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Biomedical subjects

R Suzuki

Publications and source records attributed to R Suzuki.

At least 325 records · Page 18Linked to original sources
PubMed1997

Anaplastic large cell lymphoma: a distinct molecular pathologic entity: a reappraisal with special reference to p80(NPM/ALK) expression.

The p80(NPM/ALK) expression activated by the t(2;5) (p23;q35) translocation recently has been shown to play an important role in the pathogenesis of anaplastic large cell lymphoma (ALCL). However, the clinicopathologic significance of identification of p80 among ALCL cases has not been completely resolved. Difficulties also exist in the histologic and immunophenotypic identification of ALCL and Hodgkin's disease (HD) as separate processes, often complicating the clinicopathologic evaluation of and therapeutic approach to these entities. In order to clarify these issues, 67 specimens of ALCL and 63 specimens of HD (31 of the nodular-sclerosing type [NS-HD] and 32 of the mixed-cellularity type [MC-HD]) were immunostained using anti-p80 antibody and other relevant markers on paraffin sections. The clinicopathologic and immunophenotypic features were reviewed on the basis of p80 reactivity. The expression of p80 was detected in 43 of 67 cases of ALCL (64%), but none of HD. The p80+ ALCL cases constituted a very homogeneous group of tumors, characterized by the occurrence in a much younger group and relatively more favorable clinical course than the p80- ALCL, which were in keeping with the data previously reported. They showed virtually the identical immunophenotypic findings of p80+, CD30+, EMA+, CD15-, bcl-2-, and Epstein-Barr virus (EBV) with T- and null-cell phenotype, and showed the distinct morphologic features, including three cases of lymphohistiocytic/small-cell variant, as follows: the indented nuclei, often termed as reniform, embryolike, and horseshoelike; multiple, irregular, but indistinct nucleoli; and few reactive cells of eosinophils and epithelioid cells. Conversely, the 24 p80- ALCL cases, in which epithelial membrane antigen (EMA) and bcl-2 positivities were 33% and 55%, respectively, were heterogeneous and could be subdivided into five different categories, namely (a) 11 cases of HD-like ALCLs, (b) six cases of p80 common ALCL, (c) three cases of secondary ALCL, (d) two cases of primary cutaneous ALCL, and (e) two cases of primary classical ALCL that lacked p80 expression. This study clearly demonstrated that the immunohistochemical detection of p80 is of a crucial importance in delineating the biologically distinct entity of "primary classical ALCL" from various diseases that show morphologic and immunohistologic overlap, including HD and HD-like ALCL.

Adolescent↗
PubMed1997

Somatic hypermutations in the VH segment of immunoglobulin genes of CD5-positive diffuse large B-cell lymphomas.

De novo CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBL) has recently been identified as constituting a homogeneous subgroup with distinct clinicopathologic and genotypic characteristics, but its origin remains to be elucidated. Previous studies by sequence analysis of the variable region of the immunoglobulin heavy chain (VH) have shown that CD5+ B-cell malignancies such as mantle cell lymphoma (MCL) and B-cell chronic lymphocytic leukemia (B-CLL) cells represent pre-germinal center (pre-GC) stage B cells in contrast with the post-GC stage of most DLBLs, which show somatic hypermutations in VH genes. In the present study, we investigated the VH sequence of de novo CD5+ DLBL to clarify whether CD5+ DLBL represents the pre-GC stage, as do other CD5+ B-cell malignancies, or the post-GC stage, as is typical of DLBL. All eight cases (four CD5+ DLBL and four CD5-negative (CD5-) DLBL) examined by us showed somatic hypermutations in the VH segment and two of the CD5- DLBL cases showed intra-clonal diversity, suggesting that CD5+ DLBLs were derived from the same maturation stage as CD5- DLBL, but were distinct from the other indolent CD5+ B-cell lymphomas of B-CLL and MCL. These data suggest that de novo CD5+ DLBLs do not merely lie within a continuous spectrum with B-CLL and MCL, but represent a biologically distinct variant within the diagnostic framework of diffuse large B-cell lymphoma.

Adult↗
PubMed1997

[Isolation of enterohemorrhagic Escherichia coli (O157:H7) by an immunomagnetic separation method].

