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Biomedical subjects

F Yamamoto

Publications and source records attributed to F Yamamoto.

At least 181 records · Page 10Linked to original sources

Evaluation of rapid drying hand disinfectant preparations in the intensive care unit.

MK412A (0.2% chlorhexidine in 70% ethanol) and MK412B (0.2% benzalkonium chloride in 70% ethanol), which are rapid drying and rubbing antiseptic preparations, have been evaluated for hand sterilization over a month by ICU nurses. They have been shown to have effective skin decontaminant efficacy under practical conditions in a busy ICU. There were no adverse reactions except for two cases of mild erythema in the MK412A treatment group. In a comparative in vitro study with Pseudomonas cepacia, 0.2% chlorhexidine solution alone and 0.2% benzalkonium chloride solution alone were less bactericidal than MK412A and MK412B.

Benzalkonium Compounds↗

Characterization of the human c-K-ras gene promoter.

The promoter of the human c-K-ras gene has been characterized by deletion mutagenesis in concert with stable and transient expression gene transfer experiments. The transcription initiation sites were determined by S1 mapping and RNase A protection experiments. The c-K-ras promoter region is rich in G + C, lacks TATA and CCAAT boxes and contains sequence similarities with other house-keeping genes such as the dihydrofolate reductase (DHFR) and the epidermal growth factor (EGF) receptor genes. The promoter of the c-K-ras gene consists of multiple elements and initiation of transcription occurs at multiple sites. A 54 bp DNA fragment immediately upstream from the 5' end untranslated exon controls the position of many of the transcription initiation sites and direct sufficient transcription for transformation of NIH3T3 cells. However, these sequences can be replaced by other upstream sequences which are required for optimal gene expression. In addition, sequences overlapping with the 5' end untranslated exon and therefore downstream from the major transcription initiation sites are important (although not sufficient) for transcription because their deletion greatly impairs the promoter activity of the upstream elements.

Animals↗

[A new surgical method for the creation of atrial septal defects].

For the creation of atrial septal defect (ASD), we have developed a new method (Method I) using modified Harken blade for the closed commissurotomy, in which the membranous septum of the fossa ovalis was incised in case of patent foramen ovale (PFO). When there was no or very narrow PFO, we applied Schuster's procedure to create defect in the muscular and membranous septum, however, it was sometimes found the bridging of remnant of membranous septum was left. So that, we have applied the Method I to cut it off (Method II). Up to date, eleven patients were operated with the Method I, and three patients with the Method II. As the results, nearly no pressure gradient between right and left atrium was detected postoperatively. In two cases, sufficiently created ASDs were confirmed at radical surgery. Because of the safety and reliability, our new procedures appear to be more advantageous in comparing to conventional Blalock-Hanlon or other procedures.

Child, Preschool↗

Inactivation of influenza B virus by normal guinea-pig serum.

Normal guinea-pig serum (GPS) lacking detectable antiviral antibody efficiently neutralized the infectivity of influenza B virus grown in chick embryos or MDCK cells. The inhibitor was heat-labile and sensitive to trypsin digestion. This beta-like inhibitor required Ca2+ and the complement components C1 and C4 for its activity. In contrast, GPS did not inactivate influenza A virus. Influenza B virus from which the neuraminidase activity of the spikes on the viral envelope had been eliminated by trypsin digestion was also inactivated to a level comparable to untreated virus. Complement component C1 alone bound directly to influenza B virus and inhibited its haemagglutinin activity. We suggest that the beta-like inhibitor in GPS is a component of the classical complement pathway which is triggered by the protein moiety of influenza B virus haemagglutinin, leading to virus neutralization.

Animals↗