Taro Koyama

American Orthopsychiatric Association

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Research Field

Does noncontact phased-array ultrasound promote hair regrowth?

Journal of Dermatological Science (2022)

Hiroya Takada Yasutaka Osada Mayuri Nakajima Atsushi Sakai Takayuki Hoshi

10.1016/j.jdermsci.2022.10.004

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Citations (1)

The effect of amnion-derived cellular cytokine solution on the epithelialization of partial-thickness donor site wounds in normal and streptozotocin-induced diabetic swine.

PubMed (2009)

Juri Bergmann Florian Hackl Taro Koyama Pejman Aflaki Charlotte A. Smith

The purpose of this study was to determine whether amnion-derived cellular cytokine solution (ACCS) could improve the quality of epithelialization and accelerate closure of dermatome-created partial-thickness wounds in normal and streptozotocin-induced diabetic pigs.Dermatome-created partial-thickness wounds were sealed with wound chambers in healthy and diabetic pigs and were injected with ACCS. Wound fluid was exchanged daily for total protein concentration, and biopsies were taken on days 6, 8, 10, and 12. Epithelialization, thickness of epidermis, number of epidermal cell layers, and rete ridges were evaluated.The macroscopic appearance of the wounds and speed of healing was similar in all groups at each time point. All wounds were healed by day 6. The epidermis was thicker in the ACCS-treated diabetic wounds than in the controls (140.6 microm vs 82.7 microm on day 12 in diabetic pigs). There were more cell layers (13 vs 7.7) in ACCS-treated diabetic pigs on day 12. The number of rete ridges per 2.5 mm was greater on day 12 in the ACCS-treated diabetic wounds (13 vs 8). There was also a significant increase in the number of rete ridges in ACCS-treated nondiabetic pigs but no difference in epidermal thickness or number of cell layers.In diabetic pigs, we found a significantly thicker epidermis and more cell layers and rete ridges in the ACCS-treated wounds. Healthy pigs showed more rete ridges but no difference in thickness of epidermis or number of cell layers on day 12.

Epidermis (zoology)

Dermatome

Amnion

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Citations (13)

A Three-dimensional Motion Analysis of Anterior Upper Limb Elevation with Thoracic Motion Restriction

Rigakuryoho Kagaku (2020)

Ryoji Okamune Koji Miyashita Taro Koyama Yusuke Tani Kenichiro OTA

〔目的〕胸郭運動制限を加えた際の肩関節・肩甲上腕関節・肩甲骨運動の変化について明らかにすることを本研究の目的とした．〔対象と方法〕健常男性20名を対象とした．課題動作は立位両上肢前方挙上運動，算出角度は肩屈曲，肩甲上腕関節屈曲，肩甲骨後傾角度とし，胸郭運動制限の有無による比較を行った．また，その変化の対象ごとの個別性についても分析した．〔結果〕肩屈曲，肩甲骨後傾角度は胸郭運動制限により有意に減少したが，肩甲上腕関節屈曲角度に有意差はなかった．一方で，肩甲上腕関節屈曲および肩甲骨後傾角度の増減には対象ごとに個別性が存在した．〔結語〕胸郭運動制限により肩甲骨後傾が制限された結果，肩屈曲角度の減少が生じたと考えられたが，その動態は対象により様々であった．

Elevation (ballistics)

10.1589/rika.35.217

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Citations (1)

Relationship between Range of Motion of Shoulder Internal Rotation and Shoulder Posterior Laxity in Semiprofessional Baseball Pitchers

Rigakuryoho Kagaku (2019)

Koji Miyashita Takashi HARIKI Yusuke Tani Kenichiro OTA Taro Koyama

〔目的〕投球障害肩の要因となる肩内旋制限（硬さ）と肩後方動揺性（緩さ）は一見相反する現象だが，投手の肩で併存するか明確でない．本研究は両者の関係性を明らかにすることを目的とした．〔対象と方法〕社会人投手47名を対象とした．両側の内旋・外旋可動域と後方動揺性を測定した．左右の肩内旋可動域の差が20°以上をGIRD群（24名），20°未満を健常群（23名）とした．両群間の可動域の差，後方動揺性の陽性割合の差を検定した．〔結果〕内旋可動域はGIRD群26.0 ± 12.6°，健常群50.0 ± 14.3°で有意差があった．後方動揺性は両群間で割合に有意差はなかった．〔結語〕投手の肩は内旋可動域制限がある一方，同時に後方動揺性も併存する場合があることが示された．

