Munehiro Hirayama

Adverse events associated with MMR vaccines in Japan

The largest nationwide active surveillance of four Measles‐Mumps‐Rubella (MMR) vaccines was conducted in Japan. A total of 1255 pediatricians actively participated in the study, which comprised 8.6% of all members of the Japanese Pediatric Society. The total number of registered recipients of MMR vaccines was 38 203. They were arbitrarily given one of the MMR vaccines produced by three makers (Takeda, Osaka city, Kitasato Minato‐ku, Tokyo and Biken Suita city, Japan) or the standard MMR vaccine made of designated strains (Kitasatos measles‐AIK‐C, Bikens mumps‐Urabe Am9 and Takedas rubella‐To336) produced by Takeda, Kitasato and Biken and were observed for 35 days.

Bleomycin-induced chromosomal aberrations and sister chromatid exchanges in Down lymphocyte cultures

SummaryPeripheral blood lymphocytes from three patients with Down syndrome (DS; trisomy 21; aged 5–6 years) and three age-matched control children were studied for the induction of chromosomal aberrations and sister chromatid exchanges (SCEs).Cells in G0 were exposed to bleomycin (20–100 μg/ml) for 3 h, and then cultured in medium containing 5-bromodeoxyuridine and phytohemagglutinin for 66 h. By the sister chromatid differential staining method, chromosome analyses were performed on metaphase cells that had divided one, two, or three or more times after treatment. The results indicate that DS cells exposed to bleomycin are hypersensitive to the production of dicentric and ring chromosomes compared to normal cells. Bleomycin also led to a dose-related increase in the frequency of SCEs, but no difference was found between the SCE frequencies in DS or normal lymphocytes exposed to bleomycin.

Incidence of 47,XYY karyotype in a consecutive series of newborn males in Tokyo

SummaryA series of 3545 newborn males, born consecutively at a maternity hospital in the western suburbs of Tokyo and with no detectable physical abnormalities, were studied for fluorescent Y-chromatin. Buccal cell smears from each infant were screened. Cases with ambiguous results were subjected to a second test by blood smears, which were found to be more reliable. After the second test, chromosomal analysis was carried out in five infants: three had a 47,XYY karyotype; one, the karyotype 46,XY-D,t(D:Y) (Iijima et al., in preparation); and one, a normal male karyotype. The XYY karyotype occurred in 0.11% of newborn males in this series.

Preventive Activities for Mental and Physical Handicaps in Japan

The countermeasures and services for prevention of handicaps in Japan are described and discussed, through prenatal to postnatal period. These are showing the effects for decreasing handicaps and deaths. But many unknown factors and impossible matters have been still remained.