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Isao Koshima

Publications and source records attributed to Isao Koshima.

At least 19 recordsLinked to original sources
PubMed2006

Critical time window of hedgehog-dependent angiogenesis in murine yolk sac.

Hedgehog family was reported to be involved in murine yolk sac angiogenesis. However, it has not been clarified whether impaired angiogenesis under hedgehog signaling blockade is attributable to true defect in angiogenic process or just a sequel of earlier vasculogenic abnormalities. In the present study, we examined the effects of stage-specific inhibition of hedgehog cascade on vascular morphogenesis by applying cyclopamine or jervine to culture media of whole embryo culture system from embryonic days 8.0 until 9.5. Whole-mount immunostaining revealed that cyclopamine or jervine treatment in a narrow time window impaired angiogenic remodeling such as ramification into large and small branches and pericyte recruitment, although vasculogenesis was grossly normal. Molecular analyses suggest that indian hedgehog in the yolk sac endoderm regulates the induction of VEGF, Flk-1 and Notch-1. Our results indicate that hedgehog signaling is indispensable for mouse yolk sac angiogenesis, even when vasculogenesis is not perturbed.

Angiopoietin-1↗
PubMed2006

Cartilage tissue engineering using human auricular chondrocytes embedded in different hydrogel materials.

To seek a suitable scaffold for cartilage tissue engineering, we compared various hydrogel materials originating from animals, plants, or synthetic peptides. Human auricular chondrocytes were embedded in atelopeptide collagen, alginate, or PuraMatrix, all of which are or will soon be clinically available. The chondrocytes in the atelopeptide collagen proliferated well, while the others showed no proliferation. A high-cell density culture within each hydrogel enhanced the expression of collagen type II mRNA, when compared with that without hydrogel. By stimulation with insulin and BMP-2, collagen type II and glycosaminoglycan were significantly accumulated within all hydrogels. Chondrocytes in the atelopeptide collagen showed high expression of beta1 integrin, seemingly promoting cell-matrix signaling. The N-cadherin expression was inhibited in the alginate, implying that decrease in cell-to-cell contacts may maintain chondrocyte activity. The matrix synthesis in PuraMatrix was less than that in others, while its Young's modulus was the lowest, suggesting a weakness in gelling ability and storage of cells and matrices. Considering biological effects and clinical availability, atelopeptide collagen may be accessible for clinical use. However, because synthetic peptides can control the risk of disease transmission and immunoreactivities, some improvement in gelling ability would provide a more useful hydrogel for ideal cartilage regeneration.

Atrial Appendage↗
PubMed2006

Characterization of freshly isolated and cultured cells derived from the fatty and fluid portions of liposuction aspirates.

Liposuction aspirates (primarily saline solution, blood, and adipose tissue fragments) separate into fatty and fluid portions. Cells isolated from the fatty portion are termed processed lipoaspirate (PLA) cells and contain adipose-derived adherent stromal cells (ASCs). Here we define cells isolated from the fluid portion of liposuction aspirates as liposuction aspirate fluid (LAF) cells. Stromal vascular fractions (SVF) were isolated separately from both portions and characterized under cultured and non-cultured conditions. A comparable number of LAF and PLA cells were freshly isolated, but fewer LAF cells were adherent. CD34+ CD45- cells from fresh LAF isolates were expanded by adherent culture, suggesting that LAF cells contain ASCs. Although freshly isolated PLA and LAF cells have distinct cell surface marker profiles, adherent PLA and LAF cells have quite similar characteristics with regard to growth kinetics, morphology, capacity for differentiation, and surface marker profiles. After plating, both PLA and LAF cells showed significant increased expression of CD29, CD44, CD49d, CD73, CD90, CD105, and CD151 and decreased expression of CD31 and CD45. Multicolor FACS analysis revealed that SVF are composed of heterogeneous cell populations including blood-derived cells (CD45+), ASCs (CD31- CD34+ CD45- CD90+ CD105- CD146-), endothelial (progenitor) cells (CD31+ CD34+ CD45- CD90+ CD105low CD146+), pericytes (CD31- CD34- CD45- CD90+ CD105- CD146+), and other cells. After plating, ASCs showed a dramatic increase in CD105 expression. Although some adherent ASCs lost CD34 expression with increasing culture time, our culture method maintained CD34 expression in ASCs for at least 10-20 weeks. These results suggest that liposuction-derived cells may be useful and valuable for cell-based therapies.