Internal Rotation

External rotation

10.1589/rika.34.707

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Citations (0)

Relationships between throwing shoulder injuries and strength of rotator cuff muscle in college baseball players - Analysis based on routine functional evaluation at baseball field -

Japanese Journal of Physical Fitness and Sports Medicine (2015)

Koji Miyashita Taro Koyama

To analyze the relationship of cause and effect between the onset of throwing disorders of the shoulder and decreased muscle strength, two studies were conducted at a baseball field. In study 1, shoulder joint muscle strength was measured when pain developed during practice and the relationship between pain onset and muscle strength was investigated. Decreased muscle strength was noted at the time of pain onset in 8.1% of players. Study 2 was a prospective study in which the relationship between changes in shoulder joint muscle strength from the start of pitching at the beginning of the season to one month later when competitive games began, and shoulder pain that appeared at the beginning of competitive games was analyzed. Based on the results, the possibility of shoulder joint muscle strength being a predictive factor for the onset of throwing disorders of the shoulder was investigated. However the pain group had greater muscle strength than the normal group at the beginning of the season. On the baseball field, the players’ throwing motions and joint function change daily, making it difficult to determine the reason for onset of disorders and injuries. These results suggest that onset of pain at the start of competitive games cannot be predicted from muscle strength at the beginning of the season.

Supraspinatus muscle

10.7600/jspfsm.64.453

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Quantitative analysis of the anatomical changes in the scalp and hair follicles in androgenetic alopecia using magnetic resonance imaging

Skin Research and Technology (2020)

Shigeyoshi Soga Taro Koyama Ayako Mikoshi Masahiro Jinzaki Tatsuhiko Arafune

Abstract Background Although the structural changes of the scalp in androgenetic alopecia (AGA) have been reported, these changes have been poorly understood. It is expected that modern MRI would visualize the scalp anatomy in vivo. This study aimed to explore whether AGA causes (a) changes in the thickness of the scalp, (b) anatomical changes in the hair follicles, and (c) changes in the signal intensity of MRI. Materials and Methods Twenty‐seven volunteers underwent MRI for hair and scalp (MRH) and were categorized into two according to the Hamilton‐Norwood Scale: the “AGA group” and the “normal group.” Two radiologists analyzed the thickness and signal intensity of the scalp, and the depth of hair follicles. These measurements were compared between the two groups. Results The thickness of the hypodermis and the entire scalp was significantly thinner in the AGA group than in the control group. The AGA group had significantly shallower depth of hair follicles and relative depth of the hair follicles to that of the entire scalp than the normal group. The hypodermis showed higher signal intensity in the AGA group than the normal group. Conclusion MRH allowed noninvasive visualization of the scalp anatomy and demonstrated the thinner nature of the entire scalp and hypodermis, along with the shallower depth of the hair follicles in the AGA group in comparison to the normal group. Additionally, MRH demonstrated the increased MR signal intensity in the scalp associated with AGA. MRH may be a promising new method for quantitative and objective analyses of AGA.

Intensity

10.1111/srt.12908

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Citations (10)

[Anterior thoracic injuries caused by blunt objects (1)].

PubMed (1974)

Hideyuki Ichikawa Hirofumi Tsuboi Shingo Hirao Taro Koyama Kazuma Tsukioka

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Modulation of scarring in a liquid environment in the Yorkshire pig

Wound Repair and Regeneration (2009)

