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Biomedical subjects

A Tsuji

Publications and source records attributed to A Tsuji.

At least 235 records · Page 13Linked to original sources
PubMed1995

[Comparison of MICs of new quinolones obtained using agar-dilution and broth-microdilution procedures].

Minimum inhibitory concentrations (MIC) of new quinolones against both Gram-positive and Gram-negative bacteria obtained using agar-dilution and broth-microdilution procedures were compared. A primary regression curve and a correlation coefficient (r) between 2 MICs for each of ofloxacin, ciprofloxacin, tosufloxacin, sparfloxacin or balofloxacin were calculated. For the 5 quinolones, average correlation coefficients were 0.891 for the Gram-positive bacteria tested, and 0.865 for the Gram-negative bacteria. The range of, correlation coefficients for the Gram-positive bacteria for these drugs was from 0.835 to 0.919, and that for the Gram-negative bacteria was from 0.815 to 0.865. From these data, it is clear that there is a good correlation between the 2 MICs of the new quinolones obtained using the agar-dilution and the broth-microdilution procedures. It was also shown that the value of the slope of the regression curves were nearly the same for the 5 quinolones tested. However, some particular strains of Morganella morganii, Pseudomonas cepacia, Xanthomonas maltophilia, Pseudomonas aeruginosa and Streptococcus pneumoniae exhibited different correlation coefficients from other strains.

Bacteria↗
PubMed1995

[Congenital dermoid cyst over the anterior fontanelle: case report].

We report a case of a 35-month-old Japanese boy harboring a dermoid cyst in the region of the anterior fontanelle, which is rarely reported among Japanese. A small soft subcutaneous mass was noticed in the mid-frontal region at the age of 6 months. On admission, a soft, nontender round mass (2.5cm in diameter) was located over the anterior fontanelle. Transillumination was negative. Neurological examination yielded normal findings. MRI showed a well-circumscribed mass, which was slightly hypointense on T1W1 and hyperintense on T2W1. Midsagittal MRI showed no intracranial extension. At operation, a well-encapsulated mass was found beneath the pericranium, which was easily dissected from the underlying dura mater and removed. The tumor contained caseous material and several hairs. Microscopically, the cyst wall consisted of connective tissues lined by stratified squamous epithelium. Sebaceous glands and hair follicles were found in the subepithelial layer. It is important to confirm preoperatively whether or not the extracranial mass extends into the intracranial cavity. For this purpose, midsagittal or coronal MRI seems to be most useful.

Child, Preschool↗
PubMed1995

[A case of successful acute revascularization using a long vein graft].

We experienced a case of successful acute revascularization using a long vein graft. A 68-year-old man was admitted to our department due to transient ischemic attack of the left hemiparesis. CT scan showed no infarction, but PAO-SPECT revealed moderate hypoperfusion in the right ACA and MCA area. Cerebral angiography demonstrated right IC occlusion at its origin and moderate collateral circulation via leptomeningeal anastomosis from the PCA area, and via the external carotid system, especially directly from STA. But the STA was very narrow. Three days after admission, left hemiparesis appeared again and deteriorated severely. This time the hemiparesis persisted. Although MRI demonstrated little infarction in the right frontal lobe, we decided to carry out revascularization on the same day. Right saphenous vein was harvested for a graft because of the narrow STA. The facial artery and angular artery was selected as a donor and a recipient respectively, to avoid a clamp of the EC and a craniotomy of the STA running area. Finally we performed a facial artery-vein graft-angular artery (M4) bypass. The patient showed no complication and the left hemiparesis improved enough to allow the patient to walk by himself. Revascularization using vein graft is dangerous for acute ischemia due to the possibility of a complication such as brain edema and hemorrhagic infarction. The usual style of vein graft bypass is an EC-vein graft-M2 or M3 bypass. Using this style, high pressure inside the EC is carried intracranially.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

Quantitative relationship between structure and peritoneal membrane transport based on physiological pharmacokinetic concepts for acidic drugs.

