Biomedical subjects

R Suzuki

Publications and source records attributed to R Suzuki.

At least 487 records · Page 27Linked to original sources

PubMed1992

[A case of bronchiolitis obliterans organizing pneumonia in a patient with rheumatoid arthritis who responded to corticosteroid and immunosupressant therapy].

A 56-year-old man with rheumatoid arthritis was admitted to our hospital with dyspnea on exertion, fever and right chest pain. Chest X-ray showed bilateral, predominantly lower interstitial shadows and right pleural effusion. Open lung biopsy specimen showed bronchiolitis obliterans organizing pneumonia (BOOP) with prominent alveolitis, and corticosteroid therapy was introduced. Because the patient showed little response to corticosteroids, an immunosupressant (cyclophosphamide) was added. There was marked clinical, physiological and roentgenographic improvement in response to combined therapy. The therapeutic response of some BOOP patients seems to vary according to its pathogenesis and pathological findings, and these should be taken into consideration in the selection of therapeutic strategies.

Adrenal Cortex Hormones↗

PubMed1992

Comparison of laser trabeculostimulation with laser trabeculoplasty in open-angle glaucoma.

We compared a new method, laser trabeculostimulation (LTS), with laser trabeculoplasty (LTP). The technique LTS stimulates trabecular meshwork tissue and thereby increases the outflow facility. The method LTP causes shrinkage and cicatrization of the meshwork tissue, thus limiting the reduction in postoperative intraocular pressure (IOP). The mean preoperative IOP of 40 eyes was 24.9 +/- 6.8 mmHg (mean +/- standard deviation). The LTS was applied with a 50-microns spot size, a power setting of 50mW, and an exposure time of 1 sec. With LTS, the IOP decreased and then increased afterward. Low power (50mW) was effective if used for a longer duration. The LTS can be applied repeatedly and used in addition to conventional LTP. The overall effect achieved with LTS was less than that with LTP, but it is possible to reduce IOP by selecting more reasonable parameters, e.g., a laser setting of 200mW, a 50 microns spot size and a 0.5 to 1-sec duration.

Adult↗

PubMed1992

Retinal circulation in primary open-angle glaucoma tested by videodensitometric image analysis.

To investigate the retinal circulation in primary open-angle glaucoma (POAG), we used videodensitometric image analysis of fluorescein angiography to calculate the build-up time, the time constant of the washout rate, and the mean circulation time (MCT) in both the retinal artery and vein. We found the MCT in the POAG group (23 eyes of 20 patients) was significantly longer than in the normal group (3.7 +/- 2.0 sec and 2.8 +/- 1.7 sec, respectively; P less than .05). It correlated significantly with the vertical cup-to-disc ratio (r = .32; P less than .01), the outflow facility (r = -.35, P less than .005), and the glaucomatous visual-field loss. There was no correlation between MCT and intraocular pressure tested at the same time (r = .09, not significant). Therefore, treatment to decrease the intraocular pressure may not be associated directly with improved retinal circulation.

Adult↗

PubMed1992

Remarkable postcataract against-the-rule astigmatism after phacoemulsification in 83 of 809 cases.

We analyzed 83 cases of remarkable postcataract against-the-rule (AR) astigmatism (greater than 1.5D) occurring in a total of 809 Kelman's phacoemulsification aspiration procedures, all using 10-0 polyester sutures in a double-running fashion to close the corneoscleral incisions. All operations were done by one surgeon, using the same surgical procedure and the same number of sutures. The induction and spontaneous regression of several types of astigmatism were analyzed over six months. In cases of preoperative oblique and AR astigmatism, shifts (2.09 +/- 0.22D, 1.93 +/- 0.13D, respectively) after the first week were much smaller than those of preoperative with-the-rule astigmatism. Thereafter, degrees of oblique and AR astigmatism increased and remained higher even six months after surgery. The induction and spontaneous regression of postoperative AR astigmatism was similar to that of oblique astigmatism. Compression of the lids on the eye may be a more important factor than previously considered.

Aged↗

PubMed1991

Isolation of high-molecular-weight C-type natriuretic peptide from the heart of a cartilaginous fish (European dogfish, Scyliorhinus canicula).

A high-molecular-weight form of C-type natriuretic peptide (CNP) was isolated from both cardiac atria and ventricles of European dogfish, Scyliorhinus canicula, and its primary structure was determined. The peptide consists of 115 amino acid residues, in which the C-terminal 22 residues show high homology to CNPs identified to date. This is the first direct evidence for the presence of natriuretic peptide in the cartilaginous fish, and for the presence of CNP in an organ other than the brain.

