Search PubMed⌕ Search

Biomedical subjects

M Iijima

Publications and source records attributed to M Iijima.

At least 145 records · Page 8Linked to original sources

[A case of vertical gaze palsy associated with a unilateral infarct in the thalamo-mesencephalic junction on MR imaging].

We report a case of a 54-year-old man with sudden-onset double-vision. On admission, neurological examination showed upward and downward gaze palsy on voluntary and smooth pursuit movements, and vertical oculocephalic maneuver elicited a full upward and downward response. Bell's phenomenon, horizontal eye movements and convergence were not impaired. Based on these findings, supranuclear dissociated vertical gaze palsy was diagnosed. T1-weighted MR images revealed low intensity on the medial side of the right thalamo-mesencephalic junction, which impaired the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). T2-weighted MR images revealed a high-intensity area. The posterior commissure was spared. The clinical signs gradually improved, and the vertical gaze palsy almost disappeared one month after onset. Based on these findings, unilateral infarct in the thalamo-mesencephalic junction in the distribution of the right paramedian thalamic artery was diagnosed. Only two cases of upward and downward gaze palsy in association with unilateral upper midbrain lesion without posterior commissure have been previously reported. Since we did not perform a pathological examination, we cannot deny that there may have been some denervation of fibers at the posterior commissure. Cases of upward and downward gaze palsy in association with unilateral upper midbrain lesion without posterior commissure are rare, and it is very interesting that the lesion in our patients, like that seen in the two pathological reports, was right-sided.

Cerebral Infarction↗

Biliary excretion of cholephilic organic dyes in glutathione-depleted rats.

Sprague-Dawley rats were treated with a combination of buthionine sulfoximine (2.5 mmol/kg body wt) and diethyl maleate (6.2 mmol/kg). After 4 h, the hepatic glutathione was depleted to 0.02 +/- 0.01 mumol/g liver (mean +/- SD, n = 6) (4.73 +/- 0.29 mumol/g in controls (n = 6), p < 0.005). The bile flow rate was lower in treated animals than in controls (39.0 +/- 11.2 vs. 73.7 +/- 13.7 microliters.kg-1.min-1, p < 0.005). Bile concentrations of bile acids, phospholipids, and cholesterol were not changed compared to controls, while glutathione was virtually absent from the bile. A bolus of indocyanine green (6.5 mumol/kg), rose bengal (6.5 mumol/kg), or sulfobromophthalein-glutathione conjugate (20 mumol/kg) was injected i.v. and the biliary excretion was monitored. In glutathione-depleted rats, the excretion of indocyanine green was delayed, and the cumulative excretion in 90 min was 36 +/- 8% (n = 6) of the injected dose (79 +/- 18% in controls (n = 7), p < 0.005). The bile concentration of indocyanine green was lower in the glutathione-depleted rats than in controls, while the other dyes increased. The plasma disappearance curve of indocyanine green was not significantly altered by the treatment, whereas the hepatic retention of indocyanine green 90 min after the injection was significantly increased (58 +/- 12% of the injected dose vs. 8 +/- 2% in controls, p < 0.005). The results indicate that depletion of hepatic glutathione inhibits biliary excretion of indocyanine green.

Animals↗

Reduction in the numbers of muscarinic receptors by an endogenous protein.

The soluble fraction from the ileal longitudinal muscle of guinea pigs was examined for the presence of an endogenous modulator of muscarinic receptors. In the presence of the soluble fraction, the binding of [3H]quinuclidinyl benzilate to the membranes from the tissue was inhibited in a concentration-dependent manner. The inhibitory activity in the soluble fraction was heat stable, but was inactivated by trypsin treatment. Several protease inhibitors had no effect on the inhibitory activity. These results suggest the existence of an endogenous protein that inhibits the binding of the muscarinic ligand to the receptor. Ultrafiltration demonstrated that the protein factor had a molecular mass of more than 10,000 Da. Saturation binding and dissociation kinetic experiments indicate neither a competitive nor allosteric mode of inhibitory action and suggest that an irreversible block or internalization of muscarinic receptors is induced by the endogenous protein.

Allosteric Regulation↗

Relationship between biliary excretion of bilirubin and glutathione disulfide.

