Biomedical subjects

H Iijima

Publications and source records attributed to H Iijima.

At least 127 records · Page 7Linked to original sources

PubMed1994

Photopic electroretinogram implicit time in diabetic retinopathy.

Photopic electroretinograms (ERGs) elicited with red or white flashes of various intensities under a bright background light were recorded in 119 eyes of 77 diabetic patients and 19 normal control eyes. The implicit time and amplitude of photopic ERGs were analyzed in relation to the stage of diabetic retinopathy, ie, diabetic eyes without retinopathy, eyes with mild nonproliferative diabetic retinopathy (mild NPDR), moderate NPDR, preproliferative diabetic retinopathy (PPDR) and proliferative diabetic retinopathy (PDR). The implicit time was significantly delayed in eyes with moderate NPDR, PPDR and PDR relative to eyes with mild NPDR, eyes without retinopathy or normal eyes. The delay of implicit time significantly increased as the severity of retinopathy progressed from mild NPDR to PPDR. The amplitude was reduced in PPDR and PDR, while the correlation with the severity of retinopathy was not so significant as with the delay of implicit time. These findings suggest that the photopic ERG implicit time can be a good indicator for the objective evaluation of the severity of diabetic retinopathy ranging from mild NPDR to PPDR, where retinal laser photocoagulation should be considered.

Adult↗

PubMed1994

Combined occlusion of the central retinal artery and vein.

A 56-year-old man, complaining of sudden visual loss in his left eye, demonstrated cream-colored retinal edema along a macular branch of the central retinal artery, overall delay of fluorescence in angiography and general depression of the central visual field, which were interpreted as the incomplete form of central retinal artery occlusion (CRAO) mimicking cilioretinal or branch retinal artery occlusion. After receiving paracentesis and fibrinolytic agents, the patient recovered his vision gradually, while the ophthalmoscopic findings progressed to show central retinal vein occlusion (CRVO) changes consisting of dilated and tortuous retinal veins and scattered intraretinal hemorrhages. The condition associated with the retinal edema indicated combined obstruction of the central retinal artery and the central retinal vein (combined CRAO/CRVO). Six months later, both the ocular fundus and the vision returned to normal. The similar cases in Japanese literature in which ophthalmoscopic findings of combined CRAO/CRVO was followed by aggravation of CRVO changes with or without recovery of vision were reviewed.

Fluorescein Angiography↗

PubMed1993

Epitope specificity of bee venom phospholipase A2-specific suppressor T cells which produce antigen-binding glycosylation inhibiting factor.

From the spleen cells of BALB/c mice primed with bee venom phospholipase A2 (PLA2), we established seven T cell hybridomas which constitutively secreted glycosylation inhibiting factor (GIF), expressed both CD3 and TCR alpha beta, and responded to antigen-pulsed antigen presenting cells (APC) for the formation of IgE-binding factor. Upon stimulation with antigen-pulsed APC, four of the seven hybridomas produced GIF having affinity for native PLA2. The antigen-binding GIF could suppress the anti-hapten antibody response of BALB/c mice to dinitrophenyl (DNP)-PLA2 conjugates in a carrier-specific manner and bound to immunosorbents coupled with either the mAb 14-12 or anti-TCR alpha chain, H28-710. Analysis of the epitope specificity of the TCR on the GIF-producing T hybridomas indicated that all of the hybridomas which could produce antigen-binding GIF upon antigenic stimulation recognized the synthetic peptide representing amino acid residues 19-34 in PLA2 molecules in the context of the product of the I-Ad subregion and the antigen-binding GIF formed by the cells had affinity for the peptide. The 3-D structure of bee venom PLA2 indicates that the sequence of amino acid 14-24 forms a loop in the PLA2 molecule and represents an external structure of the antigen, while peptide 25-37 forms an alpha helix. Evidence was obtained which suggests that the sequence of 25-34 contains amino acid residues interacting with Ia molecules, while peptide 19-24 contains residues involved in the interaction of p19-34-Ia complexes with TCR on the hybridomas. It was also found that not only the synthetic peptide 19-34, but also the peptides 13-28 and 19-30 inhibited the binding of antigen-binding GIF to PLA2-coupled Sepharose, while peptide 25-40 failed to do so. The results collectively indicate that the antigen-binding GIF and TCR on the cell source of the factor interact with a common epitope which is exposed on the surface of a nominal antigen.

