Silk fibroin and Nettle extract promote wound healing in a rat model: A histological and morphometrical study.

INTRODUCTION: Considering the anti-inflammatory, antimicrobial ability, and antioxidant effects besides stimulating ability of silk fibroin (SF) in cell migration and proliferation of Nettle, the current study aimed to investigate the effect of Nettle leaf extract (NLE) and SF on histology, morphometrical parameters and apoptosis on the wound in the rat model. MATERIALS AND METHODS: Wistar rats are divided into 5 groups, including 1-control (rats with healthy skin and no treatment); 2-wound (without any treatment); 3-SF (administration of silk fibroin solution for 14 consecutive days); 4- Nettle (administration of Nettle ointment for 14 consecutive days), and 5- Eucerin group (administration of Eucerin substance for 14 consecutive days) and then assessed wound area by photography, angiogenesis, inflammation, and thickness of epidermis using hematoxylin and eosin (H&E) staining, collagen deposition, and structure of dermis layers evaluated by Masson's trichrome staining and the apoptosis index determined by tunnel assay on days 7, 14 and 21. RESULTS: photographic illustrations showed that the wound surface environment on the seventh day in group 4 was significantly different from group 2 (p < 0.002). The rate of wound healing on the fourteenth day was higher in groups 3 and 4 than in group 2 (p < 0.001). Also, at this time, group 4 was significantly different from group 3 and group 5 (p = 0.003 and p = 0.000, respectively). There was a significant difference in epidermal thickness between the wound group and other experimental groups (p < 0.05). The number of apoptotic cells at the wound edges on the seventh day in both group 3 and group 4 had a significant decrease compared to other groups of wounds (p = 0.000), but there was a significant increase on the fourteenth day. Also, on the 21st day, a significant decrease in apoptotic cells was observed in both group 3 and group 4 compared to other wound groups (p = 0.000). DISCUSSION AND CONCLUSION: Nettle and SF maintain cell homeostasis and accelerate wound closure by reducing cell apoptosis and enhancing cell proliferation on the seventh day, but by increasing the apoptosis of fibroblast cells on the fourteenth day, they lead to remodeling and keratinocytes migration to epidermis formation. Increased apoptosis also seems to be one of the pathophysiological mechanisms to prevent the formation of keloid and hypertrophic scar tissue. SF and Nettle extract, by increasing cell proliferation and migration of different cell types to the site of injury, control the remodeling process by inducing and regulating apoptosis in the first two weeks of wound healing and accelerating the process of collagen deposition and epithelialization.

Evaluating the accuracy of fine needle aspiration and frozen section based on permanent histology in patients with follicular lesions.

BACKGROUND: Fine needle aspiration (FNA) has led to a decrease in unnecessary surgeries for thyroid nodules. This study was designed to compare diagnostic value of FNA and frozen section methods in the follicular lesions. METHODS: This is a cross-sectional study based on the medical records of 42 patients who were referred to surgery clinic of Rasool-e-Akram hospital in Tehran with complaint of thyroid nodules. All FNAs were diagnosed as follicular lesions in pathologic evaluation. All the patients underwent thyroid surgery and their frozen section results were also assessed. Finally, diagnostic value of the two tests was compared based on final permanent histologic report. RESULTS: Forty two patients with follicular thyroid nodules diagnosed with FNA were included. During the operation, using frozen sections, diagnosis of papillary carcinoma, non-papillary malignancies, benign lesion and intermediate cytology was made in 13 (31%), 3 (7%), 25 (59.5%), 1 (2.5%) patients, respectively. RESULTS of permanent histology showed that follicular adenoma is the most prevalent lesion which appeared in 25 (59.5%) cases. Papillary and follicular carcinomas were detected in 10 (23.8%) and 4 (9.5%) cases, respectively. CONCLUSION: RESULTS of the study demonstrate a 73% reduction in second surgery in patients with follicular thyroid lesions based on intraoperative frozen section results.