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Biomedical subjects

K Ishihara

Publications and source records attributed to K Ishihara.

At least 631 records · Page 35Linked to original sources
PubMed1987

Characterisation of the polymerised and monomeric human serum albumin binding sites on hepatitis B surface antigen.

Receptors for polymerised human albumin are present on the pre-S sequence of the envelope protein of HBV and on the hepatocyte membrane and are thought to be involved in uptake of the virus by hepatocytes. Using a solid phase radioimmunoassay we demonstrate binding of HBsAg to polymerised human serum albumin (pHSA) in both HBe antigen-positive and -negative patients, and this binding is linearly related to the HBsAg titre in both groups. There are probably several modes of interaction between HBsAg and pHSA. Here we show that pHSA binds to the 22,000-dalton polypeptide of HBsAg, which does not contain the pre-S sequence. This pHSA-HBsAg interaction is inhibited by physiological concentrations of human serum albumin, suggesting that the albumin known to be present in the envelop of HBsAg plays a role in this binding. The inhibition of pHSA/HBsAg interaction by native albumin suggests that this interaction is probably not an important mechanism of virus uptake during infection of hepatocytes.

Animals↗
PubMed1987

High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan.

In Japan, a set of experiences called kanashibari is considered identical with isolated sleep paralysis. We investigated this phenomenon by means of a questionnaire administered to 635 college students (390 men and 245 women). Of all subjects, about 40% had experienced at least one episode of kanashibari [subjects of K(+)]. Therefore, isolated sleep paralysis is apparently a more common phenomenon than is usually appreciated. About half of the subjects of K(+) reported that they had been under "physical or psychological stress" or in a "disturbed sleep and wakefulness cycle" immediately before the episode. Many subjects of K(+) experienced the first episode in adolescence. In the distribution of age of first attack, the peak occurred at an earlier age in women subjects than in men subjects. These findings suggest that two factors influence the occurrence of the phenomenon. One is exogenous physical or psychological load and the other is endogenous biological development.

Adolescent↗
PubMed1987

Differences in sleep-wake habits and EEG sleep variables between active morning and evening subjects.

This article is a survey study, followed by an experimental study, examining the differences of sleep-wake habits and sleep electroencephalographic (EEG) variables between morning and evening type subjects (Ss). In the survey study, the Japanese version of the Horne and Ostberg Morningness-Eveningness Questionnaire and Life Habits Inventory (LHI) were administered to approximately 1,500 university students. The survey results showed that the two types were significantly different from each other in terms of retiring and arising time, sleep latency, mood on arising, nap, adequate amount of sleep, number of times of staying awake all night, and variability in bedtime, arising time, and sleep length. These results suggested that evening type Ss had more irregular and/or flexible sleep-wake habits than morning type Ss. In the experimental study, 10 morning and 11 evening type Ss were selected from the population included in the survey study, and polysomnograms were obtained. The results showed that only in rapid eye movement (REM) latency did morning type Ss significantly differ from evening type Ss. REM latency might be related to personality factors, particularly to neuroticism and anxiety.

Adolescent↗
PubMed1987

Platelet-activating factor in late asthmatic response.

The role of platelet-activating factor (PAF) in the late asthmatic responses was studied. The concentrations of lyso-form of PAF in plasma were measured at 0 and 20 min, and 6 and 24 h after the antigen inhalation challenge among patients with bronchial asthma. PAF activities were measured by their aggregating ability of washed rabbit platelets after acetylation of lyso-PAF into the biological active form of PAF, when there were no detectable amounts of PAF in plasma. The concentrations of lyso-PAF were found to be significantly increased in patients with the late asthmatic response compared with patients with the single immediate response at 6 h after the antigen challenge. In contrast, lyso-PAF levels were not significantly different at 20 min after the antigen challenge between these two groups. PAF inactivator activity in plasma increased when there was a decrease in the lyso-PAF level. These results suggest that PAF may participate in the late asthmatic response and may provide a new insight into the pathogenesis and the treatment of bronchial asthma.

