence: 2c ("health outcomes").

Morbidity in the postoperative follow-up of endoscopic anterior skull base surgery

INTRODUCTION

Endoscopic access to the sellar region by videoendoscopy shows a low rate of surgical complications, with findings that indicate risk factors for reducing morbidities during and after the postoperative period.

OBJECTIVE

To evaluate, over a nine-year period, the acquisition of skills by the anterior skull base surgical team, according to the time of elimination of nasal crusts and/or the presence of morbidities in the postoperative follow-up of individuals treated in a tertiary public hospital.

METHODS

After confirming the diagnosis of skull base pathologies, the individuals in this study underwent endoscopic surgery according to the rostrocaudal or coronal axis. For the skull base reconstruction, the nasoseptal flap (associated or not with fascia lata with thigh fat) or free graft was used; clinical follow-up of individuals occurred for a minimum period of 12 months. To assess the impact of the surgical approach on patient clinical evolution, qualitative data related to smoking, post-nasal discharge, nasal flow, smell, taste, clinical symptoms of headache, cranial paresthesia, comorbidities and postoperative morbidities were obtained.

RESULTS

The most frequent diagnosis was pituitary macroadenoma (84.14%). The mean absence of crusts in this cohort was 124.45 days (confidence interval 95%=119.50-129.39). There was a low cerebrospinal fluid fistula rate (3%). Reconstruction with the nasoseptal flap with a fat graft was an independent variable that recorded the highest mean time for the elimination of nasal crusts (=145 days, confidence interval 95%=127.32-162.68). Allergic rhinitis and smoking were shown to be the most important and independent variables that increased the mean time to eliminate nasal crusts.

CONCLUSION

The mean time to eliminate nasal crusts did not change over the years during which the procedures were performed, demonstrating the adequate training of the surgical team. Debridement and nasal irrigation with saline solutions should be performed more frequently and effectively in patients with allergic rhinitis, smokers and those who received the nasoseptal flap and fascia lata graft with autologous fat.

Effects of submucosal PRP injection on wound healing in endonasal surgeries: an experimental study

PURPOSE

To investigate the effects of submucosal platelet-rich plasma (PRP) injection on nasal mucosal wound healing after endoscopic sinus surgery.

METHODS

24 New Zealand white rabbits were randomly divided into three groups. To mimic surgery, injury was created using 3-mm punch forceps on ventral turbinate mucosa for all groups. Submucosal PRP was injected to the damaged mucosa in the first group (PRP group, n = 8), where 0.9% saline solution to the second group (saline group, n = 8) and no injection to the third one (control group, n = 8). All the animals were sacrificed 14 days after surgery; histopathological examination and hydroxyproline measurements were performed on the mucosa of all groups.

RESULTS

Neutrophils, goblet cells, and collagen intensity were found significantly lower (p < 0.05) in PRP group than the control group. Also, the number of ciliary and goblet cells, and collagen intensity were found significantly lower (p < 0.05) in PRP group, than the saline group. In PRP group, hydroxyproline levels were found (p < 0.05) significantly lower than the saline and the control group, and no significant difference was found between the saline group and the control group (p > 0.05).

CONCLUSION

There are many studies in literature showing the positive effects of PRP on wound healing. The results of this study also demonstrated positive effects of PRP on the nasal mucosa. According to these results, PRP injection to the injured nasal mucosa showed anti-inflammatory, mucus-softening, and synechia-reducing effects. Therefore, submucosal PRP injection after endonasal surgeries can be considered an effective application for maintaining nasal physiology.

Protective Effect of Aerobic Exercise on the Nasal Mucosa of Rats Against the Histopathologic Changes in Cigarette Smoke Exposure

INTRODUCTION

Smoking is a public health problem that has been proven to have adverse effects on human health. Aerobic exercise has positive effects on the human body, especially on the respiratory system.

OBJECTIVE

The aim of this experimental animal model study was to determine whether regular aerobic exercise has a protective effect against the harmful effects of cigarette smoke on the nasal mucosa of rats.

METHODS

A total of 24 male Wistar albino rats were randomly separated into 3 groups of 8: group 1 (cigarette smoking), group 2 (cigarette smoking and exercise), and group 3 (control group). At the end of the experiment period, histopathological (light and electron microscopy) and immunohistochemical (GSTA 1, CYP1A1, and CYP2E1) evaluations were made of the nasal mucosa of the animals.

