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Biomedical subjects

T Miyamoto

Publications and source records attributed to T Miyamoto.

At least 163 records · Page 9Linked to original sources
PubMed2000

Transforming growth factor-beta isoform proteins in cell and matrix deposits on intraocular lenses.

PURPOSE: To determine whether the cells that adhere to poly(methyl methacrylate) (PMMA) posterior chamber intraocular lenses (PC IOLs) implanted in human eyes produce transforming growth factor-beta (TGF-beta) isoforms and whether the acellular proteinaceous deposits on these IOLs contain TGF-beta. SETTING: Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: Thirty-two PMMA PC IOLs explanted from Japanese patients were immunostained for TGF-beta1, -beta2, or -beta3, and observed under light microscopy. RESULTS: Cell deposits were observed on 12 IOLs and proteinaceous deposits on 16. Components of the cell deposits were mainly of macrophage origin. The cell and matrix deposits tested positive for each isoform of TGF-beta. CONCLUSION: The cells that adhered to implanted PMMA PC IOLs produced TGF-beta, and the extracellular matrix that accumulated on the surface of the IOLs contained TGF-beta. Transforming growth factor-beta from the cells on IOLs may influence the healing process of residual lens capsules after cataract surgery with IOL implantation.

Adult↗
PubMed2000

Running down phenomenon and acute interictal psychosis in medial temporal lobe epilepsy.

PURPOSE: To examine the relationship between presurgical acute interictal psychosis and postsurgical running down phenomenon in a strictly homogeneous group with medial temporal lobe epilepsy. METHODS: Forty patients with mesial temporal sclerosis and an ultimate excellent surgical outcome, were divided into running down positive and negative groups. Various clinical and laboratory data, including presurgical psychotic episodes, were analyzed in the two groups. RESULTS: Patients in the running down positive group exhibited a significantly high incidence of presurgical history of acute interictal psychosis. CONCLUSION: We hypothesize that areas of secondary epileptogenesis beyond the scope of the primary epileptogenic zone, suggested by postsurgical running down phenomenon, may play an important role in the blockage and shift of the habitual propagation of seizure activity from the primary epileptogenic zone, to which Wolf attributed acute interictal psychosis.

Adult↗
PubMed2000

WECHE: a novel hematopoietic regulatory factor.

Previously, we described AGM-derived endothelial cell lines that either inhibited or permitted the development of erythroid or B cells. We utilized a differential gene expression method to isolate a chemokine, termed WECHE, from one of these cell lines. WECHE inhibited the formation of erythroid cells but had no effect on either myeloid or B cell formation. WECHE repressed BFU-E development from either mouse fetal liver or bone marrow progenitor cells but had no effect on colony formation induced by IL-3 or IL-7. WECHE reduced HPP-CFC production from fetal liver-derived stem cells. WECHE hindered the growth of yolk sac-derived endothelial cells. WECHE was also chemotactic for bone marrow cells. Thus, WECHE is a novel chemokine that regulates hematopoietic differentiation.

Amino Acid Sequence↗
PubMed2000

Two new biologically active triterpene saponins from Acanthophyllum squarrosum.

Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-be ta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3 )-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L- rhamnopyranosyl-(1-->3)]-beta-D-fucopyranoside (1) and 3-O-beta-D-glucopyranosylgypsogenin-28-O-alpha-L-rhamnopyranosyl-( 1-- >2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6 )]- beta-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect in an in vitro lymphocyte proliferation assay.

Adjuvants, Immunologic↗
PubMed2000

Cytotoxic lavandulyl flavanones from Sophora flavescens.

Two new lavandulylated flavanones, (2S)-2'-methoxykurarinone (1) and (-)-kurarinone (2), were isolated from the root of Sophora flavescens, together with two known lavandulyl flavanones, sophoraflavanone G (3) and leachianone A (4), and two known isoflavonoids, formononetin and l-maakiain. The structures of 1 and 2 were determined on the basis of optical rotation and spectral evidence and by comparison with known compounds. Compounds 1-4 exhibited cytotoxic activity against human myeloid leukemia HL-60 cells.

Antineoplastic Agents↗
PubMed2000

Characterization of ferritin and ferritin-binding proteins in canine serum.