Three sporadic cases of enterohemorrhagic Escherichia coli (EHEC) O157 infection which occurred in Kanagawa in 1996 were investigated. In an attempt to determine sources of the infection, a novel method of immunomagnetic separation (IMS) was employed to isolate the bacterium from feces, foods, and other associated items. In the first case, strains of EHEC O157:H7 producing Vero toxin (VT) 2 were isolated from both feces of the patient and suspected food (cattle liver) kept at a restaurant, and the strains were found to be genotypically identical through an analysis of pulsed-field gel electrophoresis (PFGE). Subsequent investigation in the meat processing store, from which the above cattle liver had been retailed to the restaurants revealed that the store was contaminated with EHEC O157:H7 producing both VT1 and VT2. In the second case, a strain isolated from the patient was EHEC O157:H7 producing both VT1 and VT2 while strains isolated from the patient's family (without apparent symptom) and the suspected facility were O137:NM producing VT2. PFGE analysis indicated that the latter two strains were genotypically identical, suggesting that the facility thus contaminated with EHEC O157 caused the infection in question. In the third case, EHEC O157:NM producing VT2 was isolated from 4 out of 7 family members including the patient, and these strains were found to be genotypically identical by subsequent PFGE analysis. Source of the infection was, however, not determined due to lack of suspected food items. In this context, four slaughterhouses in Kanagawa Prefecture were investigated for presence of EHEC O157. As a result, strains of EHEC O157:H7 producing VT1 and VT2 were isolated from the contents of cattle's distal colon and surface of the skinned carcasses. Additional attempt was also made to determine a possibility of river water being contaminated with EHEC O157. The bacterium was, however, not isolated from water samples collected from 4 major rivers in the prefecture (at 10 collecting sites). Experiments were undertaken in order to evaluate the use of IMS in isolation of EHEC O157 from food items, with different pre-enrichment media and conditions. The results indicated that pre-enrichment by trypticase soy broth at 36 degrees C for 6 h followed by inoculating onto sorbitol MacConkey agar plate containing cefixime and tellurite was most appropriate to isolate EHEC O157 strains.

Adolescent↗
PubMed1997

Variation in effects of Cs+, UL-FS-49, and ZD-7288 within sinoatrial node.

The effects of Cs+, UL-FS-49, and ZD-7288 on action potentials recorded from central, transitional, and peripheral sites in the rabbit sinoatrial (SA) node have been investigated. In isolated right atrial preparations, including the whole SA node, Cs+ (2 mM), UL-FS-49 (1 microM), and ZD-7288 (3 microM), decreased the spontaneous rate by 12 +/- 2% (n = 21), 16 +/- 3% (n = 10), and 13 +/- 3% (n = 10). They decreased the slope of the pacemaker potential without affecting action potential characteristics. The decrease of pacemaker slope was maximal (69-120%) in the periphery and minimal (22-25%) in the center. In experiments on small ball-like tissue specimens (approximately 0.3 mm diam), a decrease in spontaneous rate and pacemaker slope by Cs+ (2 mM) was largest (approximately 19 and approximately 47%) in tissue from the periphery and least (approximately 7 and approximately 17%) in tissue from the center. Because the hyperpolarization-activated inward current (If) is reduced by each of these agents, the results suggest that this current might play a relatively minor role in the center but a more important role in the periphery of the SA node.

Action Potentials↗
PubMed1997

Regional differences in the role of the Ca2+ and Na+ currents in pacemaker activity in the sinoatrial node.

The effect of block of the L-type Ca2+ current by 2 microM nifedipine and of the Na+ current by 20 microM tetrodotoxin on the center (normally the leading pacemaker site) and periphery (latent pacemaker tissue) of the rabbit sinoatrial node was investigated. Spontaneous action potentials were recorded with microelectrodes from either an isolated right atrium containing the whole node or small balls of tissue (approximately 0.3-0.4 mm in diameter) from different regions of the node. Nifedipine abolished the action potential in the center, but not usually in the periphery, in both the intact sinoatrial node and the small balls. Tetrodotoxin had no effect, on electrical activity in small balls from the center, but it decreased the takeoff potential and upstroke velocity and slowed the spontaneous activity (by 49 +/- 10%; n = 11) in small balls from the periphery. It is concluded that whereas the L-type Ca2- current plays an obligatory role in pacemaking in the center, the Na+ current plays a major role in pacemaking in the periphery.

