Structural and functional characterization of SARS-CoV-2 nucleocapsid protein mutations identified in Turkey by using in silico approaches.

Missense mutations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus may cause changes in the structure of proteins. The nucleocapsid (N) protein is an important target for drugs and vaccines. The main purpose of this study is to detect missense mutations in the SARS-CoV-2 N protein and to reveal the effects of these mutations on protein structure by using in silico approaches. 161 missense mutations of the N protein were determined in 2286 SARS-CoV-2 genomes derived from the GISAID EpiCoV database in the Turkish population. Identified 161 missense mutations were analyzed by using sequence and structure-based methods to predict effects of mutation on function and structure of SARS-CoV-2 N protein. These analyzes revealed that some mutations showed deleterious effects and change of stability and flexibility of nucleocapsid protein. D3L, S194L, S235F, and P13L (Omicron variant) mutations were further analyzed in our study due to their importance in the literature and in our results. Even though, our findings are essential for research of SARS-CoV-2 virus, in vitro and in vivo validations are necessary. Keywords: nucleocapsid protein; SARS-CoV-2; missense mutations; protein stability; protein flexibility.

The changes in histopathology and mass in hyperbaric oxygen-treated auricular cartilage grafts in a rabbit model.

The aim of the study is to investigate the histopathologic and cartilage mass changes in hyperbaric oxygen (HBO)-treated auricular cartilage grafts either crushed or fascia wrapped in a rabbit model. This is a prospective, controlled experimental study. Sixteen rabbits were randomly allocated into control (n = 8) and treatment groups (n = 8). Each group was further grouped as crushed cartilage (n = 4) and fascia wrapped crushed cartilage (n = 4). The eight rabbits in the treatment group had HBO once daily for 10 days as total of 10 sessions. The mass of cartilage, cartilage edge layout, structural layout, staining disorders of the chondroid matrix, necrosis, calcification besides bone metaplasia, chronic inflammation in the surrounding tissues, fibrosis, and increased vascularity were evaluated in the hematoxylin and eosin (H&E)-stained sections. Fibrosis in the surrounding tissue and cartilage matrix was evaluated with Masson's trichrome stain. The toluidine blue staining was used to evaluate loss of metachromasia in matrix. The prevalence of glial fibrillary acidic protein (GFAP) staining in chondrocytes was also evaluated. Although the remaining amount of cartilage mass after implantation does not show a significant difference between the control and the study group (p = 0.322, p <0.05).The difference between control and study group in terms of positive staining with GFAP was statistically significant (p = 0.01, p <0.05). Necrosis and loss of matrix metachromasia were significantly low in the study group compared with control group (p = 0.001, p = 0.006, p <0.05). HBO therapy did not have significant effect on the mass of rabbit auricular cartilage graft. HBO therapy significantly reduced loss of metachromasia, necrosis, and GFAP staining in the auricular cartilage grafts of the animal model.

A new persistent suture technique for correction of caudal septal dislocation.

INTRODUCTION: Caudal septal dislocation is both a functional and an aesthetic problem. The caudal septum that causes nasal obstruction displaces the right or left of columella. Despite the various maneuvers currently available for treatment, this issue is still controversial. We describe a new technique that uses a nonabsorbable suture material to keep the septum in the midline in mild and moderate caudal septal dislocations and can be used in addition to other current techniques. SURGICAL TECHNIQUE: A full-length (lengthways) pocket is opened between the medial cruras, and the dislocated caudal septum is placed in it and then fixed to the soft tissue in the region of columella under the skin by a nonabsorbable suture. It is used as a complementary technique for both the swinging door and the Goldman technique. DISCUSSION: This technique prevents redeviation in the same direction, especially in the superior portion of the caudal end, due to the memory of cartilage tissue. It will therefore reduce revision rates.

Effects of Melatonin and Dexamethasone on Facial Nerve Neurorrhaphy.

