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T Mukai

Publications and source records attributed to T Mukai.

At least 235 records · Page 13Linked to original sources
PubMed1991

Analysis of upstream regulatory regions required for the activities of two promoters of the rat aldolase A gene.

Rat aldolase A gene has 2 promoters with different tissue specificities (M- and AH promoters). The M promoter is active only in adult skeletal muscle and induced during myogenesis, whereas the AH promoter is active ubiquitously in many tissues, including various cancer cells. Regulatory sequences for these promoters were investigated through assays for transient expression after introduction into myogenic and nonmyogenic cells. When M promoter-CAT fusion genes were transfected into primary cultures of chicken myoblasts, expression of CAT activity was drastically induced during myotube formation. The region comprising 202 to 85 base pairs (bp) upstream from the transcription initiation site was found to be necessary for the induction and an enhancer activity whose region includes the AT-rich recognition sequence (MEF-2 binding site). On the other hand, 2 upstream regions were found to be responsible for AH promoter activity expressed in HepG2 cells. The distal region (-280 to -260) of the promoter includes the AP1 binding sequence, whereas the proximal region (-207 to -180) contains a novel inverted repeat consisting of 22 bp but does not contain known promoter and enhancer sequences.

Animals↗
PubMed1991

A genomic scanning method for higher organisms using restriction sites as landmarks.

We have developed a powerful genomic scanning method, termed "restriction landmark genomic scanning," that is useful for analysis of the genomic DNA of higher organisms using restriction sites as landmarks. Genomic DNA is radioactively labeled at cleavage sites specific for a rare cleaving restriction enzyme and then size-fractionated in one dimension. The fractionated DNA is further digested with another more frequently occurring enzyme and separated in the second dimension. This procedure gives a two-dimensional pattern with thousands of scattered spots corresponding to sites for the first enzyme, indicating that the genome of mammals can be scanned at approximately 1-megabase intervals. The position and intensity of a spot reflect its locus and the copy number of the corresponding restriction site, respectively, based on the nature of the end-labeling system. Therefore, this method is widely applicable to genome mapping or detection of alterations in a genome.

Animals↗
PubMed1991

An additional promoter functions in the human aldolase A gene, but not in rat.

The aldolase A gene was isolated from a human DNA library, mapped and sequenced. This gene comprises 12 exons and spans 6.5 kb. From the genomic DNA sequence and from the previous sequence analysis of the cDNA, it was revealed that the first exon L1 and the second exon encode the 5' non-coding sequence of mRNA L1, while the third and forth exons (corresponding to exons M and L2) encode different mRNA, mRNA M and L2, respectively; the following eight exons (exons 5-12) are shared commonly by all the mRNA species. These results indicate that the mRNA species are generated from a single aldolase A gene from one of exons L1, M or L2, in addition to exons 5-12, and also that the usage of a leader exon is similar but clearly distinct from that of rat aldolase A gene which we analyzed [Joh, K., Arai, Y., Mukai, T. & Hori, K. (1986) J. Mol. Biol. 190, 401-410]. By comparing the promoter regions in the human and rat aldolase A genes, we found similar sequences in the rat genome corresponding to those of the human L1, M and L2 promoter. We could not, however, detect any transcripts starting from sequences corresponding to the human L1 promoter in the rat genome, although the products corresponding to human M and L2 were detected. Thus, we conclude that the L1 promoter was either acquired by the human genome or deleted from the rat genome after human and rat diverged during evolution.

Amino Acid Sequence↗
PubMed1991

The structure of the brain-specific rat aldolase C gene and its regional expression.

The rat aldolase C gene was isolated from a rat genomic DNA library. This gene comprises 9 exons and spans 3590 base pairs. A single copy of the gene occurs per haploid rat genome. The initiation of transcription occurs at two different sites. The cellular localization of aldolase C mRNA was determined in the central nervous system along with aldolase A mRNA by in situ hybridization. The result indicates the predominant expression of this gene in Purkinje cells of the cerebellar cortex, where aldolase A mRNA was rather repressed.

Amino Acid Sequence↗
PubMed1991

Some taxonomical characteristics of encapsulated Lactobacillus sp. KPB-167B isolated from kefir grains and characterization of its extracellular polysaccharide.

