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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 577 records · Page 32Linked to original sources
PubMed1993

Nerve-specific marker proteins as indicators of organic solvent neurotoxicity.

Effects of chronic exposure to n-hexane and toluene on some nerve-specific marker proteins in rat central nervous system (CNS) and peripheral nervous system (PNS) were assessed and compared. The rats were exposed to 2000 ppm n-hexane, 12 hr/day, 6 days/week, for 24 weeks, and to 1000 ppm toluene, 8 hr/day, 6 days/week, for 16 weeks. The level of neuron-specific enolase (NSE), creatine kinase-B (CK-B), and beta-S100 protein in cortex, cerebellum, spinal cord, and proximal and distal sciatic nerve was determined by enzyme immunoassay method. In n-hexane-exposed rats, the level of NSE, CK-B, and beta-S100 decreased significantly in the distal segment of the sciatic nerve, while the marker proteins in CNS and proximal sciatic nerve remained unchanged. In contrast, chronic exposure to toluene mostly affected these marker proteins in CNS tissues, displaying the increase of NSE, CK-B, beta-S100 in cerebellum, as well as the increase of beta-S100 in spinal cord. No quantitative changes of the three proteins in distal sciatic nerve were observed after exposure to toluene. n-Hexane-induced peripheral distal neuropathy and toluene-induced brain gliosis appeared to be responsible for this different pattern of biochemical changes. The present study suggests the usefulness of using these nerve-specific marker proteins to assess the solvent-related CNS and PNS neurotoxicity.

Animals↗
PubMed1993

Modification of metabolism and neurotoxicity of hexane by co-exposure of toluene.

The effects of co-exposure of hexane and toluene were investigated in field surveys and animal experiments. One field survey suggested that increase of hexane content in adhesives might have caused an outbreak of polyneuropathy in a vinyl sandal manufacture in Japan. The animal experiments proved that co-exposure of hexane and toluene decrease hexane neurotoxicity and urinary excretion of hexane metabolites in rats. The results also suggested that toluene might inhibit metabolism of hexane. Another recent field survey indicated that the ratio of urinary 2,5-hexanedione to hexane exposure in the workers co-exposed to hexane and toluene decreased in parallel with in more crease of toluene concentration. The results indicated that urinary excretion of 2,5-hexanedione could be depressed by co-exposure of toluene even in the workers exposed to relatively low concentrations. These above-mentioned results suggest that co-exposure of hexane and toluene could inhibit hexane metabolism and decrease hexane neurotoxicity in both experimental animals and workers. Although metabolism of hexane could be easily modified by toluene or other solvents and might not be a good indicator for hexane exposure in mixed exposure, urinary 2,5-hexanedione might be a good indicator for neurotoxicity of hexane even in mixed exposure.

Adhesives↗
PubMed1993

Periodic mother deprivation during the light period reversed the phase of serotonin N-acetyltransferase activity rhythm of the pineal gland in rat pups.

It has been reported that nursing mother rats can postnatally entrain the circadian rhythms of blinded rat pups, such as locomotor, drinking, and corticosterone rhythms. To gain more insight in the mechanism of the postnatal entrainment of such pups' circadian rhythms, we examined the serotonin N-acetyltransferase (NAT) activity rhythm in blinded rat pups subjected to periodic mother deprivation (PMD) in which mothers were periodically deprived of their pups during either half of a day. We found that only PMD during the light period shifted the phase of NAT activity rhythm in the pups. To cause a reversal of the NAT activity rhythm, it was necessary to repeat PMD for more than 6 days. PMD for 6 h each day also shifted the phase of the blinded rat pups, but it did not reverse the NAT rhythm, even when it was repeated for 10 days. In 9-h deprivation for 10 days, however, deprivation during the first 9 h of the light period reversed the phase, although the latter 9 h failed to cause reversal of the phase. On the other hand, restricted feeding of the mother took more than 11 days to reverse the phase and a foster mother in the cross-fostering experiment failed to affect the phase of pup's rhythm, when the rhythm was determined on the 11th postnatal day. These facts indicate that PMD during the light period is a potent entrainer of the pups' circadian NAT rhythms and provide a useful method of exploring the underlying mechanism of the entrainment of the pups' rhythm by the mother.