RESULTS

Goblet cell loss and basal membrane thickening were significantly lower in group 2 and group 3 compared to group 1. In the electron microscope evaluation, the inflammatory expressions of the goblet cells were observed in a very small area in group 2. In group 1, these were distributed over large areas between the mucosal cells. There was seen to be significant swelling of the mitochondria in group 1 compared to the other groups. No statistically significant difference was determined between the groups with respect to GSTA1, CYP2E1, and CYP1A1 scores (P > .05).

CONCLUSION

The results of this study showed that regular aerobic exercise has a protective effect against the harmful effects of smoking on the nasal mucosa of rats.

Preoperative quality-of-life measures predict acute postoperative pain in endoscopic sinus surgery

OBJECTIVES

Recent increases in opioid-related mortality have prompted a critical evaluation of postoperative pain management across all specialties. However, successfully limiting narcotic overprescription requires perioperative identification of patients who are at risk for high postoperative pain. Unfortunately, quality data to guide practice patterns are lacking. We therefore prospectively investigated several possible predictive factors of postoperative pain after endoscopic sinus surgery (ESS).

METHODS

Sixty-four consecutive patients undergoing ESS were enrolled. Baseline 22-item SinoNasal Outcomes Test (SNOT-22) and Short-Form 8 (SF-8) scores were obtained. Pain scores were collected postoperatively using a numeric rating scale. Spearman correlations and univariate linear regression models were used to investigate relationships between postoperative pain, patient factors, and SNOT-22/SF-8 domain scores. Multivariate linear regression was then performed to control for potential confounding variables.

RESULTS

Day-of-surgery pain scores were significantly correlated with the SF-8 role-physical domain (Rs = 0.32, P = 0.04). Whereas SF-8 pain scores were initially nonsignificant, at postoperative day 3 (POD3) the preoperative SF-8 pain score became correlated with self-reported pain (Rs = 0.39, P = 0.02). SNOT-22 total and subdomain scores were not associated with pain scores at any time point. Multivariate linear regression modelling identified baseline SF-8 role-physical and pain scores, smoking status, and undergoing a modified Lothrop procedure as significant independent predictors of POD3 pain (adjusted R² = 0.359, P < 0.0001).

CONCLUSION

Baseline patient-reported global quality-of-life measures are associated with postoperative pain after ESS. Large multicenter studies are necessary to validate these findings and investigate additional factors associated with postoperative pain following ESS.

LEVEL OF EVIDENCE

2c Laryngoscope, 129:1274-1279, 2019.

Cigarette smoke increases pro-inflammatory markers and inhibits osteogenic differentiation in experimental exposure model

Tobacco smokers have slowed bone growth and regeneration and more frequent implant failures than non-smokers, but the effect of cigarette smoking on the host response to bone-dwelling biomaterials is poorly understood. Macrophages and mesenchymal stem cells (MSCs) are essential in the healing response after implant placement. This study examined the effects of an experimental model of cigarette smoke exposure using cigarette smoke extract (CSE) on bone architecture in vivo and differentiation and inflammatory cytokine production on clinically relevant microstructured surfaces in vitro. CSE was prepared by bubbling mainstream smoke from one research cigarette (3R4F) in 1 mL phosphate-buffered saline. For in vivo studies, bone morphometry was examined in femurs isolated from mice injected with diluted CSE for 25 days. For in vitro studies, osteogenic markers and interleukins were measured in human MSCs and murine macrophages cultured on rough or rough-hydrophilic titanium (Ti) surfaces in culture media ± CSE for seven days. In vivo, CSE exposure decreased in bone area, volume, and interconnectivity in a dose-dependent manner. In vitro, macrophages exposed to CSE increased production of pro-inflammatory cytokines, abolishing the increase in anti-inflammatory cytokines typically seen on rough-hydrophilic surfaces. MSCs exposed to CSE had lower mRNA expression of osteoblast differentiation markers, increased levels of pro-inflammatory mRNA, and reduced production of osteogenic proteins. Our results demonstrate that CSE decreases osteogenic differentiation and anti-inflammatory interleukin production while increasing pro-inflammatory interleukin production in macrophages and MSCs, suggesting that compounds in CSE strongly affect stem cell differentiation and may compromise bone formation following biomaterial placement.

