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Biomedical subjects

N Takeda

Publications and source records attributed to N Takeda.

At least 361 records · Page 20Linked to original sources
PubMed1993

Metabolism of biogenic monoamines in the ciliated protozoan, Tetrahymena pyriformis.

1. The three-dimensional HPLC system was used to detect the presence and determine the levels of biogenic monoamines, including precursor amino acids and metabolites, simultaneously in an extract of the ciliated protozoan, Tetrahymena pyriformis. 2. Representative biogenic monoamines, such as dopamine (DA), 5-hydroxytryptamine (5-HT), epinephrine (E) and kynurenine (KYN) were found to be synthesized in Tetrahymena and released into the growth medium. 3. The following metabolic pathways were suggested to be operative: (L-DOPA)-DA-(Epinine)-E-dihydroxyphenylethyleneglycol (DOPEG)-vanillylmandelic acid (VMA) and tyrosine-4 (TYR-4)-tyramine (TYRA)-hydroxyphenylacetic acid-4 (HPAC-4) in the case of catecholamines, and tryptophan (TRP)-5-HT and TRP-KYN-xanthurenic acid (XA) in the case of indolalkylamines. 4. As judged from the released metabolites, systems for generation of biogenic monoamines in Tetrahymena seem to be active during the logarithmic phase of its growth.

Animals↗
PubMed1993

The distribution of eosinophil cationic protein positive eosinophils in the nasal mucosa of the nasal allergy patients.

The relationship between the distribution of eosinophils and epithelial damage of the nasal mucosa in nasal allergy was investigated by means of hematoxylin and eosin staining and a technique of immunohistochemistry using the anti-human EG2 mouse monoclonal antibody that reacts with the secreted form of eosinophil cationic protein (ECP). Nasal mucosa tissue of 26 adult nasal allergy patients and of 24 adult non-allergic rhinitis patients was removed surgically. Eosinophilia in the nasal mucosa of the allergy group was greater than that in the non-allergy group. A great number of ECP positive eosinophils accumulating in the nasal mucosa of the allergy group were mostly degranulated at the superficial layer of the lamina propria. Desquamation of the epithelium was observed mainly in the area of eosinophilia with degranulation of the secreted form of ECP in the nasal allergy group.

Adult↗
PubMed1993

Seasonal variations of nasal resistance in allergic rhinitis and environmental pollen counts. II: Efficacy of preseasonal therapy.

We gave Mao-bushi-saishin-to, a Chinese blended medicine, and azelastine to an adult patient with hay fever due to Japanese cedar pollen and measured nasal resistance and ambient floating pollen counts throughout the time of Japanese cedar pollination in separated years. In the patient Mao-bushi-saishin-to was effective against preseasonal increases in nasal airway resistance but could not control severe episodes of allergic rhinitis caused by high dose exposure to Japanese cedar pollen and also perhaps caused by a priming effect. Azelastine inhibited both pre- and post-seasonal increases in nasal airway resistance but not only on high pollen counts days.

Adult↗
PubMed1993

Neuroblastoma growth factors derived from neurofibroma (NF1): participation of uridine in a neuroblastoma growth.

Human glioma cell extracts were found to elicit a marked growth-promoting activity on human neuroblastoma cells. This activity was also detected in the extracts of neurofibroma type 1 (NF1; von Recklinghausen neurofibromatosis) comprising aberrant Schwann cell growth. The purified substance from the NF1 extracts by HPLC on ODS columns was identical to a pyrimidine nucleoside, uridine, the chemical structure of which was identified by gas chromatography-mass spectrometry. The authentic uridine showed a strong growth-promoting activity on human neuroblastoma cells. Other purine or pyrimidine nucleotides, their derivatives, and ribose sources for their syntheses were employed to test the activity; a purine nucleoside, adenosine, showed a stronger activity than uridine. The current study raises the possibility that human neuroblastoma cells may be affected by dysfunctions of the de novo pathway of both purine and pyrimidine nucleotide biosyntheses.

Cell Division↗
PubMed1993

Growth-promoting action of adenosine-containing dinucleotide on neuroblastoma cells: detection of adenosine-cytidine dinucleotide (ApCp) in neurofibroma (NF1) extracts.

Neurofibroma type 1 tissue was investigated for the presence of growth-promoting activity on human neuroblastoma cells. The activity was isolated by gel filtration and reversed-phase column chromatographs from neurofibroma type 1 extracts. An adenosine-containing dinucleotide (adenylyl(3'-5')cytidine-3'-phosphate) was identified as one of the major components of the activities by its enzymatic fragmentation and liquid chromatography/mass spectrometry. Synthetic adenosine-containing dinucleotide derivatives such as cytidyl(3'-5')adenosine, cytidyl(2'-5')adenosine, adenylyl(3'-5')cytidine, and adenylyl(2'-5')cytidine showed a similar action. Cytidyl(3'-5')adenosine, cytidyl(2'-5')adenosine, and adenylyl(2'-5')cytidine, which are able to release a free adenosine through enzymatic hydrolysis, in particular elicited a strong activity corresponding to that of adenosine with the highest action. These results suggest that neuroblastoma cells are able to use adenosine-containing dinucleotides as well as mononucleotides for their survival and proliferation.