Amino Acid Sequence↗

PubMed1993

Adjuvant effect of interleukin-1 on the development of late asthmatic response in guinea pigs.

The adjuvant effect of silica and IL-1 in the development of late asthmatic responses (LARs) in guinea pigs was studied. Different doses of silica or recombinant human (rh) IL-1 (1 microgram) with Ascaris suum were used for the immunization. The serum IL-1 concentration was measured after the immunization. One week after the immunization, antigen was challenged and respiratory resistance (Rrs) was measured. Rrs increased silica dose dependently in the late phase, and the increment of Rrs in the late phase was significantly correlated with the serum IL-1 concentration (p < 0.05). In addition, rhIL-1 administration showed an increase in Rrs at the late phase. Antigen-specific IgE and IgG1 were also measured and were increased in guinea pigs immunized both with silica and rhIL-1.

Adjuvants, Immunologic↗

PubMed1993

Correlative light and electron microscopy of the same sections embedded in HPMA, Quetol 523 and MMA.

Semithin sections, cut from tissues stained with acid and basic dyes after embedding in 2-hydroxypropyl methacrylate, Quetol 523 and methyl methacrylate, showed cytoplasmic components at a high resolution by light microscopy. These same sections could then be viewed, after osmium tetroxide, uranyl and lead staining, by the electron microscope. These sections had a number of inherent advantages: they could be observed with a light microscope; they facilitated analysis of cellular structures in the identical sites, and they were frequently the optimum thickness to provide three-dimensional information. We clearly established the structural detail of this same-section correlative light-electron microscopy approach by showing that the coloured materials observed in such sections of cells followed the distribution of fine structures within the same sections as determined by electron microscopy. In some instances the fidelity of the correlation between the distribution of the coloured area and cytoplasmic components in identical cells of the same section revealed significant details which could not visualized in thin sections. This technique, therefore, provided a simple and useful solution to many problems that require the localization of cellular components in identical cells selected previously by light microscopy.

Animals↗

PubMed1993

Studies on thick sections of the nucleus of mouse Sertoli cells using an electron microscope operating at 300 kV.

Examination of the three-dimensional structure of the Sertoli cell nucleus from mouse testes was performed under a high voltage electron microscope operating at 300 kV. Using an en bloc staining method along with fixation by osmium tetroxide and embedding in a mixture of Quetol 651, NSA and MNA, the structures of the nucleus were stained at a high contrast and satisfactory preservation was achieved, thus allowing their study at a high resolution within thick sections. Nuclear components could be observed clearly in 2-3 microns-thick sections of embedded material. Typical three-dimensional configurations of nucleoli and associated bodies were indicated. Thick sections permitted the observation that two or three pernucleolar bodies are usually attached on each side of the nucleoli or form a triangular shape of different sizes of vacuolar structures within the bodies. Stereoscopic observations also revealed overlapping of perinucleolar bodies and nucleoli and suggested the complexity of the components of perinucleolar and intranucleolar chromatin.

Animals↗

PubMed1993

Photopic electroretinogram implicit time in retinitis pigmentosa.

While the implicit time of cone responses in the electroretinogram (ERG) has been suggested to have some clinical implications in retinitis pigmentosa (RP), its evaluation is not always easy in cases of typical RP because of the small amplitudes of the responses. An intense flash stimulus would be expected to improve the recordability of photopic ERG, which represents the cone responses. However, the implicit time in normal eyes has been shown to be delayed with increased stimulus intensity. Therefore, we evaluated photopic ERGs to a white flash stimulus of 3 different intensities as well as to a red flash in 14 cases of typical RP. The recordability of the response to white flash improved with the increased intensity of the stimulus. Most RP cases showed prolonged implicit time compared with that in normal eyes to each flash stimulus. Some patients who showed exceptionally normal or mildly delayed implicit time were considered to have good prognosis since they had noticed night blindness at an older age and most of their rod response in ERG was recordable.