Animals↗
PubMed1997

Meningoencephalocele associated with Tripterygium wilfordii treatment.

We treated a male infant with occipital meningoencephalocele associated with the taking of Tripterygium wilfordii. The infant was delivered normally at 38 weeks of gestation with a huge cystic mass protruding from the occiput. He was diagnosed with occipital meningoencephalocele and cerebellar agenesis. His mother had taken T. wilfordii for rheumatoid arthritis early in her pregnancy. T. wilfordii is a herbal medicine used for rheumatoid arthritis and male contraception. Since its toxicity is high and its use during pregnancy is restricted, it is the most likely cause of this infant's anomalies.

Abnormalities, Drug-Induced↗
PubMed1997

Ten-year follow-up of intraocular pressure after phacoemulsification and aspiration with intraocular lens implantation performed by the same surgeon.

We evaluated the pre- and postoperative intraocular pressure (IOP) levels of 498 patients, to determine whether IOPs are affected over a 10-year period. All surgeries were performed by the same surgeon using phacoemulsification and aspiration (PEA) with posterior chamber intraocular lens (PCIOL) implantation. The mean preoperative IOP was 12.2 +/- 4.0 mm Hg, and the mean postoperative IOPs were not affected for 10 years. However, when the preoperative IOP was over 20 mm Hg, a significant decrease was achieved without glaucoma surgery. When the preoperative IOP was under 10 mm Hg, the IOP significantly increased. PEA with implantation of a PCIOL provides an excellent chance for improved intraocular tension control, providing that the surgery is properly performed.

Aged↗
PubMed1997

Trabeculectomy with a Kelly Descemet membrane punch.

The trabeculectomy procedure was modified with the introduction of the Kelly Descemet membrane punch. Using this punch, a few limbal tissue sections (0.25 x 0.30 mm) were easily excised from beneath the scleral flap base. Mitomycin C (MMC) was used. Among the 100 most recent operations in which this punch was used, no patients developed severe shallow anterior chambers over ten days. Because MMC is so effective and active for a long period, small excision surgery using this punch should be reconsidered.

Anterior Chamber↗
PubMed1997

A comparison of blood pressure changes in phacoemulsification surgery with topical and retrobulbar block local anesthesia: part II.

Although we recently compared blood pressure (BP) changes during cataract surgery between groups that received topical and retrobulbar block anesthesia, a study has not been conducted in which patients were matched for age and sex. To draw more meaningful conclusions, we conducted an age- and sex-matched study in which the daily, pre- and postoperative blood pressures of 1,398 cataract patients were compared. All surgeries were performed using the same method of phacoemulsification and aspiration with intraocular lens implantation under local anesthesia. The postoperative BPs of the retrobulbar injection group decreased significantly more than the topical application group. Even when the patients were hypertensive, the postoperative BPs decreased. Following retrobulbar block anesthesia, the BP decreased postoperatively to a greater extent than after topical anesthesia.

Administration, Topical↗
PubMed1997

Higher concentrations of matrix metalloproteinases in bronchoalveolar lavage fluid of patients with adult respiratory distress syndrome.

This study was designed to investigate possible involvement of type IV collagenolytic matrix metalloproteinases (MMPs; 72-kDa type IV collagenase [MMP-2], 92-kDa type IV collagenase [MMP-9]), and the respective specific tissue inhibitors of these MMPs (TIMP-2 and TIMP-1) in the development of adult respiratory distress syndrome (ARDS). We determined the concentrations of these enzymes in the bronchoalveolar lavage fluid (BALF) from patients with ARDS using newly developed sensitive one-step sandwich enzyme immunoassay methods. BALF obtained from the 17 patients and eight healthy volunteer control subjects were also used for the analysis of the number of the cellular component. Concentrations of the 7S portion of type IV collagen and laminin in the BALF were measured as markers of basement membrane disruption. In the BALF from the ARDS patients, the concentrations of MMP-2 (66.7 +/- 57.0 ng/ml versus < 7.0 ng/ml for controls, p < 0.01) and MMP-9 (118.0 +/- 309.3 ng/ml versus 9.0 +/- 9.5 ng/ml for controls, p < 0.05), and the specific inhibitor of MMP-9 (TIMP-1) (161.0 +/- 145.0 ng/ml versus < 50 ng/ml for controls, p < 0.01) were significantly higher compared with those for healthy control subjects. In the ARDS patients, the concentrations of MMP-2 correlated both with those of 7S collagen and laminin; MMP-9 with the concentration of 7S collagen and the number of neutrophils. These findings suggest that the increased concentration of collagenolytic MMPs in lung plays a role in the pathogenesis of ARDS.