Adenosine↗
PubMed1993

Photocytotoxicity of water-soluble metalloporphyrin derivatives.

A new water-soluble porphyrin derivative, 2,4-bis(1-decyloxyethyl)-deuteroporphyrinyl-6,7-bisaspart ic acid (C10-DP), and its metal complexes (Ga, I(n), Zn, Mn, Cu, Ni and Fe) were examined for their physicochemical properties (absorption, fluorescence, triplet lifetime and partition coefficient) and photocytotoxicity on HeLa cells. The five derivatives with longer (> 1 ms) triplet lifetimes (free base, Zn, Ga, I(n) and Sn complexes) exhibited remarkable photocytotoxicity, and the other derivatives (Mn, Cu, Ni and Fe), which had or were deduced to have fairly short (< 0.01 ms) triplet lifetimes, manifested no photocytotoxicity, indicating that the triplet lifetime of these derivatives played a significant role in their photocytotoxicity. Cellular fluorescence due to C10-DP and its gallium complex was observed mainly on the plasma membrane at the concentrations showing significant photocytotoxicity with low (< 32.6%) cytotoxicity in the dark (2-10 microM).

Aspartic Acid↗
PubMed1993

Molecular epidemiology of a variant of coxsackievirus A24 in Taiwan: two epidemics caused by phylogenetically distinct viruses from 1985 to 1989.

In order to know the phylogenetic relationship and the route of transmission of a variant of coxsackievirus A24 (CA24v), an agent that caused four sequential outbreaks of acute hemorrhagic conjunctivitis from 1985 to 1989 in Taiwan, the nucleotide sequence variations in the virus-encoded proteinase 3C region (549 nucleotides) were studied with 19 isolates. The prototype strain (EH24/70), four isolates from Japan, and two isolates from Hong Kong were used for comparison. The nucleotide sequences of the Taiwan strains from the 1985-1986 and 1988-1989 epidemics were closely related within each epidemic, while they were more distantly related between strains from two epidemics. Phylogenetic analysis by the unweighted pairwise grouping method of the arithmetic average revealed that the 19 Taiwan isolates had diverged into two groups, 1985-1986 and 1988-1989 groups. The time at which these two groups diverged was estimated to be around May 1982, more than 3 years prior to the first appearance of the CA24v epidemic in Taiwan. On each occasion, the viruses caused a 2-year epidemic and then disappeared. The Taiwan isolates from 1985 to 1986 were closely related to the Japan isolates from 1985 to 1986 and the Taiwan isolates from 1988 to 1989 were phylogenetically close to the 1989 Japan isolates, indicating that Taiwan and Japan had two common-source outbreaks. However, none of the 1988 Taiwan isolates were phylogenetically close to the 1988 Japan or Hong Kong isolates. The evidence revealed that Taiwan has had two repeated but discontinuous introductions of CA24v since its first appearance in Taiwan in 1985. None of the other CA24v strains have been detected so far.

Base Sequence↗
PubMed1993

Effect of unilateral vestibular stimulation on histamine release from the hypothalamus of rats in vivo.

1. We investigated the effect of unilateral vestibular stimulation on histamine release from the anterior hypothalamic area of urethan-anesthetized rats in vivo, using a brain microdialysis method coupled with high-performance liquid chromatography fluorometry. 2. The histamine release was increased to approximately 180% of the basal release by the electrical stimulation of the inner ear with 1 Hz, 500 microA, and 200 ms for 20 min. This effect was dependent on the current intensity. 3. Activation of the unilateral horizontal semicircular canal by middle ear irrigation for 15 min with 45 degrees C water increased the histamine release to approximately 200% of the basal release. 4. Irrigation of the middle ear with ice water for 15 min increased the histamine release to approximately 190% of the basal release. 5. The histamine release was not changed by the irrigation of the middle ear with 37 degrees C water and the irrigation of the auricle with ice water, which suggests that neither somatosensory stimulation to the middle ear nor nonspecific cold stress affects the histamine release. 6. All these findings suggest that the sensory mismatch signals induced by caloric stimulation and unilateral electrical vestibular stimulation activate the histaminergic neuron system in the brain.

Afferent Pathways↗
PubMed1993

A case of Kearns-Shy syndrome with later onset.