To describe quantitatively the peritoneal transport of drugs, the kinetic model, which involves changes in the volume and osmolality of the dialysate as well as the diffusion and convection of drugs across the peritoneum, was applied. The apparent peritoneal permeability (Pd) of unbound drugs in rats and the partition coefficient (Papp) in an octanol:water system at pH 7.4 were estimated among acidic drugs. Using the values of unbound fraction (fS), the Pd values of the drugs were estimated from concentration-time profiles in serum and the peritoneal dialysate after intraperitoneal administration of drugs. The intrinsic membrane permeability (Pdm) was calculated based on a physiological pharmacokinetic model. The fS.Pdm values of thiopental and thiamylal (6.5 and 5.4 ml/min) were 2-3 times greater than the effective peritoneal blood flow, indicating that the peritoneal transport of the barbiturates with high lipophilicity was dominantly blood flow-limited. Evidence shows a high degree of correlation between log Pdm and log Papp. By considering the relationships, we estimated the Pdm of quinolonecarboxilic acids. The fS.Pdm values of quinolonecarboxilic acids were < 10% of the peritoneal effective blood flow rate, indicating that the peritoneal transport of quinolonecarboxilic acids was dominantly diffusion-limited because of low lipophilicity. In conclusion, there was a good correlation between log Pdm and log Papp. The prediction of Pdm can be useful to describe the peritoneal pharmacokinetics.

Acids↗
PubMed1994

In vivo evidence for ATP-dependent and P-glycoprotein-mediated transport of cyclosporin A at the blood-brain barrier.

To evaluate the significance of P-glycoprotein (P-gp)-mediated active efflux on the blood-brain barrier (BBB) permeability of cyclosporin A (CsA) in vivo, we investigated the effects of ATP depletion in the brain and of a multidrug-resistant (MDR) reversing agent on the transport of CsA across the BBB. Using transient brain ischemia obtained by 4-vessel occlusion of vertebral and common carotid arteries in rats to deplete ATP content in the brain, the estimated permeability surface area product (PS) value of [3H]CsA was increased 2.7-fold compared with that in normal rats, whereas the PS value of [14C]sucrose was not altered. Additionally, when quinidine hydrochloride (QND) was infused into the brain through a microdialysis probe implanted in the rat hippocampus, the extravascular extraction of CsA was increased to approximately 2.5-fold of the control, whereas no difference in the extravascular extraction between control and normal rats having no implanted dialysis probe was observed. Furthermore, the efflux rate from brain to blood of CsA was decreased remarkably to 5% of control at steady-state by co-administration of CsA with QND directly into the brain through the dialysis probe. The ATP-dependent and QND-sensitive efflux of CsA from the brain strongly indicates that P-gp in the brain capillary endothelial cells functions as an efflux pump under the physiological state, and that P-gp-mediated efflux of CsA is a major mechanism of the restricted transfer from blood into the brain.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Analysis of polymerase chain reaction-product by capillary electrophoresis with laser-induced fluorescence detection and its application to the diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency.

Capillary gel electrophoresis with laser-induced fluorescence (CGE-LIF) has been developed to detect polymerase chain reaction (PCR) amplified samples. LIF detection was performed using Thiazole Orange as the fluorescent intercalating dye. This method was ca. 100x as sensitive as that with UV detection. The highly sensitive CGE-LIF was applied to the detection of the most prevalent mutation (lysine329-to-glutamic acid substitution) in medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency. The disorder, which shows an autosomal recessive inheritance, is known to be highly prevalent among Caucasian population and often mimics as Reye-like syndrome or sudden infant death. A DNA fragment containing the mutation site was PCR-amplified with two sets of allele specific oligonucleotide primers, followed by CGE-LIF. The mutant allele produced a 175-base pairs DNA fragment, which the normal allele generated a 202-base pairs DNA fragment. CGE-LIF clearly distinguished these PCR products, facilitating rapid diagnosis of MCAD deficiency.

Acyl-CoA Dehydrogenase↗
PubMed1994

Functional expression of intestinal dipeptide/beta-lactam antibiotic transporter in Xenopus laevis oocytes.

