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Biomedical subjects

Yuiro Hata

Publications and source records attributed to Yuiro Hata.

13 recordsLinked to original sources
PubMed2006

Postoperative complications and long-term prognosis of microsurgical reconstruction after total maxillectomy.

Between 1986-2004, 13 patients (11 males and 2 females; mean age, 63.9 years) underwent microsurgical reconstruction after total maxillectomy in our hospital. Reconstructions using a rectus abdominis musculocutaneous flap were primarily carried out in our hospital by emphasizing soft-tissue filling. No postoperative complication related to a vascular anastomosis (such as thrombosis) was noted (success rate, 100%). In 3 cases, fistula formation was observed postoperatively (23.0%). In one case reconstructed with a scapular flap with a vascularized scapula, atelectasis followed by serious pneumonia was observed, and the patient temporarily fell into a life-threatening condition. Five patients died after 1-2 years due to recurrence of maxillary sinus carcinoma, and 2 died after 3-4 years due to another tumor (lung and esophageal). The disease-specific 5-year survival rate of all 40 patients with maxillary sinus carcinoma treated in our hospital by the Kaplan-Meier method was 54.6%, and the overall survival rate was 45.8%. As the prognosis of maxillary sinus carcinoma is poor, we consider that priority should be given to filling of defects with soft tissues, and we also consider that this study is significant to reevaluate strategies for maxillary reconstruction.

Aged↗
PubMed2006

Long-term outcome of intralesional injection of triamcinolone acetonide for the treatment of keloid scars in Asian patients.

We studied the long-term outcome of injection of triamcinolone acetonide into keloid scars in Asian patients. Between 1985 and 2003, we treated 109 keloid scars in 94 patients by injecting 1 to 10?mg of triamcinolone acetonide depending on the size of the lesion at four week intervals. There was little morbidity. Thirty-one patients gave up treatment within 10 injections because of pain and lack of immediate improvement. Improvement in subjective symptoms was seen in 52 of the remaining 63 patients (82%). In objective symptoms, fair or better results were seen in 40 of 63 (63%), and good or better results in 25 of 63 (39%). The treatment method required 20-30 injections over three to five years. Although we did not achieve as good results as other authors, we think it was safer because we used a smaller dose of a steroid.

Adolescent↗
PubMed2005

In vitro cartilage formation of composites of synovium-derived mesenchymal stem cells with collagen gel.

Graft implantation is one of the more popular procedures for repairing cartilage defects; however, sacrifices of the donor site have been an issue. Mesenchymal stem cells (MSCs) are a fascinating source for regenerative medicine because they can be harvested in a less invasive manner and are easily isolated and expanded, with multi-potentiality including chondrogenesis. MSCs can be isolated from various adult mesenchymal tissues including synovium. Here, we attempted to form cartilage from the composites of synovium-derived MSCs with collagen gel in vitro. After 21 days of culture, the composites had increased their cartilage matrix, as demonstrated by toluidine blue staining and immunohistochemistry for type II collagen. The composites consisting of 5 x 10(7) and 10(8) cells/ml in gel were richer in proteoglycans than those consisting of lower cell densities. After 1 day, MSCs/gel composites contracted and the diameter decreased by 30%; however, they were stable thereafter. Round cells with short processes producing collagen fibrils showing a similar morphology to that of chondrocytes were seen in the composites by transmission electron microscopy. During composite culture, chondroitin sulfate and mRNA expression for cartilage-related genes increased, demonstrating cartilage maturation. Using an optimized method, we obtained cartilage discs with a diameter of 7 mm and a thickness of 500 microm. Our procedure should thus make it possible to produce a large cartilage matrix in vitro. The tissue engineering of autologous cartilage from the composites of synovium-derived MSCs with collagen gel in vitro for transplantation may be a future alternative to graft implantation for patients with cartilage defects.

Adult↗
PubMed2005

Evaluation of the donor site in patients who underwent reconstruction with a free radial forearm flap.