We report a case of Kearns-Shy syndrome in a 44-year-old woman. She complained of bilateral ptosis, exotropia and gait disturbance. Diffuse chorioretinal degeneration and numerous punctate whitish spots were observed in both fundi. Eye movements were severely disturbed. An electroretinogram was almost nonrecordable, while visually evoked cortical potentials to pattern stimulation were normal. The dark adaptation curve showed an elevation of rod threshold. Besides such ophthalmological findings, muscle weakness, extinguished tendon reflex and healing difficulty were observed. Blood lactate, pyruvic acid and serum creatinine kinase were at high levels. A muscle biopsy showed ragged-red fibers and partial deficiency of cytochrome c oxidase. The patient is being treated with coenzyme Q, and we are now following up the therapeutic effects of this treatment.

Adult↗
PubMed1993

[Measurement of ethylene oxide at a medical sterilization site].

Although ethylene oxide gas is widely used as a sterilizing agent for medical instruments because of its disinfection property, the effects of its use in medical settings have not been clarified. In the present study, we measured the ethylene oxide gas concentration (EOGC) within a hospital sterilization unit and in the ambient air near the unit. Before the sterilizer was turned on (about 9:00), the ambient air EOGC was below the detection limit (0.1 ppm). When the door was opened to place the instruments in the sterilizer, the maximum EOGC near the door of the sterilizer was 1.71 ppm. Before the sterilizer door was opened, the residual EOGC within the sterilizer was 0.10-24.56 ppm. During the operation of the sterilizer (9:00-17:00), ethylene oxide gas could not be detected in the air near the unit. When the sterilizer door was opened at the end of the routine operation of the sterilizer (about 17:00), EOGC near the door was 2.10-2.73 ppm. After the door was closed, the ambient air EOGC level was 0.5-0.57 ppm. These findings indicate that the personnel near the unit were exposed to ethylene oxide gas for about 15 min during the transfer. However, no ethylene gas could be detected by the ethylene oxide gas monitor (3M Co., #3551). The finding that EOGC in sterilized medical instruments after 24 h of aeration was about 2 ppm also suggests that the personnel using these instruments were exposed to ethylene oxide gas.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1993

Effects of ACNU and cranial irradiation on the mouse immune system.

The effects of ACNU and cranial irradiation on the immune system were studied in three groups of 90 mice: Group A, intraperitoneal injection of ACNU (30 mg/kg); Group B, single exposure of 10 Gy to the head; and Group C, intraperitoneal injection of ACNU (30 mg/kg) and single exposure of 10 Gy to the head. Peripheral white blood cell counts, spleen cell subsets, natural killer (NK) cell activity, lymphocyte blastogenesis, and production of interferon (IFN)-gamma were analyzed once a week for 6 weeks after treatment. In Group A, NK cell activity decreased between weeks 4-5, concanavalin A blastogenesis decreased during weeks 1-5, and the levels of L3T4 (CD4) and Lyt2 cells (CD8) and IFN-gamma production decreased during weeks 2-5. However, all tested parameters returned to the normal range at 6 weeks. In Group B, all parameters except for the L3T4 cell level and the IFN-gamma production decreased during week 1, and returned to the normal range thereafter. The concentration of L3T4 cells decreased during week 2 and between weeks 5-6. The IFN-gamma production increased during week 1, decreased during week 2, and returned to the normal range thereafter. In Group C, the suppressive effects were severe and continued for a longer period than in either Group A or B. Concanavalin A blastogenesis, L3T4 cell concentration, and IFN-gamma production were still suppressed after 6 weeks. Therefore, intensive radiochemotherapy for brain tumor may suppress the immunological function.

Animals↗
PubMed1993

Neuropharmacology of motion sickness and emesis. A review.

Histamine H1-receptors are involved in the development of the symptoms and signs of motion sickness, including emesis. On provocative motion stimulus, a signal for sensory conflict activates the histaminergic neuron system, and the histaminergic descending impulse stimulates H1-receptors in the emetic center of the brain stem. The histaminergic input to the emetic center through H1-receptors is independent of dopamine D2-receptors in the chemoreceptor trigger zone and serotonin 5HT3-receptors in the visceral afferent, which are also involved in the emetic reflex. Antihistamines block emetic H1-receptors to prevent motion sickness. Acetylcholine muscarinic receptors are involved in the generation of signals for sensory conflict. Anti-cholinergic drugs prevent motion sickness by modifying the neural store to facilitate the acquisition of habituation to provocative motion.

Animals↗
PubMed1993

Calcitonin gene-related peptide in the efferent system of the inner ear. A review.