Ferritin and ferritin-binding proteins in canine serum were characterized. A certain percentage of ferritin in canine serum, but no tissue ferritin, was precipitated by centrifugation at 16,000 x g for 30 min. The precipitated ferritin was found to contain two subunits corresponding to the H and L subunits of canine liver ferritin by immunoblotting, the H subunit being predominant. More ferritin was precipitated from canine sera which had been incubated with anti-rat liver ferritin antibody than from untreated sera, and the H chain also predominated. To evaluate the possibility that the autoantibody was responsible for the precipitation of canine serum ferritin, the ferritin-binding activities of canine antibodies were examined using liver ferritin-coated microtiter plates and alkaline phosphatase-labeled antibodies specific for canine IgM, IgA, and IgG heavy chains. The results showed that IgM and IgA, but not IgG, had considerable ferritin-binding activities. Given these results, we suggest that there is H-chain-rich isoferritin in canine serum, and that ferritin exists as an immune complex.

Animals↗
PubMed2000

Survey of recognition and utilization of guidelines for the diagnosis and management of bronchial asthma in Japan.

BACKGROUND: In Japan in 1993, the Japanese Society of Allergology (JSA) developed guidelines for diagnosis and management of asthma (JGL), which were based on the concept that asthma is a chronic inflammatory disorder of the airway. METHODS: This survey study was intended to investigate the recognition and utilization of JGL among physicians who had treated asthma. The survey comprised two methods: a quantitative mail survey and a qualitative door-to-door survey conducted by trained interviewers. RESULTS: In the mail survey, a total of 1028 physicians responded; 552 members of the JSA and 476 nonmembers. Ninety-four percent of JSA members were aware of adult asthma management guidelines, while 53% of nonmembers were aware of them. Although approximately half of the physicians, both members and nonmembers, found differences between the asthma management policies in JGL and their previous policies, most of them utilized JGL once they read it. In the qualitative door-to-door survey, 80-90% of physicians evaluated JGL as good after they read it. CONCLUSIONS: JGL was recognized and utilized by most JSA members, but only half of nonmember physicians were aware of JGL, although they utilized JGL after they read it. Further action to implement JGL among nonspecialist physicians is needed to improve management of asthma.

Adult↗
PubMed2000

Clinical factors associated with post-ictal headache in patients with epilepsy.

OBJECTIVES: To determine the incidence of post-ictal headaches (PIH) and clinical risk factors associated with the occurrence of PIH in patients with localization-related epilepsy. MATERIALS AND METHODS: The subjects were 77 patients with temporal lobe epilepsy (TLE), 34 patients with occipital lobe epilepsy (OLE), and 50 patients with frontal lobe epilepsy (FLE). The subjects were directly asked whether headaches occurred just after seizures. Medical charts were reviewed to ascertain the clinical characteristics of epilepsy in these patients. RESULTS: The incidence of PIH was 23% for TLE, 62% for OLE, and 42%, for FLE. The risk of PIH was significantly higher for OLE than for TLE or FLE, and for patients with generalized tonic-clonic seizures. Younger age at onset of epilepsy was also a risk factor for PIH. CONCLUSION: The occurrence of PIH may be related to the region of epileptic focus and the region of spread of epileptic discharges.

Adolescent↗
PubMed2000

Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitro.

Precursor cells that migrate into the thymus are still multipotent. Therefore, thymic epithelial cells (TECs) may provide microenvironments not only for T-cell development, but also for maintenance of multipotent precursor cells until they undergo T-cell commitment. In the present study, we performed long-term cultures of CD34+ bone-marrow (BM) cells on TEC lines that were derived from cortical epithelial cells of post-natal thymus, to investigate whether human TECs could maintain long-term nonlymphoid haematopoiesis. Haematopoietic cells maintained in direct contact with established TEC lines were able to generate clonogenic progeny to both myeloid and erythroid cells for periods in excess of 5 weeks. Their abilities to support colony-forming units of granulocytes-macrophages (CFU-GM) and burst-forming units of erythroids (BFU-E) were almost equal to those of BM stromal cells. We observed similar results by using cloned TEC lines derived by limiting dilution, as well as those by using parental TEC lines. Colony-forming activities were maintained even when haematopoietic progenitor cells were physically separated from TEC lines and cultured on microporous membrane. These observations indicate that haematopoiesis maintained in TEC-contact long-term cultures may depend on soluble factors produced by TEC lines. Our results suggest that thymic cortical epithelial cells have the ability to support not only the differentiation of haematopoietic cells, but also long-term survival of clonogenic myeloid/erythroid progenitor cells.