STATEMENT OF SIGNIFICANCE

The study of implantable materials' interaction with biological systems occurs nearly exclusively in healthy cell and animal models. However, 15% of the US population smokes cigarettes, which is known to modulate immune response and tissue regeneration. To explore this interaction, we created a method of capturing smoke compounds as CSE for in vivo and in vitro use. We found chronic injection into mice produced an osteoporotic, pro-inflammatory phenotype similar to direct smoke models. Furthermore, CSE attenuated osteogenic differentiation and promoted a pro-inflammatory profile in MSCs and macrophages, respectively, when cultured on titanium surfaces. These results demonstrate that this CSE model may be useful for predicting how chronic tobacco exposure may adversely affect the outcome of biomedical implants in pre-clinical models.

A Novel In Vivo Model to Study Impaired Tissue Regeneration Mediated by Cigarette Smoke

Cigarette smoke is associated with several pathologies including chronic respiratory diseases and cancer. In addition, exposure to cigarette smoke is correlated with impaired wound healing, where a significant decrease in the regenerative capacity of smokers is well documented and broadly considered a negative risk factor after trauma or surgery. So far, some in vitro and in vivo models have been described to study how exposure to cigarette smoke diminishes the regenerative potential in different organisms. However, although useful, many of these models are difficult and expensive to implement and do not allow high-throughput screening approaches. In order to establish a reliable and accessible model, we have evaluated the effects of cigarette smoke extract (CSE) on zebrafish development and regeneration. In this work, zebrafish embryos and larvae were exposed to low doses of aqueous CSE showing severe developmental abnormalities in a dose-dependent manner. Furthermore, when adult zebrafish were subjected to caudal fin amputation, we observed a significant decrease in the regenerative capacity of animals exposed to CSE. The effect was exacerbated in male and aged fish compared to female or young organisms. The establishment of a zebrafish model to assess the consequences of cigarette smoke and its effects on animal physiology could provide a new tool to study the underlying mechanisms involved in impaired tissue regeneration, and aid the development of novel approaches to treat complications associated with cigarette smoke toxicity.

Nasal cytology: Methodology with application to clinical practice and research

Nasal cytology is an easy, cheap, non-invasive and point-of-care method to assess nasal inflammation and disease-specific cellular features. By means of nasal cytology, it is possible to distinguish between different inflammatory patterns that are typically associated with specific diseases (ie, allergic and non-allergic rhinitis). Its use is particularly relevant when other clinical information, such as signs, symptoms, time-course and allergic sensitizations, is not enough to recognize which of the different rhinitis phenotypes is involved; for example, it is only by means of nasal cytology that it is possible to distinguish, among the non-allergic rhinitis, those characterized by eosinophilic (NARES), mast cellular (NARMA), mixed eosinophilic-mast cellular (NARESMA) or neutrophilic (NARNE) inflammation. Despite its clinical usefulness, cheapness, non-invasiveness and easiness, nasal cytology is still underused and this is at least partially due to the fact that, as far as now, there is not a consensus or an official recommendation on its methodological issues. We here review the scientific literature about nasal cytology, giving recommendations on how to perform and interpret nasal cytology.

A Systematic Review of the Association between Cigarette Smoke Exposure and Chronic Rhinosinusitis

Objectives Cigarette smoking and passive smoke exposure have been associated with chronic rhinosinusitis (CRS). Our goal in this systematic review was to (1) determine if there was a strong correlative effect in large population studies between cigarette smoke exposure and the prevalence of CRS, (2) investigate pathogenic mechanisms of cigarette smoke in the upper airway, and (3) determine if a history of cigarette smoking affects the medical and surgical outcomes of CRS. Data Sources MEDLINE, Embase, Cochrane CENTRAL, Web of Science SCI and CPCI-S, and websites. Methods A comprehensive literature review and quantitative meta-analysis of studies based on the PRISMA protocol and examining the relationship between cigarette smoke exposure and CRS was performed. A search strategy was developed using various terms such as sinusitis, rhinitis, rhinosinusitis, and smoking. The articles were categorized by (1) epidemiology, (2) pathophysiology, and (3) outcomes. Data regarding study design, population/setting, methods, and bias were collected. Results The initial search generated 2621 titles/abstracts with 309 articles undergoing secondary review and 112 articles for final review. We determined that there is a strong correlation between active and passive cigarette smoke with the prevalence of CRS. Cigarette smoke challenge to sinonasal epithelia results in the release of inflammatory mediators and altered ciliary beat frequency. Pediatric patients exposed to secondhand smoke appear to have particularly poor outcomes. Conclusion There is clear evidence that cigarette smoke is related to CRS, but longitudinal and mechanistic studies are required to determine a causative effect. This information is critical for greater understanding of CRS health outcomes.