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Kotaro Yoshimura

Publications and source records attributed to Kotaro Yoshimura.

At least 19 recordsLinked to original sources
PubMed2006

Neurovascular transfer does not cause skeletal muscle fiber degeneration.

BACKGROUND: The mechanisms responsible for the incomplete recovery of muscle function after microneurovascular transfer have not been fully determined. Because fiber degeneration and regeneration can impact muscle mechanical function, the authors tested the null hypothesis that ischemia-induced fiber degeneration is not responsible for the force deficits observed after neurovascular muscle transfer. METHODS: Rats were assigned to one of three groups: orthotopic, nonvascularized grafting of the extensor digitorum longus muscle (STD group); orthotopic, neurovascular transfer of the extensor digitorum longus muscle with no intraoperative ischemia (NV-0 group); or orthotopic, neurovascular transfer of the extensor digitorum longus muscle with 3 hours of intraoperative ischemia (NV-3 group). At 1 and 2 weeks, extensor digitorum longus muscle cross-sections were labeled for developmental myosin heavy chain isoforms, markers of fiber regeneration. RESULTS: In extensor digitorum longus muscles from animals in the STD group, many small cells strongly labeled for developmental myosin heavy chain were observed and identified as myoblasts, indicating recent muscle fiber necrosis with subsequent regeneration. Extensor digitorum longus muscles from rats in the NV-0 and NV-3 groups contained no cells labeled for developmental myosin heavy chain. CONCLUSIONS: After neurovascular muscle transfer (with ischemia times up to 3 hours), ischemia-induced muscle fiber degeneration and regeneration does not occur. Muscle fiber degeneration is not responsible for the force deficits observed after microneurovascular skeletal muscle transfer.

Animals↗
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

Defects in aortic fusion and craniofacial vasculature in the holoprosencephalic mouse embryo under inhibition of sonic hedgehog signaling.

Sonic hedgehog (Shh) is a well-known morphogen indispensable in facial and nervous development, and recently it has also garnered much attention as a potent angiogenic factor. We previously created an animal model of holoprosencephaly by administration of cyclopamine, a specific inhibitor of hedgehog signaling, to the mouse embryos cultured in vitro, and found several types of angiogenic defects. In this study, we focused on other angiogenic phenotypes in the same model. When cyclopamine was added for embryonic day (E) 8.0-9.5, a pair of immature dorsal aortae, which normally fuse to form the single aorta by E9.5, remained to be separated. Expressions of vascular endothelial growth factor and bone morphogenetic protein 4, putative mediators of aortic fusion, were also reduced around the aorta by blockade of Shh signaling. When cyclopamine was added for E8.5-10.5, vessels on the surface of craniofacial region (possibly external cardinal veins) were extended and malformed. These results suggest that Shh signaling is essential for some aspects of embryonic angiogenesis, and that pathophysiology of holoprosencephaly may involve, at least in part, the Shh-dependent angiogenesis.

Animals↗
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↗
PubMed2005

Participation of bone marrow-derived cells in fibrotic changes in denervated skeletal muscle.

In denervated skeletal muscle, mononuclear interstitial cells accumulate in the perisynaptic regions before fibrotic change occurs. These cells are currently considered to be fibroblasts that originate from muscle tissue. However, when we denervated hind limbs of GFP-bone marrow chimeric mice by excising the sciatic nerve unilaterally, many bone marrow-derived cells (BM-DCs) infiltrated the interstitial spaces and accumulated in the perisynaptic regions, peaking 14 days after denervation. They accounted for nearly one-half of the increase in mononuclear interstitial cells. Although BM-DCs did not incorporate into satellite cells, immunohistochemical and FACS analyses revealed that BM-DCs were both CD45 and CD11b positive, indicating that they were of macrophage/monocyte lineage. BrdU staining showed inactive proliferation of BM-DCs. Reverse transcriptase-polymerase chain reaction of mononuclear cells isolated by FACS revealed that BM-DCs did not express type I collagen or tenascin-C; however, they did express transforming growth factor-beta1, suggesting that they regulate the fibrotic process. In contrast, muscle tissue-derived interstitial cells expressed type I collagen and tenascin-C, suggesting that these populations were the final effectors of fibrosis. These findings identify elementary targets that may regulate the migration, homing, differentiation, and function of BM-DCs, leading to amelioration of the excessive fibrosis of denervated skeletal muscle.

Animals↗
PubMed2005

Simultaneous reconstruction of breast and well-projected nipple after expansion of mammary skin.

