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Biomedical subjects

Y Miyata

Publications and source records attributed to Y Miyata.

At least 271 records · Page 15Linked to original sources
PubMed1986

Immunohistochemical distribution of ferritin, lactoferrin, and transferrin in granulomas of bovine paratuberculosis.

Granulomatous lesions of bovine paratuberculosis contained ferritin, lactoferrin, and a small amount of transferrin, as demonstrated by the immunohistochemical method. Macrophages in the normal bovine ileum did not contain lactoferrin and transferrin; however, ferritin was found in individual macrophages of Peyer's patches. These results may help elucidate the relationship between intracellular growth of Mycobacterium paratuberculosis and the presence of iron-binding proteins in the granulomas.

Animals↗
PubMed1986

[The results of investigation by the Japanese version of Morningness-Eveningness Questionnaire].

Morningness-Eveningness Questionnaire (MEQ) developed by Horne & Ostberg (1976) was translated into Japanese, and then, MEQ and Life Habits Inventory were administered to approximately 1,500 university students. The distribution of MEQ scores was essentially normal, and the reliability of this questionnaire was high (r alpha = .702). Comparing among the morning, evening, and intermediate types, it was found that the morning type retired and arose significantly earlier than other types, although there was no significant differences in sleep length. Furthermore, there were significant differences between the morning and evening types in sleep latency, mood on arising, adequate amount of sleep, frequency and duration of nap, and number of staying awake all night per month. These results suggested that the evening type had more irregular sleep-waking habits than the morning type. Since the above results were obtained only from student population, further investigation on various populations is requested.

Adult↗
PubMed1986

Effects of nerve growth factor on differentiation of muscle spindles following nerve lesion in neonatal rats.

Central synaptic function of Group Ia sensory fibers has been shown to be enhanced by daily applications of NGF in neonatal rats. In the periphery, Group Ia sensory fibers are known to trigger the differentiation of muscle spindles. In the present study we examined, in neonatal rats, whether daily NGF treatment affects the number or structure of spindles formed in muscle whose nerve has been crushed. The results show that 25-35 d after nerve crush, de novo supernumerary spindles were formed by treatment with NGF in the temporarily denervated muscle. The number of spindles in the corresponding muscle on the contralateral, intact side was not affected by NGF treatment. Following nerve crush alone, the mean number of spindles in the muscle was not significantly different from the normal value. It is suggested that treatment of neonatal rats with NGF may facilitate the outgrowth of excessive peripheral collaterals of regenerating Group Ia sensory fibers, which, in turn, contributes to the formation of de novo spindles as a result of interaction with myotubes.

Animals↗
PubMed1986

Prophylactic/therapeutic effects and induction of reversal reactions with thymus transplantation in Mycobacterium leprae-infected nude mice.

The study results indicated that thymus transplantation was effective in suppressing the growth of Mycobacterium leprae in the nude mouse, and also suggested that thymus transplantation was effective as immunotherapy of experimental leprosy in nude mice. The histopathological findings revealed the induction of reversal reactions in those animals receiving thymus transplants.

Animals↗
PubMed1986

Restored pathogenicity of attenuated Mycobacterium lepraemurium in mice.

The ability of Mycobacterium lepraemurium (Mlm) to adhere to A31 cells in culture decreased with the number of passages of the bacilli on Ogawa egg-yolk medium. Pathogenic Mlm consistently grew in tissue culture cells but growth was not seen with attenuated Mlm isolated from a smooth colony. After prolonged incubation, attenuated Mlm became adapted to tissue culture growth. The pathogenicity of the attenuated bacilli was restored partially by the adaptation to tissue culture cells and restored almost completely by passage in mice. After restoration of pathogenicity by these methods, the Mlm formed rough-type colonies on Ogawa egg-yolk medium although the colonies were not completely of the rough type. Attenuated Mlm did not interfere with the growth of in vivo-derived Mlm in tissue culture or in mice.

Adhesiveness↗
PubMed1986

Effects of nerve growth factor on the survival and synaptic function of Ia sensory neurons axotomized in neonatal rats.