Adult↗
PubMed1997

Dual regulation of alkaline phosphatase activity by calcitonin in porcine kidney cells.

Intracellular signal transduction for regulation of alkaline phosphatase (ALP) activity in renal epithelial cells treated with calcitonin is not yet completely understood, although it is known that calcitonin receptors couple to cyclic AMP-dependent protein kinase (PKA) and calcium/phospholipid-dependent protein kinase (PKC). Salmon calcitonin increased the cyclic AMP content in LLC-PK1 porcine kidney cells in a concentration-dependent manner. When the confluent cells were incubated for 47 h after a 1 h-pulse exposure or continuously exposed to calcitonin and forskolin for 48 h, ALP activity in the cells was increased by calcitonin about 2-fold compared with the basal activity at the maximum level but was not dependent on the exposure time; it was markedly increased by forskolin in parallel with the exposure time. The increase in activity produced by calcitonin was abolished by a PKA inhibitor H-89, and, in contrast, potentiated by a PKC inhibitor, NA-382 to near the forskolin-induced level. These results indicate that calcitonin exerts a dual-regulation of ALP activity in LLC-PK1 cells, positively through the PKA pathway and negatively through PKC.

Alkaline Phosphatase↗
PubMed1997

Increase of eosinophilic cell population in bone marrow of rats by immunization with Ascaris suum antigen.

Immunization of rats with the antigen, Ascaris suum extract, increased the number of peripheral eosinophils. Analysis by Western blot and reverse transcription-polymerase chain reaction revealed that the levels of major basic protein and its mRNA in the bone marrow were also increased, suggesting that eosinophilic cell population in the bone marrow is increased by the immunization. These findings indicate that immunization with this antigen stimulates differentiation of progenitor cells to eosinophils in the bone marrow, and induces blood eosinophilia.

Animals↗
PubMed1997

[Studies on enrichment broth for verotoxin-producing Escherichia coli (VTEC) O157].

Growth of verotoxin-producing Escherichia coli (VTEC) O157 in conventionally recommended pre-enrichment broth media at different temperatures was evaluated. In addition, sensitivity of VTEC O157 isolates to several antibacterial drugs, which were added to the selective enrichment broth, was tested. All five isolates of VTEC O157 tested grew well in trypticase soy broth (TSB) at 36 degrees C and 42 degrees C, while the growth of one isolate was markedly suppressed in TSB supplemented with cefixime (CFIX), potassium tellurite (PT), and vancomycin (TSB-CTV) even at 36 degrees C. A significant growth suppression was also observed in three of the isolates cultured in novobiocin (NB)-supplemented modified EC broth (mEC-NB) at 42 degrees C. In mEC-NB after 24-hr incubation at 36 degrees C, the five VTEC O157 isolates grew well, although one isolate was slightly suppressed during the first 8 hours. Minimum growth inhibitory concentrations of CFIX, NB and PT for a total of 90 clinical and environmental isolates of VTEC O157 were all above the concentrations usually prescribed for mEC-NB and TSB-CTV. These findings suggest that mEC-NB and TSB-CTV should be used at 36 degrees C for growth of VTEC O157 and that use of a nonselective pre-enrichment broth medium (i.e. TSB) together with a selective one (i.e. TSB-CTV or mEC-NB) is necessary for successful isolation of VTEC O157 from various specimens.

Aeromonas↗
PubMed1997

Kinetic isotope effect and reaction mechanism of 2-deoxy-scyllo-inosose synthase derived from butirosin-producing Bacillus circulans.

