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T Mukai

Publications and source records attributed to T Mukai.

At least 19 recordsLinked to original sources
PubMed1992

Lectin-like activity of Lactobacillus acidophilus strain JCM 1026.

The lectin-like activity of the Lactobacillus acidophilus strain JCM 1026 was studied by hemagglutination and hemagglutination-inhibition assays. L. acidophilus strain JCM 1026 was found to hemagglutinate human and animal erythrocytes. Neuraminidase-treatment of human-type O erythrocytes enhanced the activity. Treatment of the bacterial cells with proteinase K reduced hemagglutinating activity significantly. Although several mono- and disaccharides did not inhibit hemagglutination, several different glycoproteins did. These data indicate that a proteinaceous lectin-like component(s) recognizing carbohydrate-containing molecules is located on the cell surface of L. acidophilus.

Animals↗
PubMed1992

New approach for detection of amplification in cancer DNA using restriction landmark genomic scanning.

We developed a new approach for detecting the gene amplification of cancer DNAs with restriction landmark genomic scanning (RLGS). In cancer research, much effort has been made to find the amplified loci of cancer DNAs, because many lines of evidence indicate association between oncogene amplification and carcinogenesis. Conventionally, such gene amplification has been detected by using Southern hybridization with DNA probes. However, only the information of one locus can be obtained by one hybridization procedure, and analysis of many loci throughout the genome is too laborious and time consuming, even if only several candidate genes are investigated. On the other hand, the "in-gel renaturation method" was reported as another alternative for detection of amplified regions. However, even though this method is much improved, it is difficult to detect less than 7-fold amplification, which is often higher than the amplification of many cancer cases. To overcome these limitations and, in addition, to locate the amplified DNA two dimensionally, we applied RLGS for analysis of DNA amplification in cancer tissues, such as breast cancer (infiltrative tubuloadenocarcinoma), neuroblastoma, meningioma (endotheliomatous meningioma), and thyroid cancer (papillary adenocarcinoma). In some cases of breast cancer, several amplified spots located on the same amplicon were detected. In thyroid cancer, in which no amplification has yet been reported, low-grade amplification was also detected. In this report, we demonstrated that RLGS allows us to screen 2000-3000 restriction landmarks distributed on the genome simultaneously, and even low-grade amplification could be detected effectively. Thus, RLGS has proven to be a very useful method in detecting DNA amplification.

Breast Neoplasms↗
PubMed1992

Endonuclease analyses of DNA of human herpesvirus-6 isolated from blood before and after bone marrow transplantation.

Three strains of human herpesvirus-6 (HHV-6) were isolated from peripheral blood mononuclear cells of a leukemic child with the antibody of HHV-6 before and after bone marrow transplantation (BMT); two strains were obtained before BMT and one after BMT. The DNA extracted from the three isolates was analyzed by six different restriction endonucleases. The cleavage profiles of two strains obtained before BMT were different, but the third strain isolated after BMT was identical with one of the two, which suggest reactivation of HHV-6 from the recipient's own body after BMT and possible mutation or super-infection of the virus in an immunocompromised patient.

Bone Marrow Transplantation↗
PubMed1992

A two-stage operation successfully performed for giant leiomyosarcoma of the esophagus with hepatic metastasis.

Leiomyosarcoma of the esophagus is a rare neoplasm, with only 95 cases having been reported in the literature. Dysphagia is the most commonly noted symptom, however, because of its location in the submucosal layer, the tumor has usually grown to a considerable size by the time this presents. We report herein a case of a 39-year-old man who had no symptoms other than a 7 month history of a cough. After several investigations, the patient underwent resection of the thoracic and abdominal esophagus with lower lobectomy of the right lung through a right and left thoracotomy. The tumor measured 18 x 15 x 8 cm in length and weighed 1,500 g, being the biggest such tumor ever reported. Forty days after the first operation, an extended right hepatic lobectomy of the liver was performed for hepatic metastasis. He was discharged from the hospital 20 days after the second operation and is now doing well. The clinical features and surgical treatment of leiomyosarcoma of the esophagus are discussed herein.

Adult↗
PubMed1992

A new method for constructing NotI linking and boundary libraries using a restriction trapper.

