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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 415 records · Page 23Linked to original sources
PubMed1984

Influence of ascending noradrenergic fibers on the neurotensin-like immunoreactive perikarya and evidence of direct projection of ascending neurotensin-like immunoreactive fibers in the rat central nucleus of the amygdala.

The influence of ascending noradrenergic neuronal input on the neurotensin (NT)-like immunoreactive neuronal perikarya located in the dorsal part of the central nucleus of the amygdala (CNA) was examined using fluorescence histochemistry and peroxidase-antiperoxidase (PAP) immunocytochemistry. Unilateral hemitransection of the ascending noradrenergic pathway by injection of 6-hydroxydopamine into the caudal mesencephalon just rostral to the locus coeruleus caused a marked depletion of immunoreactivity in NT-like immunoreactive neuronal perikarya in the CNA. Ascending noradrenergic neuronal input, therefore, is considered to facilitate production of NT-like immunoreactive substances in neuronal perikarya and to influence on the functional role of the amygdaloid complex. In addition, we obtained evidence of unilateral direct ascending projections of NT-like immunoreactive neurons into the CNA since the disappearance of NT-like immunoreactive processes occurred mainly in the ventral part of the CNA after surgical hemitransection of the ascending neuronal pathway that interrupts the ascending NT-like immunoreactive pathway arising from the neurons in the brain stem.

Amygdala↗
PubMed1984

Light and electron microscopic immunocytochemistry of neurotensin-like immunoreactive neurons in the rat hypothalamus.

Neurotensin-like immunoreactive neuronal perikarya, fibers and terminals in the rat hypothalamus, particularly in the arcuate nucleus, the paraventricular nucleus and the median eminence, were investigated by light and electron microscopic immunocytochemistry. The main distributional areas of immunoreactive neuronal perikarya were found to be the arcuate nucleus, the periventricular nucleus and the paraventricular nucleus by light microscopic immunocytochemistry. Immunoreactive neuronal perikarya showed a characteristic distributional pattern in the arcuate nucleus. In the paraventricular nucleus they were distributed in both the magnocellular and parvocellular portions. A large number of immunoreactive terminals were observed throughout the external layer of the median eminence, particularly its lateral portion. A moderate number of immunoreactive terminals were also observed in the internal layer of the median eminence. By electron microscopic immunocytochemistry immunoreactive neuronal perikarya both in the arcuate and paraventricular nuclei showed generally well-developed cell organelles such as mitochondria, r-ER, and Golgi complex. In addition, immunoreactive dense granules were dispersed throughout the perikarya. A large number of immunoreactive terminals containing immunoreactive dense granules, clear vesicles and mitochondria were observed in the vicinity of pericapillary spaces of the external layer of the median eminence. This observation strongly suggests that neurotensin-like immunoreactive substance is released into the portal capillaries.

Animals↗
PubMed1984

Influence of ascending noradrenergic fibers on the neurotensin-like immunoreactive neurons in the rat paraventricular nucleus.

Regulation of the neurotensin (NT)-producing neurons by ascending catecholamine fibers in the paraventricular nucleus of the rat hypothalamus was examined using fluorescence histochemistry and immunohistochemistry after the destruction of the ascending catecholamine pathway by 6-hydroxydopamine. On the ipsilaterally operated side, the fluorescence of the catecholamine terminals decreased remarkably in the paraventricular nucleus whereas an accumulation of catecholamine fluorescence was observed in the caudal mesencephalon rostral to the locus coeruleus. In addition, the number of neural perikarya with NT-like immunoreactivity was greatly decreased in the paraventricular nucleus on the operated side compared with the intact side as determined by peroxidase-antiperoxidase immunohistochemistry. This decrease in the NT-like immunoreactive neural perikarya may be due to the disappearance of noradrenergic input to the NT-like immunoreactive neurons through axo-somatic or axo-dendritic synapses.

Adrenergic Fibers↗
PubMed1984

Nucleus ambiguus motoneurons innervating the canine intrinsic laryngeal muscles by the fluorescent labeling technique.

