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M Katsuki

Publications and source records attributed to M Katsuki.

At least 127 records · Page 7Linked to original sources
PubMed1992

Analysis of the human tyrosine hydroxylase promoter-chloramphenicol acetyltransferase chimeric gene expression in transgenic mice.

To investigate cis-elements responsible for catecholaminergic (CAnergic) neuron-specific expression of the tyrosine hydroxylase (TH) gene, we produced lines of transgenic mice carrying 5.0-kb, 2.5-kb and 0.2-kb fragments from the 5'-flanking region of the human TH gene fused to a reporter gene, chloramphenicol acetyltransferase (CAT), and designated them as TC 50, TC 25, and TC 02, respectively, and reporter gene expression in transgenic mice was analyzed by CAT assay by immunocytochemistry with anti-CAT antibody. High-level CAT expression was observed in the brain and adrenal gland using the 5.0-kb promoter of the TC 50 mice, but ectopic expression was consistently observed in several somatic tissues, e.g. thymus, colon, and testis. In brain, expression was achieved in CAnergic neurons with the largest construct (5.0 kb), but not with 2.5 kb or 0.2 kb of 5' flanking sequence. However, TC 50 mice also expressed CAT immunoreactivity in non-CAnergic neurons. In the TC 25 line CAT immunoreactivity was detected only in some non-CAnergic neurons. In the TC 02 line no CAT immunoreactivity was detected in any of the tissues examined. These results indicate that the 5.0-kb DNA fragment of the TH gene upstream region contains activity to express CAT in CAnergic neurons and surprisingly, lacks some regulatory elements attenuating ectopic expression, and that the 2.5-kb and 0.2-kb fragment are not sufficient for the proper expression. We discuss the presence of the tissue-specific regulatory elements in the structure portion of the TH gene and/or 3'-flanking region.

Animals↗
PubMed1992

[Evaluation of aerosol therapy of streptomycin for tracheobronchial and pulmonary tuberculosis].

The clinical features of tracheobronchial tuberculosis are distinct from those of pulmonary tuberculosis in some aspects. Streptomycin (SM) is claimed by some investigators that it has a tendency to promote the development of bronchial stenosis due to scarred healing of the involved endobronchial mucosa, and, for that reason, they recommend not to use it in treatment of bronchial tuberculosis. In some patients with pulmonary tuberculosis, who have renal or hearing disturbance, SM avoided. Yet unless SM is used improvement of tuberculosis could be delayed. It is the purpose of the present investigation to point out that aerosol therapy of SM is useful for patients with respiratory tuberculosis. Furthermore, we wish to demonstrate that we can safely treat the patients with respiratory tuberculosis who suffer from renal function or hearing disorder by use of aerosol therapy of SM. Prior to clinical application of the inhalation therapy, we confirmed that the therapy was not harmful. Serum concentration of SM, when inhaled, was measured in 9 volunteers. Before and after administration of SM aerosol, spirograms were examined in 4 volunteers, nevertheless, no special abnormality was recognized. It seemed that serum concentration of SM after the administration was two low to evoke adverse reactions (less than 3.0 gamma). In 6 patients with pulmonary tuberculosis, blood gases were measured and no obvious change was observed. As a result, it was demonstrated that the endobronchial tuberculous lesions improved faster when treated by inhalation of aerosolized SM as compared with the conventional injection therapy, without evoking any apparent adverse reactions. In some of the patients with pulmonary tuberculosis, it seemed that the therapy was useful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Plasma lipoprotein metabolism in transgenic mice overexpressing apolipoprotein E. Accelerated clearance of lipoproteins containing apolipoprotein B.

