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Biomedical subjects

Y Shoji

Publications and source records attributed to Y Shoji.

At least 37 records · Page 2Linked to original sources
PubMed2000

Evaluation of a human monocytic cell line THP-1 model for assay of the intracellular activities of antimicrobial agents against Legionella pneumophila.

We examined the intracellular activities of 11 antimicrobial agents against Legionella pneumophila using a human monocyte-derived cell line, THP-1. Colony counting and microscopic examination of L. pneumophila co-incubated with THP-1 cells (5 x 105 cells/well) were performed. Both extra- and intra-cellular multiplication of L. pneumophila were observed and were dependent on the inoculum of L. pneumophila in the culture; L. pneumophila did not grow in the cell culture medium alone. Light microscopic examination confirmed that extracellular L. pneumophila originated from THP-1 cells disrupted by bacterial multiplication. L. pneumophila multiplied by 3-4 logs after 24 h incubation with THP-1 cells and their number remained stable at 106-107 cfu/mL until 72 h. The results of viability studies using four antimicrobial agents-ciprofloxacin, erythromycin, minocycline and rifampicin-demonstrated that our system was suitable for the intracellular activity assay. We used a concept of 'minimum extracellular concentration inhibiting intracellular multiplication' (MIEC) to evaluate the intracellular activity of antimicrobial agents. The MIECs of three beta-lactams were markedly higher than their conventional MICs while those of macrolides, quinolones, rifampicin and minocycline were similar to their MICs. Our results suggest that evaluation of the clinical efficacy of drugs against L. pneumophila should include determination of their intracellular activity against the bacteria, which could be measured using our assay system in THP-1 cells.

Anti-Bacterial Agents↗
PubMed2000

Isolation of a 41-kDa protein with cell adhesion activity for animal tumor cells from the mushroom Hypsizigus marmoreus by affinity chromatography with type IV collagen immobilized on agarose.

A type IV collagen-binding protein of 41 kDa was isolated from the mushroom Hypsizigus marmoreus and the protein was designated as HM41. The Western blotting analysis with anti-HM41 antibodies demonstrated that HM41 was unrelated to HM23, which had been shown to have an affinity for type IV collagen. The microsequence analysis of the membrane-blotted peptides generated by fragmentation with cyanogen bromide showed no homologous proteins reported. HM41 had cell adhesion-promoting activity for murine Lewis lung carcinoma LL2 cells and human fibrosarcoma HT1080 cells. These results indicate that HM41 is a hitherto undescribed fungus protein that can interact both with animal extracellular matrix protein type IV collagen and with animal tumor cells.

Agaricales↗
PubMed1999

Presynaptic inhibition of GABA(B)-mediated synaptic potentials in the ventral tegmental area during morphine withdrawal.

Opioids increase the firing of dopamine cells in the ventral tegmental area by presynaptic inhibition of GABA release. This report describes an acute presynaptic inhibition of GABAB-mediated IPSPs by mu- and kappa-opioid receptors and the effects of withdrawal from chronic morphine treatment on the release of GABA at this synapse. In slices taken from morphine-treated guinea pigs after washing out the morphine (withdrawn slices), a low concentration of a mu receptor agonist increased, rather than decreased, the amplitude of the GABAB IPSP. In withdrawn slices, after blocking A1-adenosine receptors with 8-cyclopentyl-1, 3-dipropylxantine, mu-opioid receptor activation inhibited the IPSP at all concentrations and increased the maximal inhibition. In addition, during withdrawal, there was a tonic increase in adenosine tone that was further increased by forskolin or D1-dopamine receptor activation, suggesting that metabolism of cAMP was the source of adenosine. The results indicate that during acute morphine withdrawal, there was an upregulation of the basal level of an opioid-sensitive adenylyl cyclase. Inhibition of this basal activity by opioids had two effects. First, a decrease in the formation of cAMP that decreased adenosine tone. This effect predominated at low mu receptor occupancy and increased the amplitude of the IPSP. Higher agonist concentrations inhibited transmitter release by both kinase-dependent and -independent pathways. This study indicates that the consequences of the morphine-induced upregulation of the cAMP cascade on synaptic transmission are dependent on the makeup of receptors and second messenger pathways present on any given terminal.

Adenosine↗
PubMed1999

Cell adhesion activity for murine carcinoma cells of a wheat germ 55-kDa protein with binding affinity for animal extracellular matrix proteins.

A wheat germ 55-kDa protein was isolated by affinity chromatography with Matrigel immobilized on agarose, followed by preparative gel electrophoresis. This Matrigel-binding protein designated as WG-55 had an amino-terminal amino acid sequence which is identical to that of a putative mature form of wheat storage protein Gbl 1. WG-55 reacted with concanavalin A, indicating its glycoprotein nature as expected from the amino acid sequence of Gbl 1. As expected, similarly, WG-55 exhibited RGD-dependent cell adhesion activity for murine carcinoma cells. These data suggest that WG-55 or mature Gbl 1 protein may play a role in plant cell adhesion.