The localization of motoneurons innervating the canine intrinsic laryngeal muscles was investigated by the fluorescent labeling technique. Labeled cells were found in the ipsilateral nucleus ambiguus. The most rostral labeled neurons for the cricothyroid muscle, the posterior cricoarytenoid muscle, the thyroarytenoid muscle, and the lateral cricoarytenoid muscle were found at progressively more caudal levels, respectively, within the nucleus ambiguus. The rostral tip of the arytenoid muscle cell column was at the same level as the lateral cricoarytenoid muscle cell column. The cells labeled from the cricothyroid muscle occupied the ventral part of the nucleus at the rostral level of the nucleus. At the middle level of the nucleus, the cells from the posterior cricoarytenoid muscle occupied the ventral part of the nucleus and the cells from the thyroarytenoid muscle, the lateral cricoarytenoid muscle and the arytenoid muscle occupied the dorsal part of the nucleus. The existence of double-labeled cells which innervated both thyroarytenoid muscle and lateral cricoarytenoid muscle was detected.

Animals↗
PubMed1984

Morphological survey of neurotensin-like immunoreactive neurons in the hypothalamus.

Neurotensin-like immunoreactive neuronal perikarya, fibers and terminals in in the rat hypothalamus were investigated by light and electron microscopic immunocytochemistry. Distributional density and pattern of these elements were clarified. Fine structure of immunoreactive neuronal perikarya with respect to development of cell organellae and immunoreactive dense granules was also elucidated. Features of immunoreactive processes, dendrites and preterminal axons were examined electron microscopically. In addition to the above findings by light and electron microscopic immunocytochemistry, we examined the coexistence of dopamine and neurotensin-like immunoreactive substances in these same neurons in the arcuate and periventricular nuclei. This was proved by the application of fluorescence histochemistry and immunocytochemistry on the same sections. Moreover, we speculated that the ascending noradrenergic neurons influence the neurotensin immunoreactive neurons in the paraventricular nucleus since a marked decrease in the number of neurotensin-like immunoreactive neuronal perikarya was observed after transection of ascending noradrenergic pathway.

Animals↗
PubMed1984

New application of catecholamine fluorescence histochemistry using glyoxylic acid for diagnosis of Hirschsprung's disease by rectal biopsy.

Catecholaminergic innervation was studied in the rectal biopsy specimen obtained from patients with Hirschsprung's disease. The histofluorescence of catecholamine was examined using glyoxylic acid and magnesium without freeze-drying. Aganglionic specimens exhibited no fluorescent network of terminals or fibres in the submucosal plexus, whereas ganglionic specimens showed ganglion cells surrounded by a network of catecholaminergic terminals and fibres. These results of rectal biopsy could be obtained easily and quickly with good reliability. Examination of the catecholaminergic innervation by this histofluorescence method provides a new approach to the diagnosis of Hirschsprung's disease.

Adrenergic Fibers↗
PubMed1984

Selective elimination of chromosomally unbalanced zygotes at the two-cell stage in the Chinese hamster.

The gametic and zygotic selection of genome imbalance was investigated in the Chinese hamster by direct chromosome analyses of spermatocytes and preimplantation embryos from crosses between chromosomally normal females and males heterozygous for a reciprocal translocation, T(2;10)3Idr, abbreviated here as T3. The karyotypes and the frequencies of embryos observed at the first cleavage in the cross +/+female X T3/+male were consistent with those expected from MII scoring in male T3 heterozygotes. Therefore, it was concluded that there was neither gametic selection against genome imbalance nor zygotic selection from fertilization until the first cleavage metaphase. However, 9.1-10.8% of embryos were arrested at the two-cell stage, and karyotypes of these embryos were confirmed as 22(2,10,10,10(2)), 21(2,10,10), and 21(2,10,10(2)). The common abnormality of these embryos was partial monosomy of chromosome 2. Among day 4 embryos, some chromosomally unbalanced embryos, mainly with a deficiency of other segments of chromosomes 2 and 10, had fewer blastomeres than chromosomally balanced embryos. This finding suggests that cleavage of these embryos had been retarded by day 4 of gestation.

Animals↗
PubMed1984

A group of bactericidal factors conserved by vertebrates for more than 300 million years.

