PDGF, NT-3 and IGF-2 in combination induced transdifferentiation of muscle-derived stem cells into Schwann cell-like cells.

Muscle-derived stem cells (MDSCs) are multipotent stem cells with a remarkable long-term self-renewal and regeneration capacity. Here, we show that postnatal MDSCs could be transdifferentiated into Schwann cell-like cells upon the combined treatment of three neurotrophic factors (PDGF, NT-3 and IGF-2). The transdifferentiation of MDSCs was initially induced by Schwann cell (SC) conditioned medium. MDSCs adopted a spindle-like morphology similar to SCs after the transdifferentiation. Immunocytochemistry and immunoblot showed clearly that the SC markers S100, GFAP and p75 were expressed highly only after the transdifferentiation. Flow cytometry assay showed that the portion of S100 expressed cells was more than 60 percent and over one fourth of the transdifferentiated cells expressed all the three SC markers, indicating an efficient transdifferentiation. We then tested neurotrophic factors in the conditioned medium and found it was PDGF, NT-3 and IGF-2 in combination that conducted the transdifferentiation. Our findings demonstrate that it is possible to use specific neurotrophic factors to transdifferentiate MDSCs into Schwann cell-like cells, which might be therapeutically useful for clinical applications.

Extension of the jejunum in the reconstruction of cervical oesophagus with free jejunum transfer using the thoracoacrominal vessels as recipients.

BACKGROUNDS: The degree to which the jejunum can reach upward is a significant consideration in cervical oesophagus reconstruction with vascularised free jejunum transfer using the thoracoacrominal vessels as recipient vessels. The present study aims to elucidate this issue. MATERIALS AND METHODS: In 30 fresh cadavers, the thoracoacrominal vessels were dissected, and the jejunums were harvested, carrying the second branches of the superior mesenteric arteries and veins as their pedicles. After the mesenteric vessels were anastomosed to the thoracoacrominal vessels, the jejunums were advanced to their maximum upward degree, and the positions of the oral ends were evaluated referring to the hyoid bone. The evaluation was performed under three conditions. In the first condition, the jejunums were simply advanced. In the second condition, tension of the mesenteriums was reduced by incising their serosa. In the third condition, mesenterial incision was also performed, and the anastomosed pedicles were placed under the clavicles. RESULTS: The jejunums can reach superior to the hyoid bone by 2.1 ± 1.5 SD cm for males and by 1.9 ± 1.5 SD for females. By incising the mesenteric serosa, these distances can be extended by about 2 cm for males and 1 cm for females. Further extension of 2 cm can be obtained for both sexes by placing the pedicle under the clavicle. CONCLUSION: With patients whose neck regions lack vessels available for vascular anastomosis, the thoracoacrominal vessels are used in free jejunum transfer for cervical oesophagus reconstruction. The findings of the present study are useful in planning this type of reconstruction.

Morphological analysis of the upper eyelid tarsus in Asians.

PURPOSE: The present study aims to evaluate morphologic variations of the upper tarsus in Asians. METHODS: Measurements of superior-inferior and medial-lateral lengths were performed on 54 embalmed cadavers. The superior-inferior length of the tarsus was measured at the central and lateral parts. On the basis of the measured values, shapes of the tarsi were evaluated and categorized. RESULTS: The tarsi were classified into 3 morphologic categories-the sickle, triangular, and trapezoid types. The upper margins of the sickle, triangular, and trapezoid type tarsi present round, triangular, and flat lines, respectively. Among the 54 examined specimens, 29 (55.6%), 16 (29.6%), and 9 (16.7%) belonged to the sickle, triangular, and trapezoid groups, respectively. CONCLUSIONS: The upper eyelid tarsi present morphologic variations with the Asian population. In performing surgical correction of blepharoptosis or surgical production of double-folds, this individual variation should be taken into consideration.

Dynamic effects of the Nuss procedure on the spine in asymmetric pectus excavatum.

OBJECTIVE: This study aimed to elucidate dynamic effects of the Nuss procedure on the spine in the treatment of patients with pectus excavatum with asymmetric thoraces. METHODS: Twenty-five patients with pectus excavatum who underwent the Nuss procedure were categorized into 4 groups by preoperative morphology of the spine and thoracic asymmetry. In group 1 (n = 8), the right side of the thorax was concave and the spine bowed to the right. In group 2 (n = 4), the right side of the thorax was concave and the spine bowed to the left. In group 3 (n = 5), the left side of the thorax was concave and the spine bowed to the right. In group 4 (n = 8), the left side of the thorax was concave and the spine bowed to the left. With computed tomographic data, finite-element models were produced to simulate each patient's thorax. Thereafter, dynamic response patterns of the spine to the Nuss procedure were examined. Validity of these biomechanical findings was verified by referring to clinical outcomes. RESULTS: In group 1 and group 4 models, deformed spines were straightened; in group 2 and group 3 models, spinal bowing increased. These biomechanical findings were compatible with clinical evaluations. CONCLUSIONS: Performance of the Nuss procedure for asymmetric pectus excavatum exerts dynamic influence on the spine. Response patterns of the spine are predictable from morphologic relationships between the asymmetric patterns of the anterior thoracic wall and the spine.

Combined fixation with plates and transmalar Kirschner wires for zygomatic fractures.

After repair of a fractured zygoma, the fixed zygoma occasionally becomes displaced. This phenomenon--generally called "relapse"--is a complication that can be prevented by fixing plural sites with plates. However, this impairs blood supply to the bone, which causes atrophy. To solve this dilemma, we developed a new concept for fixing the zygoma. Fractured zygomas are fixed by combining plate fixation at a single site with transmalar fixation with Kirschner wires. This secures stability of the fixed zygoma without impairing its blood supply. We evaluated the stability of fractured zygomas fixed by our method by doing dynamic experiments using simulation models. The stresses at the screw-bone interfaces were significantly reduced by the additional transmalar fixation with wire, indicating that zygomas fixed by our method are less likely to relapse than zygomas fixed with a single plate. We also reviewed the outcomes of patients treated by our method, which indicates its clinical usefulness.

[MAFbx and MuRF1 mRNA expression and its relationship with muscular contractility following free muscle transfer].

OBJECTIVE: To study muscle atrophy F-box (MAFbx) and muscle ring finger 1 (MuRF1) mRNA expression and its relationship with muscular contraction following free muscle transfer. METHODS: The gracilis muscle was orthotopic transferred in adult rat to establish the animal model. The muscle at the unoperated side was used as control. The expression of MAFbx and MuRF1 mRNA, the muscle contraction and muscle function were measured by real-time PCR and multiple function physiological device. The relationship among the expression of MAFbx and MuRF1 mRNA, the muscle contraction and muscle function was analyzed. RESULTS: After muscle free transfer, muscle wet weight reservation, the maximum contraction and tetanus strength reduce first and increased later, but still lower than those at control side. The expression of MAFbx and MuRF1 mRNA reached peak level 3 - 4 weeks after muscle transfer which was 7.1 and 4.1 times as that at control side. It decreased later, but still higher than that at control side, showing a significant difference between them (P< 0. 05). CONCLUSIONS: Persistent over-expression of MAFbx and MuRF1 mRNA after muscle transfer has a close relationship with muscle atrophy and muscle dysfunction. MAFbx and MuRF1 can be used as markers for early muscle atrophy, and also as potential target for drug treatment of muscle atrophy.