Animals↗
PubMed1993

Thymic nurse cell clone supports the differentiation of CD4-8- thymocytes into CD4+8+ thymocytes in vitro.

A previously reported thymic nurse cell clone, TNC-R3.1 could form a unique complex with isolated adult mouse CD4-8- (DN) thymocytes and greatly sustained the cell viability of DN thymocytes in suspension culture. In addition, the TNC-R3.1 clone supported the differentiation of DN thymocytes into CD4+8+ (DP) thymocytes in a short-term culture. Addition of IL-7 into the coculture markedly enhanced DN thymocyte-TNC interaction and induced the proliferation and differentiation of DN thymocytes, though IL-7 alone did not induce the differentiation of DN thymocytes. Separation of DN thymocytes from TNC-R3.1 monolayer using a Millicell caused a great inhibition of the DN thymocyte differentiation, suggesting that direct contact between TNC-R3.1 cells and immature thymocytes was required for the differentiation of DN thymocytes. The kinetics study demonstrated that DN thymocytes started to differentiate into DP thymocytes through CD3-CD4+J11d+ intermediate cells 8-12 h after the initiation of the culture with TNC-R3.1 plus IL-7. The generation of DP thymocytes became maximal 20 h after coculture and gradually decreased thereafter. Furthermore, we demonstrated that TNC-R3.1 could support the differentiation of CD3+CD4+CD8- or CD3+CD4-CD8+ thymocytes from CD3-CD4-CD8- thymocytes in the presence of IL-7 and IL-2. These data indicate that our established in vitro culture system mimics the early stage of the intrathymic T cell developing pathway.

Animals↗
PubMed1993

The aetiological significance of work-load in the development of osteoarthritis of the distal interphalangeal joint.

The incidence of Heberden's nodes was determined in three groups of Japanese women with different occupations to investigate the role of work-load in their pathogenesis. School cooks (n = 260), each of whom prepared 150 to 450 lunches daily, pre-school cooks (n = 222), each of whom prepared 30 to 80 lunches daily, and municipal employees (n = 298) underwent physical examination and X-ray of the hand if pathology was present. The incidence of Heberden's nodes and X-ray incidence of osteoarthritis was 19.2% and 13.5%, 8.6% and 5.4%, 5.9% and 2.0% among school cooks, pre-school cooks and municipal workers, respectively. The incidence of Heberden's nodes and osteoarthritis was significantly higher among school cooks. These findings support the concept that work-load is an aetiological factor in the pathogenesis of Heberden's nodes and also support Radin's hypothesis that women's daily work pattern explains the increased incidence of DIP joint osteoarthritis in women.

Adult↗
PubMed1993

Midbrain tegmentum as an intermediate relay station of the periaqueductal-facial pathway in the cat.

Iontophoretic injection of horseradish peroxidase (HRP) into the medial part of the facial nucleus resulted in retrograde labeling in the lateral midbrain tegmentum contralaterally which corresponded to the paralemniscal zone (PL). Further experiments in which HRP was injected iontophoretically into the PL revealed heavy retrograde labeling in the lateral portion of the ipsilateral periaqueductal gray (PAG). These light microscopic studies indicated the possibility of the pathway from the PAG to the facial nucleus via the midbrain PL. The electron microscopic observations were carried out on the lateral midbrain tegmentum containing the PL after kainic acid, and wheat germ agglutinin conjugated HRP injections were made into the PAG and the contralateral facial nucleus in the same animal, respectively. Although in the neuropil many degenerating PAG fibers and retrogradely labeled neurons were observed, it was of particular interest that the degenerating fibers made synaptic contacts with HRP-labeled somata and dendrites.

Animals↗
PubMed1993

Superior cervical ganglionic origin of sympathetic fibers in the facial nerve, and their preganglionic spinal inputs: a WGA-HRP study in Macaca fuscata.

The origin of sympathetic fibers in the facial nerve of Macaca fuscata was demonstrated using the HRP method. WGA-HRP injection into the facial nerve resulted in heavy labeling in the ipsilateral superior cervical ganglion. The majority of labeled neurons in the superior cervical ganglion had sizes ranging from 20 to 35 microns. In the present study it was of particular interest that labeled neurons are also found in the intermediolateral nucleus and lateral funiculus ipsilaterally at the level from the C8 to T4 spinal cord segments. Many labeled neurons in the lateral funiculus were located in close vicinity to the intermediolateral nucleus, and, characteristically, a few of these had a long dendrite extending to the lateral surface of the spinal cord. The labeling in the spinal cord appears to be caused by transneuronal transport of WGA-HRP.