We have reported that transgenic mice overexpressing rat apo E shows marked reduction of plasma cholesterol and triglyceride levels due to the disappearance of VLDL and LDL. In this study, we investigated the metabolism of plasma lipoproteins in transgenic mice. After intravenous injection, the rates of clearance of 125I-VLDL and 125I-LDL were 3.0- and 2.4-fold greater in transgenic mice than in controls, respectively. Furthermore, clearance of chylomicron remnants estimated by oral retinyl palmitate-loading test was markedly enhanced in transgenic mice. The hepatic expression of LDL receptors by immunoblot analysis was similar in both groups. These data suggest that elimination of lipoproteins containing apo B was due to enhanced clearance of these lipoproteins enriched with apo E through hepatic LDL receptors. When fed a high cholesterol diet, controls showed twofold elevation of plasma cholesterol levels with marked increases in VLDL and LDL cholesterol on gel filtration chromatography. In contrast, cholesterol-fed transgenic mice showed resistance against these increases. High cholesterol feeding decreased the activity of hepatic LDL receptors and had no effect on enhancement of chylomicron remnant clearance in transgenic mice. Thus, overexpression of apo E facilitates metabolism of lipoproteins containing apo B presumably primarily via the LDL receptor pathway and possibly through an interaction with the chylomicron remnant receptor.

Animals↗
PubMed1992

[A case of bronchocentric granulomatosis associated with uveitis].

A 32-year-old female was admitted to our hospital because of abnormal pulmonary shadows and a decrease in visual acuity. Analysis of peripheral blood revealed eosinophilia, and chest roentgenogram demonstrated multiple infiltrates in the right upper lung field. Pathological examination of transbronchial lung biopsy specimens revealed necrotizing granulomatous lesions in the walls of bronchioles, and a definitive diagnosis of bronchocentric granulomatosis was made. The cause of bronchocentric granulomatosis in this patient was suggested to be an allergic reaction to Aspergillus because of positive response to skin test for Aspergillus. Although it is reported that extrapulmonary involvement is rare in bronchocentric granulomatosis, the present case was associated with uveitis, and to our knowledge is the first reported case.

Adult↗
PubMed1991

Enhanced expression of human tyrosine hydroxylase in the lower brainstem of transgenic mice.

We have previously reported the distribution of human tyrosine hydroxylase (TH) transgene expression in dopaminergic neurons (ventral tegmental area and substantia nigra), adrenal gland, and non-catecholaminergic neurons in the forebrain of transgenic (Tg) mice. In this paper, we analysed the transgene expression in catecholaminergic (CAergic) neurons in the lower brainstem of Tg mice, by in situ hybridization and immunocytochemistry at the light and electron microscopic levels. High-level hybridization signals of the human TH mRNA were observed in the locus ceruleus and nucleus tractus solitarii of the Tg brain. Intense TH immunoreactivity was expressed specifically in the Tg brainstem, as was observed in non-Tg mice. These results reveal that the human TH transgene contains the regulatory elements responsible for the expression in three kinds of CAergic (dopaminergic, noradrenergic and adrenergic) neurons of the mouse brain.

Animals↗
PubMed1991

Expression of the human angiotensinogen gene in transgenic mice and transfected cells.

We have generated two lines of transgenic mice with integrated copies of a 14-kilobase pair (kb) human DNA fragment containing the angiotensinogen gene, which includes 1.3 kb of 5'- and 3'-flanking regions. In both transgenic lines, a considerable quantity of the correctly initiated and processed angiotensinogen mRNA was detected in the liver and it was detectable in heart. Unexpectedly, mRNA for the transgene was accumulated in the kidney, where is normally the minor source of angiotensinogen, to levels comparable to that in the liver. In addition, an in vitro transfection analysis suggested that the 1.3-kb 5'-flanking sequences are essential for expression of the angiotensinogen gene in hepatic and renal cells and that neither DNA segment within the 14-kb construct contributes significantly to repression of the gene expression in renal cells.

Angiotensinogen↗
PubMed1991

Human renin in transgenic mouse kidney is localized to juxtaglomerular cells.

