Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yu-ichi Yamamoto is active.

Publication


Featured researches published by Yu-ichi Yamamoto.


Journal of Dermatology | 2008

Neonatal pemphigus vulgaris

Makiko Gushi; Yu-ichi Yamamoto; Yoshiko Mine; Ryoko Awazawa; Kimiko Nonaka; Kiyohito Taira; Yutaka Asato; Keisuke Hagiwara; Hiroshi Uezato

A male newborn with skin erosions was born to a 32‐year‐old woman who was under treatment for pemphigus vulgaris that had been diagnosed 16 months earlier. Antibodies to desmoglein (Dsg)1 and Dsg3 were analyzed by enzyme‐linked immunosorbent assay. Index values of antibodies to Dsg1 and Dsg3 were 49 (normal index values, <14) and 121 (normal index values, <7), respectively. Those findings concluded a diagnosis of neonatal pemphigus vulgaris. No new vesicles or bullae appeared in the newborn after the birth. Non‐corticosteroid ointments produced prompt epithelialization on the erosive lesions. All the eruptions disappeared in 3 weeks. The level of serum anti‐Dsg3 autoantibodies when measured at the 76th day was negative (<5).


World Journal of Gastrointestinal Endoscopy | 2010

Esophagitis dissecans superficialis and autoimmune bullous dermatoses: A review

Akira Hokama; Yu-ichi Yamamoto; Kiyohito Taira; Mitsuteru Nakamura; Chiharu Kobashigawa; Manabu Nakamoto; Tetsuo Hirata; Nagisa Kinjo; Fukunori Kinjo; Kenzo Takahashi; Jiro Fujita

Esophagitis dissecans superficialis (EDS) is a rare and severe endoscopic finding characterized by sloughing of large fragments of esophageal mucosal lining. Although EDS has been reported in association with serious illnesses and certain medications, the pathophysiological association of autoimmune bullous dermatoses with EDS has gained remarkable attention. Among these dermatoses, pemphigus vulgaris and pemphigoid frequently present with various types of esophageal involvement including EDS. We review the pathophysiology and clinical features of this involvement with the presentation of our experiences. The importance of endoscopic evaluation of this entity is discussed.


Journal of Dermatology | 2008

Polymorphisms of cytochrome b gene in Leishmania parasites and their relation to types of cutaneous leishmaniasis lesions in Pakistan

Chomar Kaung Myint; Yutaka Asato; Yu-ichi Yamamoto; Hirotomo Kato; Abdul Manan Bhutto; Farooq Rahman Soomro; Muhamad Z. Memon; Jun Matsumoto; Jorge D. Marco; Minoru Oshiro; Ken Katakura; Yoshihisa Hashiguchi; Hiroshi Uezato

The exact species and/or strains of Leishmania parasites involved strongly influence the clinical and epidemiological features of leishmaniasis, and current knowledge of those influences and relationships is inadequate. We report that cytochrome b (cyt b) gene sequencing identified causal Leishmania parasites of 69 cutaneous leishmaniasis cases in Pakistan over a 3‐year period. Of 21 cases in highland areas (Quetta city, Balochistan province), 16 (76.2%) were identified as Leishmania (L.) tropica and five (23.8%) as Leishmania (L.) major. Of 48 cases from lowland areas, cities/villages in Indus valley in Sindh and Balochistan provinces, 47 (97.9%) were identified as L. (L.) major and one (2.1%) as L. (L.) tropica. Statistical analysis (Fishers exact test) revealed a significant difference (P < 0.0001) in the distribution of the two species by altitude; L. (L.) major is predominant in lowland and L. (L.) tropica at highland areas. The present result enriched our earlier finding, based on the first years cultured parasite data, that only L. (L.) tropica was found in highland areas and only L. (L.) major in lowland areas. Among Leishmania samples analyzed, three types of cyt b polymorphism of L. (L.) major were found, including 45 (86.5%) cases of type I, six (11.5%) of type II and one (2%) of type III. We report for the first time on the presence of polymorphisms in L. (L.) major (types I, II and III) based on species identification using cyt b gene sequencing from clinical samples. Moreover, we found no correlation between clinical presentation (wet‐, dry‐ and/or mixed‐types of cutaneous lesions) and causal Leishmania parasites.