A major disadvantage of free radial forearm flaps is the conspicuous donor site. However, there have been few studies on donor scars. The authors evaluated the donor site in patients who underwent oral-floor reconstruction with a free radial forearm flap. The subjects were 23 patients (19 males and four females) who underwent reconstruction with a free radial forearm flap following resection of a malignant oral tumor, and were followed for 1 year or longer. The fasciocutaneous flap collection site was closed by full-thickness skin graft (FTSG) from the groin with tie-over dressing. All grafts took perfectly. At the scar at the donor site, five items (pigmentation, scar width, depression, wrist mobility, and sensory abnormalities) were evaluated. Depression and pigmentation were often observed, but patient dissatisfaction was slight. While their main postoperative concern was the oral reconstruction site, after about 1 year, the donor site became more important to patients. However, the results were good. A 100 percent take of the FTSG at the donor site should produce good results. Surgeons should pay adequate attention not only to the outcome at the reconstruction site, but also to the closure of the donor site.

Adult↗
PubMed2005

Esthetic evaluation of immediate breast reconstruction after nipple-sparing or skin-sparing mastectomy.

BACKGROUND: It has been reported that immediate autologous tissue breast reconstruction after nipple-sparing mastectomy (NSM) or skin-sparing mastectomy (SSM) is esthetically superior to autologous tissue reconstruction after conventional mastectomy (CM). We evaluated reconstructed breasts to determine whether these methods contribute to breast appearance other than skin texture. METHODS: Between April 1992 and September 2001, forty-two patients underwent immediate breast reconstruction using autologous tissue. Mastectomy options were NSM, SSM and CM. Postoperative photographs were evaluated using a subscale (volume, contour, placement, and inframammary fold) on a 0-2 point scale. Sternal notch to nipple distances of the affected and normal sides were measured with photographs to estimate nipple-areola complex (NAC) position. No corrective procedure was performed in a later phase before evaluation. RESULTS: NSM was performed in 22, SSM in 6 and CM in 14 cases. On esthetic evaluation, the NSM and SSM groups received 4.96 and the CM group received 4.63. There were no significant differences. In the NSM and SSM group, the NAC position rose in cases with partial necrosis or fat lysis compared with the no complication group (p = 0,004). CONCLUSIONS: Autologous tissue breast reconstruction after NSM or SSM is esthetically equal to autologous tissue reconstruction after CM with regard to parameters other than skin texture. Preserved or simultaneously reconstructed NAC sometimes emphasizes nipple-areola asymmetry when breast deformity has occurred.

Adult↗
PubMed2004

Snail regulates p21(WAF/CIP1) expression in cooperation with E2A and Twist.

Snail, a zinc-finger transcriptional repressor, is essential for mesoderm and neural crest cell formation and epithelial-mesenchymal transition. The basic helix-loop-helix transcription factors E2A and Twist have been linked with Snail during embryonic development. In this study, we examined the role of Snail in cellular differentiation through regulation of p21(WAF/CIP1) expression. A reporter assay with the p21 promoter demonstrated that Snail inhibited expression of p21 induced by E2A. Co-expression of Snail with Twist showed additive inhibitory effects. Deletion mutants of the p21 promoter revealed that sequences between -270 and -264, which formed a complex with unidentified nuclear factor(s), were critical for E2A and Snail function. The E2A-dependent expression of the endogenous p21 gene was also inhibited by Snail.

Basic Helix-Loop-Helix Proteins↗
PubMed2003

Secure flap fixation to bony tissue using an anchoring system in skull-base surgery.

The reconstruction of extensive skull-base defects using flap transfer decreases crucial postoperative complications. However, flap fixation to bony tissue is often difficult, especially if there is no soft tissue to pass sutures through, and unsteady flap fixation causes dead space formation or displacement of the transferred flap due to gravity. The authors used an anchoring system for secure flap fixation in seven cases with difficult flap fixation, using the conventional suturing technique. Anchors were inserted at strategic points in the bony tissue, and secure flap fixation was achieved in all cases. Postoperative CT scans showed no dead space formation, and major postoperative complications were not observed. The anchoring system can be buried in bony tissue with a thickness of more than 4 mm, and it enables reliable flap fixation and dead space obliteration. Although the cost is relatively high, the procedure is simple and lowers the risk of crucial postoperative complications in skull-base surgery.

