Muharrem Dagli

The effect of oral isotretinoin (13-cis retinoic acid) on hearing systems in patients with acne vulgaris: a prospective study.

Isotretinoin is widely used in the treatment of extensive and nodulocystic acne. The objective of this prospective study was to investigate whether oral isotretinoin could affect the hearing system. Thirty‐eight patients with acne vulgaris (76 ears) who were diagnosed and treated at the Department of Dermatology were included in the current study. Study evaluation visits were performed at baseline and at Weeks 1, 2 and 3. Pure‐tone averages (PTAs) of air conduction thresholds at 250 Hz (PTA1); 500, 1000, and 2000 Hz (PTA2); 4000, 8000, and 10, 000 Hz (PTA3); and 12, 500, 16, 000, 18, 000 and 20, 000 Hz (PTA4) for each ear were calculated separately. Assessment of the efficacy was based on the audiometric findings. Compared with pre‐treatment evaluation, the PTAs of patients were found to be significantly different at the first week for PTA2 (P = 0.033) and PTA3 (P = 0.001), at the second week for PTA1 (P = 0.036), and at the third week for PTA4 (P = 0.002). Our results suggest that the oral isotretinoin (13‐cis retinoic acid), which is a derivative of retinol (vitamin A), improved the hearing level of the patients in all audiometric frequencies in a short‐period follow‐up.

Comparison of Histopathological Effects of Thymoquinone and Local Nasal Corticosteroids in Allergic Rhinitis in a Rabbit Model.

Background/Aims: In this study, we aimed to evaluate the histopathological effects of thymoquinone treatment of the nasal mucosa in a rabbit model of allergic rhinitis, and we compared its effects with those of nasal mometasone furoate. Methods: A total of 24 male New Zealand rabbits were used. The animals were randomly assigned to one of four groups. Group 1 received no treatment, while group 2 underwent ovalbumin (OVA) sensitization only. Group 3 was the study group; after OVA sensitization, the rabbits were treated with intranasal thymoquinone. The group 4 rabbits received mometasone furoate for 7 days after OVA sensitization. Mucosal structures were stained with hematoxylin and eosin, while toluidine blue was used to stain mast cells. Apoptosis was evaluated using a TUNEL assay. Results: In the positive control groups, including the thymoquinone and intranasal mometasone furoate groups, intraepithelial and submucosal inflammation and goblet cell hypertrophy were significantly decreased compared to group 2 (p < 0.001). The cilial structure was normal, as was the chondrocyte structure in both treatment groups. Conclusion: This is the first study to evaluate the histopathological effects of thymoquinone in an allergic rhinitis model. Thymoquinone reduced allergic inflammation and may be valuable for treating allergic rhinitis. However, additional studies are needed.

The histopathological and electrophysiological effects of thymoquinone and methylprednisolone in a rabbit traumatic facial nerve paralysis model

OBJECTIVE We aimed to determine the effects of methylprednisolone and thymoquinone on nerve healing in a traumatic facial nerve paralysis animal model. SUBJECTS AND METHODS Twenty-four rabbits were randomly divided into 4 groups: group I: control group received no medication and no trauma; group II: sham group received no medication after facial nerve trauma group III: 5mg/kg/day thymoquinone administered; group IV: 1mg/kg/day methylprednisolone administered. An initial electrophysiological assessment was performed in all the animals. The buccal branch of the facial nerve was then clipped to form a traumatic facial paralysis model. The drugs were administered for two weeks once a day. At the end of the second month, the electrophysiological assessments were performed and the distal part of the traumatic facial nerve were dissected and examined under light microscopy. RESULTS Best nerve regeneration was observed in the control and the thymoquinone groups, respectively, whereas the weakest regeneration was determined in the sham group. Thymoquinone and methylprednisolone significantly increased nerve recovery, as measured by histopathological scores and electrophysiological assessment. In the thymoquinone group, due to postoperative amplitude, axon diameter and thickness of myelin sheath values were significantly further increased nerve regeneration compared to that of the methylprednisolone group and these values were close to those of the values of the control group. CONCLUSION Thymoquinone was slightly better than methylprednisolone for functional nerve recovery. The neuroprotective effect of thymoquinone was attributed to its antioxidant and anti-inflammatory effects. Thymoquinone can have a new treatment option to ameliorate the nerve injury.