Biomedical subjects

R Takahara

Publications and source records attributed to R Takahara.

3 recordsLinked to original sources

PubMed2000

[Biopsy].

We reviewed the current devices, techniques, guiding images, indications and complications of needle biopsy with CT guidance. The development of new devices such as automated cutting needle has enabled radiologists to obtain tissue specimens of good quality at biopsy. Techniques such as the tandem or coaxial method ensure more a more accurate biopsy route. And helical CT and CT fluoroscopy have markedly shortened the time required for needle biopsy. However, we sometimes encounter minor complications, and rarely major ones, during and after needle biopsy. Some of these complications may be caused by malpractice. Therefore it is important always to pay attention to the possibility of complications of needle biopsy and to minimize radiation exposures from CT fluoroscopy.

Biopsy, Needle↗

PubMed1998

Identification of the Oka strain of the live attenuated varicella vaccine from other clinical isolates by molecular epidemiologic analysis.

A method was developed to distinguish the Oka vaccine strain of varicella-zoster virus (VZV) from other clinical isolates. The molecular characteristics of 52 clinical isolates from varicella or zoster patients with no history of VZV vaccination and the Oka strain, including vaccine and parental viruses, were analyzed by PstI cleavage of the PstI site-less (PSL) region. This was followed by single-strand conformational polymorphism (SSCP) after polymerase chain reaction amplification of repeating region 2 (R2). Most of the clinical isolates tested, especially recent isolates, had a PstI site in the PSL region, but the Oka strain did not. The SSCP patterns of R2 in Oka strain virus differed from those of other viruses. These results suggest that analysis of the PstI site followed by SSCP of R2 will be useful for identifying the Oka vaccine virus in isolates.

Cell Line↗

PubMed1998

In situ detection of chromosome bridge formation and delayed reproductive death in normal human embryonic cells surviving X irradiation.

We investigated delayed reproductive death and chromosome bridge formation in mitotic cells in colonies of normal human embryonic cells which survived exposure to 6 Gy of X rays. Eighteen primary clones each derived from control and irradiated cultures were isolated and secondary colonies were grown up. Six of the primary clones surviving the irradiation showed significantly lower cloning efficiencies than the control clones (P < 0.001), while the rest of the surviving clones showed a cloning efficiency similar to those of the control clones. The average cloning efficiency of control and surviving clones was 16.4 and 7.2%, respectively. Reduced cloning efficiencies were also observed in the tertiary colony formation, indicating that the persistent decrease in cloning efficiency was inherited over 40 generations after X irradiation in normal human cells. Five of nine primary clones surviving the irradiation also frequently contained multiple giant cells in the colonies, while this was a rare event in the progeny of control clones. Furthermore, we analyzed in situ chromosome segregation in anaphase cells appearing during the formation of the secondary colonies. A significantly higher frequency of chromosome bridge formation was found in four of the surviving clones which received 6 Gy (P < 0.001), and the frequency of micronuclei was also increased in the surviving clones. These results provide evidence that genetic instability is induced in normal human embryonic cells by low-LET radiation, and that misrejoining of the broken chromosome ends is increased in the progeny of cells surviving X irradiation.

Cell Death↗