Asthma↗
PubMed1987

Possible mechanism involved in the inhibitory action of U-50, 488H, an opioid kappa agonist, on guinea pig hippocampal CA3 pyramidal neurons in vitro.

Intracellular recordings of the CA3 pyramidal neurons in the guinea pig hippocampus were made in vitro. U-50 488H (100 microM), a selective opioid kappa agonist, decreased the synaptic response produced by stimulation of the mossy fibers but did not affect the membrane potential, the input resistance and the generation of the Na+ spikes or the Ca2+ spikes. Iontophoretically applied U-50 488H depressed the depolarization produced by L-glutamate. U-50 488H (100 microM) also depressed the consistent depolarization produced by veratrine (3 X 10(-5) g/ml) and this effect was partially antagonized by naloxone. Moreover, application of U-50 488H led to a disappearance of the anomalous rectification. These results suggest that U-50 488H depresses the synaptic activities of the CA3 pyramidal neurons by inhibiting a subtype of the Na+ channel, "Na+ channel type II" which slowly closes, of the soma and/or the dendrites of the neurons.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1987

[Skin malignant tumor. High-risk groups].

The principal diseases which fall into the high-risk category for skin malignant tumor are squamous cell carcinoma, basal cell carcinoma, malignant melanoma, Bowen's disease, Paget's disease, and the like. When considering these high-risk groups there must be an aware of radiation damage, burn and lesion scarring, chronic punctures and chronic inflammation in squamous cell carcinoma, exposure to sunlight in basal cell carcinoma, and early stage changes in morphology, coloration and size in melanoma. Bowen's and Paget's diseases also need to be closely observed over the clinical course since they run a high-risk of complication through visceral cancers.

Bowen's Disease↗
PubMed1987

[Phase I study of natural interferon-gamma].

We report a clinical study of toxicity and pharmacokinetics of intravenously administered natural interferon-gamma. Twenty three cases with metastatic cancer were given interferon-gamma at doses of 10 X 10(4)-400 X 10(4) IU in single injection. Another twenty three cases were administered at doses of 5 X 10(4)-50 X 10(4) IU/day every day for thirty days. Side effects associated with natural interferon-gamma administration were qualitatively similar to those previously reported for alpha, and beta interferon treatment. After intravenous injection, interferon-gamma was cleared monoexponentially with a short half-life of 120 minutes from the circulation. One case with disseminated thyroid cancer showed minor response.

Drug Evaluation↗
PubMed1987

[Cross-sectional visualization of regurgitant jet by color flow mapping to evaluate aortic regurgitation].

In the noninvasive evaluation of aortic regurgitation by Doppler echocardiography, flow mapping of the aortic regurgitant jet using the long-axis approach is of limited value in cases of combined mitral stenotic lesions. This is because the transmitral flow yields flow disturbances in the left ventricle, making it difficult to identify the extent of the aortic regurgitant jet. To overcome these limitations, the severity of aortic regurgitation was evaluated using the cross-sectional area of the aortic regurgitant jet at the level of the aortic valve as visualized by color flow imaging technique. The study population consisted of 16 patients with aortic regurgitation (10 with pure aortic regurgitation, five with superimposed mitral stenosis, and one with mitral valve replacement). Three normal subjects served as controls. The cross-section of the aortic regurgitant jet was visualized as a mosaic of yellow and blue in all patients with aortic regurgitation, but not in any of the controls. Planimetric measurements of the cross-sectional area of the regurgitant jet (J) and the aortic annulus area (Ao) were performed, and the Doppler parameter, J/Ao, was calculated. As a reference, the aortic regurgitant fraction (RF) was calculated from Doppler measurements of systolic aortic and pulmonary flows (AF and PF); RF (%) = (AF - RF)/AF x 100. The Doppler parameter, J/Ao, correlated well with the Doppler measurement of RF (r = 0.82, p less than 0.005), irrespective of the presence of associated mitral lesions. Thus, the cross-sectional area of the aortic regurgitant jet determined by color flow imaging technique would be a useful estimate of the severity of aortic regurgitation, even in the presence of associated mitral stenotic changes.

Adolescent↗