Biomedical subjects

T Honda

Publications and source records attributed to T Honda.

At least 235 records · Page 13Linked to original sources

PubMed1998

Reconstruction for the brilliance-upgrading project of the Photon Factory storage ring.

Reconstruction of the Photon Factory storage ring (PF ring; 2.5 GeV) is now in progress to provide very brilliant synchrotron radiation to users, i.e. the emittance is being reduced by a factor of five. Components, such as the quadrupole and sextupole magnets, vacuum chambers, beamlines and beam-position monitors, are being replaced by new ones in 16 normal-cell sections of the PF ring. The accelerating cavities, injection systems and control systems are also being replaced. Operation will commence when the improvements are completed on 1 October 1997.

Journal Article↗

PubMed1998

New beam-position monitor system for upgraded Photon Factory storage ring.

Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 micro m in both directions, which is 1/2-1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

Journal Article↗

PubMed1998

Single-pass BPM system of the Photon Factory storage ring.

At the 2.5 GeV ring of the Photon Factory, a single-pass beam-position monitor (BPM) system is being prepared for the storage ring and the beam transport line. In the storage ring, the injected beam position during the first several turns can be measured with a single injection pulse. The BPM system has an adequate performance, useful for the commissioning of the new low-emittance lattice. Several stripline BPMs are being installed in the beam transport line. The continuous monitoring of the orbit in the beam transport line will be useful for the stabilization of the injection energy as well as the injection beam orbit.

Journal Article↗

PubMed1998

X-ray contact microscopy system for spectromicroscopy of biological specimens.

An X-ray contact microscopy system has been developed for the study of molecular and elemental distributions in biological specimens based on X-ray absorption characteristics. The system consists of a chamber for measuring XANES (X-ray absorption near-edge structure) of biomolecules, and a contact microscopy system for dried specimens with an electronic zooming tube. With this system the elemental distribution of carbon, nitrogen, oxygen, Ca and Fe in an HeLa cell has been studied, and the DNA-related image using a peak from the XANES profile of the DNA at the K-absorption edge of phosphorus has been obtained.

Journal Article↗

PubMed1998

Mass screening for lung cancer with mobile spiral computed tomography scanner.

BACKGROUND: The incidence of and mortality from lung cancer have increased steadily. Most lung cancers are not localised when first detected, but early detection is mandatory to improve prognosis. Since curable early cases are hard to visualise with conventional chest radiography, a new diagnostic means must be found. We assessed whether population-based mass screening with a spiral computed tomography scanner could contribute substantially to detection of smaller cancers, and decrease mortality. METHODS: In 1996, we screened in a mobile unit 5483 individuals from the general population of Matsumoto, Japan, aged between 40 years and 74 years who had undergone annual chest radiography (miniature fluorophotography) and cytological assessment of sputum. All participants had a low-dose X-ray spiral computed tomography (CT) scan of the thorax; 3967 also underwent miniature fluorophotography. We compared smokers and non-smokers. Further assessments were done for probably benign but suspicious lesions; suspicion of cancer; and indeterminate small nodules by chest radiography and conventional CT, with additional transbronchial biopsy when possible. Thoracotomy was recommended when it was strongly suspected that the patients had lung cancer. FINDINGS: 19 patients were diagnosed as having lung cancer--14 with suspicion of lung cancer, three with benign but suspicious lesions, and two with indeterminate small nodules. 18 cases were surgically confirmed, and one was clinically diagnosed. The mean size of lesions was 17 mm (range 6-47). In four of 19 patients, lung abnormality was seen on CT and miniature fluorophotography. The lung-cancer detection rate with CT was 0.48%, significantly higher than the 0.03-0.05% for standard mass assessments done previously in the same area. CT missed one case that was found solely on a sputum cytology examination. INTERPRETATION: Our results show that miniature fluorophotography or conventional chest radiography, which have been the main diagnostic techniques for lung cancer, showed few small cancers. CT was more accurate in mass screening for lung cancer and led to early detection and an accurate diagnosis of lung cancer, and should be considered in future health plans.

Adult↗

PubMed1998

Complex formation of SMAP/KAP3, a KIF3A/B ATPase motor-associated protein, with a human chromosome-associated polypeptide.