A capsular polysaccharide-producing strain KPB-167B isolated from kefir grains was identified as a homofermentative Lactobacillus. The carbohydrate fermentation pattern and DNA base composition of the strain were different from those of other capsular Lactobacillus species previously isolated from kefir grains. The polysaccharide produced by Lactobacillus sp. KPB-167B was found similar to kefiran by 13C-NMR and methylation analysis. Lactobacillus sp. KPB-167B could grow and produce capsular polysaccharide in MRSL medium with better yield than L. kefiranofaciens, which suggested that it is suitable for kefiran production.

Animals↗
PubMed1991

A method for detecting effect of beneficial mutations in natural populations of Drosophila melanogaster.

An experimental method is proposed for detecting the effects of positive natural selection on DNA polymorphisms. Since beneficial mutations are expected to increase in frequency faster than neutral mutations, variants which have reached high frequencies in a relatively short period could be linked to some beneficial mutation. D. melanogaster has a cosmopolitan polymorphic inversion -In(2L)t- whose age in some local populations has been estimated. Setting the age of In(2L)t as the upper limit for the age of variants, we searched for variants whose frequencies were possibly influenced by positive natural selection. We detected a single candidate whose frequency and distribution met the requirements imposed by our method.

Alleles↗
PubMed1991

The genetic structure of natural populations of Drosophila melanogaster. XXIV. Effects of hybrid dysgenesis on the components of genetic variance of variability.

Eight hundred second chromosomes were extracted from the Ishigakijima population, one of the southernmost populations of Drosophila melanogaster in Japan. Half of them were extracted in Native cytoplasm (P-type), and half in Foreign cytoplasm (M-type). Various population-genetic parameters, including the frequency of lethal-carrying second chromosomes (Q = 0.235 for the Native; 0.218 for the Foreign), the allelism rate of lethal second chromosome (Ic = 0.0217 for the Native; 0.0134 for the Foreign), the homozygous detrimental and lethal loads (D = 0.179 for the Native; 0.270 for the Foreign; L = 0.262 for the Native; 0.240 for the Foreign), the average degree of dominance of mildly deleterious mutations (ĥE = 0.244 for the Native; 0.208 for the Foreign), and the components of genetic variance for viability [additive (sigma A2) and dominance (sigma D2)](ŝigma A2 = 0.0187 for the Native; 0.0172 for the Foreign; ŝigma D2 = 0.0005 for the Native; 0.0009 for the Foreign) were estimated. The data indicate that D was significantly larger and hE was significantly smaller in the Foreign cytoplasm. However, the estimates of additive and dominance variances were not significantly different between the two cytoplasms. The additive genetic variance for viability in the Ishigakijima population was greater than expected on the basis of mutation-selection balance confirming previous studies on papers of D. melanogaster in warm climates.

Animals↗
PubMed1991

The genetic structure of natural populations of Drosophila melanogaster. XXII. Comparative study of DNA polymorphisms in northern and southern natural populations.

Restriction map variation in four gene regions (Adh, Amy, Pu and Gpdh) was surveyed for 86 second chromosomes from northern (Aomori) and southern (Ogasawara) Japanese populations of Drosophila melanogaster (43 chromosomes from each population). The regions examined cover a total of 62 kilobases. Estimates of nucleotide diversity (pi) were approximately constant across the gene regions and populations examined. The distribution of restriction site polymorphisms was compatible with the expectation from the neutral mutation-random genetic drift hypothesis, but insertion/deletion polymorphisms were not consistent with it. While the two populations shared a majority of restriction site polymorphisms, frequencies of individual restriction site variants were significantly different between the two populations at 7 out of 35 segregating sites. In addition, an insertion in the Amy region was found in 15 chromosomes from the Ogasawara sample but absent in the Aomori sample. A considerable difference was observed in the number of rare insertions and deletions between the two populations. The numbers of aberrations uniquely represented were 16 in the Ogasawara sample and only 3 in the Aomori sample. These findings suggest that the two populations were differentiated from each other to some degree by means of random genetic drift and/or other factors.

Alcohol Dehydrogenase↗
PubMed1991

Physicochemical characterization of human herpesvirus 6 infectivity.