Sensory neurons with small diameters (A delta and C cells) are known to be responsive to exogenous NGF even at postnatal stages. We have examined whether large Group Ia sensory neurons (A alpha cells) arising from muscle spindles are also responsive to NGF in neonatal rats. For this purpose, monosynaptic excitatory postsynaptic potentials (EPSPs) were evoked in spinal motoneurons by Group Ia muscle afferent volleys. When a muscle nerve was crushed on the day after birth, the monosynaptic EPSPs elicited by afferent volleys from the muscle were depressed within several weeks. This synaptic depression was partially reversed by daily treatment with NGF. NGF treatment also enhanced the EPSPs evoked by stimulation of intact muscle nerves, but this effect was less marked than that on the EPSPs produced by stimulation of the previously crushed muscle nerve. Exogenous NGF was effective for the EPSPs when the treatment began on the day after birth but not when the treatment began 4 d after birth. Following crush of a muscle nerve on the day after birth, about 45% of the sensory neurons derived from the muscle were lost. The cell death of small sensory neurons was prevented by daily treatment with NGF, whereas the NGF treatment was ineffective in preventing the cell death of large sensory neurons. The results indicate that Group Ia sensory neurons are responsive to NGF during early postnatal life.

Animals↗
PubMed1985

Nerve growth factor enhances central synaptic function of Ia sensory neurons.

Daily treatment of neonatal rats with nerve growth factor (NGF) significantly enhanced monosynaptic excitatory postsynaptic potentials (EPSPs) evoked in spinal motoneurons by muscle afferent volleys. A few weeks after crush of a muscle nerve, the EPSPs elicited by afferent volleys from the muscle nerve were markedly depressed. This synaptic depression could be partly prevented by daily application of NGF. It is concluded that central synaptic function of Ia sensory neurons is responsive to exogenous NGF in postnatal animals.

Animals↗
PubMed1985

Plasma apolipoprotein A-IV levels decrease in patients with chronic pancreatitis and malabsorption syndrome.

An immunochemical method was developed for measurements of serum levels of apolipoprotein A-IV (apo A-IV). Using this technique, we found decreased levels of apo A-IV in patients with chronic pancreatitis and malabsorption syndrome and these low levels of apo A-IV in a patient with malabsorption syndrome were overcome after appropriate oral nutrition. Thus, measurements of apo A-IV may provide a good index for the assessment of fat intake and absorption.

Adolescent↗
PubMed1985

Pathological analysis of the carcinogenicity of sodium o-phenylphenate and o-phenylphenol.

Potential carcinogenicity and promoting effects of sodium o-phenylphenate (OPP-Na) in two-stage urinary bladder carcinogenesis were shown in male F344 rats pretreated with 0.01% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). However, o-phenylphenol (OPP) did not enhance the occurrence of urinary bladder lesions in rats pretreated with BBN. Scanning electron microscopy of OPP-Na-treated animals demonstrated a dose-dependent production of pleomorphic microvilli on the luminal surface of bladder superficial cells, whereas these were not observed with OPP. These results give some support to the conclusion that OPP-Na may be carcinogenic in the urinary bladder of male rats.

Animals↗
PubMed1985

Respiration in Mycobacterium leprae.

Fairly pure leprosy bacilli were easily collected from nude mouse foot pad lepromas by the Ficoll density gradient centrifugation and alkali treatment methods. The yield of bacilli available for biochemical study was 42.6%. The density of Mycobacterium leprae was very heterogeneous. The percent of solid bacilli in the light bacilli fraction was 23%; that in the heavy bacilli fraction was 40%. The endogenous respiration activity in the heavy bacilli was greater than that in light bacilli. The average coefficient of respiration in M. leprae was 1 microliter O2/mg X hr. In the whole cells of M. leprae, a cytochrome b1 absorption peak and its Soret peak were detected at wavelengths of 560 nm and 426 nm, respectively. However, a cytochrome a2-like peak (which was observed in M. lepraemurium), and a cyt c and cyt a were not detected. Catalase activity was not found in whole cells, the cell-free extract, or particle fractions of M. leprae. Any catalase activity associated with M. leprae suspensions is a tissue contaminant. NAD-peroxidase activity was also not detected in the cell-free extract of the leprosy bacillus. These results would indicate that leprosy bacilli cannot degrade hydrogen peroxide.

Animals↗