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Biomedical subjects

Y Terayama

Publications and source records attributed to Y Terayama.

At least 55 records · Page 3Linked to original sources
PubMed1990

The mechanical filtration coefficient (Lp) of the cell membrane of cultured glioma cells (C6).

The mechanical filtration coefficient (Lp) of the membrane of cultured glioma cells was determined from the rate of swelling of the cells. The swelling was induced by exposing the cells to distilled water. Assuming that cells swell in a symmetrical manner, Lp was 2.2 x 10(-8) cm/s.mmHg, or 1.7 x 10(-4) microns/s.cmH2O when calculated from changes of the cell diameter.

Cell Membrane↗
PubMed1990

[Urinary kallikrein-like activity in renal transplant recipients].

Koolen, M.I. et al. (1984) measured urinary kallikrein (UKal) in renal transplant recipients using 2 methods, S-2266 amidolytic assay and radioimmunoassay, and reported that the values by the former method showed an increase in amount at the time of acute rejection episode (ARE) despite of no variation in those by the latter. To clear the discrepancy, 24 hours excretion of UKal was measured by the amidolytic assay using Pro-Phe-Arg-MCA under 2 conditions, with and without soybean trypsin inhibitor (STI), in 10 living related kidney recipients (LR), their donors (LD), and 8 cadaver kidney recipients (CR), Furthermore, gel filtration chromatography (Sephacryl S-200) was performed in some recipients and LD to confirm whether the amidolytic activity (ALA) indicates exclusively UKal or not. The results were as follows. In LD, there were no statistical differences in ALA between not only before and after uninephrectomy but also with and without STI. On the post-operative course, some recipients showed a tendency of decrease in ALA with STI, and some kept a constant level. There occasionally appeared a difference between ALA with and without STI just after the transplantation, and at the time of ARE, acute tubular necrosis (ATN) or urinary tract infection (UTI). There was no fixed characteristic variation in ALA, both with and without STI, at the time of ARE. ALA with STI was lower in LR than in LD, and the lowest in CR, From the second week of transplantation and afterward, ALA with STI showed a positive correlation not with creatinine clearance but with urinary aldosterone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Effect of glycerol on the hemodynamics of acutely induced ischemic area in the cerebral cortex of cats.

The effect of glycerol on the hemodynamics of ischemic areas of the brain was examined. Employing a photoelectric apparatus, the CBV (vol%), mean transit time of blood(s), and CBF (ml/100 g/min) in the cortex of the left ectosylvian gyrus were determined in 16 anesthetized cats before, at 1 hr, and at 2 hr after left MCA occlusion. In 10 cats, 10% glycerol in 5% fructose saline was intravenously administered at a speed of 5 ml/kg/hr at 1 hr after MCA occlusion. The other animals served as the control. In the group given glycerol, the relation between the values of CBF at 1 hr after MCA occlusion (X) and those at 2 hr after MCA occlusion (Y) was curvilinear and could be expressed by the regression curve, Y = 0.04X2 - 0.26X + 7.68 (R2 = 0.86). In the control group without glycerol, however, a linear relation expressed by the equation, Y = 0.76X + 5.96 (R2 = 0.94), was obtained. Comparison between the two relations indicated that glycerol improved the hemodynamics in the mild ischemic area with a relatively higher CBF. Severely ischemic areas showed no improvement.

Animals↗
PubMed1989

The behavior of 99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) in blood and brain.

99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) is a reagent for scanning cerebral blood flow. We investigated how 99mTc-HMPAO changed in the blood and brain. The 99mTc-HMPAO, which was prepared by adding of 99mTcO4- to HMPAO and Sn(II), consisted of primary and secondary complexes, reduced hydrolyzed 99mTc, and 99mTc-pertechnetate. The percentage of the primary complex in 99mTc-HMPAO decreased with time after preparation. The primary complex converted to the secondary one very rapidly in the presence of plasma. When 99mTc-HMPAO was injected into patients, 99mTc activity was immediately partitioned in the plasma fraction, with approximately 60% in whole blood. In plasma, 99mTc was found to be associated with proteins such as albumin and globulin. 99mTc trapped in red cells was not washed out with either plasma or saline. Biodistribution studies showed that the less lipophilic compounds of 99mTc-HMPAO could not pass through the blood brain barrier (BBB), and therefore did not accumulate in the brain. The results of gel chromatography and equilibrium dialysis indicated that no specific 99mTc binding protein was present in the brain. Considering the instability of 99mTc-HMPAO in vivo, we proposed that the speed at which the primary complex converted to the less lipophilic compounds was important in allowing 99mTc-HMPAO to pass through the BBB and to be fixed in the brain.

Animals↗
PubMed1989

Enhanced erythrocyte aggregability in occlusive cerebrovascular disease.