A complement-dependent bactericidal factor (RaRF) specific for the Ra chemotype strains of Salmonella and for the Ra-like strains of other enterobacteria has been found in sera of mice. We show here that the anti-Ra bactericidal factors are present in sera of all species, so far tested, of mammals, birds, reptiles, amphibians, and bony and cartilaginous fish. Certain properties, such as binding specificity, requirement of divalent cations for binding, and sensitivities to heat and reducing agents, of the factor in the representative animals were the same as or similar to those of the mouse RaRF. These results indicate that these factors have been conserved by vertebrates for more than 300 million years as a result of the necessity for the resistance to rough mutants of Gram-negative bacteria.

Amphibians↗
PubMed1984

Interleukin-2 activity in chronic active liver diseases: response by T cells and in the autologous mixed lymphocyte reaction.

The T cell growth factor, interleukin-2 (IL-2), is a lymphokine which supports the immunoregulatory function of T cells. We measured the production of and response to IL-2 of peripheral blood T cell subsets from patients with chronic active liver diseases (CALD) and other liver diseases (Others) by the proliferative response of the cells activated with phytohaemogglutin P. Both production of and response to IL-2 of T cells from 24 patients with CALD were markedly decreased (P less than 0.001) in comparison with 13 controls. T cells from 10 patients with Others yielded low IL-2 titre (P less than 0.05) and responded to IL-2 in a depressed manner (P less than 0.05). OKT4+ and OKT8+ cells from five CALD patients as well as five controls equally produced IL-2 and responded to it. However, IL-2 production (P less than 0.05) and response to IL-2 (P less than 0.01) of OKT4+ cells from CALD patients were decreased in contrast to those of OKT8+ cells. We also examined the effect of IL-2 on the autologous mixed lymphocyte reaction. A highly significant increase (P less than 0.001) in the proliferative response of OKT8+ cells and unseparated T cells from 15 patients with CALD occurred with the addition of IL-2 although the values were still lower (P less than 0.01) than those of OKT8+ and unseparated T cells from 12 controls. Addition of IL-2 did not result in a significant increase of the reactivity of OKT4+ cells from patients with CALD. These results further delineate the nature of the immunoregulatory aberration in CALD.

Adult↗
PubMed1984

Increased peripheral blood Ia positive T cells and their effect on autologous mixed lymphocyte reaction in chronic active liver disease.

We measured Ia antigen bearing peripheral blood T cells, as an index of immunological stimulation, of patients with chronic active liver diseases (CALD) by the rosette assay method. We also examined the role of Ia antigen which represents the products of the genes of the major histocompatibility complex on the autologous mixed lymphocyte reaction (AMLR) since this reaction may reflect self regulation of immune responses. The percentages of Ia positive T cells of 29 patients with CALD (17.1 +/- 4.3%, P less than 0.001) and of 12 patients with other liver diseases (12.9 +/- 2.4%, P less than 0.05) were increased when compared with that of normal individuals (10.7 +/- 2.0%). However, levels of Ia positive T cells activated by phytohaemagglutinin-P in patients with CALD and other liver diseases did not differ from normal subjects. Ia positive cells in OKT8 positive cells were markedly elevated (P less than 0.001), whereas those in OKT4 positive cells were decreased (P less than 0.01) in CALD. The impaired values for the AMLR correlated inversely (P less than 0.01) with the increased percentages of Ia positive T cells in patients with CALD. Further analysis showed that there was no suppression of the proliferation of Ia and OKT4 positive cells by Ia and OKT8 positive cells although the culture of increasing numbers of Ia and OKT8 positive cells and decreasing numbers of Ia and OKT4 positive cells gave a lesser AMLR value. These data suggest that the increase in Ia positive T cells and the alteration of Ia positive cells in the T cell subsets reflect an activation of immune system and provide further evidence in favour of an abnormality of the immunoregulatory system in CALD.

Adult↗
PubMed1984

Characterization of human interleukin 2 receptor (Tac antigen) in normal and leukemic T cells: co-expression of normal and aberrant receptors on Hut-102 cells.

