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Biomedical subjects

R Tanaka

Publications and source records attributed to R Tanaka.

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

An enzyme immunoassay for pepsinogen II(PGII): chronological changes in serum PGII concentrations.

A new two-site enzyme immunoassay for pepsinogen II(PGII) has been developed. The detection limit of PGII was 0.15 ng/ml (15 pg/tube) and the optimal assay range was 1.5 to 150 ng/ml (150 pg to 15 ng/tube). Mean serum PGII concentrations in normal males and females were 17.2 and 14.6 ng/ml, respectively. The chronological analysis among 5 age groups from 20 to 69 yr, males and females together, revealed that the serum level was low (11.9 ng/ml) between 20-39 yr, gradually increased from 40 yr of age and attained the maximum (22.5 ng/ml) in the 50-yr group. Total gastrectomy markedly lowered the serum level to 1.9 ng/ml, suggesting that the majority of PGII in serum was derived from the gastric mucosa. This assay makes it possible to measure trace amounts of PGII derived from extragastric as well as gastroduodenal tissues.

Adult↗
PubMed1987

Fungi in bathwater and sludge of bathroom drainpipes. 1. Frequent isolation of Exophiala species.

Samples of bathwater from 14 homes and 22 public bathhouses and sludge in drainpipes from 19 household bathrooms were plated out onto potato dextrose agar supplemented with chloramphenicol. Several media were used to study colony morphology of the isolates and the thermotolerance and alkaline tolerance of each isolate were examined. Eleven sludge samples produced 12 isolates of Exophiala jeanselmei, 2 of E. dermatitidis and 1 of E. moniliae. Five household bathwater samples produced 2 isolates of E. jeanselmei, 4 of E. dermatitidis and 1 of E. alcalophila. One isolate of E. jeanselmei, 2 of E. dermatitidis, 3 of E. moniliae and 2 of unidentified Exophiala species were recovered from 6 samples of the bathwater dissolving 'Chinese medicine' in the bathtubs of public bathhouses. One isolate of E. jeanselmei was recovered from the 15 samples of bathwater from public bathhouses. Bathwater and sludge in bathroom drainpipes may be an important habitat of Exophiala species.

Baths↗
PubMed1987

Ultrastructural alterations of neuronal cells in a brain stem ganglioglioma.

A brain stem ganglioglioma in a 9-year-old female was examined ultrastructurally. The constituent neuronal (ganglion) cells displayed various ultrastructural features of neuronal degeneration including Hirano, Lafora and zebra bodies, inclusion-like aggregates of neurofilaments and large dilatations of rough endoplasmic reticulum. Although similar observations have been reported in peripheral neuronal tumors, this is the first reported occurrence in ganglioglioma, an uncommon tumor in the central nervous system. The coincidence of these alterations in the present tumor appeared to be of great interest, however, their exact etiology remained uncertain.

Brain Neoplasms↗
PubMed1987

Photodynamic therapy of rat liver cancer: protection of the normal liver by indocyanine green.

The application of photodynamic therapy (PDT) to hepatocellular carcinoma (HCC) has been difficult because hematoporphyrin derivatives (HpD) accumulate not only in cancer cells but also in normal hepatocytes and, hence, laser irradiation causes injuries in both tissues. Protection of the normal liver tissue from laser phototoxicity was demonstrated using indocyanine green (ICG) as a protective agent. In vitro, argon laser irradiation decolored the green tint of ICG much faster in solutions containing HpD than those without, suggesting that ICG captured singlet oxygen from HpD. Degeneration of Change hepatocytes induced by HpD and laser irradiation was prevented by an addition of ICG into the medium. In vivo, laser irradiation of the rat liver surface caused hyperemia when HpD was injected two days before, while the hyperemia was much milder in rats additionally receiving ICG injection 10 minutes before the irradiation. ICG injected into rat HCC accumulated only in the normal liver tissue. Laser irradiation of rat HCC preinjected with both HpD and ICG destroyed only the cancer tissue, while the surrounding liver tissue was preserved. Both in vitro and in vivo results suggest that ICG has a scavenger effect against excited oxygen and it might be used as a protective agent in PDT of HCC.

Animals↗
PubMed1987

Disappearance of a tumor shadow fed by the tentorial artery after embolization of the external carotid artery.

The tentorial artery is a branch of the meningohypophyseal trunk originating from the internal carotid artery; this artery sometimes becomes an enlarged feeding artery in patients with tentorial lesions, especially tentorial meningiomas. We experienced a case of a cerebellopontile angle meningioma whose angiogram revealed the disappearance of a feeding artery arising from the tentorial artery after embolization of the external carotid artery. We report this case and discuss the mechanism of this phenomenon.

Carotid Artery, External↗
PubMed1987

Subarachnoid dissemination of a pituitary adenoma.

The authors present an unusual case of a pituitary adenoma that developed into intracranial and intraspinal dissemination following intracranial surgery with adjunctive radiation, and review metastasis of pituitary adenomas in the central nervous system briefly in light of other reported cases.

Adenoma↗
PubMed1987

Functional dissociation of dual activities of glia maturation factor: inhibition of glial proliferation and preservation of differentiation by glial growth inhibitory factor.