We measured the rate of erythrocyte aggregation using our whole-blood aggregometer in 80 patients with occlusive cerebrovascular disease during the acute and chronic phases. We compared the data with values for 38 age-matched healthy controls. Mean +/- SD erythrocyte aggregability of the patients during both the acute phase (0.145 +/- 0.21/sec, n = 35) and the chronic phase (0.139 +/- 0.21/sec, n = 45) was higher than that in the controls (0.123 +/- 0.21/sec, n = 38; p less than 0.01). Erythrocyte aggregability was positively correlated with the plasma concentration of globulin and fibrinogen and inversely correlated with the albumin:globulin ratio. However, these correlations did not necessarily exclude the possibility that some unknown substance(s) released from ischemic tissue might enhance erythrocyte aggregability.

Acute Disease↗
PubMed1988

[Plasma normetanephrine and metanephrine levels and their relationship to norepinephrine and epinephrine].

To study the relation of normetanephrine (NM) and metanephrine (M) to norepinephrine (NE) and epinephrine (E), plasma free NM (f-NM), free M (f-M), total NM (t-NM) and total M (t-M) were measured in normal subjects and patients with pheochromocytoma (PHEO), neuroblastoma, Cushing's syndrome, primary aldosteronism and chronic renal failure (CRF) by radioimmunoassay. Plasma f-NE and E were measured by radioenzymatic assay. Both f- and t-NM were high in PHEO, neuroblastoma and CRF. f- and t-M were also high in some patients with PHEO and CRF. Positive correlation was observed not only in f-NE with f-NM and t-NM, but also in f-E with f-M and t-M except for CRF. Although upright posture induced an elevation in f-NE and f-NM, t-NM was unchanged in normal subjects. In patients with PHEO, metoclopramide induced a prompt elevation in f-NE and E but no-change in t-NM and M levels. f-NE, f-E, f-NM, t-NM, f-M and t-M decreased rapidly after the resection of PHEO and reached the normal level on the third day after the surgery. In CRF patients, f-NM, t-NM, f-M and t-M decreased after hemodialysis despite an increase of f-NE. From these results, it was suggested that plasma NM and M levels reflected plasma NE and E to a certain extent in normal subjects and patients with normal renal function, and that the impaired renal function provoked an elevation of plasma NM and M due to the accumulation of them.

Adolescent↗
PubMed1988

Experimental mumps labyrinthitis in monkeys (Macaca irus)--immunohistochemical and ultrastructural studies.

Three monkeys (Macaca irus) were inoculated with mumps virus into unilateral cochleas and their inner ear were examined by immunofluorescent microscopy and transmission electronmicroscopy. The temporal bones were removed after survival period of 14 days when serological tests disclosed elevation of anti-mumps antibody titers. Immunofluorescent microscopy revealed that the viral antigen was positive in the stria vascularis. The ultrastructural study revealed that the pathologic changes in the cochleas were marked in the organ of Corti and stria vascularis. The outer hair cells were more susceptible to the infection than the inner hair cells. In the stria vascularis, both marginal and intermediate cells were affected. It was possible to find some of marginal cells in the basal turn shedding a large number of mature virions into the endolymph. These pathologic changes observed in the cochleas of the monkeys were similar to those previously revealed in the guinea pig cochleas and thus were considered as the specific features of acute mumps labyrinthitis.

Animals↗
PubMed1988

Comparison between the photoelectric method and H2 clearance method for measuring cerebrocortical blood flow in cats.

The photoelectric method using carbon black as a nondiffusible tracer of blood was compared with the hydrogen clearance (H2) method in nine anesthetized cats. A photoelectric apparatus and H2 electrode were applied to a small region of the cerebral cortex (left ectosylvian gyrus) for simultaneous measurement of the regional CBF. The values of CBF(H2) and CBF(photoelectric) were 50.7 +/- 19.2 and 52.1 +/- 14.5 ml.100 g-1.min-1, respectively. CBF(H2) and CBF(photoelectric) were found to correlate well (r = 0.588, p less than 0.01) when changes in CBF were induced by CO2 inhalation, exsanguination, hyperventilation, and occlusion of the middle cerebral artery. The correlation between CBF(H2) and CBF(photoelectric) was much better in the case of intraindividual comparisons (r = 0.957, p less than 0.01). In addition to its merits in common with the H2 clearance method, such as handiness, low cost, and strict regionality, the photoelectric method displayed the following advantages: time-to-time measurements of CBF (less than 20 s), immediate display of the microcirculatory flow pattern, and simultaneous monitoring of cerebral blood volume. However, measurements from deep structures of the brain are better performed by the H2 method despite the disadvantage of the use of a potentially explosive gas.

Animals↗
PubMed1988

Bilateral hemispheric reduction of cerebral blood volume and blood flow immediately after experimental cerebral hemorrhage in cats.