The effects of two glutathione-oxidizing agents, t-butyl hydroperoxide and diamide, on biliary excretion of bilirubin and glutathione disulfide were investigated in anesthetized male Sprague-Dawley rats. Bilirubin (unconjugated) was infused at a constant rate of 100 nmol/kg/min through the jugular vein. When biliary excretion of bilirubin was stabilized, either of the glutathione-oxidizing agents was administered via the mesenteric vein. Biliary excretion of glutathione disulfide increased temporarily after the administration and returned to its basal levels within 20 min. The biliary excretion of bilirubin decreased during the same period and returned to the former levels thereafter. Changes in bile flow rates remained within 20% of the basal levels. A linear correlation was found between the increments in the bile concentration of glutathione disulfide and the decrements in that of bilirubin. Furthermore, separate experiments revealed that reduction of hepatocellular glutathione per se had little effect on biliary excretion of bilirubin. The results thus indicate that the reduction of biliary excretion of bilirubin by glutathione-oxidizing agents was due to the increase in biliary excretion of glutathione disulfide, and suggest that a common biliary excretory mechanism is shared, at least partially, by bilirubin and glutathione disulfide in Sprague-Dawley rats.

Animals↗

An autopsy case of Binswanger's disease without hypertension and associated with cerebral infarction in the terminal stage.

We report here an autopsy case of Binswanger's disease (BD) without hypertension and associated with cerebral infarction in the terminal stage. The female patient, who was 74 years old at the time of death, had initially demonstrated manic-depressive disorder-like mental disorder, followed by dementia and neurological deficits. A brain CT scan showed white matter low attenuation bilaterally and symmetrically. BD was clinically diagnosed despite the lack of hypertension. In the terminal stage, she suffered an infarction in the left anterior cerebral artery region, and died of pneumonia. Neuropathologically, we found the infarction of the left anterior cerebral artery region, demyelination, fibrillary gliosis, lacunae and arteriosclerosis of the small arteries and arterioles in the white matter.

Aged↗

Activity of the carbapenem panipenem and role of the OprD (D2) protein in its diffusion through the Pseudomonas aeruginosa outer membrane.

Evidence of permeation of panipenem through the OprD (D2) channel of Pseudomonas aeruginosa outer membrane was shown by using OprD protein-producing and -nonproducing strains which contained plasmid pHN4, which codes for L-1 beta-lactamase of Xanthomonas maltophilia. Permeation by panipenem was determined by measuring hydrolysis of the carbapenem by beta-lactamase in the periplasmic space. Permeation by panipenem was also determined by counting uptake of [14C]panipenem into P. aeruginosa PAO1 and its OprD protein-deficient mutant, and this permeation of PAO1 was inhibited by L-lysine. These results indicate that panipenem, as well as imipenem, uses the OprD channel, which functions as a specific channel for diffusion of basic amino acids. Panipenem and imipenem showed stronger activities against PAO1 and clinical isolates in human serum than in Mueller-Hinton broth, which contains more amino acids than human serum does. The activities of the carbapenems were reduced by addition of L-lysine to human serum. Similar results were obtained with mouse serum and ascitic fluid. In contrast, such a change in the activities of carbapenems was not observed with an OprD protein-deficient mutant, suggesting that the main reason for the strong activities of carbapenems in biological fluids is a decrease in competition between the antibiotics and basic amino acids for permeation through the OprD channel. Panipenem and imipenem showed much stronger therapeutic efficacies against experimental infections with P. aeruginosa in mice than did the reference antibiotics. Their in vivo activities were more consistent with their MICs in biological fluids than with those in Mueller-Hinton broth.

Animals↗

Psychiatric complications after ocular surgery.

Delirium was demonstrated after cataract surgery in a 64-year-old man (case 1). The patient struck his head against the floor; thereafter an extradural hematoma was found and extracted. Postoperative delirium was also noted in a 58-year-old woman (case 2) and in a 26-year-old woman (case 3) with rhegmatogenous retinal detachment. All 3 patients recovered from their psychiatric complications within 1 month.

Adult↗

Methods of evaluation of release of carbon dioxide from effervescent suppositories.

Two different test methods were studied for the evaluation of release profiles of carbon dioxide, CO2, from effervescent suppositories. Three lots of commercial suppositories containing sodium bicarbonate and anhydrous sodium dihydrogen phosphate were used. The volume of CO2 released from these suppositories in normal saline with or without polysorbate 80 as a medium was measured with a gas burette. In the measurement performed using the apparatus without stirring, method 1, only 60% of CO2 was released from the suppositories in the medium without polysorbate 80. In this measurement, a native release profile was detected because the medium was not stirred. In the case with stirring, however, method 2, 100% was released from those suppositories in the medium containing 1% polysorbate 80 with comparatively low standard deviations. These findings indicate that method 1 is most beneficial for a test comparing the effects of various factors such as additives and melting points on the release profiles of CO2 from the effervescent suppositories. However, this method is not practical for quality control of formulations because of the incomplete release of CO2; method 2, in contrast, is useful because of its complete release and low standard deviations. These results suggest that methods 1 and 2 for release tests of CO2 are most applicable to the early and late formulation studies of effervescent suppositories, respectively.