Adipocytes↗
PubMed2006

Penile reconstruction with bilateral superficial circumflex iliac artery perforator (SCIP) flaps.

The free radial forearm flap is a very common material for penile reconstruction. Its major problems are donor-site morbidity with large depressive scar after skin grafting, urethral fistula due to insufficiency of suture line for the urethra, and need for microvascular anastomosis. A new method using combined bilateral island SCIP flaps for the urethra and penis is developed for gender identity disorder (GID) patients. The advantages of this method are minimal donor-site morbidity with a concealed donor scar, and possible one-stage reconstruction for a longer urethra of 22 cm in length without insufficiency, even for GID female-to-male patients. A disadvantage is poor sensory recovery.

Adult↗
PubMed2006

Volumetric changes in the transferred flap after anterior craniofacial reconstruction.

The goal of craniofacial reconstruction is not only life-saving but also facial aesthetics. From this viewpoint the authors evaluated the facial symmetry of patients after craniofacial reconstruction. The subjects were seven patients reconstructed after craniofacial resections. Their CT or MR images were evaluated just after surgery, 1 month after surgery, and 6 months after surgery. Based on these images, the proportion of simple area (PSA) and the proportion of overlapped area (POA) were calculated. The PSA is the proportion of the reconstructed quarter to the contralateral one, and the POA is the proportion of the overlapped area in the reconstructed quarter to the normal one. These values were assessed in two groups: five patients without and two with split calvarial bone grafts. Results demonstrated that the volumetric change of the reconstructed face with the bone graft was relatively stable.

Adolescent↗
PubMed2006

A supermicrosurgical flap model in the rat: a free true abdominal perforator flap with a short pedicle.

BACKGROUND: Perforator flaps have recently gained considerable popularity in reconstructive surgery, and their importance and advantages over conventional flaps have been widely accepted. Given the improvements in microsurgical techniques, researchers have encouraged the search for further perforator flap sources, such as a perforator flap with a short pedicle only. The purpose of this study was to describe a true perforator flap model with a short vascular pedicle in the abdominal region in the rat. METHODS: Twenty-six adult Sprague-Dawley rats weighing 400 to 500 g were used. In 10 rats, the perforator vascular anatomy of the abdominal region was determined by anatomic dissection. In the remaining 16 rats, a true abdominal perforator-based flap was created based on a short segment of deep epigastric vessels. In eight rats, the flap was transferred to the groin region as a free flap, and anastomosis was performed between the artery and vein of the flap and the superficial inferior epigastric artery and vein of the recipient site. In addition, in two of these flaps, the long thoracic vein of the flap was anastomosed to the femoral vein. In the remaining eight rats, the flap was transferred to the groin region, but in this group anastomosis was not performed. The latter group was designated as the control group. RESULTS: The skin islands of seven free perforator flaps survived completely, and the one remaining flap was determined to be necrotic. All the flaps in the control group underwent complete necrosis. CONCLUSIONS: Not only is the free abdominal perforator flap a reliable and true perforator flap model for future physiological, biological, and pharmacological studies, it is also an excellent self-controlled supermicrosurgical training model for learning proper techniques, meticulous intramuscular dissection of true perforator flaps, and anastomosis of small-caliber vessels.

Anastomosis, Surgical↗
PubMed2006

Repeated treatment protocols for melasma and acquired dermal melanocytosis.

