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Featured researches published by Yutaka Asato.


Experimental Parasitology | 2009

Phylogenic analysis of the genus Leishmania by cytochrome b gene sequencing.

Yutaka Asato; Minoru Oshiro; Chomar Kaung Myint; Yu ichi Yamamoto; Hirotomo Kato; Jorge D. Marco; Tatsuyuki Mimori; Eduardo A. Gomez; Yoshihisa Hashiguchi; Hiroshi Uezato

In a previous report (Luyo-Acero et al., 2004), we demonstrated that cytochrome b (Cyt b) gene analysis is an effective method for classifying several isolates of the genus Leishmania; hence, we have further applied this method to other Leishmania species in an effort to enhance the accuracy of the procedure and to construct a new phylogenic tree. In this study, a total of 30 Leishmania and Endotrypanum WHO reference strains, clinical isolates from our patients assigned to 28 strains (human and non-human pathogenic species) and two species of the genus Endotrypanum were analyzed. The Cyt b gene in each sample was amplified by PCR, and was then sequenced by several primers, as reported previously. The phylogenic tree was constructed based on the results obtained by the computer software MEGA v3.1 and PAUP* v4.0 Beta. The present phylogenic tree was almost identical to the traditional method of classification proposed by Lainson and Shaw (1987). However, it produces the following suggestions: (1) exclusion of L. (Leishmania) major from the L. (L.) tropica complex; (2) placement of L.tarentolae in the genus Sauroleishmania; (3) L. (L.) hertigi complex and L. (V.) equatorensis close to the genus Endotrypanum; (4) L. (L.) enrietti, defined as L. (L.) mexicana complex, placed in another position; and (5) L. (L.) turanica and L. (L.) arabica are located in an area far from human pathogenic Leishmania strains. Cyt b gene analysis is thus applicable to the analyzing phylogeny of the genus Leishmania and may be useful for separating non-human pathogenic species from human pathogenic species.


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).


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.


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 | 2007

Case of pemphigus foliaceus that shifted into pemphigus vulgaris after adrenal tumor resection

Ryoko Awazawa; Yu-ichi Yamamoto; Makiko Gushi; Kiyohito Taira; Nobutake Yagi; Yutaka Asato; Keisuke Hagiwara; Hiroshi Uezato

A 79‐year‐old Japanese woman visited our hospital on 6 May 2003, who had suffered from erythema and crusted vesicles located on the head, face and trunk. The eruptions first appeared in February 2003. Histopathological findings included blister formation spreading from just below the horny layers to the upper squamous layers, where acantholytic cells were observed. Direct immunofluorescence disclosed immunoglobulin G depositions in the epidermal intercellular spaces. Enzyme‐linked immunosorbent assay showed an elevated titer of anti‐desmoglein (Dsg)1 autoantibodies (154 index value), but almost normal levels of anti‐Dsg3 autoantibodies (8 index value in serum). The diagnosis at first was made as pemphigus foliaceus (PF). Topical use of corticosteroids alone could control the eruptions well. Systemic examinations on admission revealed a right adrenal tumor that had caused Cushings syndrome. Its resection was performed on 24 July 2003. Histopathological diagnosis of the removed tumor was a functional adrenal adenoma. The symptoms had worsened after the resection. Topical use of corticosteroids alone could no longer control the symptoms. Additional p.o. medications of minocycline hydrochloride and nicotinic acid amides improved the symptoms to some extent. However, oral cavity erosions appeared in December 2004, and the titer of anti‐Dsg3 autoantibodies in serum elevated, suggesting a transition from PF to pemphigus vulgaris (PV). p.o. administration of corticosteroids started, which improved the symptoms significantly. To date, there have been no reports of pemphigus complicated with an adrenal tumor that caused Cushings syndrome in Japan. The present case is particularly interesting in that the symptoms became worse after the tumor resection and that the first diagnosis of PF shifted into PV after the operation.


Journal of Dermatology | 2008

Case of chromoblastomycosis appearing in an Okinawa patient with a medical history of Hansen's disease

Hideki Miyagi; Yu-ichi Yamamoto; Shinako Kanamori; Kiyohito Taira; Yutaka Asato; Chomar Kaung Myint; Susumu Kayo; Atsushi Hosokawa; Keisuke Hagiwara; Hiroshi Uezato

Chromoblastomycosis is one of several chronic infectious skin diseases caused by various species of dematiaceous fungi. It is clinically characterized by verrucous skin eruptions and occurs most commonly in tropical and subtropical regions. In Okinawa, a subtropical area, there have been only three reported cases of chromoblastomycosis including the present one. Direct microscopic examination of crust specimens and findings of sclerotic cells in histopathology can confirm the diagnosis, and cultures of crust and/or tissue specimens can identify the causative fungi. We herein report the third case of chromoblastomycosis in Okinawa; it arose in an 87‐year‐old Japanese woman with a history of Hansens disease, who lived in a leprosarium in Miyako Island. To identify the causative agent as Fonsecaea pedrosoi, we used the polymerase chain reaction and direct sequencing analysis in addition to the usual methods, which include 20% potassium hydroxide microscopy, histopathological confirmation of sclerotic cells by periodic acid‐Schiff stain, culture by Sabourauds glucose agar, slide culture method, and observation of conidia by scanning electron microscopic examination.

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Hiroshi Uezato

University of the Ryukyus

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Kiyohito Taira

University of the Ryukyus

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Ryoko Awazawa

University of the Ryukyus

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Osao Arakaki

University of the Ryukyus

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Kimiko Nonaka

University of the Ryukyus

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Makiko Gushi

University of the Ryukyus

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Susumu Kayo

University of the Ryukyus

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