Amino Acid Sequence↗

PubMed1991

Construction of scrA::lacZ gene fusions to investigate regulation of the sucrose PTS of Streptococcus mutans.

The scrA gene coding for sucrose EnzymeII of the phosphoenolpyruvate dependent phosphotransferase system previously isolated from Streptococcus mutans was fused in vitro to the promoterless lacZ' gene to monitor the expression of the scrA gene. The scrA::lacZ gene fusion was introduced back into S. mutans GS-5IS3 by two independent transformation procedures involving either linear or plasmid DNA to produce both scrA and scrA+ mutants. These mutants should prove useful for analyzing the regulation of sucrose transport in S. mutans.

Biological Transport, Active↗

PubMed1991

Murine thymic nurse cell clone supports the growth of fetal thymocytes in the presence of interleukin 2.

To investigate the role of thymic nurse cells (TNC) in activation and differentiation of fetal CD4-CD8- (double-negative) thymocytes, we have co-cultured murine fetal thymocytes (14-15 days of gestation) with an established murine TNC clone. We show here that TNC induced the growth of the fetal double-negative thymocytes in the presence of recombinant interleukin 2 (rIL2). Activated fetal thymocytes markedly formed lymphocyte-TNC complexes and proliferated extensively after 5 days in the co-culture. The activated fetal thymocytes in this co-culture condition remained double negative after 10 days in culture. None of them gave rise to phenotypically and functionally competent lymphocytes during this period. TNC alone and the supernatant of TNC had no effect on activation. The presence of both TNC and rIL2 was necessary for the growth of fetal thymocytes in our system. The proliferation of fetal thymocytes was inhibited by a monoclonal antibody against mouse IL2 receptors (IL2R). The fetal thymocytes could be maintained further in this co-culture condition. The prolonged cultivation of fetal thymocytes resulted in the establishment of the fetal thymocyte line and its several clones. CD4 single-positive cells of activated fetal thymocytes first appeared 14 days after the onset of culture and their number increased, whereas CD8+ cells or CD4CD8 double-positive cells were not observed. These results indicate that fetal CD4-CD8- thymocytes underwent phenotypic change after long periods of culture. All established clones of fetal thymocytes are CD4 single positive showing lymphocyte-TNC interactions but do not express CD3 complex. Northern blot analysis detected mRNA for the gamma T cell receptor, but no messages for the delta, alpha or beta T cell receptor. Chemical cross-linking of 125I-labelled IL2 revealed that the 90-kDa band (presumably considered to be the IL2R beta chain) was clearly present in IL2-responsive fetal clones, whereas freshly isolated day 14-15 fetal thymocytes lacked the band. Taken together, TNC might be involved in the differentiation and/or expansion of murine fetal thymocytes by inducing IL2R beta chain, which forms the functional IL2R together with IL2R alpha chain and CD4, one of the T cell accessory molecules, on the cell surface through direct cell-cell interaction.

Animals↗

PubMed1991

Production of granulocyte-macrophage colony-stimulating factor or GM-CSF-like growth factor by rat thymic epithelial cell line.

An epithelial cell line, IT-45R1, has been established from a thymus of normal Wistar rat and was found to produce growth factor which stimulated the proliferation of bone marrow cells. This growth factor induced the formation of colonies composed of macrophages, granulocytes, or both, in semi-solid medium and stimulated the proliferation of an interleukin 3 (IL3)/granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent clone. Neither IL3-dependent clone nor IL6-dependent clone responded to IT-45R1 factor. Additionally, IT-45R1 factor acted on both rat and mouse bone marrow cells but not on human bone marrow cells. Molecular weight of IT-45R1 factor was 30 kD and its isoelectric point was 4.5. To determine whether IT-45R1 factor is GM-CSF or not, Northern blot analysis and neutralization with anti-mouse GM-CSF antibody were carried out. IT-45R1 expressed GM-CSF mRNA, but neither M-CSF nor IL6 transcripts. However, antiserum specific for mouse GM-CSF did not neutralize IT-45R1 factor. Taken together, a rat thymic epithelial cell line, IT-45R1, constitutively produces GM-CSF or GM-CSF-like growth factor.

Animals↗

PubMed1991

Effects of ultraviolet radiation and visible light on hamster pupil.