Richard G. Reish Baraa Zuhaili Juri Bergmann Pejman Aflaki Taro Koyama

ABSTRACT Decreased inflammatory response seen in wet wound healing may be correlated with diminished scarring. This study seeks to test this hypothesis and to validate a model of scarring in the Yorkshire pig. Four Yorkshire pigs were used to create 36 dorsal wounds per pig (144 wounds total) in the following groups: full-thickness excisional, partial thickness, meshed split-thickness skin grafts, sheet split-thickness skin grafts, minced skin, and incisional wounds. Wounds were randomized into wet and dry groups. Wet wounds were enclosed in polyurethane chambers with 2 mL of normal saline. Dry wounds were covered with regular gauze. Terminal biopsies were performed at 72 hours and day 28. Histology demonstrated significantly less inflammatory infiltrate, thicker neoepidermis, more pronounced rete ridge formation, and decreased scar tissue thickness in wet wounds. The mean macroscopic scar surface area was significantly decreased in full-thickness excisional wet wounds compared with dry wounds (61.2 mm(2) vs. 150.8 mm(2), p<0.01). Hydroxyproline content was decreased in full-thickness wet compared with dry groups (44.81 vs. 62.21 mg/g, p<0.01). Tensile strength was 90% greater in full-thickness wet compared with dry groups (p<0.01). Healing in the liquid environment significantly reduced scar formation. This model will allow for future investigation of high-concentration topical scar-modulating agents in the liquid environment.

Hydroxyproline

Histology

10.1111/j.1524-475x.2009.00546.x

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Citations (34)

Standardized Scalp Massage Results in Increased Hair Thickness by Inducing Stretching Forces to Dermal Papilla Cells in the Subcutaneous Tissue.

PubMed (2016)

Taro Koyama Kazuhiro Kobayashi Takanori Hama Kasumi Murakami Rei Ogawa

In this study, we evaluated the effect of scalp massage on hair in Japanese males and the effect of stretching forces on human dermal papilla cells in vitro.Nine healthy men received 4 minutes of standardized scalp massage per day for 24 weeks using a scalp massage device. Total hair number, hair thickness, and hair growth rate were evaluated. The mechanical effect of scalp massage on subcutaneous tissue was analyzed using a finite element method. To evaluate the effect of mechanical forces, human dermal papilla cells were cultured using a 72-hour stretching cycle. Gene expression change was analyzed using DNA microarray analyses. In addition, expression of hair cycle-related genes including IL6, NOGGIN, BMP4, and SMAD4 were evaluated using real-time reverse transcription-polymerase chain reaction.Standardized scalp massage resulted in increased hair thickness 24 weeks after initiation of massage (0.085 ± 0.003 mm vs 0.092 ± 0.001 mm). Finite element method showed that scalp massage caused z-direction displacement and von Mises stress on subcutaneous tissue. In vitro, DNA microarray showed gene expression change significantly compared with nonstretching human dermal papilla cells. A total of 2655 genes were upregulated and 2823 genes were downregulated. Real-time reverse transcription-polymerase chain reaction demonstrated increased expression of hair cycle-related genes such as NOGGIN, BMP4, SMAD4, and IL6ST and decrease in hair loss-related genes such as IL6.Stretching forces result in changes in gene expression in human dermal papilla cells. Standardized scalp massage is a way to transmit mechanical stress to human dermal papilla cells in subcutaneous tissue. Hair thickness was shown to increase with standardized scalp massage.

Dermal papillae

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Citations (19)

Eleven pairs of Japanese male twins suggest the role of epigenetic differences in androgenetic alopecia

European Journal of Dermatology (2013)

Taro Koyama Kazuhiro Kobayashi Nagaoki Wakisaka Nobuo Hirayama Sawako Konishi

ejd.2012.1898 Auteur(s) : Taro Koyama koyama@fml.ne.jp, Kazuhiro Kobayashi, Nagaoki Wakisaka, Nobuo Hirayama, Sawako Konishi, Takanori Hama, Katsuyuki Takeda, Yoshio Nakamizo, Masaya Kawakami Future Medical Laboratory, 14 F, 1-22-2 Nishishinjuku, Shinjuku-ku, Tokyo, Japan Genetic factors play an important role in androgenetic alopecia (AGA), as Nyholt reported its heritability as 0.81 [1]. On the other hand, environmental factors, such as smoking and levels of high-density lipoprotein cholesterol, [...]

Missing heritability problem

10.1684/ejd.2012.1898

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Citations (6)