We have recently isolated SMAP (Smg GDS-associated protein; Smg GDS: small G protein GDP dissociation stimulator) as a novel Smg GDS-associated protein, which has Armadillo repeats and is phosphorylated by Src tyrosine kinase. SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. We isolated here a SMAP-interacting protein from a human brain cDNA library, identified it to be a human homolog of Xenopus XCAP-E (Xenopus chromosome-associated polypeptide), a subunit of condensins that regulate the assembly and structural maintenance of mitotic chromosomes, and named it HCAP (Human chromosome-associated polypeptide). Tissue and subcellular distribution analyses indicated that HCAP was ubiquitously expressed and highly concentrated in the nuclear fraction, where SMAP and KIF3B were also present. SMAP was extracted as a ternary complex with HCAP and KIF3B from the nuclear fraction in the presence of Mg-ATP. The results suggest that SMAP/KAP3 serves as a linker between HCAP and KIF3A/B in the nucleus, and that SMAP/KAP3 plays a role in the interaction of chromosomes with an ATPase motor protein.

Adaptor Proteins, Signal Transducing↗

PubMed1998

Lecithinized superoxide dismutase attenuates phorbol myristate acetate-induced injury in isolated dog lung.

Lecithinized superoxide dismutase, a lecithin derivative bound to recombinant human CuZn superoxide dismutase, has a higher affinity for cells such as polymorphonuclear leukocytes and endothelial cells than recombinant human CuZn superoxide dismutase has. We determined the protective effects of lecithinized superoxide dismutase on the increased microvascular permeability induced by phorbol myristate acetate (PMA) in isolated dog lungs. Microvascular permeability was assessed by the capillary filtration coefficient (Kf,c) and solvent drag reflection coefficient (sigma(f)). PMA (13.3 microg) increased microvascular permeability, as evidenced by an increase in Kf,c and the small sigma(f) value. Lecithinized superoxide dismutase at both low (4800 U) and high doses (48,000 U) inhibited the PMA-induced increase in Kf,c, but only the high dose of lecithinized superoxide dismutase attenuated the decrease in sigma(f). Recombinant human CuZn superoxide dismutase did not affect the PMA-induced increase in vascular permeability at either a low (4800 U) or a high dose (48,000 U). These findings suggest that lecithinized superoxide dismutase has a protective effect against oxygen radical-induced lung injury in isolated dog lungs.

Animals↗

PubMed1998

Complete nucleotide sequences of 93-kb and 3.3-kb plasmids of an enterohemorrhagic Escherichia coli O157:H7 derived from Sakai outbreak.

Enterohemorrhagic Escherichia coli (EHEC) O157:H7, derived from an outbreak in Sakai city, Japan in 1996, possesses two kinds of plasmids: a 93-kb plasmid termed pO157, found in clinical EHEC isolates world-wide and a 3.3-kb plasmid termed pOSAK1, prevalent in EHEC strains isolated in Japan. Complete nucleotide sequences of both plasmids have been determined, and the putative functions of the encoded proteins and the cis-acting DNA sequences have been analyzed. pO157 shares strikingly similar genes and DNA sequences with F-factor and the transmissible drug-resistant plasmid R100 for DNA replication, copy number control, plasmid segregation, conjugative functions and stable maintenance in the host, although it is defective in DNA transfer by conjugation due to the truncation and deletion of the required genes and DNA sequences. In addition, it encodes several proteins implicated in EHEC pathogenicity such as an EHEC hemolysin (HlyA), a catalase-peroxidase (KatP), a serine protease (EspP) and type II secretion system. pOSAK1 possesses a ColE1-like replication system, and the DNA sequence is extremely similar to that of a drug-resistant plasmid, NTP16, derived from Salmonella typhimurium except that it lacks drug resistance transposons.

DNA, Bacterial↗

PubMed1998

Novel triterpenoids suppress inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) in mouse macrophages.