BACKGROUND AND OBJECTIVE: Melasma and acquired dermal melanocytosis (ADM; acquired bilateral nevus of Ota-like macules) are both seen most commonly symmetrically on the face of women with darker skin and are also known as difficult conditions to treat. METHODS: Our topical bleaching protocol with 0.1 to 0.4% tretinoin gel and 5% hydroquinone was performed repeatedly (1-3 times) for melasma (n=163), and a combination treatment with topical bleaching and Q-switched ruby (QSR) laser was performed repeatedly (1-3 times) for ADM (n=62). RESULTS: There is a significant correlation between clinical results (clearance of pigmentation) and the number of sessions in both melasma (p=.019) and ADM (p<.0001). CONCLUSION: The repeated treatment protocol for melasma and ADM showed successful clinical results compared with conventional ones, and they may be applied to other pigment conditions. It may be better that epidermal and dermal pigmentations are treated separately, especially in dark-skinned people who are more likely to suffer postinflammatory hyperpigmentation after inflammation-inducing therapies.

Adult↗
PubMed2006

Fibular osteoadiposal flap for treatment of tibial adamantinoma: a case report.

We treated a case with left tibial adamantinoma by use of a contralateral fibular osteoadiposal flap. The donor site of conventional fibular osteocutaneous flap must be covered with a skin graft because if we close the donor skin defect directly, compartment syndrome might occur. We were able to close the donor skin defect because this combined type flap included only a small monitoring skin paddle. We present herein the utility of the osteoadiposal flap and show the value of a skin-sparing approach with a minimal aesthetic defect.

Adamantinoma↗
PubMed2005

Treatment of lymphedema with lymphaticovenular anastomoses.

Although lymphedema in the extremities is a troublesome adverse effect following radical resection of various cancers, conventional therapies for lymphedema are not always satisfactory, and new breakthroughs are anticipated. With the introduction of supermicrosurgical techniques for the anastomosis of blood or lymphatic vessels less than 0.8 mm in diameter, we have developed a novel method of lymphaticovenular anastomosis for the treatment of primary as well as secondary lymphedema in the extremities. Here, we review the pathophysiological aspects of lymphedema, emphasizing the importance of smooth-muscle cell function in the affected lymphatic walls. We then describe the theoretical basis and detailed operative techniques of our lymphaticovenular anastomoses. Although technically demanding, especially for beginners, we believe that this method will become a new clinical standard for the treatment of lymphedema in the near future.

Anastomosis, Surgical↗
PubMed2005

Facial augmentation with groin osteoadiposal flap transfer.

The authors report the advantages of the groin osteoadiposal flap for facial augmentation, which include the possibility of a conjoint type of flap harvesting with one main set of vessels (usually, the superficial circumflex iliac vessels); one-stage augmentation without secondary defatting; a donor scar in a concealed area; and rigid flap fixation with bone plating.

Adipose Tissue↗
PubMed2005

Posterior tibial adiposal flap for repair of wide, full-thickness defect of the Achilles tendon.

Wide, full-thickness defects on the posterior aspect of the distal lower leg involving the Achilles tendon are usually repaired with free fasciocutaneous flaps or local skin flaps. The former require microvascular techniques; there is a donor-site scar due to skin grafting; and a longer operating time. The latter results in a wide scar near the donor defect. The authors developed a new reconstructive procedure using local fascia turned over to create a new Achilles tendon, and wrapping it with a posterior tibial adiposal island flap based on the dominant perforator of the posterior tibial artery, which was elevated from the medial aspect of the lower leg. The advantages of this method are that no donor scar appeared on the posterior aspect of the lower leg, and there was no need for microvascular techniques. This method is especially suitable for young women.

Achilles Tendon↗
PubMed2005

Changes in angiogenic gene expression in a case of expanded capillary malformation: does an expanded capillary malformation grow?