Carbon Dioxide↗

Effects of bases and additives on release of carbon dioxide from effervescent suppositories.

For the formulation of effervescent containing sodium bicarbonate and anhydrous sodium dihydrogen phosphate, the effects of bases and additives on the release profile of carbon dioxide, CO2, from the suppositories were studied by an in vitro release test using a gas burette. The suppository bases employed were Witepsol H-15, W-35 and E-85, and the additives were Aerosil 200 and soybean lecithin. The melting points and viscosities of the suppositories were also measured to interpret the CO2 release profiles. The rate and amount of CO2 released from suppositories prepared with bases having different melting points and hydroxyl values decreased with increasing melting point and decreasing hydroxyl value. The addition of Aerosil 200 to the suppository bases considerably reduced the rate and amount of CO2 released owing to the increasing viscosity of the melted bases, while the addition of soybean lecithin to those bases increased the rate and amount of CO2 released because of the improved wettability. Thus, the release profiles of CO2 from the effervescent suppositories were considerably influenced by the hydroxyl values related to the contents of mono- and di-glycerides, the melting points of the bases, Aerosil 200 and soybean lecithin. This suggests that the rate and amount of CO2 released from the suppositories can be freely controlled by the combination of these various factors.

Carbon Dioxide↗

Delaminomycins, novel extracellular matrix receptor antagonist. IV. Structure-activity relationships of delaminomycins and derivatives.

Delaminomycins A, B, C and their derivatives were prepared and investigated biological activities of them. Among these compounds, spiro compounds (A2, B2 and C2) showed stronger inhibitory activity than natural products (A1, B1 and C1) on B16 melanoma cells adhesion assay and Con A-induced proliferation of murine splenic lymphocytes assay. In MLCR and antimicrobial assay, however, A1, B1 and C1 showed more potent inhibitory activity than spiro compounds (A2, B2 and C2). On the other hand, as to C-5' substituents of pyrrolidine ring, the order of inhibitory activity was R = OH > R = OCH3 > R = H on Con A-induced proliferation of murine splenic lymphocytes assay. In MLCR and antimicrobial assay, however, the order of inhibitory activities were R = H > R = OCH3 > R = OH. Inhibitory activities of A4 which was lacked pyrrolidine ring were reduced on B16 melanoma cells adhesion assay and on cytotoxicity against tumor cells in vitro in comparison with those of A1.

Animals↗

Delaminomycins, novel nonpeptide extracellular matrix receptor antagonist and a new class of potent immunomodulator. I. Taxonomy, fermentation, isolation and biological activity.

In order to develop a new class of immunomodulator we have searched for a low molecular weight inhibitors of cell adhesion to components of extracellular matrix (ECM), fibronectin (FN), laminin (LM) and collagen type IV (CL), and succeeded to find a group of novel antibiotics, named delaminomycins. Delaminomycins were isolated from the mycelium and cultured broth of Streptomyces albulus MJ202-72F3. It was purified by use of centrifugal partition chromatography (CPC), preparative reverse phase HPLC and Sephadex LH-20 and was obtained as a white powder. Delaminomycins with inhibitory activity for cell adhesion to ECM components suppressed immune responses in vitro and in vivo and exhibited antimicrobial activity on Gram-positive bacteria.

Adjuvants, Immunologic↗

Immortalization of normal human cells is a multistep process and a rate limiting step of neoplastic transformation of the cells.

Three normal human fibroblast strains were immortalized by treatment with either 4-nitroquinoline 1-oxide (SUSM-1 and OUMS-24F lines) or 60Co gamma rays (KMST-6 line). Immortalization of normal human cells with these agents required repeated treatments. Before immortalization, most of the cells treated with these mutagenic agents showed more or less chromosome aberrations, but immortalized cells appeared very rarely. This suggests that several mutational events are involved in the immortalization process itself. The immortalized cells showed polygonal or epithelial-like morphology, prominent numerical and structural abnormalities of chromosomes, requirement of serum growth factors for their growth, and no tumorigenicity. The immortalized KMST-6 and OUMS-24F were further transformed into neoplastic ones by the ras oncogene, but not by transfection with the mutant p53 gene. Normal human fibroblasts which are mortal were not immortalized nor neoplastically transformed with the ras oncogene or the mutant p53. These findings strongly indicate that the immortalization of human cells is prerequisite for neoplastic transformation of the cells.

4-Nitroquinoline-1-oxide↗

[Cranial MRI in hepatic disease--relationship between MR imaging and clinical symptoms and laboratory analysis of liver function].

