Ultrathin chitosan–poly(ethylene glycol) hydrogel films for corneal tissue engineering

Due to the high demand for donor corneas and their low supply, autologous corneal endothelial cell (CEC) culture and transplantation for treatment of corneal endothelial dysfunction would be highly desirable. Many studies have shown the possibility of culturing CECs in vitro, but lack potential robust substrates for transplantation into the cornea. In this study, we investigate the properties of novel ultrathin chitosan–poly(ethylene glycol) (PEG) hydrogel films (CPHFs) for corneal tissue engineering applications. Cross-linking of chitosan films with diepoxy-PEG and cystamine was employed to prepare ～50 μm (hydrated) hydrogel films. Through variation of the PEG content (1.5–5.9 wt.%) it was possible to tailor the CPHFs to have tensile strains and ultimate stresses identical to or greater than those of human corneal tissue while retaining similar tensile moduli. Light transmission measurements in the visible spectrum (400–700 nm) revealed that the films were >95% optically transparent, above that of the human cornea (maximum ～90%), whilst in vitro degradation studies with lysozyme revealed that the CPHFs maintained the biodegradable characteristics of chitosan. Cell culture studies demonstrated the ability of the CPHFs to support the attachment and proliferation of sheep CECs. Ex vivo surgical trials on ovine eyes demonstrated that the CPHFs displayed excellent characteristics for physical manipulation and implantation purposes. The ultrathin CPHFs display desirable mechanical, optical and degradation properties whilst allowing attachment and proliferation of ovine CECs, and as such are attractive candidates for the regeneration and transplantation of CECs, as well as other corneal tissue engineering applications.     

Phytochemical constituents,biological activities,and health‐promoting effects of the genus Origanum

Origanum species are mostly distributed around the Mediterranean, Euro‐Siberian, and Iran‐Siberian regions. Since time immemorial, the genus has popularly been used in Southern Europe, as well as on the American continent as a spice now known all over the world under the name “oregano” or “pizza‐spice.” Origanum plants are also employed to prepare bitter tinctures, wines, vermouths, beer, and kvass. The major components of Origanum essential oil are various terpenes, phenols, phenolic acids, and flavonoids with predominant occurrence of carvacrol and thymol (with reasonable amounts of p‐cymen and ‐terpinene) or of terpinene‐4‐ol, linalool, and sabinene hydrate. Many species of Origanum genus are used to treat kidney, digestive, nervous, and respiratory disorders, spasms, sore throat, diabetes, lean menstruation, hypertension, cold, insomnia, toothache, headache, epilepsy, urinary tract infections, etc. Origanum essential oil showed potent bioactivities owing to its major constituents' carvacrol, thymol, and monoterpenes. Several preclinical studies evidenced its pharmacological potential as antiproliferative or anticancer, antidiabetic, antihyperlipidemic, anti‐obesity, renoprotective, antiinflammatory, vasoprotective, cardioprotective, antinociceptive, insecticidal, and hepatoprotective properties. Its nanotechnological applications as a promising pharmaceutical in order to enhance the solubility, physicochemical stability, and the accumulation rate of its essential oils have been investigated. However, Origanum has been reported causing angioedema, perioral dermatitis, allergic reaction, inhibition of platelet aggregation, hypoglycemia, and abortion. Conclusive evidences are still required for its clinical applications against human medical conditions. Toxicity analyses and risk assessment will aid to its safe and efficacious application. In addition, elaborate structure–activity studies are needed to explore the potential use of Origanum‐derived phytochemicals as promising drug candidates.     

Medial peritalar dislocation

In this paper, a case of closed medial subtalar dislocation and accompanying talar head fracture in a 22-year-old man which occurred while walking on a downhill road is reported. Closed reduction under general anesthesia was unsuccessful. The obstacle for closed reduction was determined at surgery for open reduction and internal fixation as buttonholing of the talar head through the extensor retinaculum. At the 26-month follow-up, he was pain-free in his daily activities.     