Amino Acid Sequence↗
PubMed1999

Current trends in restorative proctocolectomy: introduction of an ultrasonically activated scalpel.

PURPOSE: We evaluated the usefulness of an ultrasonically activated scalpel (Harmonic Scalpel) for mucosal proctocolectomy and ileal J-pouch-anal anastomosis. METHODS: Seventy-four patients with ulcerative colitis (70 patients) and familial adenomatous polyposis (4 patients) underwent mucosectomy using the Harmonic Scalpel since 1997. We compared the clinical and functional results with those of the monopolar electrocoagulator (forceps coagulation technique, 86 patients with colitis and 7 with polyposis). RESULTS: We performed graduated mucosal proctectomy by using the Harmonic Scalpel. The operative time (Harmonic Scalpel, 42 minutes vs. forceps coagulation technique, 85 minutes) and blood loss (Harmonic Scalpel, 33 ml vs. forceps coagulation technique, 86.8 ml) were significantly reduced by this method. The Harmonic Scalpel enabled restorative proctocolectomy by the synchronous approach within three hours. The functional results and complications were not significantly different between the two groups. CONCLUSION: The Harmonic Scalpel shortened the operative time, decreased blood loss, and was useful for restorative proctocolectomy in our study.

Adult↗
PubMed1999

Transanal mucosectomy using an ultrasonically activated scalpel for ulcerative colitis.

We describe herein our technique of using an ultrasonically activated scalpel (Harmonic Scalpel [HS]) to simplify the procedure of anorectal mucosectomy for ulcerative colitis (UC). This technique was successfully employed to perform restorative proctocolectomy and ileoanal anastomosis (IAA) in ten patients with UC. By using the HS, thermal injury of the internal anal sphincter was avoided during mucosectomy, and we were able to dissect the inflamed mucosa sharply without causing bleeding. HS reduced the operative time and blood loss compared with the traditional forceps-coagulation technique. These results indicate that the introduction of this new scalpel will facilitate an increase in the number of cases of mucosectomy for IAA.

Adolescent↗
PubMed1999

Fontan with pedicled pericardium.

Pedicled pericardium is a useful viable material for cardiac surgery. In an adolescent case, the extracardiac lateral tunnel of a Fontan connection was successfully constructed with pedicled pericardium. This procedure is expected to allow the growth of the tunnel and to need no anti-coagulant therapy, while careful long-term follow-up is necessary.

Child↗
PubMed1999

3-Methylglutaconic aciduria type I: clinical heterogeneity as a neurometabolic disease.

3-Methylglutaconic (3-MGC) aciduria with 3-methylglutaconyl-CoA hydratase deficiency (3-MGC aciduria type I) is a rare inherited metabolic disease of L-leucine catabolism. We describe a 9-month-old Japanese boy with this disorder who showed progressive neurological impairments presented as quadriplegia, athetoid movements and severe psychomotor retardation from 4 months of age. This finding indicates the existence of clinical heterogeneity in 3-MGC aciduria type I, suggesting it may present as a neurometabolic disease.

Acidosis, Renal Tubular↗
PubMed1999

Carcinoembryonic antigen facilitates experimental metastasis through a mechanism that does not involve adhesion to liver cells.

Carcinoembryonic antigen (CEA) injected intravenously into athymic nude mice increases the ability of weakly metastatic human colorectal carcinoma (CRC) cells to colonize liver in an experimental metastasis assay. Since CEA acts as an intercellular adhesion molecule in vitro, several investigators have postulated that this facilitation of experimental metastasis may be mediated through adhesion between CEA on CRC and CEA-binding proteins on Kupffer or other cells lining the hepatic sinusoid. The present work tested this postulate both by intravital fluorescence videomicroscopy in vivo and in adhesion assays in vitro to enriched populations of Kupffer cells and hepatic sinusoidal endothelial cells (SEC). The data indicate that CEA expression does not effect adhesion to enriched Kupffer cells or SEC in vitro. These data suggest that CEA enhances liver colonization through another mechanism, possibly one that involves modulation of the hepatic response to tumor cell implantation.

Animals↗
PubMed1999

Primary systemic carnitine deficiency is caused by mutations in a gene encoding sodium ion-dependent carnitine transporter.