Adolescent↗

PubMed1993

Saucerisation (recession) of neuro-retinal rim is characteristic of glaucoma.

Colour stereophotographs of the optic disc and surrounding retina were assessed by a Humphrey analyser system in a series of Japanese individuals. When compared with 9 age- and sex-matched control eyes (9 controls), the 10 eyes of 10 patients with early open-angle glaucoma showed a significantly lower level of the mid-point of the neuroretinal rim relative to the level of the surface of the retina about 1/4 of a disc diameter beyond the disc edge. When the mid-point of the rim was related to the surface of tissue at the disc edge, the level of the former was significantly lower at the three measurement points on the nasal side and at 6 o'clock. In the 9 normal controls, the lower half of the neuro-retinal rim was at a significantly lower level than the upper half, relative to the surface of tissue at the disc edge. We conclude that saucerisation and/or recession of the neuro-retinal rim frequently accompanies glaucoma and we suspect it is an early sign of it.

Adult↗

PubMed1993

Preoperative evaluation by laser interferometry in cataractous eyes with retinitis pigmentosa.

Measurements of visual acuity were carried out preoperatively by laser interoferometry in 16 cataractous eyes of 13 patients with retinitis pigmentosa who were older than 60 years of age. Subsequently, all patients underwent uneventful extracapsular cataract extraction and posterior chamber intraocular lens implantation. Postoperative visual acuity, which was evaluated as the best acuity during the first postoperative year, was improved in all eyes and it correlated well with the preoperative acuity determined by laser interferometry. Laser interferometry can be useful in predicting postoperative acuity and deciding on cataract surgery for elderly cataractous patients with retinitis pigmentosa.

Aged↗

PubMed1993

[A modification of the Aulhorn flicker test with results of physiological and pathological conditions].

The Aulhorn flicker test measures the subjective brightness of various frequencies of flickering light. We modified an Aulhorn flicker test with light emitting diode (LED) and the results of 21 normal eyes and 18 affected eyes (7 eyes with idiopathic optic neuritis, one eye with rhinogenous optic neuropathy (ethmoid sinus mucocele), two eyes with preoperative pituitary tumor, one eye with empty sella, one eye with anterior ischemic optic neuropathy, one eye with syphilitic optic neuritis, five eyes with primary open angle glaucoma) were presented. All normal eyes showed the Brücke-Bartley effect which refers to an enhanced subjective brightness at lower frequencies. Six eyes with idiopathic optic neuritis and one eye with rhinogenous optic neuropathy in the acute stage demonstrated the Aulhorn effect which refers to a reduced subjective brightness at lower frequencies. Four eyes with the Aulhorn effect that were followed up showed less prominent Aulhorn effect. One eye with idiopathic optic neuritis and 10 eyes with other conditions did not show the Aulhorn effect. It was suggested that the modified Aulhorn flicker test with LED is a useful method for diagnosis of optic neuritis in the acute stage.

Adult↗

PubMed1993

[Effect of thromboxane receptor antagonist, BAY u 3405 on the late phase pulmonary response in guinea pigs].