Journal of Dermatology | 2008

Case of skin injuries due to stings by crown-of-thorns starfish (Acanthaster planci)

Hironobu Sato; Yuichiro Tsuruta; Yu-ichi Yamamoto; Yutaka Asato; Kiyohito Taira; Keisuke Hagiwara; Susumu Kayo; Setsuko Iwanaga; Hiroshi Uezato

A case of skin injuries due to stings by crown‐of‐thorns starfish, Acanthaster planci, in a 53‐year‐old Okinawan woman is reported. She went to a beach to gather shellfish on 8 April 2001 and fell to the ground with her left palm on a crown‐of‐thorns starfish that happened to be close to her. She hurried to the emergency section of our hospital. An emergency doctor sterilized the wound and administered an antibiotic, an analgesic agent and an injection of a tetanus antitoxin. He tried to remove the remaining spines from the palm with great difficulty. Because swelling and subcutaneous indurations of the left palm had persisted thereafter, oral and topical administration of corticosteroid started on 13 April. Physical examination at the dermatology section revealed approximately 10 stab wounds of the left palm with pus, subcutaneous bleeding and many abrasions around them. X‐rays of the left hand showed foreign bodies, 2–10 mm in size, located on the lesions. The patient was treated with a topical injection of 2 mg triamcinolone acetonide (Kenacort‐A), diluted fivefold with 1% Xylocaine, once a week. Some of the foreign body granulomatous lesions improved but pain and subcutaneous indurations persisted in most of the lesions. Because the X‐ray photographs showed many remaining spines, surgical excision to remove them was performed under local anesthesia 3 months after the injury. All the symptoms improved after the operation. Scanning electron microscopic examination of the spines revealed that their tips had fragile lattice‐like structures.


Journal of Dermatology | 2009

Necrotizing fasciitis caused by Streptococcus pneumoniae

Etsuko Yamashiro; Yutaka Asato; Kiyohito Taira; Ryoko Awazawa; Yu-ichi Yamamoto; Keisuke Hagiwara; Hajime Tamaki; Hiroshi Uezato

A 69‐year‐old woman presented with shivering and pain in the lower extremities on 5 April 2006; she was referred to the dermatology division of our hospital on the following day with difficulty in walking. She had been suffering from non‐viral, non‐alcoholic liver cirrhosis, and was being treated by the Division of Internal Medicine. Physical examination showed edema in the lower extremities and light purpuras on the groin and legs. Low blood pressure had been observed since admission. Necrotizing fasciitis (NF) was suspected on the basis of the skin symptoms, systemic conditions, and magnetic resonance imaging. During surgical debridement under general anesthesia, cardiopulmonary arrest occurred, and the patient died 12 h after admission. NF, in its early stages, exhibits few skin changes. In order to differentiate it from other skin infections, it is necessary to take into account blood pressure, abnormal systemic conditions, and severe pain out of proportion to its minor skin changes. In the present case, Streptococcus pneumoniae was detected by blood culture. Soft tissue infectious diseases caused by S. pneumoniae, especially NF, are very rare. We have reviewed reported cases of NF caused by S. pneumoniae.


Journal of Dermatology | 2008

Case of linear immunoglobulin A bullous dermatosis associated with acquired hemophilia

Osao Arakaki; Yu-ichi Yamamoto; Ryoko Awazawa; Kimiko Nonaka; Kiyohito Taira; Yutaka Asato; Keisuke Hagiwara; Bungo Oyama; Norito Ishii; Takashi Hashimoto; Hiroshi Uezato

Linear immunoglobulin (Ig)A bullous dermatosis is a rare autoimmune subepidermal bullous dermatosis caused by circulating IgA autoantibodies directed against the antigens at the basement membrane zone. Most linear IgA bullous dermatosis cases are idiopathic, but some are associated with the use of certain drugs, infections, lymphoproliferative disorders, internal malignancies, autoimmune disorders, collagen diseases or, very rarely, other skin diseases, including autoimmune bullous diseases. Acquired hemophilia is also rare; it is a coagulation disease caused by anti‐factor VIII IgG antibodies. Acquired hemophilia has been reported to be associated with malignant tumors, pregnancy or postpartum, drug reactions, collagen diseases such as rheumatoid arthritis, autoimmune disorders, and skin diseases such as psoriasis and pemphigus. We report a case of hemophilia acquired during the course of linear IgA bullous dermatosis and review reported cases of autoimmune bullous dermatoses associated with acquired hemophilia.


Journal of Dermatology | 2011

Allergic contact dermatitis due to diclofenac sodium in eye drops

Hitona Miyazato; Sayaka Yamaguchi; Kiyohito Taira; Yutaka Asato; Yu-ichi Yamamoto; Keisuke Hagiwara; Hiroshi Uezato

Eyelid dermatitis and/or periocular dermatitis (ED/PD) is commonly seen in a variety of skin diseases such as seborrheic dermatitis, atopic dermatitis and psoriasis, but is most often associated with allergic contact dermatitis (ACD). Here, a case of ACD in an 82‐year‐old man is described; he used 0.1% diclofenac sodium eye drops and exhibited pruritic erythema on the eyelids. Patch test for diclofenac sodium eye drops was positive. Further patch tests revealed a positive reaction to diclofenac sodium (monosodium 2‐[2, 6‐dichlorophenylamino] phenylacetate), which was the main component in the eye drop medicine. Diclofenac sodium is a non‐steroidal anti‐inflammatory drug (NSAID), and is frequently used in everyday oral medications, topical ointments, gel agents and eye drops. Case reports on ACD caused by diclofenac sodium eye drops are extremely rare. Nevertheless, it is necessary to consider ACD due to diclofenac sodium when a patient with ED/PD has a history of use of diclofenac sodium eye drops.