To examine whether expression of human renin in the transgenic mouse kidney is regulated in a cell-specific manner, we have characterized monoclonal antibodies against human renin and determined the renin-production site by immunohistochemistry. By using a monoclonal antibody specific for human renin, A6-11-6, we demonstrated that human renin in the transgenic mouse kidney is localized to the juxtaglomerular cells of afferent arterioles.

Animals↗
PubMed1991

Fate of haploid parthenogenetic cells in mouse chimeras during development.

The developmental capability of haploid parthenogenetic cells was investigated by studies on haploid parthenogenetic in equilibrium fertilized mouse chimeras. Two chimeras were born. One female chimera was smaller at birth and grew slower than its littermates. The distribution of haploid-derived cells in the chimeras was analyzed 11 months after their birth. Cells derived from haploid embryos were found only in the brain, eyes, pigment cells in hair follicles, and spleen, in which they constituted 30%, 20%, 10%, and less than 5%, respectively, of the cells. The correlation between the parthenogenetic contribution to the brain and growth retardation is discussed. All of the cells examined in these chimeric organs (brain and eyes) contained a diploid amount of DNA, suggesting that diploidization of the haploid parthenogenetic cells occurred during development. Possibly, the haploid state is not sufficient for cell growth, even in chimeras with fertilized embryos.

Animals↗
PubMed1991

Tissue-specific and high-level expression of the human tyrosine hydroxylase gene in transgenic mice.

Transgenic mice carrying multiple copies of the human tyrosine hydroxylase (TH) gene have been produced. The transgenes were transcribed correctly and expressed specifically in brain and adrenal gland. The level of human TH mRNA in brain was about 50-fold higher than that of endogenous mouse TH mRNA. In situ hybridization demonstrated an enormous region-specific expression of the transgene in substantia nigra and ventral tegmental area. TH immunoreactivity in these regions, though not comparable to the increment of the mRNA, was definitely increased in transgenic mice. This observation was also supported by Western blot analysis and TH activity measurements. However, catecholamine levels in transgenics were not significantly different from those in nontransgenics. These results suggest unknown regulatory mechanisms for human TH gene expression and for the catecholamine levels in transgenic mice.

Adrenal Glands↗
PubMed1991

Localization of the gene encoding myelin basic protein to mouse chromosome 18E3----4 and rat chromosome 1p11----p12.

The location of a gene encoding myelin basic protein in rat (MBP) and mouse (Mbp) was determined by in situ hybridization using the mouse Mbp cDNA labeled with biotin-11-dUTP as a specific probe. The localization of biotin signals in the mouse was found on Chromosome 18E2----3. The result is consistent with the previous report that the Mbp gene is located on the distal half of Chromosome 18. In the rat, the signals localized on chromosome 1p11----p12, suggesting homology between mouse Chromosome 18 and the short arm of rat chromosome 1.

Animals↗
PubMed1991

Chemically induced tumors in transgenic mice carrying prototype human c-Ha-ras genes.

Three independent transgenic mouse lines carrying human prototype c-Ha-ras genes were established. Approximately 50% of the transgenic offspring of these lines developed spontaneous tumors within 18 months. Types of tumors were restricted to angiosarcomas, skin papillomas and lung or Harderian adenocarcinomas. Interestingly, all angiosarcomas (16/16) had point mutations at the 61st codon of the transgenes. Furthermore, they were also very susceptible to the chemical carcinogens, N-methyl-N'-nitrosourea (MNU) and dimethyl-benzanthracene (DMBA). Within 12 weeks after administration of MNU, the transgenic mice developed forestomach papillomas and then carcinomas very frequently, at the rate of almost 100% and almost all of the tumors had point mutations in their transgenes at the 12th codon from GGC (Gly) to GAC (Asp). All the carcinomas of the forestomach, lung and spleen induced by DMBA had point mutations at the 61st codon from CAG (Gln) to CTG (Leu). Because no somatic point mutations in the transgenes have ever been detected in normal tissues of the affected mice, these mutations seemingly activated the human prototype c-Ha-ras transgene. From these results, it is suggested that the somatic mutation of the human c-Ha-ras transgene plays a causative role in the occurrence of natural tumors and those induced by MNU or DMBA administration in transgenic mice. This transgenic mouse provides a unique screening system for chemicals that induce or suppress the tumorigenesis.