We have developed a novel method for constructing NotI linking and boundary libraries using a modified "solid-supported ligation primer" (restriction trapper). The restriction trapper could be used to purify the DNA fragments with a specific restriction enzyme cutting site(s) at their ends. The method uses a ligation and recutting reaction with double-stranded DNA ends of a hairpin-shaped oligolinker which is connected covalently to the surface of the latex beads. Selectivity is based on the specificity of the restriction enzyme for its recognition site, resulting in efficient purification. We applied this technique to the construction of high-quality NotI linking and NotI boundary libraries, which contain almost all the NotI sites of the genome and, in addition, are free of illegitimately ligated clones.

Base Sequence↗
PubMed1992

cDNA cloning and expression of rat tissue factor pathway inhibitor (TFPI).

Tissue factor pathway inhibitor (TFPI) is a factor Xa-dependent inhibitor for the factor VIIa-tissue factor complex. We isolated cDNA for rat TFPI by screening a lambda gt10 rat liver cDNA library. We determined the 1,228 bp nucleotide sequence, comprising a 88 bp 5' non-coding region, a 906 bp open reading frame, and a 234 bp 3' non-coding region, which encodes a protein of 302 amino acid residues. On Northern blot analysis of rat TFPI mRNA, rat TFPI mRNA was detected as two forms with different molecular sizes, 4.0 and 1.4 kb, which were expressed abundantly in heart, lung, kidney, and aortic endothelial cells. The homology of the amino acid sequence of rat TFPI with those of human and rabbit TFPI was found to be 60.7 and 57.4%, respectively. The lengths of the three tandem Kunitz-type inhibitor domains were strictly conserved not only among TFPI from the three species, but also among other proteins containing Kunitz-type inhibitor domains. The homology of the Kunitz-type domains in TFPI among the three species was 57, 86, and 69% in the 1st, 2nd, and 3rd domains, respectively. There was no significant difference in hydropathy profiles of TFPI from man, rabbit, and rat.

Amino Acid Sequence↗
PubMed1992

Interferon and natural killer cell activity in patients with exanthem subitum.

Early immune response was studied by assessing interferon (IFN) and natural killer cell activity in 13 patients with exanthem subitum associated with human herpesvirus 6 infection during the acute and convalescent phases. Only IFN-alpha showed a significant increase in the plasma of patients during the acute febrile phase compared with the convalescent period. The inhibitory effect of IFN-alpha and IFN-beta on human herpesvirus 6 replication was demonstrated in vitro with cord blood mononuclear cells. Natural killer cell activity was also significantly augmented in the acute phase, especially in the exanthem period, rather than in the convalescent phase (P less than 0.01). These results suggest that the enhanced IFN-alpha response and natural killer cell activity in the acute early phase of the disease may play pivotal roles in the recovery from exanthem subitum.

Cytotoxicity, Immunologic↗
PubMed1992

Experimental infection of cynomolgus and African green monkeys with human herpesvirus 6.

Cynomolgus and African green monkeys were inoculated with human herpesvirus 6 (HHV-6). An antibody response was first observed 10 days and 5 days after inoculation of cynomolgus monkeys and African green monkeys, respectively, and was detectable for the duration of the experiment (33 days). HHV-6 DNA was first detected by the polymerase chain reaction in mononuclear cells of one cynomolgus monkey and one African green monkey 10 days after virus inoculation, and in a total of three of four cynomolgus monkeys (75%) and four of five African green monkeys (80%) later after inoculation. Furthermore, HHV-6 DNA was detected in the lymph nodes and spleen of monkeys killed 33 days after virus inoculation. A rash was observed on the trunk of one African green monkey 13 days after virus inoculation, otherwise the infection was asymptomatic. When mononuclear cells from both groups of monkeys were cultured in medium containing concanavalin A and interleukin 2, and infected with HHV-6 in vitro, virus replication was observed. The data suggest that HHV-6 infects these species of monkey and that this system could be useful as an animal model of HHV-6 infection.

Animals↗
PubMed1992

Human herpesvirus 6 (HHV-6) infection in the central nervous system.

Human herpesvirus 6 (HHV 6) was isolated from patients with exanthema subitum (ES) with a high frequency, and it is now believed that this virus causes ES as a primary infection in childhood. HHV 6 infection is highly prevalent in early childhood and this virus may infect infants through the saliva mainly from mother to child. HHV 6 has a tropism to CD4+ cells and destroys cells in vitro. Although children recover from ES without any sequelae, neurological symptoms associated with exanthema subitum are often observed, and we could detect HHV 6 in the cerebrospinal fluid of ES patients. This result suggests that HHV 6 may invade the central nervous system and cause neurological symptoms.