We have synthesized more than 80 novel triterpenoids, all derivatives of oleanolic and ursolic acid, as potential anti-inflammatory and chemopreventive agents. These triterpenoids have been tested for their ability to suppress the de novo formation of two enzymes, inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2), using IFN-gamma-stimulated primary mouse macrophages or lipopolysaccharide (LPS)-activated RAW 264.7 macrophages as assay systems. Two synthetic oleananes, 3,12-dioxoolean-1-en-28-oic acid (TP-69) and 3,11-dioxoolean-1,12-dien-28-oic acid (TP-72), were highly active inhibitors of de novo formation of both iNOS and COX-2. Both TP-69 and TP-72 blocked the increase in iNOS or COX-2 mRNA induced by IFN-gamma or LPS. In addition, TP-72 suppressed NF-KB activation in primary macrophages treated with the combination of IFN-gamma and LPS or IFN-gamma and tumor necrosis factor. The 3-alpha(axial)-epimer of ursolic acid suppressed de novo formation of COX-2, in contrast to naturally occurring 3-beta(equatorial)-ursolic acid. Inhibitory effects of TP-69 or TP-72 on iNOS formation were not blocked by the glucocorticoid receptor antagonist RU-486, indicating that these triterpenoids do not act through the glucocorticoid receptor, nor does TP-72 act as an iNOS or COX-2 enzyme inhibitor when added to RAW cells in which synthesis of these two enzymes in response to LPS has already been induced. It may be possible to develop triterpenoids as useful agents for chemoprevention of cancer or other chronic diseases with an inflammatory component.

Animals↗

PubMed1998

Profiles of circulating inflammatory- and anti-inflammatory cytokines in patients with hemolytic uremic syndrome due to E. coli O157 infection.

The systemic inflammatory response to Escherichia coli O157 infection was studied from the profiles of circulating inflammatory and anti-inflammatory cytokines. Twelve patients transferred sequentially to our hospital for the intensive care with acute illness due to Escherichia coli O157 infection and the possible form of haemolytic uraemic syndrome were included in this study. Increased circulating concentrations of tumour necrosis factor, interleukin 6, interleukin 8, granulocyte colony-stimulating factor, and interleukin 10 were found in patients with various stages of this infection and haemolytic uraemic syndrome. Especially, the degree of the increase of circulating interleukin 10 in those who had a typical signs of haemolytic uraemic syndrome was higher than those of other inflammatory cytokines. Two groups of E. coli infection could be classified into one with a typical haemolytic uraemic syndrome and the other with atypically bacteremic state over haemolytic uraemic syndrome according to these cytokine levels.

Adult↗

PubMed1998

Mycobacterium avium-intracellulare pulmonary infection in patients without known predisposing lung disease.

We tried to characterize the clinical features and findings on chest high resolution computed tomography (HRCT) of patients with Mycobacterium avium-intracellulare (MAI) pulmonary infection without known predisposing lung disease and with no immunodeficiency. We also aimed to clarify the small airway and alveolar inflammation using bronchoalveolar lavage (BAL) from the affected regions. MAI infection was diagnosed in 53 patients from respiratory samples, including sputum and materials obtained using a fiberoptic bronchoscope. None had a predisposing lung disease or immunodeficiency, as assessed by medical history, routine laboratory data, and previously normal chest radiographs and/or CT scans. The mean age of the 53 patients was 60 +/- 11 years, and 48 were nonsmoking females. They had few respiratory symptoms, although 42% had chronic paranasal sinusitis. Chest HRCT findings showed centrilobular small nodules and ectasia of small bronchi and/or bronchioles located mainly in segment (S) 2, 3, 4, and 5. S1, which is usually affected by pulmonary tuberculosis, was completely free of these opacities. The BAL study revealed that the predominant cells were activated T lymphocytes and neutrophils. The CD4+/CD8+ ratio increased significantly. Bacteriology was negative for other bacteria and fungi. Although our patients did not present with distinct respiratory symptoms, the regions affected by MAI showed a chronic inflammation of mainly neutrophils and activated T lymphocytes. The presence of chronic sinusitis may be merely coincidental. However, its high prevalence and the finding of bronchiectasis in chest HRCT raise the question of whether silent bronchiectasis may be a predisposition.