Animals↗
PubMed1993

Vesicle transport and processing of the precursor to 2S albumin in pumpkin.

Cell fractionation of pulse-chase-labeled developing pumpkin cotyledons demonstrated that proprotein precursor to 2S albumin is transported from the endoplasmic reticulum to dense vesicles and then to the vacuoles, in which pro2S albumin is processed to the mature 2S albumin. Immunocytochemical analysis showed that dense vesicles of about 300 nm in diameter mediate the transport of pro2S albumin to the vacuoles. The primary structure of the precursor (16,578 Da) to pumpkin 2S albumin has been deduced from the nucleotide sequence of an isolated cDNA insert. The presence of a hydrophobic signal peptide at the N-terminus indicates that the precursor is a pre-proprotein that is converted into pro2S albumin after cleavage of the signal peptide. N-terminal sequencing of the pro2S albumin in the isolated vesicles revealed that the signal peptide is cleaved off cotranslationally on the C-terminal side of alanine residue 22 of prepro2S albumin. By contrast, posttranslational cleavages occur on the C-terminal sides of asparagine residues 35 and 74, which are conserved among precursors to 2S albumin from different plants. Hydropathy analysis revealed that the two asparagine residues are located in the hydrophilic regions of pro2S albumin. These findings suggest that a vacuolar processing enzyme can recognize exposed asparagine residues on the molecular surface of pro2S albumin and cleave the peptide bond on the C-terminal side of each asparagine residue to produce mature 2S albumin in the vacuoles.

Albumins↗
PubMed1993

Molecular characterization of a vacuolar processing enzyme related to a putative cysteine proteinase of Schistosoma mansoni.

Proproteins of various vacuolar proteins are post-translationally processed into mature forms by the action of a unique vacuolar processing enzyme. If such a processing enzyme is transported to vacuoles together with proprotein substrates, the enzyme must be a latent form. Immunocytochemical localization of a vacuolar processing enzyme, a 37-kD cysteine proteinase, in the endosperm of maturing castor bean seeds places the enzyme in the vacuolar matrix, where a variety of proproteins is also present. To characterize a molecular structure of vacuolar processing enzyme, we isolated a cDNA for the enzyme. Deduced primary structure of a 55-kD precursor is 33% identical to a putative cysteine proteinase of the human parasite Schistosoma mansoni. The precursor is composed of a signal peptide, a 37-kD active processing enzyme domain, and a propeptide fragment. Although the precursor expressed in Escherichia coli has no vacuolar processing activity, a 36-kD immunopositive protein expressed in E. coli is active. These results suggest that the activation of the vacuolar processing enzyme requires proteolytic cleavage of a 14-kD C-terminal propeptide fragment of the precursor.

Amino Acid Sequence↗
PubMed1993

Alternate-day GnRH therapy for ovarian hypofunction induced by weight loss: treatment of six patients who remained amenorrhoeic after weight gain.

OBJECTIVE: Body weight loss has an adverse effect on the pituitary-ovarian function, and no restoration of the function occurs in 20-30% of patients even after the recovery of body weight. In the present study, the efficacy of alternate-day GnRH therapy was investigated in six patients whose pituitary-ovarian function had not recovered at 15 months to 6 years after the recovery of body weight. DESIGN: Synthetic GnRH (100 micrograms) was injected intramuscularly on alternate days for a total of 12 doses. On the completion of GnRH administration the efficacy of clomiphene-human chorionic gonadotrophin (hCG) therapy was evaluated. A GnRH loading test and evaluation of LH secretion patterns were also performed to investigate the changes in hypothalamic-pituitary-ovarian function secondary to GnRH treatment. RESULTS: All six patients ovulated in response to clomiphene-hCG therapy after 1-3 courses of GnRH treatment. The ovulatory response to clomiphene-hCG continued during follow-up periods of 5 months to 5 years. The initial hormonal change induced by GnRH treatment was a rise in the basal serum FSH level and a return of the FSH response to GnRH loading. This was followed by an increase in serum LH and the return of LH response to GnRH loading. In all six patients, pulsatile LH secretion was absent before starting GnRH treatment. GnRH treatment produced LH pulses in five of the six patients, although the pulse frequency was less than that in normally cycling women. A further increase in the pulse frequency was observed during clomiphene therapy. CONCLUSIONS: Alternate-day GnRH administration is effective in inducing responsiveness to clomiphene in patients with anovulation secondary to weight loss.