Antibodies, Viral↗
PubMed1992

A single MEF-2 site is a major positive regulatory element required for transcription of the muscle-specific subunit of the human phosphoglycerate mutase gene in skeletal and cardiac muscle cells.

In order to analyze the transcriptional regulation of the muscle-specific subunit of the human phosphoglycerate mutase (PGAM-M) gene, chimeric genes composed of the upstream region of the PGAM-M gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were constructed and transfected into C2C12 skeletal myocytes, primary cultured cardiac muscle cells, and C3H10T1/2 fibroblasts. The expression of chimeric reporter genes was restricted in skeletal and cardiac muscle cells. In C2C12 myotubes and primary cultured cardiac muscle cells, the segment between nucleotides -165 and +41 relative to the transcription initiation site was sufficient to confer maximal CAT activity. This region contains two E boxes and one MEF-2 motif. Deletion and substitution mutation analysis showed that a single MEF-2 motif but not the E boxes had a substantial effect on skeletal and cardiac muscle-specific enhancer activity and that the cardiac muscle-specific negative regulatory region was located between nucleotides -505 and -165. When the PGAM-M gene constructs were cotransfected with MyoD into C3H10T1/2, the profile of CAT activity was similar to that observed in C2C12 myotubes. Gel mobility shift analysis revealed that when the nuclear extracts from skeletal and cardiac muscle cells were used, the PGAM-M MEF-2 site generated the specific band that was inhibited by unlabeled PGAM-M MEF-2 and muscle creatine kinase MEF-2 oligomers but not by a mutant PGAM-M MEF-2 oligomer. These observations define the PGAM-M enhancer as the only cardiac- and skeletal-muscle-specific enhancer characterized thus far that is mainly activated through MEF-2.

Animals↗
PubMed1992

Preparation of 5-alkyl-3-carboxymethylrhodanines and their aldose reductase inhibitory activity.

5-Alkyl-3-carboxymethylrhodanines (2) were prepared from 5-alkylmethylidene-3-carboxymethylrhodanines (1). The exo double bond of 1 was successfully reduced with NaBH4. The 1,4-addition reaction path was confirmed on the basis of proton nuclear magnetic resonance spectrum of the product (4b) obtained from the reduction of 3 using NaBD4. Optical resolution of the tert-butyl compound (2i) was achieved upon epimerization-crystallization method using L-3-amino-epsilon-caprolactam. The alkyl compounds (2) and the optical active compounds ((+)-2i, (-)-2i) were evaluated for aldose reductase inhibitory potency.

Aldehyde Reductase↗
PubMed1992

Histamine-induced depolarization and the cyclic AMP--protein kinase A system in isolated guinea pig adipocytes.

The relationship between histamine (Hi)-induced depolarization and the cyclic AMP system in adipocytes was studied in guinea pigs, which seem to be more sensitive than rats to Hi. Hi caused a dose-dependent depolarization in guinea pig mesenterial and epididymal adipocytes with EC50 values of 1.69 x 10(-7) M and 1.19 x 10(-7) M, respectively. Guinea pig adipocytes were 280-750 times more sensitive than rat adipocytes to Hi. Isoproterenol, forskolin and 3-isobutyl-1-methylxanthine (IBMX) also caused a depolarization, and the slopes of the concentration response lines for these drugs were almost the same as that for Hi. Furthermore, pretreatment with these drugs resulted in a potentiation of Hi-induced depolarization at lower concentrations which are not effective when each drug is used alone. In addition, Hi-induced depolarization was inhibited by pretreatment with prostaglandin E1 (PGE1) and insulin dose-dependently. The content of cyclic AMP in adipocytes was increased by Hi (10(-7) M) in association with a decrease in membrane potential. KT5720, a protein kinase A inhibitor, which provides no significant effect even at a concentration of 10(-6) M, showed an antagonistic effect on Hi-induced depolarization.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Spontaneous mutations affecting glycerol-3-phosphate dehydrogenase enzyme activity in Drosophila melanogaster.