Adolescent↗
PubMed2003

Usefulness of palatal mucoperiosteal grafts for artificial eye socket contracture.

The authors performed palatal mucoperiosteal grafting for contracture of the artificial eye socket in 4 patients. Mucoperiosteal grafts were collected from the paramedian area of the hard palate. After release of contracture, the grafts were sutured with absorbable thread to the defective areas on the conjunctival side of the artificial eye socket after release of contracture. All patients showed mucoperiosteal graft survival without problems, no recurrence of contracture, and good courses of artificial eye wear. The mucoperiosteal donor areas showed closed healing after 3 to 4 weeks. Palatal mucoperiosteal grafts can be collected en bloc and are relatively rigid, which allows the simultaneous reconstruction of the conjunctival side and supportive tissue of the eyelid. Although the size of graft collection is limited, grafts with adequate size for partial reconstruction can be collected. Mucoperiosteal grafts are a good reconstruction material for contracture of the artificial eye socket.

Aged↗
PubMed2002

Functional analysis of the carbohydrate recognition domains and a linker peptide of galectin-9 as to eosinophil chemoattractant activity.

Human galectin-9 is a beta-galactoside-binding protein consisting of two carbohydrate recognition domains (CRDs) and a linker peptide. We have shown that galectin-9 represents a novel class of eosinophil chemoattractants (ECAs) produced by activated T cells. A previous study demonstrated that the carbohydrate binding activity of galectin-9 is indispensable for eosinophil chemoattraction and that the N- and C-terminal CRDs exhibit comparable ECA activity, which is substantially lower than that of full-length galectin-9. In this study, we investigated the roles of the two CRDs in ECA activity in conjunction with the sugar-binding properties of the CRDs. In addition, to address the significance of the linker peptide structure, we compare the three isoforms of galectin-9, which only differ in the linker peptide region, in terms of ECA activity. Recombinant proteins consisting of two N-terminal CRDs (galectin-9NN), two C-terminal CRDs (galectin-9CC), and three isoforms of galectin-9 (galectin-9S, -9M, and -9L) were generated. All the recombinant proteins had hemagglutination activity comparable to that of the predominant wild-type galectin-9 (galectin-9M). Galectin-9NN and galectin-9CC induced eosinophil chemotaxis in a manner indistinguishable from the case of galectin-9M. Although the isoform of galectin-9 with the longest linker peptide, galectin-9L, exhibited limited solubility, the three isoforms showed comparable ECA activity over the concentration range tested. The interactions between N- and C-terminal CRDs and glycoprotein glycans and glycolipid glycans were examined using frontal affinity chromatography. Both CRDs exhibited high affinity for branched complex type sugar chain, especially for tri- and tetraantennary N-linked glycans with N-acetyllactosamine units, and the oligosaccharides inhibited the ECA activity at low concentrations. These results suggest that the N- and C-terminal CRDs of galectin-9 interact with the same or a closely related ligand on the eosinophil membrane when acting as an ECA and that ECA activity does not depend on a specific structure of the linker peptide.

Base Sequence↗
PubMed2002

Quantification of galectin-7 and its localization in adult mouse tissues.

We developed a method to quantify galectin-7 extracted from adult mouse tissues by Western blot analysis. More than 0.5 ng of galectin-7 per mg of tissue was detectable by this method. The amounts of galectin-7 in tissues were determined as follows: skin, 62 +/- 3 ng/mg; esophagus, 23 +/- 8 ng/mg; stomach, 18 +/- 6 ng/mg; anus, 13 +/- 1 ng/mg; and tongue, 12 +/- 2 ng/mg. This indicates that galectin-7 production coincides with the degree of stratification of the epithelia. Interestingly, we also detected significant amounts of galectin-7, 5.9 plus minus 1.4 and 2.7 +/- 0.6 ng/mg, in the trachea and ovaries, respectively. Moreover, we found that galectin-7 is localized in the pseudostratified epithelium of the trachea and stromal epithelium of the ovaries by immunohistochemistry. Thus, galectin-7 protein might be produced primarily in stratified epithelia, but also in some wet epithelia, and plays a unique role in cell-mucus contact, or the growth of ovarian follicles.

Animals↗