Adolescent↗
PubMed1993

Inhibition of the formation of oral calcium phosphate precipitates: beneficial effects of Chinese traditional (kampo) medicines.

Screening tests on the formation of calcium phosphate precipitates using 23 different kinds of Kampo medicines (Chinese traditional medicines) were carried out, at concentrations where the effects of chelation are not significant. Four of them, Hochu-ekki-to (TJ-41), Kyuki-kyogai-to (TJ-77), Oren-to (TJ-120) and Inchin-ko-to (TJ-135) showed an inhibitory effect on the formation of amorphous calcium phosphate (ACP). The inhibitory effect on the induction time and the rate of transformation to hydroxyapatite (HAP) varied greatly among the 23 Kampo medicines. We classified them according to their effects on increasing the induction time and/or decreasing the rate of HAP transformation. Ethane-1-hydroxy-1, 1-diphosphonate (EHDP) was used as the standard. This compound is a common toothpaste additive which decreases dental calculus formation. Two of the 23 Kampo medicines showed little or no inhibition either on the induction time or on the rate of HAP transformation. Twelve of them reduced the rate of HAP transformation by 20-40% and with 1.9- to 4.0-fold increases in the induction time. The remaining nine showed even greater activity. Keishi-ninjin-to (TJ-82), Dai-kenchu-to (TJ-100), Toki-to (TJ-102), Rikko-san (TJ-110) and San'o-shashin-to (TJ-113) showed the same inhibitory effect as EHDP. Shigyaku-san (TJ-35;5.2-fold), Dai-kanzo-to (TJ-84;4.9-fold), Oren-gedoku-to (TJ-15;12.7-fold) and Inchin-ko-to (TJ-135;9.5-fold) had a greater effect on the increase of induction time than EHDP and reduced the rate of HAP transformation by 50-60%. These results suggest that these nine kinds of Kampo medicines may have potential as anticalculus agents in toothpastes and mouthwashes.

Calcium↗
PubMed1993

Mutation of amino acids within the gibbon ape leukemia virus (GALV) receptor differentially affects feline leukemia virus subgroup B, simian sarcoma-associated virus, and GALV infections.

The three type C retroviruses, gibbon ape leukemia virus (GALV), simian sarcoma-associated virus (SSAV), and feline leukemia virus subgroup B (FeLV-B), infect human cells by interacting with the same cell surface receptor, GLVR1. Using LacZ retroviral pseudotypes and murine cells transfected with mutant GLVR1 expression vectors, we show that the same 9-amino-acid region of human GLVR1 is critical for infection by the three viruses. Rat cells were not susceptible to infection by LacZ (FeLV-B) pseudotypes because of a block at the receptor level. We found multiple amino acid differences from human GLVR1 in the 9-amino-acid critical region of rat GLVR1. Expression of a human-rat chimeric GLVR1 in murine cells demonstrated that rat GLVR1 could function as a receptor for GALV and SSAV but not for FeLV-B. Substitution of human GLVR1 amino acids in the critical region of rat GLVR1 identified three amino acids as responsible for resistance to FeLV-B infection; two of these affect SSAV infection, but none affects GALV infection.

Amino Acid Sequence↗
PubMed1993

Comprehensive health evaluation of workers in the ceramics industry.