The effect of the specific thromboxane (Tx)A2 receptor antagonist, BAY u 3405 on the late asthmatic response (LAR) was investigated in guinea pigs which are sensitized actively with Ascaris suum antigen. Respiratory resistance (Rrs) of awake guinea pigs was measured by 30 Hz oscillation method for 6 hours after antigen challenge. %Rrs was calculated as the increase rate of Rrs to baseline Rrs (pre-challenge value). Ten mg/kg of BAY u 3405 or vehicle (0.5% methyl cellulose) was administered orally after the end of immediate asthmatic response, i.e., 2 hours after antigen challenge. %Rrs of the control group at 4 and 5 hours after antigen challenge were 101.4 +/- 27.5% and 77.5 +/- 19.9%, respectively. Those of the BAY group were 32.5 +/- 6.2% and 23.5 +/- 5.0%, respectively. %Rrs of the BAY group were significantly lower than those of the control group at both timings (p < 0.05). No significant difference was shown between the BAY group and the control group in the results of the bronchoalveolar lavage (BAL) 4 hours after challenge. Concerning the results of BAL at 6 hours after challenge, the total cell count and its segment, eosinophils count and lymphocytes count in the BAY group were 274.9 +/- 70.5, 62.5 +/- 13.1, 11.3 +/- 3.3 (x 10(5) cells), respectively, resulting in significantly smaller numbers (each p < 0.05) than those in the control group which were 491.9 +/- 55.1, 198.6 +/- 43.9, 32.1 +/- 7.3 (x 10(5) cells), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗

PubMed1992

Structural determination of the active site of a sweet protein. A 1H NMR investigation of pMNEI.

pMNEI, a single chain sweet protein related to monellin, has been studied by means of 1H NMR at 500 MHz. A partial sequential assignment performed by means of the MCD method allowed the determination of the secondary structure of a large portion of the beta-sheet of pMNEI that contains a likely 'sweet finger': the loop connecting the beta-strands from residue 59 to residue 78, corresponding to segment 16-35 of the A chain of monellin. The detailed three-dimensional structure of the loop (Tyr66-Ala67-Ser68-Asp69), determined from several interresidue and intraresidue NOEs and subsequent energy minimization, shows that the side chains of Tyr66 and Asp69 fit our model of the sweet receptor in a manner very similar to that of the side chains of Phe and Asp of aspartame.

Amino Acid Sequence↗

PubMed1992

Exon 16 del: a novel form of human neutral endopeptidase (CALLA).

The enzyme neutral metalloendopeptidase (E.C. 3.4.24.11), also known as the common acute lymphocytic leukemia antigen, neutral endopeptidase, or enkephalinase, functions as an inactivator of a wide variety of signaling oligopeptides such as substance P, neurokinin A, enkephalins, endothelin, atrial natriuretic factor, and formyl chemotactic peptides. A cDNA clone isolated from a human lung library encodes a fragment of neutral metalloendopeptidase containing an internal 81 base pair deletion when compared with the human placental cDNA for this enzyme. Comparison of the deleted cDNA sequence with the intron-exon structure recently determined as the common acute lymphocytic leukemia antigen reveals that the 81 base pairs corresponds precisely with exon 16. RNA analysis using splice junction oligonucleotides indicates that the 16 del form constitutes a minor but significant fraction of the RNA species present in human lung. Expression of constructs containing "wild type" and "exon 16 del" neutral endopeptidases in COS-7 cells reveals that deletion of this 27 amino acid segment reduces enzymatic activity toward the synthetic substrate glutaryl-alanyl-alanyl-phenyl-alanyl-4-methoxy-2-naphthylamide to barely detectable levels.

Amino Acid Sequence↗

PubMed1992

Effects of biological response modifiers with different modes of action used separately and together on immune responses in mice with syngeneic tumours.

The effect of a protein-bound polysaccharide (PSK) obtained from cultured mycelia of the Basidiomycetes Coriolus versicolor on activities involved in the host defence mechanism of C57BL/6 mice bearing adenocarcinoma 755 was compared with that of live bacille Calmette-Guérin (BCG). Delayed footpad reaction, the activity of splenic natural killer cells and interferon production induced by concanavalin A in splenic cells of healthy mice were little affected by PSK, but in mice bearing tumours PSK prevented the tumour-induced reduction in these activities. Live BCG augmented these activities in healthy mice but had little effect on the reduction of activities induced by a tumour. The immunosuppressive activity of the serum of tumour-bearing mice was reduced by PSK administration; live BCG did not have this effect. The combined use of live BCG and PSK improved these activities in the host, with synergistic increases in the antitumour effect. These results suggest that the combined use of live BCG and PSK, which have different modes of action, may be useful in the treatment of cancer.