Many calcitonin gene-related peptide-like immunoreactive (CGRP-IR) fibers were found in the vestibular end-organs and the cochlea of rats. CGRP-IR fibers in the vestibular end-organs originated in the bilateral cell groups dorsolateral to the genu of the facial nerve. These fibers formed a fiber plexus at the base of the sensory epithelia in the maculae of the otolith organs and the ampullae of the semicircular canals, and formed synaptic contacts with the nerve chalice on type I vestibular sensory cells. CGRP-IR fibers in the cochlea originated in the ipsilateral lateral superior olivary nucleus. Most of them existed in the inner spiral bundle under the inner hair cells, and formed synaptic contacts with afferent terminals on the inner hair cells. These findings suggest a postsynaptic modulation of CGRP on the vestibular and cochlear information at the level of type I vestibular sensory cells and the inner hair cells.

Animals↗
PubMed1993

Neurogenic inflammation in nasal allergy: histochemical and pharmacological studies in guinea pigs. A review.

The role of neuropeptides in nasal allergy was examined in guinea pigs by histochemical and pharmacological study. Intranasal application of toluene diisocyanate (TDI) induced nasal allergy-like behaviors: sneezing and watery rhinorrhea, and decreased histamine content in the nasal mucosa in guinea pigs sensitized with TDI. The immunoreactivity of substance P (SP) and calcitonin gene-related peptide (CGRP) in the nerve terminals in the nasal mucosa was increased after intranasal application of TDI. We also observed a decrease in the immunoreactivity of SP and CGRP, and an increase in their mRNA expression in the trigeminal ganglion neurons. These findings indicate that exposure to TDI enhanced the biosynthesis of both SP and CGRP in the trigeminal ganglion neurons and their axonal transportation to the terminals in the nasal mucosa. In animals pretreated with capsaicin before sensitization, TDI did not induce nasal allergy-like behaviors and histamine release in the nasal mucosa. Since capsaicin depletes SP and CGRP in the sensory nerves, this finding indicates neuropeptide-mediated histamine release in the nasal mucosa. All these findings suggest that, on exposure to TDI, the antidromic release of SP and CGRP in the nasal mucosa triggers the release of histamine, resulting in the development of symptoms of nasal allergy.

Animals↗
PubMed1993

Motion sickness induced by sinusoidal linear acceleration in rats.

The characteristics of linear acceleration to cause motion sickness of rats were examined using pica as a behavioral index of motion sickness. A vestibular sled was used to generate sinusoidal linear acceleration. At 0.4 Hz and with a peak acceleration of 0.15 G, the effectiveness of linear acceleration in inducing motion sickness was X-axis > Y-axis > Z-axis. At 0.4 Hz and along the X-axis, rats suffered from more severe motion sickness with a high peak G load (0.15 G) than with a low one (0.08 G). Along the X-axis and with a peak acceleration of 0.15 G, the severity of motion sickness was not related to frequency (0.4, 0.6 Hz).

Acceleration↗
PubMed1993

Nystagmus responses in normal subjects during eccentric sinusoidal rotation.

Earth vertical axis rotation provides a method of stimulating the horizontal semicircular canals. By placing subjects off from the axis of rotation, the otolith organs may also be stimulated by additional linear acceleration forces. In the present study, we compared the rotation with subjects placed on axis to those placed in an eccentric position, either facing outward or turned 90 degrees facing the direction of the rotation. When the subject was facing outward, sinusoidal eccentric rotation at 0.64 Hz produced a significantly higher vestibulo-ocular reflex (VOR) gain than did on-axis rotation. No increase in VOR gain was observed during eccentric rotation with the subject facing the direction of the rotation. These findings suggest that the gain enhancement due to eccentric rotation is a result of tangential linear acceleration, probably sensed by the utriculus. This study raises the possibility of using eccentric rotation for the diagnosis of the patients with otolith dysfunction.

Acceleration↗
PubMed1993

Enhanced proliferative potential in culture of cells from p53-deficient mice.

Normal somatic cells are endowed with limited doubling potential in culture, and the process of immortalization is an inevitable step in neoplastic transformation of the cells. To examine the roles of p53 in this process, the cells of p53-deficient mice were examined for doubling potential. Fibroblast-like cells from a variety of tissues of these mice proliferated continuously without showing aging or crisis. The aneuploid cells overcome the population with passage, but cloning experiment indicated that chromosomal changes were not essential to this process. The enhanced proliferative potential in culture of cells from the p53-deficient mice was also observed in epithelial cells of lens, mammary glands and seminal vesicles and in neural precursor cells. Proliferation of bone marrow cells in response to stem cell factor was enhanced in long term culture, but not in in vitro colony assay; no permanent cell lines could be obtained. No effects of p53-deficiency were found in proliferation of cardiac muscle cells or hepatocytes.

Aneuploidy↗