Antigens, CD34↗
PubMed2000

Identification and characterization of human Wee1B, a new member of the Wee1 family of Cdk-inhibitory kinases.

BACKGROUND: In eukaryotic cells, the kinase activity of the mitosis-promoting complex composed of cyclin B and Cdc2 (Cdk1) is negatively regulated by the phosphorylation of Cdk1 on threonine or tyrosine residues within its ATP binding domain. RESULTS: We identified human Wee1B by searching a sequence database. The predicted human Wee1B protein comprises 561 amino acids. Northern blot analysis revealed that human Wee1B mRNA is particularly abundant in testis. Interestingly, RT-PCR using early embryos revealed that the Wee1B product was readily detectable at the mature oocyte, but abruptly disappeared at embryonic day 2.5, suggesting that the amount of Wee1B mRNA is dependent on the maternal expression. GFP-Wee1B showed a predominantly nuclear localization in HeLa cells. Human Wee1B was able to rescue the lethal phenotype of the fission yeast wee1-50Deltamik1 mutant, and over-expression of the human protein in these cells resulted in cell elongation as a result of arrest of the cell cycle at the G2-M transition. Recombinant Wee1B effectively phosphorylated cyclin B-associated Cdk1 on tyrosine-15, resulting in an inactivation of the kinase activity of Cdk1. CONCLUSION: We identified human Wee1B as a novel Cdk1-inhibitory kinase. The identification of this new member of the Wee1 family suggests that inhibition of Cdk1 is mediated at multiple levels in mammals.

Amino Acid Sequence↗
PubMed2000

Brainstem function in rapid eye movement sleep behavior disorder: the evaluation of brainstem function by proton MR spectroscopy (1H-MRS).

Brainstem function was evaluated by proton magnetic resonance (MR) spectroscopy (1H-MRS) in a 69-year-old man with idiopathic rapid eye movement (REM) sleep behavior disorder. An analysis of spectral peak area ratios revealed an increase in the choline/creatine ratio. This change suggests that brainstem neurons have functional impairment at the cell membrane level. Further, our results suggest that 1H-MRS may provide for non-invasive, metabolic evaluation of brainstem neuronal function in REM sleep behavior disorder and find application in the differentiation of secondary REM sleep behavior disorders with neurodegenerative disorders from idiopathic disorders.

Aged↗
PubMed2000

A double-blind, placebo-controlled steroid-sparing study with budesonide Turbuhaler in Japanese oral steroid-dependent asthma patients. Japanese Pulmicort Turbuhaler study group.

OBJECTIVE: The aim of this study was to evaluate the oral steroid-sparing capacity of budesonide Turbuhaler. METHODOLOGY: One hundred and thirteen oral steroid-dependent patients were treated for 6 months with placebo or budesonide 800 microg or 1600 microg daily. Every second week the oral steroid dose was reduced if asthma control permitted. RESULTS: The reductions in oral steroid doses were 9, 35 and 60% in the placebo and budesonide 800 microg and 1600 microg groups, respectively. Oral steroid treatment could be discontinued in 4% (placebo), 15% (800 microg) and 23% (1600 microg). Mean peak expiratory flow values increased by 21 and 24 L/min in the budesonide groups but decreased by 6 L/min in the placebo group. Asthma attack, activity and sleep scores remained unchanged showing maintained efficacy. Plasma cortisol levels increased and an adrenocorticotropic hormone test showed improved adrenocortical response in both budesonide groups, indicating improved safety. Adverse drug reactions were infrequent and mild in all study groups. CONCLUSION: Budesonide Turbuhaler, 800 microg and 1600 microg daily, resulted in a significant reduction in oral steroid usage in steroid-dependent patients. The effect was achieved with maintained asthma control together with improvements in lung and adrenal functions.