Glial growth inhibitory factor (GGIF), derived from the culture medium of mouse neuroblastoma cell (NAs-1), lowered the DNA synthesis and cell multiplication of normal rat glioblasts induced by glia maturation factor (GMF). The inhibitory action of GGIF depended on the concentration of GMF in the culture medium, and was of an uncompetitive type on kinetic analysis. GGIF showed the inhibitory activity at a late stage of the G1 phase or early stage of the S phase. The factor, however, failed to inhibit the differentiation-promoting activity of GMF. The data strongly suggest that the dual activities of GMF, the promotion of glial proliferation and differentiation, may be elicited by mutually independent intracellular processes.

Animals↗
PubMed1987

The effect of L-threo-DOPS on synaptic transmission to soleus motoneuron in normal subjects and patients with Parkinson's disease.

The effect of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on synaptic transmission to the soleus motoneurons was studied using the H-reflex method in 12 normal subjects and in 4 patients with Parkinson's disease. A long-lasting depression of the test H-reflex, which was evoked by a conditioning group I volley in the homonymous tibial nerve with an onset latency of ca. 30 ms and a duration of more than 1 s and was regarded to represent the transmitter depletion caused by a preceding volley, diminished significantly after the oral administration of L-threo-DOPS both in the normal subjects and in the patients. On the other hand, no change was recognized in the slow depression which was caused by a group I volley of the heteronymous common peroneal nerve and was regarded as the presynaptic inhibition. The findings suggest that L-threo-DOPS influences the reduction of transmitter depletion.

Adult↗
PubMed1987

The effects of "yusho" type PCB on triglyceride lipase and fatty acid composition.

Yusho type polychlorinated biphenyl (Y-PCB) was prepared in order to study lipid disorder of the PCB poisoning "yusho." Y-PCB caused hypertriglyceridemia and hypercholesterolemia in the rat. Triglyceride lipase (TGL) activities in liver and postheparin serum were suppressed by Y-PCB administration, whereas it was not suppressed in fat. In in vitro experiments, Y-PCB did not suppress TGL in either liver or fat. Although Y-PCB increased fatty acids in the liver 2.5-fold, the relative proportion of fatty acids composition was not changed so remarkably as that in absolute concentrations. These findings suggested that liver is the target of Y-PCB -mediated alteration of lipid metabolism.

Adipose Tissue↗
PubMed1987

Antitumor effect of recombinant murine interferon-beta against mouse malignant glioma.

A study was made on the antitumor effect of recombinant murine interferon-beta (rMuIFN-beta) against virus-induced mouse malignant glioma. In in vitro experiments, a dose-dependent and a time-dependent manner were observed for 24 h in the antiproliferative activity of rMuIFN-beta. In in vitro experiments, the growth of subcutaneously transplanted gliomas in mice treated with intraperitoneal administration of rMuIFN-beta was inhibited slightly, whereas, with intratumoral administration, it was inhibited more effectively. In immunological studies, natural killer (NK) cell and cytotoxic T-lymphocyte activities of spleen cells were enhanced with intraperitoneal administration of rMuIFN-beta. The analysis of IFN-induced change in a subpopulation of peripheral blood lymphocytes revealed a decrease of Thy.1,2-positive cells and an increase in the ratio of Lyt.1/Lyt.2-positive cells. But these immunological effects of rMuIFN-beta declined on the 7th day with daily administration. Such hyporeactivity may be noteworthy for the clinical application of IFN.

Animals↗
PubMed1987

Analysis of cerebellar motor disorders by visually-guided elbow tracking movement. 2. Contribution of the visual cues on slow ramp pursuit.

In visually-guided slow ramp elbow tracking, patients with cerebellar ataxia show irregular undulations of pursuit velocity which result in a position tracking pattern unlike the smooth constant velocity or rate tracking pattern of normal controls (Beppu et al., 1984). This task provides ample opportunity to use both visual and proprioceptive feedback information for correcting errors. The present study investigated the role of visual information for generation of this saccadic pursuit pattern in the patients. A television screen was divided into upper and lower halves in each of which a vertical strip was displayed. The upper strip (T, target) was moved horizontally from the centre of the screen to the left or right by ramp voltage. The lower strip (D, displacement of the handle) was moved in proportion to angular displacement of the handle by a potentiometer coupled to the handle axis. The subject, while sitting in front of the screen, had to make D match the movement of T by controlling the handle with his arm. The range of T movement was 30 deg in terms of the angular movement of the handle. T velocity was 6.0 or 7.5 deg/s. After a training session, the test was performed in which D or T was suddenly erased from the screen during pursuit, depriving the subject of visual information about the moving limb and/or performance. The procedure gave only minor effects on the performance of the control subjects, but it reduced significantly the velocity undulation of the patients with cerebellar ataxia, producing a smoother continuous pursuit. There were no significant differences in performance between D or T erase tasks. The result supports the hypothesis that the marked undulation pattern during pursuit movement in cerebellar ataxia is due to repeated visually-guided error correction responses. The relative importance of the visual pathway for conveying position information and the proprioceptive pathway for movement velocity information in this visual slow ramp tracking task is also discussed.

Adult↗