Light does not cause a miotic response in mammals after a topical application of atropine. However, such common sense is based on the pupillary response to visible light. We found ultraviolet (UV) caused slight but evident miosis, even when the patient did not perceive visible light. In order to understand this mechanism further, we conducted in vitro experiments using hamsters. The in vitro hamster iris contracted even when the retina was withdrawn in an incubation solution. The contraction of the hamster pupil caused by visible light was inhibited by procaine, quinacrine, and by the withdrawal of divalent cations, but not by indomethacin, AA861, FPL55712 or autonomic blocking agents. UV-induced miosis was very delayed, continuing after cessation of UV stimuli. Nordihydroguaiaretic acid did not inhibit the miosis induced by UV and/or visible light. The UV-induced miosis was not significantly affected by allopurinol or verapamil, suggesting mechanisms other than neuronal mediation and oxidative stress. This study shows that the isolated hamster iris can react to UV and visible rays. UV-induced miosis is different from the miosis caused by light reflex. To our knowledge, UV-induced miosis has not yet been reported.

Animals↗

PubMed1991

Low dose irradiation for limb salvage in malignant bone tumours.

We have assessed the value of adding low dose radiotherapy to preoperative chemotherapy in 20 patients with high grade malignant bone tumours. Histology of the resected specimens showed a considerable tumouricidal effect and a distinct capsule enclosing the extraosseous part of the tumour. There were no serious side effects.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1991

Symptomatic cerebral vasospasm of unusually late onset after aneurysm rupture.

An unusually late occurrence of symptomatic cerebral vasospasm is reported. The case involves a 50-year-old male who was uneventfully operated on for a ruptured anterior communicating artery aneurysm, with no symptom of cerebral vasospasm, 17 days after sustaining the subarachnoid haemorrhage. Two days after surgery, a right hemiparesis developed and angiography disclosed severe cerebral vasospasm. This case history and the aetiological factors of symptomatic vasospasm are discussed.

Cerebral Angiography↗

PubMed1991

Orosomucoid typing of apes (family Pongidae) by isoelectric focusing: among primates do only humans have two functional orosomucoid loci?

It has been demonstrated that human orosomucoid (ORM) is controlled by more than one functional loci, while Macaca ORM is controlled by one locus. To examine the time when the ORM gene was duplicated in the evolution of primates, plasma samples from 118 apes (family Pongidae) belonging to 4 genera and 12 species were investigated for ORM polymorphism using isoelectric focusing followed by immunoprinting. The band patterns of ORM in the subfamily Ponginae showed quantitatively different products as in humans. A pedigree study of common chimpanzees supported the two-locus model for ORM. Gibbons (subfamily Hylobatinae) displayed highly variable band patterns, but the number of loci was not determined unequivocally. Thus, this study shows that duplication of the ORM gene in primates occurred either before or after the divergence of Hylobatinae and Ponginae, consistent with a previous prediction from the molecular evolutionary rate of ORM.

Alleles↗

PubMed1991

Malignant amelanotic melanoma of the esophagus.

The clinical, histological, and electron microscopic features of a case of malignant amelanotic melanoma of the esophagus are described. Amelanotic melanoma is difficult to distinguish from other malignant lesions, but in our case electron microscopy was helpful in the diagnosis.

Diagnosis, Differential↗

PubMed1991

Possible mechanism of the preventive effect of BCG against diabetes mellitus in NOD mouse. I. Generation of suppressor macrophages in spleen cells of BCG-vaccinated mice.

With the aim of clarifying the mechanism of the suppressive action of BCG against insulitis and overt diabetes in NOD mice, we studied the effects of BCG on spleen cell populations and on the in vitro immune responses of spleen cells. The spleen cells of BCG-vaccinated mice showed much lower responsiveness to various mitogens such as Con A, PHA, PWM, and LPS than those of saline-treated mice. Low responsiveness to alloantigens was also observed. Flow cytometric analysis of the spleen cells revealed that Mac-1+ and Mac-2+ cells had increased while T and B cells had decreased in the BCG-vaccinated mice compared with the saline-treated mice at the time when the maximum level of inhibition of mitogen responses of BCG-vaccinated mice was observed. This suggests that the decreased in vitro immune response was due to the increase in macrophages which suppress lymphocyte functions. Support for this interpretation comes from the following two findings: (1) the restoration of mitogen responses of spleen cells when macrophages were eliminated by plastic adhesion or FACS sorting and (2) resuppression of PHA and Con A responses of plastic-nonadherent spleen cells by addition of adherent cells or flow cytometrically sorted Mac-1+ cells obtained from BCG-vaccinated mice. These results indicate the generation of suppressor macrophages after BCG vaccination and suggest that these macrophages prevent the autoimmune pathogenesis leading to diabetes in NOD mice.

Animals↗

PubMed1991

Isolation and characterization of Japanese eel prolactins.