Significant genetic variance in glycerol-3-phosphate dehydrogenase (GPDH) activity was observed between chromosome lines of Drosophila melanogaster that had each accumulated spontaneous mutations for approximately 300 generations. No restriction map variation was found in a 26-kb region surrounding the entire Gpdh gene. The restriction analysis used is capable of detecting insertions/deletions larger than 0.05 kb. The survey would also detect chromosomal recombinations that include the entire Gpdh coding region. Therefore, if the spontaneous mutations that affected the enzyme activity are located inside the Gpdh gene region, then they are base pair substitutions or structural changes that are smaller than the limit in resolution described above.

Alcohol Dehydrogenase↗
PubMed1992

Variance component analysis of bristle characters in local populations of Drosophila melanogaster.

The genetic variabilities of sternopleural and abdominal bristle numbers existing in local natural populations were assessed. Using second chromosome lines of Drosophila melanogaster extracted from three natural populations in Japan (the Ishigakijima, Ogasawara and Aomori populations), experiments were conducted to estimate the components of genetic variances, additive and dominance variances. The following results were obtained: For both sternopleural and abdominal bristle numbers, the additive genetic variances (sigma 2A) were much larger than the dominance variances (sigma 2D) especially in the southern populations. For example, in the Ishigakijima population, for females sternopleural bristle numbers of the inversion-free chromosome group, the additive and dominance variances were estimated to be 1.255 +/- 0.2034 and 0.0552 +/- 0.0180, respectively. The magnitudes of the estimates of additive genetic variances were nearly equal from north to south. By comparing the additive genetic variances of the inversion-free chromosome group with those of the In(2L)t-carrying chromosome group, it was inferred that sufficient number of generations to achieve the equilibrium state has not passed since the introduction of a single or a small number of the In(2L)t-carrying chromosomes to the Ishigakijima population.

Animals↗
PubMed1992

Diagnosis of asphyxia on the sudden infant death--prone sleeping position and vomit aspiration.

An inevitable conclusion of studies in the Netherlands, Great Britain, the United States and Japan is that sudden infant death syndrome (SIDS) is intimately linked to the prone sleeping position of infants. But this cause of death cannot be explained by the conventional view of SIDS. Although asphyxia would be the most plausible explanation, the cause of death in the majority of SIDS-related deaths in Japan are ruled as SIDS, primarily because administrative autopsies in this country are delayed and the diagnosis is most often made from an external examination only. This lack of autopsy reports also hampers research in this area. Moreover, even where autopsies have been conducted, because of the lack of clear criteria for diagnosis, inconsistent rulings are rendered depending on the judgment of the presiding pathologist. Given these considerations, we undertook to examine the diagnostic criteria for death by asphyxiation among infants sleeping in the prone position, and the problems associated with such a diagnosis.

Asphyxia↗
PubMed1992

Transformation of large granular lymphocytic leukemia during the course of a reactivated human herpesvirus-6 infection.

A patient with CD3+ large granular lymphocytic (LGL) leukemia developed transformation (TF). The phenotype of the leukemic cells was CD3+, CD4+ and CD8-. The leukemic cell count increased rapidly; the cells became large and the nuclear outline, which had been reniform, became lobulated. Anti-HTLV-1 and anti-HIV antibodies were negative in the serum of the patient and no HTLV-1 specific sequences were detected in the cDNA of the leukemic cells by polymerase chain reaction (PCR). Comparison of the karyotype abnormality of the leukemic cells before and after TF revealed an abnormality of the 21 trisomy in 90% of mitotic cells of the patient. Analysis of the cell cycle revealed that 13.7% of the leukemic cells were in DNA synthesis phase which was not previously found. The titer of anti-human herpesvirus-6 (HHV-6) immunoglobulin G which had been high at chronic phase (1:1640 compared to normal titer of less than 1:160), became 1:20,000 at TF. The titer of anti-HHV-6 immunoglobulin M also increased from less than 1:4 at the chronic phase to 1:120 at TF (normal value less than 1:4). A HHV-6-specific DNA sequence was detected by PCR in the peripheral mononuclear cells collected at TF but not at the chronic phase. These data suggests that TF occurs not only in CD3-negative but also in CD3-positive LGL leukemia. HHV-6 reactivation is therefore a possible cause in immunocompromised hosts whose general conditions are deteriorated.

Aged↗
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↗