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Biomedical subjects

T Onodera

Publications and source records attributed to T Onodera.

At least 109 records · Page 6Linked to original sources

Aqueous flare increase after light exposure in age-related macular degeneration.

An increase in anterior chamber flare is associated with many ocular conditions, including retinal diseases. We assessed anterior chamber flare in 18 patients (19 eyes) with exudative age-related macular degeneration using the Kowa flare-cell meter immediately before and 1 hour after exposure to 40 light flashes at a flash intensity of 300 W/s delivered with a Topcon fundus camera. Fourteen eyes showed a significant increase in flare 1 hour after light exposure (T = -3.452, p < 0.003, t-test). A second measurement in a subgroup of 10 patients exposed to 40 light flashes at a flash intensity of 36 W/s showed no significant change in flare 1 hour after light exposure. Multiple analysis of variance (two-way interaction) showed a highly significant difference between the two groups (F[1,27] = 8.66, p < 0.0066). We discuss possible mechanisms that may have produced these changes as well as implications of light exposure in various diagnostic and therapeutic settings.

Aqueous Humor↗

Isolation of the chicken NF-kappa B p65 subunit-encoding cDNA and characterization of its products.

NF-kappa B is a heterodimeric transcription factor consisting of subunits of 50 kDa (p50) and 65 kDa (p65). cDNA clones encoding the chicken NF-kappa B p65 subunit were isolated. Sequence analysis showed that chicken p65 is approximately 55% identical to the mouse and human p65 proteins, and contains the Rel homology domain (RHD) in its N-terminal 286 amino acids (aa) and the putative transactivation domain in its C-terminal region. The RHD is particularly highly conserved between the chicken and mammalian p65 proteins. Northern blot hybridization analysis detected the expression of a 2.6-kb transcript of p65 in various organs, with the highest level in spleen. A fusion protein containing the RHD of chicken p65 was found to bind to a consensus kappa B-site in an electrophoretic mobility shift assay (EMSA). This binding was specifically inhibited by the presence of fusion proteins containing the C-terminal ankyrin repeats domain (ARD) of chicken p105, the precursor protein for the p50 subunit. Immunoprecipitation analysis showed that p65 formed a complex(es) with multiple cellular proteins, including p50, p105 and c-Rel in chicken spleen cells.

Amino Acid Sequence↗

Na+/H+ exchanger and reperfusion-induced ventricular arrhythmias in isolated perfused heart: possible role of amiloride.

The roles of the Na+/H+ exchange system in the development and cessation of reperfusion induced ventricular arrhythmias were studied in the isolated perfused rat heart. The hearts were perfused in the working heart mode with modified Krebs Henseleit bicarbonate (KHB) buffer and whole heart ischemia was induced by a one-way ball valve with 330 beat/min pacing. Ischemia was continued for 15 min followed by 20 min of aerobic reperfusion (control). Amiloride (1.0 mM), an inhibitor of the Na+/H+ exchange system, was added to the KHB buffer only during reperfusion (group B) or only during ischemic periods (group C). Electrocardiographic and hemodynamic parameters were monitored throughout the perfusion. Coronary effluent was collected through pulmonary artery cannulation and PO2, PCO2, HCO3- and pH were measured by blood-gas analyzer. The incidence of reperfusion induced ventricular arrhythmias was 100%, 100% and 0% in control, group B and group C, respectively. The mean onset time of termination of reperfusion arrhythmias was significantly shorter in group B than in control. PCO2 increased from 39.0 +/- 0.9 to 89.3 +/- 6.0 mmHg at the end of ischemia in control and from 40.6 +/- 0.4 to 60.5 +/- 5.8 in group C, the difference between groups was statistically significant. HCO3- level decreased from 21.8 +/- 0.1 to 18.3 +/- 0.5 mmol/l in control, however, this decrease was significantly inhibited in group C (from 22.0 +/- 0.5 to 20.3 +/- 0.2). The increase in PCO2 and the decrease in HCO3- in group B were similar over time to those observed in control.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗

Infection of reovirus type 3 in Mongolian gerbils (Meriones unguiculatus)--lesions in pancreas and brain.