Aged↗

PubMed1998

Equator ring efficacy in maintaining capsular bag integrity and transparency after cataract removal in monkey eyes.

BACKGROUND: The purpose of the study was to evaluate the efficacy of the equator ring in maintaining capsular bag integrity at the equator and transparency of the posterior capsule after cataract surgery. using cynomolgus monkeys. METHODS: After lens removal using an infusion-aspiration method, a flexible silicone ring with a groove on its inner surface was inserted in the bag through a window made by continuous circular capsulorhexis in six eyes. Of these, four monkey eyes underwent posterior chamber intraocular lens (IOL) implantation and two monkey eyes did not receive IOLs. Lensectomy without ring insertion was performed as a control in the six fellow eyes. Of these, four eyes received an IOL and two did not. The eyes were followed for an average of 5.9 +/- 1.1 months before enucleation. The effects were evaluated by stereo and light microscopy. RESULTS: The ring effectively maintained the circular contour of the capsular bag (ratio of the short and long axes, 0.97 +/- 0.01) and posterior capsule transparency (P = 0.017). CONCLUSIONS: This study demonstrated that the equator ring is a promising device for maintaining capsular bag integrity and minimizing posterior capsule opacification after cataract surgery.

Animals↗

PubMed1998

Churg-Strauss syndrome (allergic granulomatous angitis) presenting with ileus caused by ischemic ileal ulcer.

We report a rare case of Churg-Strauss syndrome (CSS) in a 41-year-old Japanese man with a history of middle-age onset of bronchial asthma who had severe abdominal pain. He presented with ileus caused by an annular ulcer of the ileum, attributable to mucosal ischemia resulting from necrotizing vasculitis of the mesenteric artery. He also had marked hypereosinophilia (51.5%), elevated serum IgE levels (34040 IU/ml), and generalized enlargement of the superficial cervical lymph nodes, containing eosinophilic granulomas. A stenotic lesion caused by an annular ulcer in the ileum was found and resected by laparotomy. Microscopic examination of the resected specimen revealed luminal narrowing or occlusion of small arteries in the ulcer base, subserosa, and mesenterium resulting from marked fibrotic intimal thickening with fragmentation or lack of the internal elastic lamina. These findings were diagnosed as vasculitis, scar stage. The postoperative course was uneventful, with the patient receiving a maintenance dose of prednisolone (10-15 mg/day) for 7 years subsequently. We must carefully diagnose and treat patients with middle-age onset asthma, because the symptom may be a lung manifestation of CSS, in which various organs including gastrointestinal tract are involved as a result of systemic necrotizing vasculitis.

Adult↗

PubMed1998

Rational lymphadenectomy for early gastric cancer with submucosal invasion: a clinicopathological study.

Among all the patients who underwent gastrectomy for primary solitary gastric cancer at our department from 1979 to 1994, 228 patients had gastric cancer that invaded the submucosal layer. These cases were thus examined clinicopathologically, including the extent of submucosal invasion. No lymph node metastasis was found in any of the cancers measuring less than 2 cm in diameter. Macroscopic type I lesions or various combined types (IIa + IIc, IIc + IIa, IIc + III) were more likely to infiltrate deeply and were also associated with a high incidence (18%-25%) of lymph node metastasis. No lymph node metastasis or vascular invasion was found in any simple type IIa lesions. The incidence of lymph node metastasis was 3% in simple type IIc cancers measuring 3 cm or less. In addition, submucosal microinvasion (sm1) simple type IIc cancers showed no accompanying lymph node metastasis or vascular invasion. We thus conclude that a full-thickness partial resection of the stomach, such as a laparoscopic local resection, is applicable to cancers measuring 3 cm or less provided that they are either simple macroscopic type IIa or simple type IIc sm1 cancers.

Endosonography↗

PubMed1998

Inflammatory cytokines in BAL fluid and pulmonary hemodynamics in high-altitude pulmonary edema.

