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Biomedical subjects

K Maki

Publications and source records attributed to K Maki.

At least 109 records · Page 6Linked to original sources
PubMed1994

Targeted pituitary tumorigenesis using the human thyrotropin beta-subunit chain promoter in transgenic mice.

We have generated transgenic mice that express the simian virus 40 (SV40) large T antigen under the control of a 1109 bp 5'-flanking sequence of the human thyrotropin beta-subunit (TSH beta) gene. The hybrid gene, termed TTP-1, was microinjected into fertilized mouse eggs and 11 transgenic mice were obtained. One of the transgenic mice, a female, a phenotypical dwarf, developed a pituitary tumor and wasted away from 7 to 9 weeks after birth. To establish the transgenic mouse line, her ovaries were transferred to a normal female, whose ovaries were removed beforehand. To examine the tissue specificity of transgene expression, mRNA of SV40 large T antigen was monitored in various tissues from the transgenic mice by the reverse transcriptase-polymerase chain reaction analysis, and was detected only in the pituitary. Histological and immunohistochemical analyses showed that the pituitary tumors of the transgenic mice were composed of poorly differentiated pituitary cells expressing SV40 large T antigen. These results indicated that the 1109 bp sequence of the human TSH beta 5'-flanking region is essential for pituitary-specific expression of SV40 large T antigen in transgenic mice, which exhibited a dwarf phenotype and developed pituitary tumors. The tumors were composed of undifferentiated cells and did not produce thyrotropin. These transgenic mice should provide a valuable animal model for studying the pathogenesis of anterior pituitary tumors.

Animals↗
PubMed1994

Clinical evaluation of a light-cured glass ionomer lining cement.

This study was a clinical evaluation of a light-cured glass ionomer lining material (Fuji Lining LC) applied to prepared cavities in 45 primary teeth of children aged 3-5 years. The overall assessment, based on clinical and radiographic findings, was 'good' in 42 cases and 'fair' in the other three cases. The material had no effect on the shade of the composite resin restorative material that was used. The findings indicate that Fuji Lining LC has significant value in clinical practice.

Child, Preschool↗
PubMed1994

Cloning and nucleotide sequences of the homoserine dehydrogenase genes (hom) and the threonine synthase genes (thrC) of the gram-negative obligate methylotroph Methylobacillus glycogenes.

We have cloned the homoserine dehydrogenase genes (hom) from the gram-negative obligate methylotrophs Methylobacillus glycogenes ATCC 21276 and ATCC 21371 by complementation of an Escherichia coli homoserine dehydrogenase-deficient mutant. The 4.15-kb DNA fragment cloned from M. glycogenes ATCC 21371 also complemented an E. coli threonine synthase-deficient mutant, suggesting the DNA fragment contained the thrC gene in addition to the hom gene. The homoserine dehydrogenases expressed in the E. coli recombinants were hardly inhibited by L-threonine, L-phenylalanine, or L-methionine. However, they became sensitive to the amino acids after storage at 4 degrees C for 4 days as in M. glycogenes. The structures of the homoserine dehydrogenases overexpressed in E. coli were thought to be different from those in M. glycogenes, probably in subunit numbers of the enzyme, and were thought to have converted to the correct structures during the storage. The nucleotide sequences of the hom and thrC genes were determined. The hom genes of M. glycogenes ATCC 21276 and ATCC 21371 encode peptides with M(r)s of 48,225 and 44,815, respectively. The thrC genes were located 50 bp downstream of the hom genes. The thrC gene of ATCC 21371 encodes a peptide with an M(r) of 52,111, and the gene product of ATCC 21276 was truncated. Northern (RNA) blot analysis suggests that the hom and thrC genes are organized in an operon. Significant homology between the predicted amino acid sequences of the hom and thrC genes and those from other microorganisms was found.

Amino Acid Sequence↗
PubMed1994

[Multiple myeloma with massive ascites fluid--immunophenotypic analysis of myeloma cell and its IL-6-dependent growth].

