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Biomedical subjects

M Takekoshi

Publications and source records attributed to M Takekoshi.

25 records · Page 2Linked to original sources
PubMed1987

A new human cytomegalovirus isolate has an invertible subsegment within its L component producing eight genome isomers.

A HindIII cleavage map of the genome DNA of a new isolate of human cytomegalovirus (HCMV), strain Tanaka, was constructed by cosmid cloning and Southern blot hybridization of virion DNA. The genome was found to be unique in that its long (L) component was composed of two subsegments, L1 and L2, and subsegment L2 underwent inversion relative to L1 at high frequency. In addition to the normal inversions of the L and short (S) components, this produced eight genome isomers. The novel invertible subsegment was flanked by an inverted sequence distinct from the inversion-specific a sequence present in the terminal and junction regions of the genome.

Cell Line↗
PubMed1987

High-frequency transfection of mouse FM3A mammary carcinoma cells in suspension culture with plasmid DNA.

High-frequency transfection of mouse FM3A cells, grown in suspension, with plasmid pSV2neo DNA was achieved by incubation of the cells with DNA plus polybrene for 6 h followed by an osmotic shock with a hypertonic NaCl solution. When incubated for 20 min at 34 degrees C, FM3A cells showed resistance to the osmolarity change from 0.1 to 9.0% NaCl in the medium. Within this concentration range, 5-7% gave the highest efficiency of transfection. Both linear and circular forms of plasmid DNA produced transformants with equal efficiency. This method was simple, reproducible, and carrier DNA was not required. The efficiency was about 100 times higher than that of the method with DNA-calcium phosphate precipitates. Transformed cells were stable and different numbers of plasmid DNA copies were detected.

Animals↗
PubMed1986

Cleavage maps of human cytomegalovirus genome (strain Towne) determined by the use of cosmid cloning system.

Virion DNA of human cytomegalovirus strain Towne was partially digested with endonuclease Hind III and fragments larger than 29 kbp were ligated to cosmid pHC79. The whole viral DNA sequence has been cloned in large overlapping segments carried by 32 recombinant cosmid clones (a pIT series). A whole set of Hind III fragments has also been cloned (a pHI series). By using these, we have constructed corrected cleavage maps of strain Towne DNA for Hind III, Bam H I, EcoR I and Xba I.

Chromosome Mapping↗
PubMed1984

Transformation of human colostrum lymphocytes with Epstein-Barr virus and the production of IgA in culture.

Human colostrum lymphocytes obtained on day 2-5 after delivery were found to be as susceptible to transformation with Epstein-Barr virus (EBV) as peripheral lymphocytes. An enzymelinked immunosorbent assay showed that the proportion of transformed cells producing IgA, IgG, and IgM varied from colostrum specimen to specimen. 1 microgram/ml of IgA could be produced by freshly transformed cell mixture. But the capacity to produce IgA was lost or decreased by one order of magnitude during and after cloning of producing cells; the highest production with cloned cell cultures was about 0.2 micrograms/ml. Immunofluorescence staining of IgA-positive cells showed instability of the capacity of transformed cells to produce IgA.

Cell Transformation, Viral↗
PubMedDate not supplied

Purification and cDNA cloning of evolutionally conserved larval cuticle proteins of the silkworm, Bombyx mori.

A specific set of structural proteins termed larval cuticle proteins (LCPs) accumulates in integuments during larval development of the silkworm, Bombyx mori. Two major larval cuticle proteins, LCP17 and LCP22, were purified from the guanidine hydrochloride extract of the larval cuticle, and specific antibodies were raised against these proteins. Immunoblot analysis revealed that both LCPs are actively synthesized during larval intermolt stages, whereas the LCP17 epitope is also slightly but significantly detectable in pupal integuments. cDNA clones for LCPs were isolated by immunoscreening of the cDNA expression library constructed from larval epidermal mRNA. Predicted amino acid sequences of LCP17 and LCP22 are homologous to cuticle proteins from other insect species, including Manduca sexta, Drosophila melanogaster and Locusta migratoria. This fact suggests that these cuticle protein genes originated from a common ancestral gene and have been conserved during evolution. Northern blot hybridization demonstrated that the expression of LCP17 as well as LCP22 mRNA is controlled in a stage-specific manner in the epidermis of the final instar larvae, suggesting a common regulatory mechanism for transcription of these two intermolt genes.

Amino Acid Sequence↗