Treatment of rupture of the Achilles tendon with fibrin sealant

BACKGROUND: The optimal management strategy for acute Achilles tendon ruptures is controversial. These injuries historically were treated by nonoperative methods (cast immobilization, bandaging); however, operative repair of the ruptured tendon has become popular. METHODS: Thirty-two patients who had rupture of the Achilles tendon were treated operatively with use of fibrin sealant, and clinical and functional performance measures were assessed after a mean followup of at least 6 months between November, 1998, and July, 2003. All of the patients were male. Average age was 38.18 (30 to 45) years. All of the patients were followed for at least 18 months after surgery. Average followup time was 22.4 (18 to 56) months. We evaluated all patients according to the scoring system of Thermann et al. RESULTS: Our results were excellent in 24 patients and good in eight patients. One patient had rerupture 3 weeks after surgery. CONCLUSION: Fibrin sealants are biologically compatible, hemostatic agents derived from human plasma that can be used instead of suture or suture support. We think that the treatment of rupture of the Achilles tendon with fibrin sealant is a useful treatment, and there is less risk of complications, such as deep infection, than in other operative procedures. We had no wound closure problems, the incision size was small, and the operating time was short. However, it must be remembered that the risk of disease transfer by fibrin sealant application is still present.     

Proximal oblique crescentic osteotomy in hallux valgus

Twenty-six patients with moderate-to-severe hallux valgus deformities were evaluated before and after treatment. All of the patients had incongruent great toe joints. The patients underwent modified proximal crescentic osteotomy, which was termed proximal oblique crescentic osteotomy. The results were evaluated at an average follow-up time of 55 weeks. Objective criteria were hallux valgus angle, intermetatarsal angle, shortening of the first metatarsal, and angulation at the osteotomy site. Clinical evaluation was made according to the rating system of the American Orthopaedic Foot and Ankle Society. The mean correction of the hallux valgus and intermetatarsal angles was 22.1 degrees and 9.9 degrees, respectively. Short-term results indicate that proximal oblique crescentic osteotomy is effective in the treatment of hallux valgus; its advantages over other procedures include its technical ease and low rate of complications.     

Correction of syndactyly using a dorsal separated V-Y advancement flap and a volar triangular flap in adults

Skin grafts and local flaps are conventional methods of repair for congenital syndactyly, but the results obtained are not always as functional and aesthetic as desired and frequently leave postoperative scars and residual syndactyly. In this article, we describe a new surgical technique for web reconstruction in the correction of simple, incomplete syndactyly. The technique consists of a dorsal separated V-Y advancement flap and a volar triangular flap to cover the newly created web space, thus avoiding skin graft in this space. In all, 15 web spaces in 10 patients were treated using this method. A follow-up period of 6 months to 2 years showed neither recurrence of the deformity nor web creep of any degree. The technique is rapid, safe, easily performed, and reproducible and requires a single surgical procedure. It uses donor tissue identical in color, texture, and thickness, which renders acceptable cosmesis in cases of simple, incomplete syndactyly, therefore, avoiding the use of skin grafts and resulting postoperative scar contracture in the web space.     

The Effect of Donor- and Recipient-Related Factors on Corneal Graft Survival in Penetrating Keratoplasty

Purpose: To investigate the impact of donor and recipient factors on graft survival in penetrating keratoplasty (PK).

Material and Methods: This retrospective study included 365 eyes that underwent PK using corneas from 231 donors between June 2010 and June 2015. Patients were divided into three groups (group 1: primary endothelial diseases; group 2: iatrogenic endothelial disorders; and group 3: other pathologies with a healthy endothelium) according to PK indications. The primary outcome measure was corneal graft survival at the last visit (clear or opaque). Graft clarity was assessed using Kaplan–Meier survival analysis.

Results: The most frequent PK indication was keratoconus (KC) (20.5%) followed by pseudophakic bullous keratopathy (PBK) (18.9%). Donor age had a negative impact on endothelial cell density (ECD) measured by an eye bank specular microscope (p < 0.001). Median best-corrected visual acuity in logarithm of the minimum angle of resolution units increased from 2.1 to 0.8 at 1 year after PK (p < 0.001). The clear graft rate was 96.7% at year 1, 88.8% at year 2, and 85.5% at year 3. Overall graft survival was 84.9% during a median of 39 months (range: 24–79 months) of follow-up. A higher graft survival rate (67.2%) was observed in KC compared to PBK during 6 years (p < 0.001). Recipients younger than 50 years of age showed a better graft survival rate than those older than 70 years of age (p = 0.037). Donor ECD, time between excision and death, and preservation time had no significant effect on graft survival. Frequent graft rejection episodes (GREs) and additional procedures during surgery had a negative impact on graft survival (p < 0.001 and p = 0.014, respectively). A worse graft survival was observed in group 2 compared to groups 1 and 3 (p = 0.042).

Conclusions: Young recipient age and KC were associated with a better graft survival. Graft endothelial density and preservation time had no impact on graft survival. PBK, low vision at baseline and year 1, frequent GREs, and additional interventions during surgery had a negative impact on graft survivals.