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Biomedical subjects

N Sekine

Publications and source records attributed to N Sekine.

At least 55 records · Page 3Linked to original sources
PubMed1979

Absence of interferon production in a newly established human cell line.

A cell line established from human embryonic lung, HEL-R66, was demonstrated to be highly susceptible to herpes simplex virus types 1 and 2, vaccinia virus, Newcastle disease virus (NDV), Japanese encephalitis virus (JEV), western equine encephalitis (WEE) virus, Sindbis virus, vesicular stomatitis virus (VSV), and rabies virus. The maximal yields of NDV, JEV, WEE virus, and rabies virus in this cell line exceeded by 2--4 logs those in control human embryonic lung cells. Inability of this cell line to produce interferon upon treatment with native and UV-irradiated forms of virogenic and lentogenic strains of NDV and with poly I:C was revealed. A refractory state to challenging VSV did not develop in HEL-R66 cells treated with the inducers. Furthermore, pretreatment of HEL-R66 cells with interferon did not potentiate the capacity to produce interferon in response to the addition of poly I:C, whereas the same treatment enhanced the production of interferon in normal human embryonic lung cells.

Cell Line↗
PubMed1977

An analysis of factors influencing the isolation rate of herpes simplex virus.

Attempts were made to improve the rate of isolation of herpes simplex virus (HSV) from clinical specimens by minimizing loss of virus infectivity during transportation and employing the most sensitive cells for isolation. Basical analyses using standard strains of type 1 and type 2 HSV indicated that virus titer decrease was marked even at low temperatures in environments free of proteinous stabilizer such as normal serum or tissue extract, negating the generally held concept that HSV is stable in distilled water. YLE (Earle-lactalbumin HYDROLYSATE-YEAST EXTRACT) medium containing 20% inactivated calf serum was determined to be a transport medium of choice, because degradation of suspended virus during storage and freeze-thawing was negligible and loss of virus during Millipore filtration was minimal. Special coating of the membrane could also be obviated by the use of this solution. In a cell susceptibility test using clinical specimens, secondary rabbit kidney (SRK) cells were the most sensitive, showing a quick development of cytopathic effect. Vero and RK-13 cells were the second best, whereas monkey kidney, HeLa and L cells were far less sensitive. A total of 136 specimens from suspected cases, sent by dermatologists, were tested using SRK cells, and 99 strains of type 1 and 15 strains of type 2 HSV were isolated. Excluding one case from which vaccinia virus was isolated, the isolation rate of HSV was 84.4%.

Animals↗
PubMed1976

Enhanced growth and plaquing of rabies virus in static chick embryo cell culture.

The 7-day egg passage line of HEP Flury strain of rabies virus was inoculated to primary chick embyro (CE) cells prepared in different ways to compared efficiencies of viral growth and plaquing. Special care to minimize cellular damage due to trypsin at the step of monodispersion and sowing a comparatively large number of cells for monolayer preparation were required for rabies plaquing, whereas such cares were not necessary for plaquing of vesicular stomatitis virus. Plaque number and size were increased by incorporation of a high concentration of thymidine into cell growth medium. Various other means to produce a static state of CE cells were tested, and a maximal plaquing efficiency was obtained when dishes receiving a massive number of dispersed cells in MEM plus 1% calf serum were incubated at 37 C for 1 day without any buffering for monolayer preparation and postinfection incubation was done at 32 C in a CO2-incubator. Bottle cultures of CE cells prepared in a similar manner, when infected with HEP Flury virus, yielded a markedly higher titer of virus that CE cells prepared by our previous standard method.

Animals↗