Journal of Dermatology | 2012

Systemic lupus erythematosus complicated with protein-losing enteropathy: a case report and review of the published works.

Ryoko Awazawa; Yu-ichi Yamamoto; Yoshiko Mine; Ikumi Nakamura; Kazuto Kishimoto; Fukunori Kinjyo; Keisuke Hagiwara; Jiro Fujita; Hiroshi Uezato; Kenzo Takahashi

A 45‐year‐old man was referred to our hospital with a history of multiple erythematous skin lesions of several months’ duration. Blood examination revealed extreme hypoproteinemia and hypoalbuminemia, as well as the presence of antinuclear antibodies. A skin biopsy specimen showed liquefaction degeneration at the dermoepidermal junction and dense lymphocyte and neutrophil infiltration around the vessels and appendages in the upper and middle dermis. Chest X‐ray and computed tomography showed a pleural effusion and thoracic paracentesis revealed a mononuclear cell‐dominant cell infiltration, suggestive of serositis. Technetium‐99m (99mTc)‐labeled human serum albumin scintigraphy and α1‐antitrypsin clearance revealed protein leakage along the digestive tracts from the stomach to the jejunum. From the above findings, the patient was diagnosed with systemic lupus erythematosus (SLE) complicated by protein‐losing enteropathy (PLE). Treatment with oral prednisolone significantly improved his clinical symptoms and hypoalbuminemia. This case highlighted the utility of 99mTc‐labeled human serum albumin scintigraphy and α1‐antitrypsin clearance in the diagnosis of PLE. We also present a published work review on PLE associated with connective tissue disease revealing a relatively higher prevalence in patients of Asian ethnicity, including Japanese.


European Journal of Dermatology | 2008

Detection of human papillomavirus type 11 in a case of Buschke-Löwenstein tumor

Yutaka Asato; Kiyohito Taira; Yu-ichi Yamamoto; Hiroshi Uezato

We here report a 31-year-old male affected by a papillary tumor in his pubic region. At 26 years of age, he consulted a nearby clinic and was prescribed a topical cream. Although the condition was not relieved, he left the disease untreated. The gradually growing tumor adversely affected his quality of life, and he consulted another clinic, where he was referred to our hospital for surgery. The tumor had infiltrated the tissue at the base of the penis, but not the glans. After careful examination, we performed local excision of the tumor and a split-thickness skin graft. On pathological examination, elongation of the epidermis and koilocytes in the uppermost portion of the spinous layer were observed. Moreover, PCR examination confirmed the presence of human papillomavirus (HPV) type 11 in the tumor tissue. These findings supported a diagnosis of Buschke-Löwenstein tumor (BLT).


Journal of Dermatology | 2013

Fixed eruption due to quinine in tonic water: A case report with high‐performance liquid chromatography and ultraviolet A analyses

Aoi Ohira; Sayaka Yamaguchi; Takuya Miyagi; Yu-ichi Yamamoto; Satoshi Yamada; Hideo Shiohira; Keisuke Hagiwara; Tsukasa Uno; Hiroshi Uezato; Kenzo Takahashi

Fixed drug eruption is a common cutaneous adverse reaction in young patients with a characteristic clinical appearance. However, the diagnosis and identification of the substance may be difficult if food or food additives provoke the fixed eruption. A 26‐year‐old man had a history of two episodes of cutaneous erythema with residual pigmentation. Close examination of the history including his diet in addition to an oral challenge test and patch testing led to the diagnosis of fixed eruption secondary to quinine in tonic water. We examined for the presence of quinine in commercially available brands of tonic water using ultraviolet A and irradiation and high‐performance liquid chromatography. Both Schweppes and CANADA DRY brands of tonic water emitted fluorescent light upon ultraviolet A irradiation, and contained quinine at concentrations of 67.9 and 61.3 mg/L, respectively. Quinine contained in some tonic waters may trigger fixed eruption.

Collaboration


Dive into the Yu-ichi Yamamoto's collaboration.

Top Co-Authors

Avatar

Hiroshi Uezato

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Kiyohito Taira

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Yutaka Asato

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ryoko Awazawa

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Takuya Miyagi

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Osao Arakaki

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Yoshiko Mine

University of the Ryukyus

View shared research outputs
Researchain Logo
Decentralizing Knowledge