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

The effect of antimicrobial photodynamic therapy on human ciliated respiratory mucosa

BACKGROUND

Chronic recurrent sinusitis (CRS) is one of the most common chronic conditions in the United States. There is a significant subpopulation of CRS patients who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. Antimicrobial photodynamic therapy (aPDT) is a noninvasive nonantibiotic broad spectrum antimicrobial treatment. Our previous in vitro studies demonstrated that aPDT reduced CRS polymicrobial biofilm and planktonic bacteria and fungi by > 99.9% after a single treatment. Prior to human treatment however, aPDT treatment must be demonstrated to not result in histologic damage to the sinus ciliated respiratory epithelium. The objective of this study was to demonstrate the safety of aPDT treatment on a living human ciliated respiratory mucosal model (EpiAirway).

METHODS

A study of aPDT treatment of EpiAirway was performed. Treatment groups included a nontreatment control, laser light alone, photosensitizer alone, and therapeutic photosensitizer and light combination (aPDT). At completion of treatment, the EpiAirway tissue was fixed in 10% formalin, paraffin-embedded, sectioned, H&E stained and mounted. All samples were blinded and microscopically examined by a human pathologist to assess any effect of aPDT on the tissue, cilia, or mucosal glands. The results were correlated with the treatment parameters.

RESULTS

The EpiAirway histologic study demonstrated no histologic alteration of the respiratory cilia or mucosal epithelium in any of the treatment groups.

CONCLUSIONS

aPDT is a safe treatment for CRS resulting in no histologic alteration of human ciliated respiratory mucosa as is found in the human sinuses.

Effects of ovariectomy and estrogen replacement therapy on laryngeal tissue: a histopathological experimental animal study

OBJECTIVE

To determine the histopathological effect of estrogen deficiency and hormone replacement treatment on laryngeal tissue in ovariectomized rats.

STUDY DESIGN

Animal study.

SETTING

The study was conducted at the animal experiment laboratory of Marmara University School of Medicine, Istanbul, Turkey.

SUBJECTS AND METHODS

Six-month-old female Wistar albino rats were divided into the following 3 groups (n = 8 per group): sham-operated control, ovariectomized, and ovariectomized with estrogen replacement. Rats in the ovariectomized with estrogen replacement group received 17 β-estradiol valerate (200 µg/kg, subcutaneously) once a week. Animals were killed after 8 weeks of intervention.

RESULTS

Significant changes were observed in the ovariectomized group when edema in lamina propria, inflammation in squamous, respiratory epithelia and lamina propria, pseudostratification, and cilia loss were assessed. Except cilia loss, there were no significant differences in the assessments between the sham-operated control and ovariectomized with estrogen replacement groups.

CONCLUSIONS

On the basis of histopathological evaluations, it was shown that estrogen replacement helped to improve laryngeal changes due to experimentally induced menopause.