The problem of postoperative reduction of projecting reconstructed nipples remains to be resolved. To this end we did a clinical study of reconstructing the nipple at the same time as the breast. A tissue-expander was placed under the skin of the breast at the first operation, and then the breast and nipple were reconstructed at the second. A nipple was reconstructed using a dermal-fat flap harvested from the myocutaneous flaps used for reconstruction of the breast. A small hole was made in the corresponding site of the skin of the breast, and the reconstructed nipple was projected through the hole. This method was used in 8 cases. This method is useful in reconstructing a breast without a pad of skin and a projected nipple simultaneously. Its disadvantages are the relatively weak blood supply of the flaps, and difficulty in calculating the position of the nipple. The procedure may be beneficial for selected cases.

Adult↗
PubMed2005

Construction of pigmented skin equivalent and its application to the study of congenital disorders of pigmentation.

We have constructed a pigmented skin equivalent and used it to study the hyperpigmentation seen in café-au-lait macules to elucidate whether the pigmented skin equivalent could be used as a model of congenital hyperpigmentary disorders. When we used fibroblasts derived from café-au-lait macules of neurofibromatosis type 1, the amount of pigment was significantly greater than in models using cells derived from normal skin. Quantities of pigment were not seen when keratinocytes derived from solitary café-au-lait macules were used, a possible reason being that keratinocytes on the skin equivalent are in a proliferating condition and are not well-differentiated enough to act on other cells. Our results suggested that our pigmented skin equivalent is useful for the study of congenital hyperpigmentary disorders, although insufficient differentiation of keratinocytes might be a disadvantage.

Cafe-au-Lait Spots↗
PubMed2005

Epidermal hyperpigmentation in non-syndromic solitary cafe-au-lait macules may be associated with increased secretion of endothelin-1 by lesional keratinocytes.

To clarify the mechanism of accentuated melanisation in non-syndromic solitary cafe-au-lait macules we used an enzyme-linked immunosorbent assay (ELISA) to measure the concentration of melanogenic cytokines secreted by cultured keratinocytes and fibroblasts derived from the skins of the macules and compared them with those derived from normal people. Endothelin-1 (ET-1) was significantly increased in cultured keratinocytes in the macules compared with the normals. In contrast, the secretion of other cytokines secreted by keratinocytes or fibroblasts did not differ between the groups. It may be that the increased secretion of ET-1 by epidermal keratinocytes has a role in the accentuated epidermal melanisation seen in non-syndromic macules.

Adolescent↗
PubMed2005

Craniofacial anomalies of the cultured mouse embryo induced by inhibition of sonic hedgehog signaling: an animal model of holoprosencephaly.

The pathogenesis of holoprosencephaly is multifactorial, and blockage of Sonic hedgehog signaling is one of the most important causative factors in animal models and human cases. In this study, the authors analyzed facial anomalies of mouse embryos, which were cultured in vitro and exposed to cyclopamine, an alkaloid blocker of Sonic hedgehog signaling. When cultured with cyclopamine for embryonic day 8.5 to 10.5, the whole body size was smaller than normal, and the distance and angle between the nasal placodes were remarkably reduced. Extension of the cranial surface vessels also was noted. No cyclopia was observed. Migration of the cranial neural crest cells seemed to be intact. Expressions of Patched-1 and Gli-1, downstream genes of Sonic hedgehog signaling, also were down-regulated in in situ hybridization and real-time reverse transcriptase-polymerase chain reaction analyses. The authors consider that these facial anomalies represent milder phenotypes of holoprosencephaly.

Animals↗
PubMed2005

Angle-splitting ostectomy followed by face lift for elderly patients with prominent mandibular angles.

A prominent mandibular angle is a relatively common aesthetic problem among Asians, and the reduction angle-splitting ostectomy is now becoming a very popular procedure in Asian countries. Although this operation is usually performed on young patients, the same aesthetic demands are also seen in the elderly. In this report, the authors describe their experience with angle-splitting ostectomies followed by face lifts in three patients older than 50 years. The angle-splitting procedure was the same as that performed in young patients, and clinical results were assessed with photographs and three-dimensional computed tomographic scans. The facial contours after angle-splitting ostectomy were satisfactory, but the patients showed postoperative redundancy of the skin, especially along the jaw line, because of the loss of bony protrusion laterally. Therefore, the patients underwent subsequent superficial musculoaponeurotic system cheek lifts. The final aesthetic results were satisfactory in all cases. When surgeons want to perform the angle-splitting ostectomy safely and effectively on the elderly, they should be aware of the risks and indications specific for elderly patients, and a multidisciplinary support system should be available. Subsequent face lifts can improve skin redundancy and lead to better cosmetic results.

Aged↗
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

[A case of pulmonary infection due to Mycobacterium simiae].

