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Yasuyuki Morishima

Publications and source records attributed to Yasuyuki Morishima.

6 recordsLinked to original sources
PubMed2005

Molecular discrimination between individual metacercariae of Paragonimus heterotremus and P. westermani occurring in Thailand.

To accurately discriminate between individual metacercariae of Paragonimus heterotremus and P. westermani occurring in Thailand, polymerase chain reaction (PCR)-based molecular methods were established and subjected to an evaluation. We first amplified and sequenced the second internal transcribed spacer (ITS2) region of the nuclear ribosomal DNA of the two species. Based on their nucleotide differences, P. heterotremus and P. westermani were unequivocally discriminated from each other. These nucleotide differences were further utilized to select the ApaL1 endonuclease site for PCR-restriction fragment length polymorphism (PCR-RFLP) analyses and to design species-specific primers for multiplex PCR reactions. Both PCR-RFLP and multiplex PCR methods allowed a more rapid and labor-effective species discrimination. Furthermore, the multiplex PCR method enabled the most efficient discrimination because species identification involved a single round of PCR in a single tube. In Thailand, P. heterotremus is the only species affecting humans. Thus, the methods established in the present study can be used as reliable tools to identify the lung fluke metacercariae that cause human disease.

Animals↗
PubMed2004

Paragonimus ohirai metacercariae in crabs collected along the Arakawa River in Tokyo, Japan.

Brackish water crabs infected with Paragonimus ohirai metacercariae have been reported in various regions in Japan. However, infected crabs have not been identified in Tokyo. We therefore collected the crab, Chiromantes dehaani, between August 2002 and July 2003 from 12 locations along the Arakawa River that flows through Tokyo. Of the 922 captured crabs, 177 (19%) from 6 locations were infected with Paragonimus metacercariae. The prevalence of metacercariae at these 6 locations ranged from 5 to 89%. The number of metacercariae per infected crab ranged from 1 to 190, with an average of 13.1. The morphological features of the metacercariae and of adult worms recovered from test rats infected with metacercariae showed that the metacercariae in the infected crabs were P. ohirai Miyazaki, 1939. The ITS2 sequence data support this conclusion. This paper is the first description of P. ohirai infection of crabs in Tokyo.

Animals↗
PubMed2003

[Cystic hydatidosis--its occurrence and prevention in Japan].

The history of cystic hydatidosis (CH) in Japan is reviewed on the basis of case reports and other references during the period from 1881 to 2003. A total of 76 cases were identified as CH patients in Japan of which 47 were reported prior to 1945 and 29 thereafter. The occurrence was divided into 2 stages before and after the Slaughterhouse Act that was brought into force in 1906. The presence of endemic foci of CH was suggested before the Act was introduced in Japan, especially in southwestern prefectures, and the development of cattle breeding and unsanitary small slaughterhouses in the areas were thought to be cause. Japan emphasized cattle as a dietary protein source and also for various military accouterments such as shoes and rucksacks for soldiers. China was a transit port to Japan from Europe and also a big endemic area of CH. Japan had sent a huge number of soldiers and citizens to China in the Japanese-Sino and Japanese-Russian War and a number of cattle, pet dogs and people have also came to Japan from China. After enforcement of the Slaughterhouse Act in 1906, the number of CH cases decreased dramatically, and only 2 cases were reported for the 30 years between 1920 and 1950 in Japan. The situation regarding CH in Japan thus suggested the existence of endemic foci in southwestern prefectures, although direct evidence was lacking because no one had found E. granulosus in dogs of the area. Almost all of the patients recently presenting with CH appear to have been infected in overseas endemic countries. The available information strongly suggest that sanitary control of slaughterhouses is essential for preventing CH in endemic areas. Diagnostic laboratory examinations and appropriate medical intervention are clearly important. An animal quarantine system against echinococcal infestation of pet dogs should also be established urgently in Japan, because hundreds of pet dogs are being imported annually from endemic countries in Europe and Asia.

Adolescent↗