Conventional tracheal reconstruction techniques are not successful at restoring functional units in situations with extensive damage involving more than half the length of the trachea. For the first time, we investigated in vivo tissue-engineered trachea regeneration from a decellularized cadaveric trachea matrix with seeded adult adipose tissue-derived mesenchymal stem cells (MSCs) and investigated the integration of the matrix into the recipient tracheal side. For the procedure, 1.8-cm grafts were prepared from 3.5-cm tracheas of three donor rabbits. Then, tracheal grafts were rendered nonimmunogenic using a decellularization technique. MSCs isolated from recipient rabbit adipose tissue were cultured and marked before being seeded in the decellularized matrix. A total of 1.8 cm of the recipient tracheas was replaced with either a decellularized tracheal matrix (group 1) or tracheal matrix-seeded MSCs (group 2). Rabbits survived 17 ± 2 days in the first group, and the causes of death were separation in the anastomosis region, airway obstruction, and infection. In the second group, animals were sacrificed on the 30th, 60th, and 90th days of follow-up. Histopathological analysis revealed the integration of MSCs seeded-decellularized cadaveric tracheas to the recipient tracheal sides and increased angiogenesis. The MSCs were traced by fluorescence microscopy in the ciliated epithelium, under the epithelium, and in the cartilage of the integrated new trachea. Tracheas generated by autologous cells and tissue-engineering techniques will be a great source for the treatment of life-threatening tracheal injuries after the completion of related studies.

Application of Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test to healthy Turkish volunteers, obtain normative data set and analyse the role of age, sex and smoking on olfactory scores. The present study was conducted at Bezmialem Vakif University, Department of Otorhinolaryngology. Total of 426 healthy volunteers were subjected to CCCRC olfactory test which consists of n-butanol smell threshold test and smell identification test. Olfactory function score was assessed (0: worst score; 7: best score) and mean scores were calculated. Mean age was (36.7 ± 11.1; range, 17-68). 46.2 % of the subjects were male and 53.8 % were female; 37.1 % were smokers and 62.9 % were non-smokers. Mean n-butanol threshold score was 6.36 out of 7, mean identification score was 6.34 and mean total score was 6.35. According to CCCRC score: there were no anosmic individuals, 0.5 % were severely hyposmic, 2.6 % were moderately hyposmic,15.3 % were mildly hyposmic and 81.6 % were normosmic. CCCRC olfactory test is cost-effective, simple and practical. It can be easily applied in clinical settings. The CCCRC olfactory test is appropriate for assessment of olfactory function: Turkish population is familiar in terms of the odors used in CCCRC test. The power of this study is that it provides a normative data set against which many factors can be compared.

Objective This study aimed to define the clinical course of anosmia in relation to other clinical symptoms. Methods 135 patients with COVID-19 were reached by phone and subsequently included in the study. Olfactory functions were evaluated using a questionnaire for assessment of self-reported olfactory function. Patients were divided into four subgroups according to the presence of olfactory symptoms and temporal relationship with the other symptoms: group1 had only olfactory complaints (isolated, sudden-onset loss of smell); group2 had sudden-onset loss of smell, followed by COVID-19 related complaints; group3 initially had COVID-19 related complaints, then gradually developed olfactory complaints; and group4 had no olfactory complaints. Results In total, 59.3% of the patients interviewed had olfactory complaints during the disease course. The olfactory dysfunction severity during COVID-19 infection was significantly higher in group1 compared to groups 2 and 3. In groups1-3, the odor scores after recovery from COVID-19 disease were significantly lower compared to the status prior to disease onset. The residual olfactory dysfunction was similar between groups1 and 2, but was more evident than group3. Mean duration for loss of smell was 7.8 ± 3.1 (2-15) days. Duration of loss of smell was longer in groups1 and 2 than in group3. Odor scores completely returned back to the pre-disease values in 41 (51.2%) patients with olfactory dysfunction. Rate of complete olfactory dysfunction recovery was higher in group3 compared to groups1 and 2. Conclusion In isolated anosmia cases, anosmia is more severe, and complete recovery rates are lower compared to the patients who have other clinical symptoms. Level of evidence Level 4.

ObjectivesThe purpose of this study is to shorten the decellularization time of trachea by using combination of physical, chemical, and enzymatic techniques.MethodsApproximately 3.5-cm-long tracheal segments from 42 New Zealand rabbits (3.5±0.5 kg) were separated into seven groups according to decellularization protocols. After decellularization, cellular regions, matrix and strength and endurance of the scaffold were followed up.ResultsDNA content in all groups was measured under 50 ng/mg and there was no significant difference for the glycosaminoglycan content between group 3 (lyophilization+deoxycholic acid+de-oxyribonuclease method) and control group (P=0.46). None of the decellularized groups was different than the normal trachea in tensile stress values (P>0.05). Glucose consumption and lactic acid levels measured from supernatants of all decellularized groups were close to group with cells only (76 mg/dL and 53 mg/L).ConclusionUsing combination methods may reduce exposure to chemicals, prevent the excessive influence of the matrix, and shorten the decellularization time.