Infectivity of human herpesvirus 6 (HHV-6) was physicochemically characterized. Virus particles were excreted from infected cord blood mononuclear cells into the culture supernatant at a concentration of 10(8) to 10(9) virus particles/ml. The virus particle/infectivity ratio of HHV-6 in the culture supernatant was approximately 10(3):1 and that in the sonicated infected cells was 10(4):1. Infectivity was stable below 37 degrees C and at neutral pH (7.0 to 8.5). These fundamental data may be useful for serological and biological research on HHV-6.

Cells, Cultured↗
PubMed1991

Distribution and immunochemical specificities of fimbriae of Porphyromonas gingivalis and related bacterial species.

Rabbit polyclonal antibody (Poly-1) and mouse monoclonal antibodies (mAbs) TO-11, TO-14 and TO-M1 specific for Porphyromonas gingivalis 381 fimbriae were prepared. Poly-1 and the 3 mAbs were screened for their reactivity with whole cells oral and nonoral black-pigmented bacterial species by enzyme-linked immunosorbent assay (ELISA) and the binding experiment using [125I]Poly-1 and [125I]mAbs. ELISA revealed that Poly-1 definitely reacted with whole cells of all the 11 strains of P. gingivalis tested. However, 8 of 11 P. gingivalis strains reacted with mAbs TO-11, TO-14 and TO-M1. These results were confirmed by the specific binding of radiolabelled Poly-1 and mAb TO-11 to the 8 strains. The M(r) of the fimbrial subunit protein (fimbrilin) isolated and purified from P. gingivalis strains 381, BH18/10, HW24D-1, 6/26 and OMZ 314 was 41 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis. It was found by immunoblotting that mAbs TO-11 and TO-14/TO-M1 recognized different epitopes of fimbrial protein from P. gingivalis strains. Immunoelectron micrographs of whole cells and the purified fimbriae of P. gingivalis strains visualized similar serotype-specific antibody bindings to the fimbriae. These results indicate that 11 strains of P. gingivalis could be divided into at least 2 separate groups based on the immunochemical specificities of the fimbriae.

Animals↗
PubMed1991

Experimental studies on coronary laser angioplasty.

To establish the method of coronary laser angioplasty using the argon laser, we investigated the optimal condition of laser ablation and the relationship between the size of laser probe and the diameter of the vessel. First, the relationship between laser energy and tissue reaction to the laser was examined using human cadaveric arteries. Subsequently, we recognized that repeated laser ablation is the optimal method with each shot being limited to 5 10 watts (W) in output and 2 seconds of ablation time when using a metal tip probe (MTP) of 1.5 mm in diameter. According to the experimental condition described above, we examined the response of normal coronary arteries to the laser in vivo. If the size of MTP was not suitable for the diameter of the vessel, thermal constriction of the coronary artery was observed; MTP/vessel diameter ratio should be 0.7 or less to avoid vessel constriction by thermal damage from the laser. Neither perforation nor spasm of the coronary artery was found in this experiment. In addition, the ablated area on the coronary artery was healed completely without thrombus formation and coronary stenosis, and it was covered with new endothelium 8 weeks after laser thermal ablation.

Angioplasty, Balloon, Coronary↗
PubMed1991

Comparative study of P element activity in two natural populations of Drosophila melanogaster.

Population structure concerning P element activity was investigated in two natural Drosophila populations. These populations are very different as far as in the viability spectrum is concerned. In one population, the Raleigh, United States population, genetic loads related to viability have been kept at a fairly high level. In the other population, the Nagasaki, Japan, population, the genetic loads tend to be stable at very low levels. In the Raleigh population it is estimated that on the average 4 copies of intact P elements that possess transposase activity exist in the genome. On the other hand only 0.7 complete copies are estimated to exist in the genome of the Nagasaki population. Heterogeneity in the P element copy number and significant positive linkage disequilibrium among occupied sites were detected in the Raleigh population. Our results, with some evidences which indicate that high mutation rate was caused by the P element, suggests that the large genetic loads in the Raleigh population are caused by the rapid invasion of P element in this population.

Animals↗
PubMed1991

[A case of a large invasive thymoma successfully treated by using a combination of artery infusion of CDDP and operation].