Gerbils were inoculated with reovirus type 3 (Abney strain), and the pancreas, brain and other organs histopathologically evaluated. Male Mongolian gerbils (Meriones unguiculatus) aged 5-10 days (newborn, 9 animals), 4 weeks (juvenile, 5 animals), and 12 weeks (adult, 5 animals) were used. Gerbils inoculated intraperitoneally with the virus were sacrificed 3, 5, 7, or 10 days later. Tissues were observed by light and electron microscopy. The pancreas of newborns showed inflammatory edema with infiltrates of neutrophilis and mononuclear round cells, degranulation of acinar cells and dissociation of lobules and acini with necrosis at 3 days or later after inoculation but not degeneration of pancreatic islets. Brains of newborns had necrosis of neurons and aggregation of microglial cells in the brain stem and cerebral hemisphere. Azurophilic inclusion bodies were seen in the cytoplasm of some neurons. In electron micrographs, virus particles (60-80 nm in diameter) were observed around the nucleus of neurons in the brain stem. No changes were observed in the juvenile and adult gerbils.

Animals↗

Demonstration of hydroxyl radical and its role in hydrogen peroxide-induced myocardial injury: hydroxyl radical dependent and independent mechanisms.

We investigated the mechanism of hydrogen peroxide (H2O2) action on myocardial injury in relation to hydroxyl radical (.OH) formation. Isolated rat hearts were perfused with a concentration of H2O2 (300 microM) known to produce cardiac injury. Perfusion of H2O2 for 15 min caused severe myocardial dysfunction, morphological damage, ATP depletion, and lipid peroxidation. Hydrogen peroxide concentration in the coronary effluent was reduced approximately 40% reflecting a myocardial H2O2 consumption of 12.7 +/- 0.9 mumol/15 min/g wet tissue (n = 12). One of the .OH-generated derivatives, 2,3-dihydroxybenzoic acid (2,3-DHBA), formed from reaction with salicylic acid, was detected in the coronary effluent by high-performance liquid chromatography at 23.16 +/- 4.05 nmol/15 min/g wet tissue. Catalase (200 U/ml, n = 6) added to the perfusate attenuated all parameters of myocardial injury by eliminating H2O2 from the perfusate, and thus .OH was not detected in the effluent. Deferoxamine (5 mM, n = 7) added to the perfusate reduced morphological damage and lipid peroxidation, but not dysfunction or ATP depletion. Deferoxamine significantly reduced .OH production; 2,3-DHBA was 5.22 +/- 3.56 nmol/15 min/g wet tissue. The present study provides evidence that .OH is produced in the H2O2-perfused heart. The adverse H2O2-mediated myocardial outcomes documented in this study appear to arise from both .OH-dependent and .OH-independent mechanisms.

Adenosine Triphosphate↗

Analysis of chicken CD4 by monoclonal antibodies indicates evolutionary conservation between avian and mammalian species.

We have created a panel of mouse monoclonal antibodies detecting different epitopes on avian CD4 molecule. Two-color immunofluorescence analysis shows that chicken peripheral alpha beta T cells are either CD4 or CD8 single positive whereas most gamma delta T cells are CD4-negative both in the thymus and peripheral tissues. Unlabeled antibody competition analysis by flow cytometry demonstrates that several different epitopes on chicken CD4 are recognized by these antibodies. Antibodies precipitate a monomeric glycoprotein from surface-labeled chicken thymocytes and T cells with relative molecular mass (M(r) of 64 kd as analyzed by SDS gel electrophoresis. Removal of N-linked carbohydrates by endoglycosidase-F increases the electrophoretic mobility and reveals the core protein size with M(r) of 45 kd. The anti-CD4 antibodies inhibit antigen-induced cellular proliferation of a keyhole limpet hemocyanin (KLH) -specific T cell line. They synergize in the blocking of T cell proliferation with anti-class II major histocompatibility complex (MHC)-specific antibodies indicating that chicken CD4 is involved in antigen recognition process by CD4+ T cells. We also show that chicken CD4 is down-modulated in a similar manner as its mammalian equivalent when thymocytes are stimulated in vitro with phorbol esters. Altogether these findings suggest functional and biochemical conservation of the CD4 molecule in evolution.