A 61-year-old woman presented to our hospital with a chronic cough. She had been diagnosed with pulmonary infection due to non-tuberculous mycobacteria by her previous doctor and had received antimycobacterial chemotherapy for 1 year. Chest radiography and computed tomography on the first visit to our hospital revealed nodular shadows with a cavity in the right upper lung field and infiltrative shadows with bronchiectasis in the lingular segment. Mycobacterium simiae was identified using DNA hybridization methods. Analysis of base sequences from sputum samples using 16S rRNA confirmed the identity of all tested isolates as Mycobacterium simiae, and the organism was isolated repeatedly from sputum mycobacterial tests. Pulmonary infection due to Mycobacterium simiae was diagnosed. Rifampicin, Ethambutol and Clarithromycin were administered to the patient, but clinical symptoms have continued, and findings on chest radiography have deteriorated. Cases of pulmonary infection due to Mycobacterium simiae are rare, and this represents the first such case reported in Japan.

Female↗
PubMed2005

[A case of lung adenocarcinoma of the lung with disappearance of brain metastasis by re-treatment with gefitinib].

BACKGROUND: Tumor response rate to gefitinib by previously treated patients with advanced non-small-cell lung cancer was approximately 20%. However, there are few reports about effect of re-treatment with gefitinib. CASE: A 40-year-old man was given a diagnosis of adenocarcinoma of lung (c-T2N3M1). Response was not obtained with chemotherapy (paclitaxel + carboplatin, vinorelbine + gencitabin). He developed brain metastasis and received whole brain radiation therapy. He was then given gefitinib. Reduction of the primary tumor, brain metastasis, pulmonary metastasis and liver metastasis was seen. Recurrence of pulmonary metastasis and liver metastasis was discovered 8 months after treatment with gefitinib. Therefore, treatment by gefitinib was stopped. Response was not achieved with chemotherapy (docetaxel and amrubicin). At the request of the patient, retreatment with gefitinib was resumed. Disappearance of brain metastasis was achieved. However, primary tumor, pulmonary metastasis and liver metastasis progressed. CONCLUSION: We reported a case whose brain metastases disappeared with re-treatment with gefitinib. This report is thought to be useful in terms of information about the acquired resistance of gefitinib. Further investigations are needed to determine the indication of re-treatment with gefitinib.

Adenocarcinoma↗
PubMed2004

Surgical correction of retracted nostril rim with auricular composite grafts and anchoring suspention.

Among concerned nasal appearances, a deformity with supero-lateral displacement of the nostril rim, called retracted nostril rim or elevated nostril rim is commonly seen and is considered one of the most difficult types of cases to treat aesthetically. A new surgical method for treating retracted nostril rim was performed in 10 patients, using the combination of auricular composite graft, internal fixation with a retainer, and external continuing suspension with anchoring sutures. The procedure was successful in maintaining the grafted cartilage in the ideal position and in avoiding recurrence of retraction or elevation of the constructed alar rim. The presented method merits consideration as a standard operative approach for correction of retracted nostril rim.

Adult↗
PubMed2003

Differential expression of heparin-binding EGF-like growth factor (HB-EGF) mRNA in normal human keratinocytes induced by a variety of natural and synthetic retinoids.

It was recently revealed that epidermal growth following topical treatment with all-trans retinoic acid (atRA) was at least partly induced by heparin-binding epidermal growth factor-like growth factor (HB-EGF) released from suprabasal keratinocytes. Since proliferation of keratinocytes appears to be one of the critical roles of atRA in depigmentation treatment and promotion of wound healing, HB-EGF is considered suitable for assessing the therapeutic value of topical retinoids. In this study, HB-EGF mRNA expression in normal human keratinocytes after atRA treatment was examined, and the effects of a variety of natural and synthetic retinoids were compared. The results of reverse transcription polymerase chain reaction (RT-PCR) suggested that induction of differentiation increased HB-EGF mRNA expression in cultured keratinocytes. Real-time PCR analyses revealed that HB-EGF mRNA expression was elevated dose-dependently with atRA, peaking at 12 h. This elevation was more prominent in confluent keratinocytes than in subconfluent cells, suggesting that differentiated keratinocytes are more subject to stimulation of HB-EGF expression by atRA than proliferating keratinocytes. HB-EGF mRNA was upregulated in differentiation-induced keratinocytes by all retinoids used in this study at 1 micromol/l, and marked upregulation was seen when treated with three isotypes of retinoic acid (atRA, and 9-cis and 13-cis retinoic acid). RARalpha-selective agonists (Am80, Am580, ER-38925, and TAC-101) and a panagonist of RARs (Re80) caused relatively low elevation of HB-EGF transcripts, as did all-trans retinol (Rol) and all-trans retinal (Ral). Although another panagonist (Ch55) showed the highest elevation of HB-EGF mRNA, it was relatively cytotoxic at the concentration employed. Ral and Rol were found to upregulate HB-EGF when used at 100 micromol/l to 1 mmol/l, to a similar extent of atRA at 1-10 micromol/l. The capacity of retinoids to upregulate HB-EGF may be an important index for investigation and development of an ideal synthetic retinoid, which has maximum benefits and minimum side-effects

Cells, Cultured↗