Adjuvants, Immunologic↗

PubMed1992

The substitution of cysteine 17 of recombinant human G-CSF with alanine greatly enhanced its stability.

Human recombinant granulocyte-colony stimulating factor (rhG-CSF) has one free cysteine at position 17 and has two disulfide bridges (Cys36-Cys42 and Cys64-Cys74). The Cys17 of rhG-CSF was substituted with Gly, Ala, Ser, Ile, Tyr, Arg, and Pro, or deleted using site-directed mutagenesis in order to improve its thermostability. With the exception of Pro17-rhG-CSF, all mutant proteins retained biological activity which promotes the growth of mouse bone marrow cells in vitro. Among these mutant proteins, Ala17-rhG-CSF had more than 5 times higher stability than rhG-CSF. But Ser17-rhG-CSF had almost same stability as rhG-CSF and other mutant proteins had only lower stability.

Alanine↗

PubMed1992

Staining of semithin tissue sections embedded in HPMA, quetol 523 and MMA.

Various tissues fixed in a mixture of formaldehyde and glutaraldehyde, and embedded in an improved 2-hydroxypropyl methacrylate mixture were employed for studying the fine structures of cells and tissues by light microscopy. The embedding mixture contained Quetol 523 and methyl methacrylate as a plasticizer without a cross-linker. The catalyst was QCU-1. The mixture had a low viscosity, was easy to handle and penetrated readily and completely into the specimen, producing a homogeneous block from which it was easy to cut sections of 1-2 microns in thickness. A wide variety of stains have been employed with such sections and those reported here are hematoxylin-eosin, Azan and PAS. There was excellent preservation of alkaline phosphatase activity. A method of poststaining immunoperoxidase labeling was also applied to the mouse pancreas and examples of staining with insulin are included.

Aminosalicylic Acid↗

PubMed1992

[Masticatory training with chewing gum on young children].

Mastication is a developmental function. It matures through learning experiences. The biting force is one of the components of masticatory function. The biting force increases with age. During the developmental stage, it is believed feasible to enhance the maturation of the masticatory function by increasing the biting force. The previous results of masticatory training for adults and school children had revealed 20% to 30% increase of the biting force. In this study, masticatory training with specially fabricated chewing gum for young (preschool) children was performed. The subjects were 5 males and 5 females from 3 years old to 5 years old. These children were instructed to bite on the chewing gum for 5 minutes, 2 times a day, for 3 months. The results show that there was a 94% average increase of biting force after 3 months of training. It was also noted that the rate of the increase of the biting force was remarkable during the first month of training.

Age Factors↗

PubMed1992

Enhancement of effector cell activities in mice bearing syngeneic plasmacytoma X5563 by a biological response modifier, PSK.

We investigated the effect of PSK, a protein-bound polysaccharide obtained from Coriolus versicolor of basidiomycetes, on antitumor immunity in tumor-bearing mice. PSK prolonged significantly the life span of C3H/He mice bearing syngeneic plasmacytoma X5563 in a schedule- and dose-dependent manner. PSK was most effective when administered at 100 mg/kg every other day ten times starting from the day after tumor inoculation. The administration of PSK enhanced significantly the cytostatic activity of peritoneal exudate plastic-adherent cells and the cytolytic activity of spleen cells after in vitro incubation with mitomycin C-treated tumor cells. In addition, PSK restored the cytokine-producing capacity of spleen cells suppressed in tumor-bearing mice after in vitro incubation with mitogen. Sera from tumor-bearing mice suppressed the activity of such effector cells as well as the interleukin 2-producing capacity of spleen cells, but sera from PSK-treated tumor-bearing mice prevented this suppression. These results suggest that PSK enhances antitumor immunity by reducing immunosuppressive activity of serum from tumor-bearing mice.

Adjuvants, Immunologic↗