Animals↗

Isolation of scrapie agent from the placenta of sheep with natural scrapie in Japan.

A five-month-pregnant Suffolk sheep histologically diagnosed as spontaneous scrapie was studied. Western blot analysis was performed with rabbit serum against the sheep scrapie-associated fibrils (SAF). In the proteinase K (pk)-treated parental brain and spleen samples, three major bands (15 K, 18 K, and 23 K) were detected. These major bands were not detected from the placenta. Infectious agents were isolated in mice from the brain samples but not from the placental homogenates. In another case of a three-month-pregnant Corriedale sheep without any clinical sign of, but histologically diagnosed as scrapie, was also studied in a similar approach. In the parental brain samples, three major bands (15 K, 18 K and 23 K) were detected. SAF protein was not detected in the parental spleen and placenta. No bands reactive with the antiserum were detected in any other samples from the fetal brain and spleen in both cases. However, infectious agents were isolated in mice from both brain and placental homogenates. Since the placenta is an important site of natural infection, it is worthwhile to study these tissues for the epidemiological study of scrapie infection.

Animals↗

An unusual heterotopia of pyloric glands of the stomach with inverted downgrowth.

A rarely reported, large heterotopia of gastric glands in the submucosal layer of the stomach is observed in a 79 year old Japanese man with early gastric cancer. Histologically, it consists of marked hyperplasia of benign foveolar-type epithelia and tubular glands which instead of growing upwards grow downwards into the submucosa. Immunohistochemically, many gastrin-positive G cells are observed within it, indicating the existence of independent pyloric-type glands from the surrounding mucosa with intestinal metaplasia. Muscle actin-positive fascicles, derived from the muscularis mucosae, are demonstrated to branch into it and to encapsulate it. This result suggests that the present lesion may not represent a truly submucosal ectopic location, but an inverted downgrowth of the mucosa into the submucosa, thus resembling an inverted polyp of the colon. An awareness of this unique lesion is important in order that it not be mistaken for a submucosal extension of the primary adenocarcinoma.

Aged↗

A serological survey of encephalomyocarditis virus infection in pigs in Japan.

A total of 1502 pig sera collected between 1990 and 1991 at 65 farms in 22 prefectures were subjected to neutralization test to encephalomyocarditis (EMC) virus. Of them, three hundred eighty seven pigs (25.8%) from the 55 farms (84.6%) had antibody against EMC virus. The positive rates were rather high in Ehime (53.1%), Tottori (49.1%), Shimane (44.4%) and Nagasaki (38.7%). The positive rate and geometric mean titer of antibody tended to increase with the age. These serological results suggest that the EMC viral infection have been occurred among pigs in Japan.

Age Factors↗

Aqueous flare and cell number in healthy eyes of Caucasians.