OBJECTIVES: To investigate the effects of topical and systemic administrations of melatonin and dexamethasone on facial nerve regeneration. MATERIALS AND METHODS: In total, 50 male albino Wistar rats underwent facial nerve axotomy and neurorrhaphy. The animals were divided into 5 groups: control, topical melatonin, systemic melatonin, topical dexamethasone, and systemic dexamethasone. Nerve conduction studies were performed preoperatively and at 3, 6, 9, and 12 weeks after drug administrations. Amplitude and latency of the compound muscle action potentials were recorded. Coapted facial nerves were investigated under light and electron microscopy. Nerve diameter, axon diameter, and myelin thickness were recorded quantitatively. RESULTS: Amplitudes decreased and latencies increased in both the melatonin and dexamethasone groups. At the final examination, the electrophysiological evidence of facial nerve degeneration was not significantly different between the groups. Histopathological examinations revealed the largest nerve diameter in the melatonin groups, followed by the dexamethasone and control groups (p<0.05). Axon diameter of the control group was smaller than those of the melatonin (topical and systemic) and topical dexamethasone groups (p<0.05). The melatonin groups had almost normal myelin ultrastructure. CONCLUSION: Electrophysiological evaluation did not reveal any potential benefit of dexamethasone and melatonin in contrast to histopathological examination, which revealed beneficial effects of melatonin in particular. These agents may increase the regeneration of facial nerves, but electrophysiological evidence of regeneration may appear later.

Evaluation of life quality, self-confidence and sexual functions in patients with total and partial laryngectomy.

OBJECTIVE: In this study patients who have undergone partial (PL) or total laryngectomy (TL) were evaluated for life quality, self-esteem and sexual dysfunctions. METHODS: 108 patients who received TL or PL without tracheostoma were included in this study. During patient interview, sociodemographical data form, European Organization for Research and Treatment of Cancer, Life Questionnaire Core 30 Items, Cancer and Head and Neck module-35 Items (EORTC QLQ-C30 and H&N35) were filled and patients were also asked to fill in Arizona Sexual Experiences Scale (ASEX), Beck's Depression Inventory (BDI), Beck's Anxiety Inventory (BAI) and Rosenberg Self-Esteem Scale (RSES) forms. RESULTS: Depression and anxiety scores and points taken from RSES were significantly different between TL and PL patients (p=0.045, p=0.041 and p=0.006 respectively). Although the difference was not significant in ASEX (p=0.174), the average scores of sexuality subunit (QL-35 59-60) of EORTC QLQ-H&N35 module were significantly different in these patients (p<0.001). Besides, it was shown that 90.3% of TL patients and 63.9% of PL patients have experienced negative effects in sexual functions. CONCLUSION: TL patients were more often observed to have problems regarding depression, anxiety, self-esteem and sexual functions and it is concluded that they may need psychosocial support more than PL patients.

Cochlear functions in children with familial Mediterranean fever: any role of the severity of the disease?

OBJECTIVES: The aim of the study was to compare the cochlear functions of children diagnosed with familial Mediterranean fever (FMF) with healthy controls and to determine their cochlear functions according to their disease severity. METHODS: Seventy-three children with FMF and 30 healthy controls were included in the study. All the patients and controls were evaluated by audiologic evaluation, including high-frequency pure-tone audiometry and distortion product otoacoustic emission tests (DPOAE). The disease severity was evaluated by scoring systems adapted from those used by Pras et al. and with severity scoring systems from the Sheba Medical Center. RESULTS: High-frequency pure-tone audiometry and DPOAE levels were normal in both patients and controls. Significant differences in the hearing levels of FMF patients were not found, according to both adapted severity scoring systems. CONCLUSIONS: Cochlear functions in children with FMF had been evaluated by previous studies, but in our study we evaluated hearing functions according to both controls and disease severity. As a unique study comparing cochlear functions according to severity scores, no significant differences were shown between the groups and controls.