We examined a 59-year-old woman with a capillary malformation (CM) in her thigh, which was serially excised. Interestingly, the remnant CM after the first excision was enlarged at the time of the second excision. To investigate whether this phenomenon was caused by mere passive expansion or regrowth, the CM specimens of the first operation (nonexpanded) and the second operation (expanded) were examined. Expressions of angiogenic genes Tie2 and Angiopoietin-1 were up-regulated within the expanded CM compared with the nonexpanded lesion, suggesting angiogenesis in the expanded CM. Expression pattern of the endothelial marker von Willebrand factor and the capillary densities were unchanged after the excision, suggesting that angiogenesis seen in the expanded CM resulted in reorganization of vascular networks. We consider that our data support a hypothesis that the expanded lesion in this case was caused by regrowth, not a passive expansion, of the CM.

Angiopoietin-1↗
PubMed2005

Gene expression changes of sonic hedgehog signaling cascade in a mouse embryonic model of fetal alcohol syndrome.

Fetal alcohol syndrome (FAS) is a congenital anomaly attributable to prenatal maternal excessive intake of ethanol. The authors made a mammalian model of FAS by culturing mouse embryos with high ethanol for embryonic day 7.8 to 9.5 in the whole embryo culture system. The embryos exposed to high ethanol were smaller and less advanced in development than were the embryos in the control group and showed craniofacial abnormalities, such as a fusion defect of the neural tube. The expression patterns of CRABP-I and AP-2 as markers of the neural crest cells were mostly unchanged in the in situ hybridization. However, the density and area of the expression were decreased, possibly because of the death of the neural crest cells. The expression patterns of the Sonic hedgehog signaling cascade genes (Shh, Ptc-1 and Gli-1) were mostly unchanged in the in situ hybridization, but the quantitative expressions of Ptc-1 and Gli-1 were increased in real-time reverse transcriptase-polymerase chain reaction analyses, quite contrary to the findings of a previous study using chick embryos. These findings suggest Shh signaling also is involved in the pathogenesis of FAS in mammalian embryo, but in a mode different from that in the chick embryo.

Animals↗
PubMed2005

Angiogenesis within the developing mouse neural tube is dependent on sonic hedgehog signaling: possible roles of motor neurons.

Embryonic morphogenesis of vascular and nervous systems is tightly coordinated, and recent studies revealed that some neurogenetic factors such as Sonic hedgehog (Shh) also exhibit angiogenetic potential. Vascularization within the developing mouse neural tube depends on vessel sprouting from the surrounding vascular plexus. Previous studies implicated possible roles of VEGF/Flk-1 and Angiopoietin-1(Ang-1)/Tie-2 signaling as candidate molecules functioning in this process. Examining gene expressions of these factors at embryonic day (E) 9.5 and 10.5, we unexpectedly found that both VEGF and Ang-1 were expressed in the motor neurons in the ventral neural tube. The motor neurons were indeed located in the close vicinity of the infiltrating vessels, suggesting involvement of motor neurons in the sprouting. To substantiate this possibility, we inhibited induction of the motor neurons in the cultured mouse embryos by cyclopamine, a Shh signaling blocker. The vessel sprouting was dramatically impaired by inhibition of Shh signaling, together with nearly complete loss of the motor neurons. Expression of Ang-1, but not VEGF, within the neural tube was remarkably reduced in the cyclopamine treated embryos. These results suggest that the neural tube angiogenesis is dependent on Shh signaling, and mediated, at least in part, by the Ang-1 positive motor neurons.

Angiopoietin-1↗
PubMed2005

Sex reassignment surgery for male to female transsexuals: initial experience in Okayama university hospital.

The first case of sex reassignment surgery (SRS) in our hospital was performed in January 2001; as of February, 2005, 4 cases of MTF-SRS had been performed. In the 2 most recent cases, we used penile and scrotal skin flaps to avoid complications. The depth and width of the new vagina was made to be adequate for sexual intercourse. Future attention should be focused on devising a surgical technique that will help prevent the complications of partial necrosis of the epidermal skin and wound dehiscence. Although ours is only an initial experience, we describe our surgical technique herein.

Female↗