An intestinal active transport system specific to small peptides and peptide-like drugs such as beta-lactam antibiotics was functionally expressed in Xenopus laevis oocytes after microinjection of messenger RNA (mRNA) derived from rat intestinal mucosal cells. The transport activity was evaluated by measuring the uptake of a tripeptide-like cephalosporin antibiotic, ceftibuten, which has high affinity for the intestinal peptide/H+ co-transporter and is resistant to peptidases. Ceftibuten transport in mRNA-injected oocytes was pH dependent (a proton gradient is the driving force), stereo selective (uptake of the cis-isomer of ceftibuten was about 4-fold higher than that of the trans-isomer), saturable and temperature dependent. Furthermore, various dipeptides showed cis-inhibitory and trans-stimulatory effects on the uptake of ceftibuten by mRNA-injected oocytes, suggesting that ceftibuten and dipeptides are transported by a common carrier protein. These results are in accordance with the functional properties of native proton-coupled peptide transporter previously clarified by studies with isolated intestinal brush-border membrane vesicles and other experimental systems. A protein with a molecular mass of about 130 kDa expressed in the membrane of mRNA-injected oocytes was identified as the transport protein by specific labeling with a photoreactive beta-lactam antibiotic, [3H]benzylpenicillin, followed by SDS-PAGE analysis of the radiolabeled protein. Furthermore, an experiment with mRNA size-fractionated by sucrose density gradient centrifugation indicated that the peptide transporter is encoded by mRNA of between 1.8 and 3.6 kb. These results, obtained using a heterologous gene expression technique, confirm that intestinal absorption of beta-lactam antibiotics occurs through a carrier-mediated mechanism and show that biologically stable beta-lactam antibiotics can be useful probes for molecular analysis of intestinal peptide transporter.

Affinity Labels↗
PubMed1994

The tissue distribution of mRNAs for the PACE4 isoforms, kexin-like processing protease: PACE4C and PACE4D mRNAs are major transcripts among PACE4 isoforms.

In the previous study [Biochem. Biophys. Res. Commun. (1994) 200, 943-950] we identified two novel cDNAs (PACE4C and PACE4D) encoding human Kexin-like protease, the PACE4 isoforms. In this study, we examined the expression of PACE4 isoform transcripts in various rat tissues. To detect very low levels and to distinguish among these isoforms, we used the reverse transcriptase-polymerase chain reaction (RT-PCR). PACE4C and PACE4D transcripts were detected in most tissues like PACE4A transcripts, however their tissue distribution profiles and the extent of expression differ. PACE4C and PACE4D transcripts are expressed at a much higher level than PACE4A transcript. These results indicate that PACE4C and PACE4D mRNAs are major transcripts of PACE4.

Animals↗
PubMed1994

A novel member, PC7, of the mammalian kexin-like protease family: homology to PACE4A, its brain-specific expression and identification of isoforms.

By polymerase chain reaction (PCR) with primers corresponding to the sequences of catalytic domain conserved among the mammalian kexin-like protease family, a cDNA fragment encoding a novel member of the family was obtained from rat pituitary. A cDNA for the novel protease was obtained from three overlapping clones isolated from a rat pituitary cDNA library using the PCR product as a screening probe. The protein, designated as PC7, encoded by this cDNA contained a putative activation site with the sequence RXKR, subtilisin-like catalytic domain and a homo B region which are typical of mammalian kexin-like proteases, and short cysteine-rich region at the carboxyl-terminal end. It exhibited surprising sequence similarity to PACE4A. The PC7 transcript was expressed at high levels in the brain. However it was undetectable in the liver, kidney, heart, and spleen. The presence of PC7 isoforms (PC7A and PC7B) was also shown.

Amino Acid Sequence↗
PubMed1994

Identification of novel cDNAs encoding human kexin-like protease, PACE4 isoforms.

PACE4 has been identified as a second human subtilisin-like protease by Keifer et al. [DNA and Cell Biology (1991) 10, 757-769]. In this study, we isolated two novel cDNAs coding for PACE4 isoforms (PACE4C and PACE4D) from a human placenta cDNA library. The deduced PACE4C protein sequence (652 amino acids) lacks the cysteine-rich region located at the carboxy terminus of PACE4. The DNA sequence of the 3'-untranslated region (1 kb) of PACE4C is not homologous to the PACE4 sequence. The protein (497 amino acids) encoded by PACE4D cDNA lacks a signal peptide, a propeptide and the cysteine-rich region. These isoform cDNAs were also isolated from rat pituitary cDNA library.

Amino Acid Sequence↗
PubMed1994

Analysis of polymerase chain reaction product by capillary electrophoresis and its application to the detection of single base substitution in genes.

Capillary gel electrophoresis (CGE) was studied for the direct analysis of polymerase chain reaction (PCR) amplified samples. A low cross-linked polyacrylamide gel (3%T, 0.5%C) was used for CGE with treated and untreated silica capillaries. CGE showed high reproducibility and resolution in the separation of DNA fragments (ca. 100-1000 base pairs) produced by PCR. The CGE system was applied to the detection of an amplification refractory mutation system (ARMS) and PCR-restriction fragment length polymorphism (PCR-RFLP), which are detection methods of single base substitution in genes using PCR. With the CGE system, full automation of PCR product detection is feasible.