Animals↗
PubMed1991

Microtia as an autosomal dominant mutation in a transgenic mouse line: a possible animal model of branchial arch anomalies.

Microtia was found in a transgenic mouse 643 and all offspring with microtia had the transgene. No anomalies, other than occasional low set ear and abnormal biting, were identified in other tissues and organs. In the developmental analysis, on the 9th and 10th days of gestation, hypoplasia of the second branchial arch was observed, while various kinds of malformed hillocks were noted on the 12th day. All of these anomalous embryos were transgenic. Histologically, hemorrhage and subsequent phagocytosis were noted at the second branchial arch. Left sided anomalies were predominant and in bilaterally defective ones asymmetry existed. These findings closely resembled to those in experimental animals with a phenocopy of the first and second branchial arch syndrome in humans. Since all other transgenic mouse lines with the same transgene as 643 appeared normal, this dysmorphic phenotype may be caused by an insertional mutation of a host gene, although inappropriate expression of the transgene should be examined further as a possible cause. These results suggest that this transgenic mouse line 643 may be useful as an animal model of branchial arch anomalies in humans.

Animals↗
PubMed1990

Transgenic mice demonstrate that epithelial homing of gamma/delta T cells is determined by cell lineages independent of T cell receptor specificity.

gamma/delta T cells with different TCR repertoires are compartmentalized in different epithelia. This raises the possibility that the TCR-gamma/delta directs homing of T cells to these epithelia. Alternatively, the signals that induce TCR-gamma/delta expression in developing T cells may also induce homing properties in such cells, presumably in the form of cell surface receptors. We have examined this issue by studying the homing of gamma/delta T cells in transgenic mice constructed with specific pairs of rearranged gamma and delta genes. In such mice, most gamma/delta T cells express the transgene-encoded TCR. We find that homing to both skin and gut epithelia is a property of T cells and is not determined by the type of gamma and delta genes used to encode their TCR. We also studied the effect of TCR replacement on the expression of Thy-1 and CD8 proteins on the gamma/delta T cells associated with gut epithelia. Our results show that the expression of the appropriate type of TCR-gamma/delta is not required for the Thy-1 expression by these T cells, suggesting that Thy-1 is not an activation marker. In contrast, CD8 expression by gut gamma/delta T cells seems to depend on the expression of the appropriate type of TCR.

Animals↗
PubMed1990

The human renin gene in transgenic mice.

We have obtained three transgenic mouse lines carrying the human renin gene. All three lines have been shown to transmit the introduced human gene to progeny. In the present study, we have demonstrated that the human renin gene was expressed and correctly spliced in the kidneys of both transgenic parents and progeny.

Animals↗
PubMed1990

[Production of normal young following transfer of mouse embryos obtained by in vitro fertilization using cryopreserved spermatozoa].

Spermatozoa from cauda epididymis of mature mice were suspended in preservation solution (Dulbecco's PBS containing raffinose in combination with glycerol, DMSO or skim milk as freezing protective agents). The suspension was frozen by the dry ice-alcohol method and preserved for 1-120 days in liquid nitrogen (-196 degrees C). Highest sperm viability after thawing was obtained with a combination of 10% raffinose and 5% glycerol or with a combination of 10% raffinose and 10% DMSO. These frozen thawed sperm were found to have fertilizing capacity when used for in vitro fertilization. The 2-cell embryos obtained through the above procedures developed into normal pups at a high rate when transferred into the oviducts of pseudopregnant female mice.

Animals↗