A prospective study was conducted using the laser flare-cell meter to determine aqueous flare intensity and cell counts in normal Caucasian eyes and to investigate factors which may have an effect on these measurements. The factors included age, iris color, pupillary size and pharmacologic dilation. We also compared the measurements of flare and cells in the right versus left eyes of the same individual to determine whether any difference exists between the aqueous protein concentration or cell count of two normal eyes. Ninety-two healthy Caucasians (184 eyes) whose ages ranged from 21 to 79 years were enrolled in the study. We found that there was no significant difference between the flare and cell measurements of the right and left eyes. The flare intensity range in this study population was between 1.3 and 7.6 photon count/ms. Flare increased significantly with aging (r = 0.562, P = 0.000). The baseline anterior chamber cell number did not vary significantly by age in the 3rd to 7th decades. Only in the 8th decade did a significant increase in cell number occur. No correlation between the undilated pupil size and the amount of flare or cells was found. After pharmacological pupillary dilation, anterior chamber flare significantly decreased and cell number significantly increased. The flare-cell meter is a sophisticated and sensitive instrument used to assess the condition of the blood aqueous barrier, but for accurate evaluations, the patient's age and the pharmacologic dilation of the pupil must be taken into consideration.

Adult↗

Effects of cycloplegia and iris pigmentation on postoperative intraocular inflammation.

Using the Kowa laser flare cell meter, we investigated the relation between anterior chamber inflammation following phacoemulsification and posterior chamber intraocular lens implantation, and (1) iris color and (2) the use of 1% cyclopentolate hydrochloride for 1 week postoperatively. One hundred sixty eyes, randomized into either a cycloplegic or noncycloplegic group, and classified into four different iris color groups--blue, brown, green, and hazel--were studied. Eyes with brown irides had significantly more intense flare 2 weeks postoperatively than eyes with blue irides. Overall, postoperative flare tended to be related to the degree of iris pigmentation. Use of 1% cyclopentolate hydrochloride for 1 week postoperatively failed to decrease anterior chamber inflammation in any of the eyes.

Adult↗

[The effect of intraocular lens (IOL) length and design on anterior chamber depth under contraction and relaxation of the ciliary muscle].

We compared the effect of intraocular lens (IOL) length and its design on the anterior chamber depth (ACD) change during contraction and relaxation of the ciliary muscle. We performed phacoemulsification or extra capsular cataract extraction using continuous circular capsulorhexis on 100 eyes, and implanted in 23 eyes a short one-piece IOL, in 22 eyes a short three-piece IOL, in 25 eyes a long one-piece IOL, and in 30 eyes a long three-piece IOL. All IOLs were fixed in the capsular bag. ACD changes after administration of 2% pilocarpine and 1% cyclopentolate were measured with a pachymeter between 3 and 6 months postoperatively. The compatibility of the IOLs with ciliary muscle contraction and relaxation was, in descending order, the short one-piece IOL, the short three-piece IOL, the long one-piece IOL, and the long three-piece IOL. The results indicated that short IOLs are more physiologically fixed in the capsular bag, with less stress on the zonules of Zinn.

Aged↗

[Hepatic arterial infusion chemotherapy combined with calcium antagonist for liver metastases].

We noticed inactivation of calcium antagonists in liver and investigated treatment with combined intraarterial chemotherapy. Both verapamil (VER) and adriamycin were infused into the hepatic artery of patients with liver metastases. The serum concentration of VER in the hepatic vein was 0.325 +/- 0.203 g/ml at maximum in 11 cases receiving bolus infusion. Blood pressures, heart rates and electrocardiograms were stable. The concentration in the peripheral vein was lower (0.089 +/- 0.027 g/ml) in 4 cases receiving 3-hour continuous infusion. Five patients received more than 10 infusions, and a partial response was observed in 2 cases. A more appropriate dose and the corresponding prognosis should be studied in the future.

Adult↗

Antitumor effect of methionine-depleting total parenteral nutrition with doxorubicin administration on Yoshida sarcoma-bearing rats.