The mechanism of 2-deoxy-scyllo-inosose synthase reaction, a carbocycle formation step from D-glucose-6-phosphate in the biosynthesis of the 2-deoxystreptamine aglycon of clinically important aminocyclitol antibiotics, was investigated with a partially purified enzyme from butirosin-producing Bacillus circulans SANK 72073, Nonlabeled and double-labeled D-[4-2H, 3-15O]glucose-6-phosphate were used for cross-over experiment, and the oxime-TMS ether derivative of the 2-deoxy-scyllo-inosose product was analyzed by GC-MS. The deuterium label at C-4 of the substrate appeared to be retained at C-6 of the inosose product without scrambling of the double-labeled isotopes. Since the transient reduction of NAD+ cofactor was proved to be essential in the 2-deoxy-scyllo-inosose reaction, the hydride abstraction and returning appeared to take place within the same glucose molecule. The observed kinetic isotope effect was estimated to be kH/kD = 2.4. These results strongly suggest that this carbocycle formation is catalyzed by a single 2-deoxy-scyllo-inosose synthase enzyme with catalytic requirement of NAD+, the mechanism of which appears to be resembled closely to the 2-deoxy-scyllo-inosose synthase in the Streptomyces fradiae.

Anti-Bacterial Agents↗
PubMed1997

Investigation of Vicia graminea lectin- and Vicia unijuga lectin-binding glycoproteins as novel oncofetal antigens in cyst and ascitic fluids of human ovarian tumors in benign, dysplastic, and malignant stages.

Perchloric acid-soluble fractions (PASFs) were obtained from cyst fluids of human benign ovarian mucinous cystadenoma, benign dermoid cyst, "borderline" mucinous cystadenoma, and malignant ovarian clear cell carcinoma, and from fluids of malignant embryonal carcinoma and malignant serous cystadenocarcinoma. PASFs from benign lesions did not react with Arachis hypogaea lectin (PNA), Vicia graminea lectin (VGA), or Vicia unijuga lectin (VUA). PASFs from "borderline" lesions reacted with PNA but did not react with VGA and VUA. PASFs from malignant tumors reacted with PNA, VGA, and VUA. These PASFs did not react positively against anti-M or -N sera. These results show that VGA- and VUA-binding glycoprotein (Vgu glycoprotein) exist in PASFs from malignant ovarian tumors, and that PNA-binding glycoprotein was present in PASFs from malignant and "borderline" ovarian tumors. Furthermore, we found the existence of Vgu glycoprotein in PASFs from various human cancer cell lines; however, the antigens were not found in PASFs from benign human cell lines.

Antigens, Neoplasm↗
PubMed1997

[Effects of beta-adrenergic agonists and phosphodiesterase inhibitors on the outflow facility of the eye].

Changes in the outflow facility of perfused bovine eyes and in the shape of cells in cultured trabecular meshwork (TM) were studied after exposure to adrenergic drugs. Dobutamine, a selective beta 1 agonist caused confluent TM cells to change from their usual polygonal shape to a characteristic stellate shape. Salbutamol, a selective beta 2 agonist showed no effect. The phosphodiesterase (PDE) inhibitors, isobutylmethylxanthine (IBMX), theophylline, and caffeine were also very effective in producing this shape change. Epinephrine, isoproterenol, dobutamine or salbutamol did not increase the outflow facility, at temperatures of 22 degrees C or 36 degrees C, whereas theophylline, caffeine and IBMX increased the facility in a dose-dependent manner. The high concentrations of beta-adrenergic agents required to produce even a small change in outflow facility and the cell shape argue against the involvement of adrenergic receptor mediation; on the other hand, the enhancement of the effects of epinephrine by PDE inhibitors and a similar effect produced by cAMP suggest that the changes in the cell shape are produced by beta-receptor activation. The beta-adrenergic agents were ineffective on changing outflow facility but the PDE inhibitors were remarkably effective in producing both shape change and increasing facility. PDE inhibition has much greater influence on and around the outflow channels than pure beta-adrenergic agonists, at least in enucleated bovine eyes.

1-Methyl-3-isobutylxanthine↗