A 75-year-old female was diagnosed as having multiple myeloma (IgG.lambda type. Stage IIA) with plasmacytoma of the head and back in October, 1989. She obtained partial remission by MCNU and MP therapy, but relapsed with massive ascites in January, 1991. VAD therapy was not effective and she died of multiple organ failure on February 23. Her ascites contained a large number of myeloma cells, and the phenotypic analysis and the response to interleukin-6 (IL-6) of these myeloma cells were examined. The myeloma cells were positive for CD33, CD45, CD45RA, CD63, CD71, plasma cell associated antigens such as CD38, PCA-1, BL3, and various kinds of adhesion molecules: CD11a/CD18 (LFA-1), CD29 (VLA-beta 1), CD44 (H-CAM), CD49d (VLA-4), CD54 (ICAM-1), CD56 (N-CAM), CD58 (LFA-3). IL-6 level in the ascites was increased at 91.0pg/ml. The myeloma cells showed an IL-6 dependent growth, which was inhibited by anti-IL-6 antibody (Ab) and anti-IL-6 receptor Ab in vitro. Myeloma cells appearing in ascites have rarely been reported. Our case suggested that IL-6 was a potent growth factor of myeloma cells through an autocrine mechanism in the ascites, and resulted in an aggressive myeloma.

Aged↗
PubMed1993

Synthesis of the laminara-oligosaccharide methyl beta-glycosides of dp 3-8.

Ethyl 2,3,4,6-tetra-O-acetyl-1-thio-alpha-D-glucopyranoside has been prepared in a good yield by anomerization of the corresponding beta-thioglucoside with tin(IV) chloride and transformed, in three steps, into ethyl 2-O-benzoyl-4,6-O-benzylidene-1-thio-alpha-D-glucopyranoside (18). Chloroacetylation of 18, followed by treatment of the product with chlorine gave crystalline 2-O-benzoyl-4,6-O-benzylidene-3-O-chloroacetyl-beta-D-glucopyranosyl chloride (20). This was coupled with methanol in the presence of silver carbonate-silver perchlorate and the product was O-dechloroacetylated to afford methyl 2-O-benzoyl-4,6-O-benzylidene-beta-D-glucopyranoside (22). Silver triflate-promoted glucosylation of 18 with 20 gave a beta-(1-->3)-linked disaccharide derivative, reaction of which with chlorine yielded crystalline O-(2-O-benzoyl-4,6-O-benzylidene-3-O-chloroacetyl-beta-D-glucopyranosyl) - (1-->3)-2-O-benzoyl-4,6-O-benzylidene-beta-D-glucopyranosyl chloride (24). Likewise, condensation of 22 with 20 gave a beta-(1-->3)-linked disaccharide glycoside, which was partially deprotected to give methyl O-(2-O-benzoyl-4,6-O-benzylidene-beta-D-glucopyranosyl)-(1-->3)-2-O-benz oyl- 4,6-O-benzylidene-beta-D-glucopyranoside (26). The methyl beta-glycosides of a homologous series of (1-->3)-linked beta-D-gluco-oligosaccharides from the tri- to the octa-saccharide have been synthesized in a blockwise manner by using 22 and 26 as the glycosyl acceptors, 24 as the disaccharide donor, and silver triflate as the promoter.

Carbohydrate Conformation↗
PubMed1993

High level expression of human alpha-fetoprotein in transgenic mice.

Transgenic mice were produced by the microinjection of the cDNA of human alpha-fetoprotein (AFP) under control of the enhancer/promoter of the human beta-actin gene. Among the 4 mouse lines where the transgene were stable transmitted to the progeny, 3 produced human AFP. The expression was not developmental stage-specific nor tissue-specific as predicted from the properties of enhancer/promoter. The serum human AFP levels of adult mice were 30-600-fold higher than those of mouse AFP. These mice could be useful for the studies of possible biological functions of AFP during development as well as in malignancies.

Actins↗