Methionine-depleting total parenteral nutrition (methionine-depleting TPN), which infuses an amino acid solution devoid of L-methionine and L-cysteine as the sole protein source, showed enhancement of the effect of several anti-cancer agents. In this study, the combined effect of the methionine-depleting TPN with the administration of doxorubicin was examined in Yoshida sarcoma (YS)-bearing rats with regard to effects on the primary tumor growth, the extension of metastasis, and the host animal's life span. In the first experiment, immediately after receiving methionine-depleting TPN for 8 days, the animals were killed. Pathologic findings evaluated tumor growth in the implanted site and extension of the metastasis. In the second experiment, the survival period was determined after animals received methionine-depleting TPN for 10 days, with subsequent oral feeding until they died naturally. Proliferation of YS was markedly suppressed. In particular, hematogenous metastasis, which is a characteristic of YS, was suppressed, and a longer survival period (42.7 +/- 15.6 days, mean +/- SD) was attained in rats in the group treated with the methionine-depleting TPN combined with the administration of doxorubicin.

Animals↗

A specific RFLP type associated with the occurrence of sheep scrapie in Japan.

We have investigated restriction fragment length polymorphism (RFLP) on the PrP gene and the frequencies of RFLP patterns in 35 healthy Suffolk sheep randomly collected. According to the combinations of PrP encoding DNA fragments generated by restriction enzymes Eco RI and Hind III, the RFLP patterns were classified into six types and designated as types I to VI. The frequencies of these types were as follows: I, 8.6%; II, 11.4%; III, 17.6%; IV, 11.4%; V, 28.6%; and VI, 22.9%. In 10 sheep diagnosed as having natural scrapie, RFLP types, I, III, IV, and V were determined. To examine the correlation between the RFLP type and the occurrence of scrapie, the frequencies of RFLP types in sheep infected with natural scrapie were compared with those in healthy sheep. It was found that the frequency of type I in the sheep with natural scrapie was 70%, about eight times higher than that in randomly collected healthy sheep. In the 13 experimentally infected sheep that had been used for other purposes, however, no relationship between the RFLP type and onset of scrapie was found.

Animals↗

Induction of protective immunity and neutralizing antibodies to pseudorabies virus by immunization of anti-idiotypic antibodies.

Xenogenic anti-idiotypic antibodies (anti-Id) were prepared in rabbits against three murine neutralizing monoclonal antibodies (MAbs) directed to pseudorabies virus glycoproteins. These anti-Id were highly specific to idiotopes on the corresponding MAb molecules. Because the binding of MAb to the corresponding anti-Id was inhibited by the addition of viral envelope protein, these anti-Id seemed to contain a subpopulation of antibodies against the antigen-combining site (paratope) or the region related to the paratope of the MAb molecules. One of the anti-Id to a MAb directed against glycoprotein gp50 induced neutralizing antibodies to PrV. Mice immunized with the anti-Id were protected from lethal infection of PrV.

Animals↗

Macrophage function in the acute phase of lactic dehydrogenase virus-infection of mice: suppression of superoxide anion production in normal mouse peritoneal macrophages by interferon-alpha in vitro.

The effect of interferon (IFN)-alpha on the release of superoxide anions (O2-) by normal mouse macrophages (PEM) was examined. Sera from LDV-infected mice at 1 day, but not at 7 days post-infection, suppressed the O2- release by PEM. When PEM were exposed in vitro for 24 h to IFN-alpha, their capacity to release O2- was significantly suppressed. Progressive suppression of O2- release with increasing IFN-alpha concentration was observed. These results suggest that IFN-alpha in the circulation may be one of several suppressive factors on macrophage function in the early phase of infection and IFN-alpha may play a modulatory role in inflammation and immunity.

Animals↗

Increased superoxide anion release by peritoneal macrophages in mice with a chronic infection of lactic dehydrogenase virus.

The function of macrophages in mice chronically infected by lactic dehydrogenase virus (LDV) was studied. Superoxide anion (O2-) release was examined by using peritoneal macrophages. O2- release increased markedly from 3 weeks to 12 months, but not at 1 week post infection. O2- release was 1.2 to 1.5 times greater than in uninfected mice. Increased O2- release from macrophages in LDV-infected mice may explain, at least in part, suppressive effects on tumour growth seen in the chronic phase of infection.

Animals↗