Magnetic resonance imaging studies on 12 cases with hepatic disease were performed. In 11 adult patients with chronic hepatic failure, T1-weighted images demonstrated increased signal in the globus pallidus in 7 patients (63.6%) and in some parts of the cerebral peduncles in 6 patients (54.5%), in the substantia innominata in 4 patients (36.3%). There might be some correlation between the abnormality of MR imaging and clinical symptoms of hepatic encephalopathy. There was a significant correlation between the intensity of the signal and Fischer's ratio of amino acid analysis. In one patient with Wilson's disease, who developed symptoms of central nervous system, T1-weighted images demonstrated increased signal in the globus pallidus. After treatment of D-penicillamine, the signal of the globus pallidus decreased.

Adult↗

[A case of cavernous angioma--usefulness of magnetic resonance imaging and magnetic resonance angiography in diagnosis].

We reported a case of cavernous angioma in the middle cranial fossa, which was diagnosed with magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). The patient was a 56-year-old female, who presented with sudden onset right-sided headache with nausea. Her neurological findings were normal. On CT scan a high density area with a surrounding thin low density area was shown in the right posterior temporal region without contrast enhancement. Cerebral angiography of the left vertebral artery revealed only a small stain at the end of the right posterior temporal artery. On T2-weighted MRI after one month, the same region exhibited a central area of mixed signal intensities surrounded by a rim of decreased signal. MRA showed an area with remarkable 10mm mass with some contiguous vessels in the right posterior temporal region. That mass was resected operatively. It's pathological diagnosis was cavernous angioma. For diagnose of cavernous angioma, MRI and MRA were very useful. The specificity of these methods are superior to better than CT or angiography.

Brain Neoplasms↗

[Relationship between biliary excretion of conjugated sulfobromophthalein and glutathione disulfide in rats].

Relationship between biliary excretion of sulfobromophthalein conjugated with glutathione (BSP-GSH) and glutathione disulfide (GSSG) was investigated in Sprague-Dawley rats. BSP-GSH solution was infused intravenously at three different rates. After administration of a glutathione-oxidizing agent, diamide, biliary excretion of GSSG increased temporarily and that of BSP-GSH decreased during the same period. A linear correlation was found between the increments in biliary excretion of GSSG and the decrements in that of BSP-GSH only when BSP-GSH was infused at a rate near its biliary transport maximum. The results may indicate competition in vivo between GSSG and BSP-GSH for a common transporter on canalicular membrane.

Animals↗

Inhibition of biliary excretion of indocyanine green by the thiol-oxidizing agent, diazenedicarboxylic acid bis[N,N'-dimethylamide].

Biliary excretion of Indocyanine green (ICG) in Sprague-Dawley rats during constant intravenous infusion of the dye in vivo was inhibited by intraperitoneally administered diazenedicarboxylic acid bis[N,N'-dimethylamide] (diamide, 0.5 mmol/kg body wt), a glutathione-specific thiol-oxidizing agent. Significant inhibition of ICG excretion was observed also when ICG was injected rapidly 90 min after diamide administration. Disappearance of ICG from the plasma was not affected by diamide. Oxidized glutathione in bile increased transiently following diamide administration but returned to the basal level within 30 min. Hepatic concentrations of reduced and oxidized glutathione were not different from those of controls when determined 90 min after diamide administration. The inhibition of ICG excretion was completely prevented by subsequent administration of dithiothreitol (0.5 mmol/kg) 30 min after that of diamide. The results, therefore, suggest that the biliary excretion of ICG was inhibited by secondary changes in the redox status of thiols in hepatocytes caused by a transient increase in oxidized glutathione.

Animals↗

Effects of F- on apatite-octacalcium phosphate intergrowth and crystal morphology in a model system of tooth enamel formation.

In order to study the effect of F- on tooth enamel-like apatite formation, crystal growth experiments were carried out in the presence of 0.1 approximately 2 ppm F- at 37 degrees C and at pH 6.5 in a model system of enamel formation where octacalcium phosphate (OCP) was stable. Morphology changed from long and thin ribbons to small needle-like plates, and the product changed from OCP to apatite with an increase in F- concentration. In the presence of 0.1-1 ppm F-, apatite-OCP intergrowth took place, and crystals composed of apatite and OCP lamellas were formed. These crystals showed long and thin plate-like morphology and embeded an OCP lamella in the center of the crystal. The OCP lamella and its (100) planes were parallel to the (100) planes of apatite. The thickness of OCP decreased and that of apatite increased with an increase in F- concentration. Some apatite crystals obtained at 1 ppm F- embedded a central plane instead of the distinct OCP lamella. The result indicates that initially formed, thin, plate-like OCP acted as a template for the subsequent epitaxial overgrowth of apatite and, moreover, F- played an important role in regulating the apatite-OCP intergrowth.

Apatites↗