A 21-year-old male was admitted with SVC syndrome. Chest X-ray film showed an abnormal density on the upper mediastinum, that was recognized thymoma on the needle aspiration specimen. The large tumor, which extensively infiltrated the surrounding tissues (SVC, the right brachiocephalic vein, bilateral lungs and the pericardium) led us to choose preoperative chemotherapy. CDDP (cisdiammin-edichloroplatinum) was infused through the right IMA (internal mammary artery). After obtaining the major response the tumor mass was resected with adjacent structure accompised vessels reconstructions. Histological examination revealed totally necrosed tissue. Three years after initiation of therapy, the patient is doing well. The therapy with CDDP injection into selective IMA for invasive thymoma before operation was considered to be very useful utilized.

Adult↗
PubMed1991

[The effectiveness of CDDP in metastatic adenocarcinoma with unknown origin].

A 28-year-old man with inoperable metastatic adenocarcinoma in the retroperitoneum was referred to our hospital for a further evaluation for its origin. The tumor was measured 80 x 107 mm by abd. U.S. and showed papillary adenocarcinoma, histologically. Chemotherapy with intravenous administration of CDDP at the dose of 80 mg/m2 for 6 times at 2-3 week intervals was started, and CDDP concentration of binding-form and free-form in serum and urine were measured in time course. The tumor has reduced for 29 weeks after the discontinuance of CDDP. Free-CDDP, which was thought to have an anticancerous effect, immediately went up high levels in serum and rapidly excreted to urine, while total-CDDP in serum remained in high concentration for more than 10 weeks. Thus it was suggested that anticancerous effect of CDDP could not be contributed only to free-CDDP and the mechanism of CDDP will be clarified by the elucidation of metabolism of both free and total CDDP, especially in the tumor tissue.

Adenocarcinoma↗
PubMed1990

Gene duplication and concerted evolution of the GPDH locus in natural populations of Drosophila melanogaster.

The sn-glycerol-3-phosphate dehydrogenase (GPDH, EC 1, 1, 1, 8) locus of Drosophila melanogaster is polymorphic with respect to the number of tandemly duplicated genes in natural populations. The duplicated genes were cloned and the nucleotide sequences were determined. The duplication deletes both the first and second exons and has a size of 4500 b.p. The fact that there is no sequence variation at the junction point of the duplicated units among strains suggests a single origin for the duplication event. Comparison of the nucleotide sequences among the duplicates indicates that the frequent transfer of genetic information occurs from one to the other of the duplicates on the same chromosome either by gene conversion or by unequal crossing over. Because the GPDH duplication is partial and therefore a kind of pseudogene, the observed polymorphism of the number of tandemly duplicated GPDH genes appears to have been driven mainly by random genetic drift.

Animals↗
PubMed1990

[Immunohistochemical study of fibronectin and laminin on gastric cancer].

Frozen samples of normal gastric tissue (n = 80), gastric adenocarcinoma (n = 80), lymphnode metastases (n = 17) and liver metastases (n = 2) were investigated immunohistochemically for determination of fibronectin (FN) and laminin (LM). On monoclonal antibody, FN was seen in the gland basement membrane, scattered tissue and the vessel basement membrane in normal gastric tissue. On polyclonal antibody, FN was seen in the gland surface cells, the stomach gland cells and some portions of muscle fiber cells in normal gastric tissue, too. On both monoclonal and polyclonal antibody, LM was seen in the gland basement membrane, the vessel basement membrane, the vessel endothelial cells, and the fibroblast in normal gastric tissue. But on polyclonal antibody, LM staining in gland basement membrane was thicker than monoclonal antibody. These demonstrated that the monoclonal antibody was superior to the polyclonal antibody in specificity. In gastric adenocarcinoma, FN was not seen in the carcinoma gland basement membrane but in the tissue around the carcinoma. These suggested that FN had a share in the malignant transformation and the fibrous tissue formation. LM was seen in the carcinoma gland basement membrane in eighteen of thirty-six well-differentiated adenocarcinomas and two of fourteen moderately-differentiated adenocarcinomas. Well-differentiated adenocarcinoma were divided into two groups; a LM-positive group, and LM-negative group. These two groups were then compared for vein eroding, and lymph-node metastases, and the differences between the two groups found to be slight and not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