A cross sectional study on ceramics workers in the Seto area of Japan was conducted to determine whether there are differences in the morbidity pattern and overall health among the working populations employed by different sized companies engaged in the ceramics industry. The study population consisted of 3324 male ceramics workers (age range 40-69) who participated in the Seto occupational health screening programme in 1990. The prevalences of pulmonary diseases (silicosis and tuberculosis) and findings of some nonpulmonary diseases were compared in terms of company size by categories of 1-19, 20-49, 50-99, and 100 or more employees. The values of various screening tests were subjected to principle component analysis to extract factors representing key indices of health state. The average factor scores stratified by company size were used to quantitatively evaluate the comprehensive health level. Both prevalence and multivariate analysis showed that the employees working for smaller companies had overall worse health. The smaller the company, the higher the prevalence and the lower the health scores for silicosis and pulmonary tuberculosis tended to be; significantly increased rates and lower health scores for hypertension, anaemia, and glucosuria among small companies were also found when compared with larger companies. The high morbidity of silicosis and pulmonary tuberculosis in smaller companies contributed most to the decline in the overall health level.

Adult↗
PubMed1993

Glomerular growth in the remnant kidney after a contralateral nephrectomy.

A unilateral nephrectomy enhances growth or weight gain in the remaining kidney, although it is not known whether the mechanism involves the division of glomerular cells. We have isolated glomeruli from the remnant kidney at different time intervals after a nephrectomy and measured the percentage of cells in the G1, G2 + M and S phases by flow cytometry. All the steady-state glomerular cells remained in G1 phase, while a significant percentage had progressed into the S phase by 4 h after the uninephrectomy. The rise in the number of cells in the S phase gradually decreased to control values by 48 h, during which time the number of cells in both G1 and G2 + M phases increased concomitantly. Neither DNA nor RNA content per glomeruli was altered by 4 and 24 h after uninephrectomy. The data suggest an early division of the glomerular cells in the remnant kidney after a contralateral nephrectomy.

Animals↗
PubMed1993

Involvement of the local immune response in a case of advanced cervical cancer in a patient with systemic lupus erythematosus.

Although patients with systemic lupus erythematosus (SLE) have frequently accompanying malignancies, there are few documented cases in the literature of advanced cervical cancer patients with SLE. This report describes a case of advanced cervical cancer in a 39-year-old patient with a 20-year history of SLE (FIGO stage IIIb) and evaluates the immunological response of the tumor. The clinical course of this patient with SLE, with rapid growth of cervical cancer and a poor prognosis, may suggest that T cells play a key role in the growth of cancer.

Adult↗
PubMed1993

Increased plasma endothelin levels in Kawasaki disease: a possible marker for Kawasaki disease.

Plasma immunoreactive endothelin (iET) levels were investigated in patients with Kawasaki disease (KD). The iET level was 2.49 +/- 0.13 pg/mL in KD patients and 1.32 +/- 0.06 in age-matched control subjects, showing a significant increase with KD. The iET level was not increased in patients with febrile inflammatory diseases of bacterial origin without KD (non-KD group). Parameters indicating an inflammatory reaction, such as C-reactive protein, platelet count, white blood cell count, and interleukin-6 level, were increased in the KD patients. However, they were similarly increased in the patients with febrile diseases of bacterial origin and showed no significant differences between the two groups. This study is the first to report that plasma iET levels are elevated in a disease mainly involving vasculitis. These results suggest that blood iET levels are increased in KD patients as a result of the associated vascular endothelial damage and that iET can be a useful marker for the diagnosis of KD.

Biomarkers↗
PubMed1993

Evaluation of brain collateral circulation by the transcranial color Doppler-guided Matas' test.

For the determination of the indication for reconstruction of the carotid artery in patients with head and neck cancer, a color Doppler-guided Matas' test was performed to examine brain collateral circulation and blood flow of the middle cerebral artery (MCA) and internal carotid artery (ICA). Both SSA-270A convex (3.75 MHz) and linear (3.75 MHz and 2.5 MHz) array probes (Toshiba Co, Ltd) were used for this investigation. A temporary occlusion test (60 seconds) by digital pressure on the common carotid artery was performed on 30 patients with head and neck cancer. The results were classified into four groups according to the relative flow volume (percent blood flow volume before the test) of the MCA: group A, with a flow volume of 87% or more; group B, with a flow volume between 72% and 86%; group C, with a flow volume between 57% and 71%; and group D, with a flow volume of 56% or less. The relative flow volume of the MCA was correlated with the ICA stump pressure and single photon emission computed tomography during a balloon Matas' test (ICA occlusion). This test seems to be useful in predicting the risk of carotid resection without reconstruction and in determining the indication for reconstruction of the carotid artery.

Adult↗