To evaluate the pathogenesis of high-altitude pulmonary edema (HAPE), we performed bronchoalveolar lavage (BAL) and pulmonary hemodynamic studies in seven patients with HAPE at its early stage. We measured cell counts, biochemical contents, and concentrations of pro-inflammatory cytokines including interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-alpha and of anti-inflammatory cytokines including IL-1 receptor antagonist (ra) and IL-10 in the BAL fluid (BALF). All patients showed increased counts for total cells, alveolar macrophages, neutrophils and lymphocytes, and markedly elevated concentrations of proteins, lactate dehydrogenase, IL-1beta, IL-6, IL-8, TNF-alpha and IL-1ra. The levels of IL-1alpha and IL-10 were not increased. Patients also showed pulmonary hypertension with normal wedge pressure. Both the driving pressure obtained as pulmonary arterial pressure minus wedge pressure and the PaO2 under room air were significantly correlated with the concentrations of IL-6 and TNF-alpha in the BALF. These findings suggest that the inflammatory cytokines play a role at the early stage of HAPE and might be related to pulmonary hypertension.

Adult↗

PubMed1998

Nicking sites in a subunit of cholera toxin and Escherichia coli heat-labile enterotoxin for Vibrio cholerae hemagglutinin/protease.

We analyzed the nicking site of the A subunit of Escherichia coli heat-labile enterotoxin for hemagglutinin/protease produced by Vibrio cholerae non-O1 (NAG-HA/P). The determined nicking site was the Thr193-Ile194 junction, which was distinct from that for a protease of V. cholerae (Ichinose et al., European Journal of Epidemiology 8, 743-747, 1992). We further analyzed proteolytic cleavage by NAG-HA/P of a synthetic peptide corresponding to the nicking region of cholera toxin A subunit and determined the cleavage site to be preferentially between Ser194 and Met195, and in addition between Ser193 and Ser194.

Bacterial Toxins↗

PubMed1998

Activation of tau protein kinase I/glycogen synthase kinase-3beta by amyloid beta peptide (25-35) enhances phosphorylation of tau in hippocampal neurons.

According to the amyloid hypothesis for the pathogenesis of Alzheimer's disease (AD), amyloid beta peptide (Abeta) directly affects neurons, leading to neurodegeneration and tau phosphorylation, followed by the production of paired helical filaments (PHF) in neurofibrillary tangles (NFT). To analyze the relationship between the phosphorylation sites of tau and the activation of kinases in response to Abeta, we treated cultured rat hippocampal neurons with a peptide fragment of Abeta, Abeta(25-35). Abeta(25-35) treatment activated tau protein kinase I/glycogen synthase kinase-3beta (TPKI/GSK-3beta) but not glycogen synthase kinase-3alpha (GSK-3alpha) or mitogen activated protein kinase (MAP kinase) in primary culture of hippocampal neurons. Using antibodies that recognize phosphorylated sites of tau, we showed that tau phosphorylation was enhanced in at least five sites (Ser199, Ser202, Ser396, Ser404, and Ser413 numbered according to the human tau isoform containing 441 amino acid residues), to an extent that depended on the level of TPK I/GSK-3beta. Treatment with TPK I/GSK-3beta antisense oligonucleotide inhibited the enhancement of tau phosphorylation induced by Abeta(25-35) exposure. Thus, TPK I/GSK-3beta activation by Abeta(25-35) may lead to extensive tau phosphorylation.

Amyloid beta-Peptides↗

PubMed1998

Risk factors and prophylactic tenosynovectomy for extensor tendon ruptures in the rheumatoid hand.

The cases histories of 51 rheumatoid arthritis patients (58 hands) were examined retrospectively with respect to the incidence of tendon rupture. Factors that were associated with tendon rupture such as X-ray changes in the wrist joint and clinical findings of the hand preceding the tendon rupture were statistically analysed. In a separate study, prophylactic tenosynovectomy and wrist synovectomy were performed on 42 joints in 35 patients who had two or more risk factors. This group of patients was then analysed for subsequent tendon rupture and recurrent synovitis. The risk factors for the extensor tendon rupture in the dorsal wrist joint were found to be: dorsal dislocation of the distal ulna; a scallop sign on X-ray; and tenosynovitis persisting for at least 6 months. Prophylactic surgery effectively prevented rupture of the tendons in patients who had two or more risk factors for extensor tendon rupture.

Adult↗