Acute cerebral circulatory changes following experimental cerebral hemorrhage were investigated in eight cats. The cerebral hemorrhage was produced in the right basal ganglia by introducing arterial blood via a thin catheter, using the systemic arterial blood pressure of the cat as a driving force. Local cerebral blood volume was measured continuously in the bilateral parietotemporal cortexes employing photoelectric apparatuses. Carbon black dilution curves were recorded from the regions, and the mean transit time of blood was calculated. Local cerebral blood flow was estimated from mean transit time and cerebral blood volume. Intracranial pressure was monitored continuously in the right parietal epidural space. Five minutes after cerebral hemorrhage, intracranial pressure increased by 24.0 +/- 6.1 mm Hg, while mean arterial blood pressure increased by only 2.9 +/- 2.0 mm Hg. Cerebral blood volume decreased by 1.60 +/- 0.24 vol% in the hemorrhagic and 1.14 +/- 0.30 vol% in the nonhemorrhagic hemisphere. Cerebral blood flow decreased by 30.0 +/- 4.5 ml/100 g brain/min in the hemorrhagic (initially 64.5 +/- 13.6) and by 30.3 +/- 7.5 ml/100 g brain/min in the nonhemorrhagic (initially 60.9 +/- 6.9) hemisphere. Increased intracranial pressure appeared to be the main cause of the observed cerebral blood volume/flow reduction shortly after experimental hemorrhage in the basal ganglia. Several other factors and mechanisms involved are discussed.

Animals↗
PubMed1988

Rapidly progressive sensorineural hearing loss (rapid deafness).

28 ears of 28 patients, aged 15 to 60 years, whose sensorineural hearing loss had developed over a period of a few hours to 3 days, were defined as having rapidly progressing sensorineural hearing loss (rapid deafness), in comparison with so-called sudden deafness with instantaneous onset. For other criteria, their hearing loss was idiopathic and the rate of hearing loss was confirmed by reliable means. The rate was greatest within the first 1-3 days. Of the 28 patients, 12 (43%) recovered completely, while another 12 improved markedly. The prognosis in rapid deafness was relatively good, but the recovery time was longer than in spontaneously healing sudden deafness. Sensorineural hearing loss in contralateral ears more often preceded rapid deafness (9 cases, 32%). No clear-cut difference could be found between rapid deafness and sudden deafness.

Adolescent↗
PubMed1988

Experimental mumps virus-induced labyrinthitis. Immunohistochemical and ultrastructural studies.

Guinea pigs were inoculated with mumps virus (Torii strain) by the intralabyrinthine or intravascular route and their cochleas were examined by immunofluorescence and electron microscopy. In these animals, viral antigen was detected in the cochleas, most often in the stria vascularis. However, viral infection was produced only in those with intralabyrinthine inoculation. The cochlear lesion commonly observed in this study was severe degeneration of the organ of Corti, which was usually found in the basal turn. Morphological evidence of viral infection, as depicted by intracellular strands of nucleocapsids and budding of the virus at the endolymphatic surface, was prominent in both the stria vascularis and Reissner's membrane. The cochlear location of mumps infection correlated closely with that of the viral antigen formerly reported in newborn hamsters.

Animals↗
PubMed1987

[Watery diarrhea, hypokalemia, achlorhydria syndrome due to recurrent malignant pheochromocytoma].

A case of malignant pheochromocytoma, with a recurrence 15 years after adrenalectomy and with an associated watery diarrhea, hypokalemia, achlorhydria syndrome, is reported. Histological evaluation of the tumors revealed composite malignant pheochromocytoma-ganglioneuroblastoma (well differentiated type). Vasoactive intestinal polypeptide and catecholamine levels were high both in the plasma and in the tumors. Somatostatin was also rich in the metastatic tumor of the liver, but not in the plasma. Immunohistochemical studies have demonstrated that immunoreactive vasoactive intestinal polypeptide is present in the ganglioneuroblastoma component, and that immunoreactive somatostatin is present in the pheochromocytoma component. Literature on the watery diarrhea, hypokalemia, achlorhydria syndrome associated with pheochromocytoma was reviewed.

Achlorhydria↗
PubMed1987

Numerous phosphates of microtubule-associated protein 2 in living rat brain.

Microtubule-associated protein 2 (MAP 2) purified from microwave-irradiated rat head contained about 46 esterified phosphates (mole/mol), which were not bound covalently to lipids and did not assemble with microtubules. After some phosphates were released by calf intestinal alkaline phosphatase, the phosphate content of MAP-2 decreased to 16 mol of phosphate and the protein assembled in vitro. MAP-2 purified after microtubule assembly cycles and also the cytosolic heat-stable fraction without assembly cycles had 10 mol of phosphate, and both assembled with microtubules. The MAP-2 with 46 phosphates and that with 10 had different pI in isoelectric focusing, but the components, MAP-2a and -2b, were always near each other. In high-pressure liquid chromatography, MAP-2 containing 46 mol of phosphate appeared after that 10 mol of phosphate. Phosphoserine, phosphothreonine, and phosphotyrosine were recovered from tryptic digestion of MAP-2 with 46 mol of phosphate. These findings suggest that two kinds of MAP-2, one with 46 phosphates and not bound to tubulin and the other with 10-16 phosphates and bound to tubulin, are present in the living rat brain.

Alkaline Phosphatase↗