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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 433 records · Page 24Linked to original sources
PubMed1983

Purification and characterization of neutrophil chemotactic factors of Streptococcus sanguis.

Two neutrophil chemotactic factors were isolated from the culture filtrates of Streptococcus sanguis ATCC 10556 and were chemically characterized as N-terminal blocked peptides of low molecular weight. One of the factors consisted of proline, valine, methionine, isoleucine and leucine and the other of methionine, isoleucine, leucine and phenylalanine. In both factors, methionine was detected as the sole N-terminal amino acid, but the amino group was blocked. The removal of N-terminal methionine yielded several N-terminal amino acids, suggesting that S. sanguis produced several N-terminal blocked methionyl peptides, all of which could be chemotactically active.

Amino Acids↗
PubMed1983

Coexistence of dopamine and neurotensin in hypothalamic arcuate and periventricular neurons.

The coexistence of dopamine and neurotensin in the same neuronal perikarya in the arcuate nucleus of the rat hypothalamus was examined by combined fluorescence histochemistry and immunohistochemistry on the same tissue sections and we obtained the evidence of the coexistence of two substances. The functional significance of those two substances for the prolactin release from the anterior pituitary was also briefly discussed.

Animals↗
PubMed1983

Neo-kyotorphin (Thr-Ser-Lys-Tyr-Arg), a new analgesic peptide.

The amino acid sequence of a newly isolated pentapeptide, neo-kyotorphin from bovine brain was synthetically verified to be Thr-Ser-Lys-Tyr-Arg corresponding to the C-terminal portion of hemoglobin alpha-chain. The synthetic neo-kyotorphin showed the dose-dependent analgesia in mice which was approximately equal to that of Leu-enkephalin.

Amino Acid Sequence↗
PubMed1983

Some cellular characteristics of somatostatin neurons and terminals in the periventricular nucleus of the rat hypothalamus and median eminence. Electron microscopic immunohistochemistry.

Somatostatin neuronal perikarya and their processes, presumably dendrites, in the periventricular nucleus of the rat hypothalamus and terminals in the median eminence were observed by electron microscopic immunohistochemistry. Neuronal perikarya and processes contained immunoreactive dense granules (100-120 nm in diameter) and other cellular components such as polysomes, rER membranes occasionally showed high electron density. Few axo-somatic terminals were found on the somatostatin neurons, but we could detect a number of preterminal axons on immunoreactive processes, presumably dendrites. Therefore, we considered that somatostatin neurons receive mainly neuronal input through axo-dendritic synapses rather than through axo-somatic ones. In the somatostatin terminals in the external layer of the median eminence immunoreactivity was completely restricted on the granules.

Animals↗
PubMed1983

VIP (vasoactive intestinal polypeptide)-like immunoreactive amacrine cells in the retina of the rat.

Vasoactive intestinal polypeptide (VIP)-like immunoreactivity was demonstrated in the rat retina, using the peroxidase anti-peroxidase (PAP) method. VIP-like immunoreactivity was observed in the cytoplasm of amacrine cells of the inner nuclear layer (INL) and their varicose processes ramifying in the inner plexiform layer (IPL). VIP-like immunoreactive amacrine cells were present in both central and peripheral retinal regions. In some sections fine ramifications of varicose processes in the IPL could be clearly traced. VIP-like immunoreactivity was detected in both 'stratified' and 'diffuse' amacrine cells. VIP-like immunoreactive amacrine cells were classified into four types.

Animals↗
PubMed1983

Isolation from bovine brain of a novel analgesic pentapeptide, neo-kyotorphin, containing the Tyr-Arg (kyotorphin) unit.

A novel analgesic peptide, isolated from the bovine brain, was found to contain the Tyr-Arg (kyotorphin) unit at the C-terminal portion. This peptide, in the methanol-soluble fraction, was isolated by gel filtration and cation exchange chromatography. This peptide was termed "neo-kyotorphin" and the amino acid sequence is Thr-Ser-Lys-Tyr-Arg. The synthetically prepared neo-kyotorphin proved to have a dose-dependent analgesic effect in mice. The median analgesic dose, ED50 of neo-kyotorphin was 195 nmol/mouse (intracisternal injection), with the tail pinch test, and the potency was approximately equal that of Leu-enkephalin.

Amino Acids↗
PubMed1983

Time of vasopressin neuron origin in the mouse hypothalamus: examination by combined technique of immunocytochemistry and [3H]thymidine autoradiography.

A time-course study on production of vasopressin neurons (VP-neurons) in the mouse hypothalamus was carried out by application of [3H]thymidine autoradiography and PAP-immunocytochemistry simultaneously on the same tissue sections. In the paraventricular nucleus (PVN) and the supraoptic nucleus (SON), heavily [3H]thymidine-labeled VP-neurons were detected only in the specimens of the animals exposed to the isotope on the gestational day 12. While in the suprachiasmatic nucleus (SCN), heavily isotope-labeled VP-neurons were observed in the specimens of the animals exposed to the isotope on the gestational day 12 or day 14. Therefore, the production of the VP-neurons in the SCN is prolonged and slightly more delayed than that in the SON or PVN.

Animals↗
PubMed1983

Distribution of the VIP-like immunoreactive neurons in the cat central nervous system.

Immunohistochemical topographic localization of the vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons in the cat brain was investigated using a peroxidase anti-peroxidase technique. VIP-like immunoreactive neurons were mainly localized in the cerebral cortex, limbic cortex, hypothalamic nuclei; suprachiasmatic nucleus, supraoptic nucleus, paraventricular nucleus, periventricular nucleus and arcuate nucleus, and in the midbrain; such as the central grey and the raphe nucleus. It was demonstrated that VIP-like immunoreactive neurons were widely distributed in the cat brain, particularly in the hypothalamus, compared with those of the rat and mouse; though whether these differences were species-related or due to differences in the physiological conditions remains to be determined. This is the first report of VIP neuronal perikarya in the arcuate nucleus of mammalian species, although these cells are present in the arcuate nucleus of birds.