Primary systemic carnitine deficiency (SCD; OMIM 212140) is an autosomal recessive disorder characterized by progressive cardiomyopathy, skeletal myopathy, hypoglycaemia and hyperammonaemia. SCD has also been linked to sudden infant death syndrome. Membrane-physiological studies have suggested a defect of the carnitine transport system in the plasma membrane in SCD patients and in the mouse model, juvenile visceral steatosis. Although the responsible loci have been mapped in both human and mouse, the underlying gene has not yet been identified. Recently, we cloned and analysed the function of a novel transporter protein termed OCTN2. Our observation that OCTN2 has the ability to transport carnitine in a sodium-dependent manner prompted us to search for mutations in the gene encoding OCTN2, SLC22A5. Initially, we analysed the mouse gene and found a missense mutation in Slc22a5 in jvs mice. Biochemical analysis revealed that this mutation abrogates carnitine transport. Subsequent analysis of the human gene identified four mutations in three SCD pedigrees. Affected individuals in one family were homozygous for the deletion of a 113-bp region containing the start codon. In the second pedigree, the affected individual was shown to be a compound heterozygote for two mutations that cause a frameshift and a premature stop codon, respectively. In an affected individual belonging to a third family, we found a homozygous splice-site mutation also resulting in a premature stop codon. These mutations provide the first evidence that loss of OCTN2 function causes SCD.

Amino Acid Sequence↗
PubMed1999

Inhibitory effects of tetragalloylglucose and digalloylhamamelose on adhesion and in vitro invasion of mouse lung carcinoma cells.

Tetragalloylglucose (TgG) and digalloylhamamelose (DgH) were found to inhibit adhesion to and invasion through Matrigel of mouse Lewis lung carcinoma LL2-Lu3 cells, which are highly metastatic. TgG inhibited matrix metalloproteinases (MMPs) from the tumor cells like (-)-epigallocatechin gallate, whereas DgH did not. These results suggest that TgG and DgH inhibit tumor cell invasion by inhibiting MMPs and/or cell adhesion of the tumor cells.

Animals↗
PubMed1999

Genetic epidemiology of the carnitine transporter OCTN2 gene in a Japanese population and phenotypic characterization in Japanese pedigrees with primary systemic carnitine deficiency.

Serum free-carnitine levels were determined in 973 unrelated white collar workers in Akita, Japan. Fourteen of these participants consistently had serum free-carnitine levels below the fifth percentile (28 microM for females and 38 microM for males). The OCTN2 (organic cation transporter) gene was sequenced for these 14 subjects, for 22 subjects whose carnitine levels were below the fifth percentile in the first screening but were normal in the second measurement and in 69 individuals with normal carnitine levels for two separate measurements. Polymorphic sequences defined three major haplotypes with equal frequency. Mutations were identified in nine subjects with low carnitine levels: Trp132X (three individuals), Ser467Cys (four), Trp283Cys (one) and Met179Leu (one). In vitro expression studies in HEK cells indicated that Ser467Cys and Trp283Cys, but not Met179Leu, significantly reduced L-carnitine uptake relative to the normal control. Trp132X and Ser467Cys were associated with specific haplotypes, suggesting a founder effect. A conservative estimate of the overall prevalence of heterozygotes was 1.01% in the Akita prefecture, Japan, giving an estimated incidence of primary systemic carnitine deficiency (MIM 212140) as 1 in 40 000 births. An echocardiographic study of the families of patients with primary carnitine deficiency revealed that the heterozygotes for OCTN2 mutations were predisposed to late onset benign cardiac hypertrophy (odds ratio 15.1, 95% CI 1.39-164) compared with the wild-types. Sequencing of DNA isolated from three deceased siblings (1.5-8 years) in two families retrospectively confirmed that all three deceased subjects were homozygous for the OCTN2 mutations.

Base Sequence↗
PubMed1999

[Diagnosis of ulcerative colitis and the biopsy method].

The biopsy specimen should be oriented flat on a ground glass slide or on a piece of filter paper so that the submucosa is on the slide and the mucosa uppermost to allow proper histopathological interpretation. It is important to perform the biopsy based on a full knowledge of features of inflammatory diseases of the large intestine. Biopsies should be taken from apparently normal and abnormal mucosa. It is necessary to observe the mucosa of the colon carefully for any mass lesions to find dysplasia or cancer complicating the ulcerative colitis. Any suspicious areas should be liberally biopsied. Biopsies should also be performed at random, because of possible existence of dysplasia or cancer which is not visible at endoscopy. This occurs especially in the rectum; biopsies can also be performed after inversion of the endoscope.

Biopsy↗
PubMed1998

Isochronous storage ring of the New SUBARU project.

The aims of the New SUBARU project are to promote industrial applications in the VUV and soft X-ray region and to develop research and development towards new light sources. The main facility of the New SUBARU project is the 1.5 GeV electron storage ring which is under construction at the SPring-8 site in Harima Science Garden City, Japan. The storage ring is quasi-isochronous and has variable momentum dispersion for the deep study of beam dynamics in very short bunches.

Journal Article↗
PubMed1998

A crowbarless power supply for klystrons.

A new crowbarless power supply is to be installed at the New SUBARU storage ring. A high-power switching inverter unit eliminates the need for expensive and unstable crowbar circuits for the klystron power supply. It also realizes a very small voltage ripple in the low-frequency region. This is an important characteristic, especially in a quasi-isochronous storage ring such as New SUBARU.

Journal Article↗