A highly purified prolactin (PRL) was isolated from the pituitary of the Japanese eel (Anguilla japonica) by extraction with acid-acetone, gel filtration on Sephadex G-75, and reversed-phase HPLC on TSK-gel ODS 120T and on TSK-gel TMS 250. Eel PRL is comprised of two variants (ePRL I and II), which were separated by HPLC on an ODS column. The two PRLs were also secreted by organ-cultured pituitaries in a defined medium. After being dialyzed against distilled water and lyophilized, the medium was dissolved in 0.01 M ammonium acetate (pH 9.0), and then the insoluble fraction was subjected to HPLC on an ODS column to isolate the secreted PRLs. The ePRL I and II were equipotent in retaining plasma Na in the hypophysectomized killifish, Fundulus heteroclitus, transferred from sea-water to fresh water. The putative PRL-producing cells in the rostral pars distalis of the eel pituitary were specifically stained with the antiserum against the mixture of ePRL I and II. Both PRLs had a molecular weight of 22 kDa in SDS-PAGE, an isoelectric point of 10.1 by gel electrofocusing, and an N-terminal residue of valine. Amino acid compositions and the partial amino acid sequences of ePRL I and II show that they are highly homologous with a limited number of substitutions, and that they are more closely related to those of teleostean PRLs than to those of mammalian PRLs.

Amino Acid Sequence↗

PubMed1991

Development of a homologous radioimmunoassay for eel prolactin.

A highly specific and homologous radioimmunoassay (RIA) for the measurement of prolactin (PRL) in the plasma and the pituitary of the eel was developed using a rabbit antiserum to eel PRL. PRL was purified from the pituitary of Japanese eel (Anguilla japonica). Pituitary extracts and plasma from the Japanese and European eels exhibited displacement curves parallel to the eel PRL standard. Plasma and pituitary extracts from chum salmon, rainbow trout, Japanese charr, tilapia, goldfish, and carp, as well as plasma from hypophysectomized eel, showed negligible cross-reactivity. PRL and growth hormone (GH) preparations from chum salmon, tilapia, and sheep, carp PRL, and eel GH did not cross-react with the antibody. The RIA sensitivity was less than 0.1 ng eel PRL per milliliter. Intra- and interassay coefficients of variations were 2.4 and 11.8%, respectively. The immunoreactive PRL levels in plasma and pituitary of the eel adapted to 50% seawater were significantly lower than those of the eel in fresh water. Plasma PRL levels increased maximally 2 days after transfer from seawater to fresh water, as would be expected from the well-established role of PRL in freshwater adaptation in several euryhaline teleosts.

Adaptation, Physiological↗

PubMed1991

Perioperative complications of encephalo-duro-arterio-synangiosis: prevention and treatment.

We performed encephalo-duro-arterio-synangiosis on 169 sides of 81 Moyamoya and 8 non-Moyamoya patients in the past 10 years. The advantage of this operation is its minimal operative invasion, giving rise to few operative complications. During 10 years of practice, however, we encountered some perioperative problems. Perioperative cerebral infarction of varying severity was seen in six Moyamoya patients. Severe hyperventilation with crying was the main trigger of infarction. Two patients developed wound infection with Gram-negative rods. Removal of an infected bone flap was necessary. One Moyamoya patient developed malignant hyperthermia during the operation. One acute epidural hematoma necessitated an emergency hematoma removal. Five patients showed a temporary aggravation of involuntary movements. Prolonged mild fever and temporary and limited hair loss around the wound were often observed. Cases and their treatment are presented with discussion of preventive measures.

Adolescent↗

PubMed1991

Comparison of protective effects with tetra-valent glycolipid antigens and whole cell-inactivated vaccine in experimental infection of Leptospira.

The protective antigens (PAgs), glycolipid substance, were extracted from Leptospira interrogans serovars autumnalis, hebdomadis, australis and copenhageni, which were considered as main causal serovars of human leptospirosis in Japan, with chloroform-methanol-water (1:2:0.8, [vol/vol/vol]) solution. The tetra-valent formalin-inactivated leptospiral vaccine (Weil's disease and Akiyami combined vaccine) composed of the four serovars mentioned are used as vaccine to protect human from leptospiral infection in Japan. The protective effect, agglutinating antibody-inducing activity and opsonin-inducing activity of tetra-valent PAgs were compared with those of vaccines now in use, which were supplied by two companies, Takeda Chemical Industries, Ltd., and Denka-Seiken Co., in Japan. The tetra-valent PAgs which contained 10 micrograms of each PAg protected hamsters and cyclophosphamide-treated mice from lethal infection of serovar copenhageni and induced agglutinating antibodies against the four serovars in the same degrees as vaccines. These results suggested that the tetra-valent PAgs might be useful as a component vaccine against leptospiral infection instead of formalized whole cells vaccines for human.

Agglutination Tests↗