Human interleukin 2 receptors ( IL2R ) from various cell sources such as mitogen-activated normal human T cells, adult T cell leukemia (ATL)-derived cell line cells (MT-1, ATL-6, Hut-102), and a natural killer-like cell line YT cells, were studied both by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with a monoclonal anti- IL2R antibody (anti-Tac). In synthetic labeling with [35S]methionine, anti-Tac specifically precipitated two glycoproteins, one with m.w. of 60,000 to 65,000 and pI 4.2 to 4.7, and the other with m.w. about 40,000 and pI 6.2 to 6.5. A study of surface iodination revealed that the former component was membrane-associated mature IL2R , and a pulse-chase study showed that the latter component was a precursor for IL2R that already possessed tunicamycin-sensitive N-linked sugar side chain(s). This precursor was found to be posttranslationally processed into mature IL2R by further glycosylation within 240 min. Among the cells studied, a human T cell leukemia virus-positive leukemic cell line, Hut-102, was distinctive in that it possessed an additional membrane glycoprotein (m.w. 55,000 to 60,000, pI 4.2 to 5.0) also defined by anti-Tac. This unique glycoprotein of Hut-102 cells appeared to be an aberrant IL2R .

Adult↗
PubMed1984

Duplicated immunoglobulin gamma 2a genes in wild mice.

The Japanese wild mouse, Mus musculus molossinus, has duplicated immunoglobulin gamma 2a genes, whereas most of the laboratory-strain mice have single gamma 2a genes. This duplication provides a unique system in which molecular mechanisms of the evolutionary rearrangement of the immunoglobulin gene can be studied. For this purpose it is important to elucidate the organization of the immunoglobulin genes surrounding the duplicated gamma 2a genes. It is also interesting to assess the distribution of this haplotype among the wild mouse population. Partially overlapping chromosomal segments that encompass the gamma 2b, gamma 2a-1, gamma 2a-2, and epsilon genes were isolated from phage libraries containing DNA fragments from M. m, molossinus. The organization of this region has been elucidated as 5'-gamma 2b-(18 kb)-gamma 2a-1-(19 kb)-gamma 2a-2-(14 kb)-epsilon-3'. Both gamma 2a-1 and gamma 2a-2 genes have their own switch regions in the 5' flanking region. Two homology units of 13 kb, each containing the gamma 2a gene, were identified. The homology units alternate with repetitive sequences of low homology, making the location of the recombination site obscure. Seventeen of 31 Japanese and Chinese wild mice screened had duplicated gamma 2a genes, indicating a wide distribution of this genetic event in the Asian wild mouse population. Moreover, three alleles each of the gamma 2b and gamma 2a loci have been observed in this small sample population. An unequal crossing-over event between heterologous haplotypes is proposed to account for the duplication of the gamma 2a gene, and a candidate for one member of the pair was identified among wild mouse haplotypes. These results suggest that the immunoglobulin heavy-chain gene family of the Japanese and Chinese wild mouse subspecies has accumulated not only polymorphic divergence due to point mutations, but also dynamic rearrangements such as gene duplication, during its recent evolution since divergence of these subspecies from the European subspecies about one million years ago.

Animals↗
PubMed1984

Association of the liver peroxisomal fatty acyl-CoA beta-oxidation system with the synthesis of bile acids.

The association of liver peroxisomal fatty acyl-CoA beta-oxidizing system (FAOS) with the synthesis of bile acids was investigated. When rats were given clofibrate, a peroxisome proliferator and stimulator of peroxisomal FAOS, the biosynthesis of bile acids was significantly increased. Di(2-ethylhexyl)phthalate, another peroxisome proliferator, also increased the biosynthesis of bile acids. On the other hand, administration of orotate, an inhibitor of mitochondrial FAOS activity, did not affect the biosynthesis. It is known that fatty acyl-CoA oxidase [EC 1.3.99.3] in peroxisomal FAOS conjugates with catalase [EC 1.11.1.6]. When the catalase activity of liver peroxisomes was irreversibly inhibited by administration of 3-amino-1,2,4-triazole (amino-triazole), the biosynthesis of bile acids was suppressed to about one-third, and the serum cholesterol level was increased. However, the bile acid components of the bile obtained from aminotriazole-treated rats were not essentially different from those of control rats, and no accumulation of intermediates of bile acid synthesis was found in this experiment. Peroxisomal FAOS activity of the liver from amino-triazole-treated rats was considerably lower than that of control liver. The above results indicate that liver peroxisomes play a role in the biosynthesis of bile acids in vivo.

Acyl Coenzyme A↗