Administration, Inhalation↗
PubMed2000

A double-blind, placebo-controlled dose-response study with budesonide Turbuhaler in Japanese asthma patients. Japanese Pulmicort Turbuhaler study group.

OBJECTIVE: The aim of this study was to investigate the dose-response for inhaled budesonide via Turbuhaler in Japanese patients with mild to moderate asthma. METHODOLOGY: Inhaled budesonide 100 microg, 200 microg, 400 microg or placebo was administered twice daily via Turbuhaler for 6 weeks, to 267 adult Japanese patients (mean age 51 years) with mild-to-moderate, non-steroid-dependent bronchial asthma, in a double-blind, placebo-controlled, randomized, parallel group study. The patients had to be symptomatic for more than 3 days/week and have an average morning peak expiratory flow (PEF) 50-80% of predicted normal value. RESULTS: The response to budesonide was rapid, all treatments showing a significant improvement in morning PEF after 1 week (P<0.05). During week 6, mean improvements of 15, 45, 53 and 71 L/min were observed for the placebo, 200 microg, 400 microg and 800 microg budesonide groups, respectively. Compared with placebo all improvements in the budesonide groups were statistically significant and a significant dose-response was demonstrated (P<0.001). The difference between the 200 microg and 800 microg doses was significant. Also, for several secondary efficacy variables (e.g. evening PEF, symptom score, treatment score, daily activity score and sleep score) significant dose-responses were shown. Other variables included the investigators' assessments of improvement and usefulness. They also showed statistically significant dose-response relationships and confirmed the rapid onset of action. Budesonide was well tolerated at all tested doses, with a low incidence of adverse events, all of which were minor in severity. CONCLUSIONS: Budesonide Turbuhaler in the doses 100 microg to 400 microg twice daily was effective, well tolerated and showed a rapid onset of action in patients with mild-to-moderate asthma. Dose-response was demonstrated for several variables of clinical efficacy.

Administration, Inhalation↗
PubMed2000

Psychotic episodes during zonisamide treatment.

Several articles have appeared over the last years devoted to mental side effects during zonisamide (ZNS) treatment. In this study, we were particularly interested in psychotic episodes. Seventy-four epileptic patients with a history of ZNS treatment were surveyed retrospectively over the period spanning 1 March 1984 to 30 June 1994. They were divided into two groups according to the presence or absence of psychotic episodes during ZNS treatment. We analysed various factors pertaining to psychotic episodes during ZNS treatment. Of the 74 patients 14 had psychotic episodes. We found that the incidence of psychotic episodes during ZNS treatment was several times higher than the previously reported prevalence of epileptic psychosis, and that the risk of psychotic episodes was higher in young patients. In 13 patients, psychotic episodes occurred within a few years of commencement of ZNS. In children, obsessive-compulsive symptoms appeared to be related to psychotic episodes. It is important to terminate ZNS as soon as possible if psychotic episodes develop and never restart, even if seizures become worse. It cannot definitely be proved that ZNS causes psychotic episodes, as information on mental side effects during ZNS monotherapy is scant, but it does appear likely that ZNS contributes to psychotic episodes during polytherapy.

Adult↗
PubMed2000

Disturbance of semantic processing in temporal lobe epilepsy demonstrated with scalp ERPs.

We investigated event-related potentials (N400, LPC and CNV) elicited in temporal lobe epilepsy (TLE) patients and control subjects from scalp electrodes, using a word-pair category matching paradigm. Each prime consisted of a Japanese noun (constructed from 2-4 characters of the Hiragana) followed by a Chinese character (Kanji) as the target, the latter representing one of five semantic categories. There were two equally probable target conditions: match or mismatch. Each target was preceded by a prime, either belonging to, or not belonging to, the same semantic category. The subjects were required to respond with a specified button press to the given target, according to the condition. We found RTs to be longer under the mismatch condition in both subject groups. The N400 amplitude was reduced in TLE subjects under both conditions, although LPC and CNV amplitudes showed no significant differences. These results suggest that scalp N400 is capable of demonstrating disturbance of semantic processing in TLE non-invasively.

Adult↗