Animals↗
PubMed1983

Effect of maltose on glucan synthesis by glucosyltransferases of Streptococcus mutans.

The effects of added maltose on the activities of a preparation of crude glucosyltransferases (GTases) and purified dextransucrase (DS) were investigated to elucidate the inhibition mechanism of maltose on the synthesis of water-insoluble glucan (ISG) in Streptococcus mutans HS-6. Tri- and tetra-saccharides produced by crude GTases from sucrose in the presence of maltose were identified as panose (4-alpha-isomaltosylglucose) and 4-alpha-isomaltotriosylglucose which were responsible for the activity of DS involved in crude GTases. Kinetic studies on crude GTases in the presence of maltose showed similar results to those of DS except that the synthesis of ISG in the crude GTases was inhibited. Comparative studies of soluble products of crude GTases and DS in the presence of maltose were performed employing gel filtration on Sephadex G-15. The existence of oligosaccharides above hexasaccharide was revealed as the products of DS but not of crude GTases. These findings were interpreted in terms of the previously proposed mechanism of ISG synthesis by S. mutans, i.e., ISG should be synthesized from the preformed soluble glucan. It was indicated that oligosaccharides above hexasaccharide are utilized for ISG synthesis in the crude GTases system. From these results, the inhibitory mechanism of added maltose on ISG synthesis by crude GTases is considered as follows: DS synthesizes a series of 4-alpha-isomaltodextrinylglucose from sucrose and maltose, and the increase of added maltose results in the decrease of oligosaccharides responsible for synthesis of ISG.

Glucans↗
PubMed1983

Immunochemical properties of glucosyltransferases from Streptococcus mutans.

Antiserum against purified mutansynthetase (EC 2.4.1.?) of Streptococcus mutans 6715 (serotype g), which is responsible for the synthesis of water-insoluble glucan (ISG) in the presence of both sucrose and water-soluble glucan, was prepared. The specificity of the antiserum was tested by using crude enzyme preparations (CEPs) of S. mutans strains of various serotypes. On immunodiffusion, the antiserum cross-reacted with CEPs from strains of serotypes a (HS-6 and AHT), d (OMZ176), and g (OMZ65 and KIR), but not with those from strains of serotypes b (BHT and FA-1) and c (GS-5 and Ingbritt). The antiserum inhibited the synthesis of ISG by crude or purified mutansynthetase of S. mutans 6715. The activities of ISG synthesis by CEPs from the strains antigenically related in the foregoing immunodiffusion were inhibited by the antiserum against strain 6715 mutansynthetase. The antiserum, however, also inhibited the enzyme activity of the strains of serotype b. The finding that the antiserum against purified dextransucrase of S. mutans HS-6 inhibited ISG synthesis by a CEP of strain HS-6 and also by CEPs of antigenically related strains suggested that dextransucrase activity is involved in ISG synthesis.

Cross Reactions↗
PubMed1983

Origin of adult T-cell leukemia virus. Implication for its zoonosis.

Adult T-cell leukemia virus (ATLV) is a retrovirus infecting man. The ATLV genome consists of long terminal repeat (LTR), gag, pol, env and pX sequences and does not carry a typical v-onc gene. The function of the pX sequence is unknown. To search for the origin of ATLV, segments of the ATLV genome were hybridized to DNAs of various species. The sequences homologous to the pX region of ATLV are represented in the genomes of mouse and rat but not in other species including primates and the human. Neither the pol nor U3 sequence of LTR is conserved in any cellular DNA examined. Sequences slightly homologous to the U3R sequence are found in rabbit, chicken and Xenopus. The results suggest that the pX sequence of ATLV might have derived from rodents. Since ATLV can infect primates, rabbit and rat, ATLV might have been prevalent among a wide variety of mammals and exchanged genetic segments (zoonotic) like influenza virus. If we assume that the original host of ATLV is a rodent rather than man, the pX sequence is homologous to host cellular sequences and reminiscent of the v-onc gene although the function of the pX sequence is not clear.

Animals↗
PubMed1982

An immunohistochemical investigation of vasoactive intestinal polypeptide in the colon of patients with Hirschsprung's disease.

The distribution of vasoactive intestinal polypeptide (VIP) in the colon of patients with Hirschsprung's disease was investigated by the peroxidase-antiperoxidase (PAP) immunohistochemical method. Three colonic segments, ganglionic, oligoganglionic and aganglionic, were stained by the unlabeled antibody enzyme method. VIP immunoreactive nerve cell bodies, nerve fibers and nerve endings were distributed throughout the ganglionic and oligoganglionic segments. In contrast, the aganglionic segment contained no VIP nerve endings and the number of fibers was reduced. These differences are thought to be a cause of constriction of the colon in Hirschsprung's disease and VIP neurons are therefore believed to participate in the relaxation of smooth muscle.

Child↗
PubMed1982

The localization of the motor neurons innervating the cricothyroid muscle in the adult dog by the fluorescent retrograde axonal labeling technique.

Injection of 4'6-diamidino-2-phenylindol 2 HCl (DAPI) into the cricothyroid muscle of the adult dog resulted in blue fluorescence of cells found exclusively in the rostral part of the ipsilateral nucleus ambiguus. These labeled neurons on the average extended 1.8 mm from the level just caudal the facial nucleus to the caudal extension. In the rostral tip of the nucleus, labeled cells were located in a scattered ventral group of larger neurons of the nucleus.

Animals↗