Bacteriophage phi X 174↗
PubMed1994

Identification of targeting proteinase for rat alpha 1-macroglobulin in vivo. Mast-cell tryptase is a major component of the alpha 1-macroglobulin-proteinase complex endocytosed into rat liver lysosomes.

The alpha 1-macroglobulin-proteinase complex endocytosed into rat liver lysosomes was purified by a series of column chromatographic steps on concanavalin A-Sepharose, Sephacryl S-300, DEAE-cellulose and TSK gel DEAE-5PW columns. The complex contained no detectable alpha 2-macroglobulin. Studies on the substrate specificity indicated that the complex had tryptase-like activities towards various synthetic substrates, but no elastase, chymotrypsin, cathepsin-B and cathepsin-L activities. The proteinase activity was completely inhibited by di-isopropyl fluorophosphate, leupeptin and antipain, indicating that the proteinase bound to alpha 1-macroglobulin is a serine proteinase. Two protein bands (62 and 59 kDa) of the complex were labelled with [3H]diisopropyl fluorophosphate and both bands cross-reacted with anti-(mast-cell tryptase)antibody. These results suggest that mast-cell tryptase is a major targeting proteinase for alpha 1-macroglobulin in vivo. The main alpha-macroglobulin-proteinase complex in the adjuvant-treated rats was also the alpha 1-macroglobulin-tryptase complex, even though the plasma level of alpha 2-macroglobulin was elevated.

Amino Acid Sequence↗
PubMed1994

A severe outbreak of haemorrhagic colitis and haemolytic uraemic syndrome associated with Escherichia coli O157:H7 in Japan.

UNLABELLED: In 1990, an outbreak of Escherichia coli O157:H7 infection occurred in 174 children in a nursery school in Saitama, Japan. The organism was isolated from tap water supplied from the well in the school. Clinical manifestations varied from asymptomatic infection to non-bloody diarrhoea, haemorrhagic colitis, haemolytic uraemic syndrome (HUS) and death. Among culture-confirmed 42 cases of E. coli O157:H7, 7 children were asymptomatic, 21 children had only diarrhoea, and 14 children developed HUS. Bloody diarrhoea with abdominal pain following initial frequent diarrhoea appeared to be associated with subsequent HUS. In patients with HUS, both leucocyte count and lactate dehydrogenase activity continued to increase in the early phase of the disease, and on day 3 of illness attained markedly higher levels than in patients without HUS. These two parameters seemed to be important as predictors of the development of HUS. CONCLUSION: E. coli O157:H7 is a common pathogen causing colitis. It should be kept in mind in paediatric practice and public health.

Child↗
PubMed1994

Hepsin.

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Amino Acid Sequence↗
PubMed1994

Entrapping efficiency and drug release profile of an oil-in-water (o/w) emulsion formulation using a polydimethylsiloxane-coated glass bead assay.

Evaluation of entrapping efficiency is difficult for an o/w emulsion formulation containing a lipophilic oily drug, isocarbacyclin methyl ester (TEI-9090), by commonly employed techniques (dialysis, ultrafiltration, or gel filtration), because of its adsorption to the system materials. Employing this characteristic of TEI-9090, we developed an adsorption technique with polydimethylsiloxane-coated glass beads (PDMS-GB). The assay is based on the quantitative adsorption of unentrapped TEI-9090 to the PDMS-GB. The entrapping efficiency of a 10% soybean oil emulsion containing [3H]TEI-9090 (1 microgram/mL) assayed by this method approached 100%. The PDMS-GB assay was performed for the emulsion diluted 100 times with physiological saline at different time intervals after dilution over a period of 24 hr. A plot of [3H]TEI-9090 in the emulsion particles versus time showed rapid release within 1 hr, followed by very slow release, reaching equilibrium. Applying first-order kinetics, the data were found to fit to a biexponential equation over the first hour of release. The terminal release resembled the first-order release of the drug from the phospholipid-rich infranatant, which was separated from the creamy layer by ultracentrifugation of the emulsion and contained 35% [3H]TEI-9090. These results suggest that the drug is released from two components in the emulsion.

Chemical Phenomena↗