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Biomedical subjects

M Okazaki

Publications and source records attributed to M Okazaki.

At least 73 records · Page 4Linked to original sources
PubMed2001

Role of cellulose-binding domain of exocellulase I from white rot basidiomycete Irpex lacteus.

The core fragment (designated P-42), devoid of the cellulose-binding domain (CBD) in the C-terminus and prepared from Irpex lacteus exocellulase I (Ex-1), was isolated by limited proteolysis using papain. Both the hydrolytic activity and binding ability of the isolated P-42 toward insoluble cellulose were lower than those of the native Ex-1, whereas Ex-1 and P-42 showed similar hydrolytic activities toward soluble substrates. These results indicate that the CBD of I. lacteus Ex-1 is the important domain which could enhance hydrolytic activity and binding ability of the enzyme toward insoluble cellulose. In addition, the isolated P-42 was different from the native Ex-1 in terms of enzymatic properties such as pH and temperature stabilities. These differences in stability, with regard to pH and temperature, between P-42 and the native Ex-1 are probably due to the O-linked sugar chains existing in the linker region.

Journal Article↗
PubMed2001

Cloning and characterization of a chitosanase gene from the koji mold Aspergillus oryzae strain IAM 2660.

A genomic copy of the gene coding for chitosanase (csnA) was isolated from Aspergillus oryzae IAM 2660. A. oryzae csnA contains an open reading frame that encodes a polypeptide of 245 amino acids with a calculated molecular mass of 26,500 Da. The deduced amino acid sequence of A. oryzae csnA indicates extensive similarities to those of other fungal chitosanases.

Amino Acid Sequence↗
PubMed2001

Intracranial hypotension.

The authors present the case of a 55-year-old man suffering from intractable spontaneous intracranial hypotension, in whom conservative treatment with 19 weeks of bed rest was not effective. In this period the patient twice underwent surgery for bilateral chronic subdural hematoma, a complication of spontaneous intracranial hypotension. Conventional radionuclide cisternography, magnetic resonance imaging, and computerized tomography myelography did not demonstrate cerebrospinal fluid (CSF) leakage. Repeated radionuclide cisternography with the patient in an upright position revealed leakage of the tracer at upper cervical levels. Computerized tomography myelography with breath holding also showed CSF leakage of the contrast medium bilaterally at upper cervical levels. The patient underwent surgery, and bilateral C-2 and C-3 spinal nerve root pouches were sealed off from the subarachnoid space with oxidized cellulose cotton and fibrin glue. Epiarachnoid spaces around the root sleeves were also sealed to ensure complete resolution of the CSF leakage. After the surgery, the patient was completely free of the disease. In the case of intractable persistent spontaneous intracranial hypotension, surgical treatment is preferable to long-term conservative management. To identify CSF leakage, radionuclide cisternography with the patient in the upright position is useful. When obvious leakage is encountered, surgical sealing of the lesion should be performed via a subarachnoid approach.

Humans↗
PubMed2001

Molecular and epidemiological study of the first outbreak of vanB type vancomycin-resistant Enterococcus faecalis in Japan.

In July, 1999, an outbreak of vancomycin-resistant Enterococcus faecalis (VREF) with the vanB genotype occurred for the first time in Japan at Hokushin General Hospital, Nakano City, Nagano Prefecture. Four VREF strains were isolated from the clinical specimens of four inpatients, and 16 VREF strains were isolated by the screening of asymptomatic carriers and by surveillance of the hospital environment. All of the isolates possessed vanB genes. In a pulsed-field gel electrophoresis analysis, 19 out of 20 VREF isolates exhibited the indistinguishable restriction endonuclease digestion patterns of the chromosomal DNA. Additional investigation by Southern hybridization using the vanB probe implied that the vanB gene of these 19 isolates was encoded on a 110-kb plasmid. These findings indicate that the outbreak was principally caused by a single clone. The restriction endonuclease digestion patterns of the remaining single isolate was different from those of the other isolates. The vanB gene was encoded on the chromosome.

Aged↗
PubMed2001

A loop-forming duplicate recurrent laryngeal nerve: report of a case and clinical relevance in thyroid surgery.

This is a report of a unilateral loop-forming duplicate recurrent laryngeal nerve and its clinical relevance. A 72-year-old woman with a giant goiter underwent a total thyroidectomy. At operation we identified two recurrent laryngeal nerves on the right side and one on the left side. The nerve on the right was smaller and displaced laterally by the goiter, whereas the other was adjacent to the trachea and behind the goiter, and it was accidentally divided. Both nerves were united before innervating the larynx. The divided nerve was microsurgically reanastomosed but a postoperative assessment revealed hoarseness. This case report of an anomalous loop-forming duplicate recurrent laryngeal nerve indicates that it may not be sufficient to identify a single recurrent laryngeal nerve on one side during thyroid surgery especially when the observed recurrent nerve is relatively smaller than usual.

Aged↗
PubMed2001

[Outpatient chemotherapy for advanced lung cancer].

We reviewed the records of outpatient chemotherapy for advanced lung cancer in our institution. Thirty-two patients received 122 courses of cisplatin-free chemotherapy as outpatient treatments. Before outpatient treatment, every patient received the first chemotherapy as an inpatient treatment and the dose of cytotoxic drugs was reduced accordingly when side effects were judged to be untolerable. Only 1 patient needed hospitalization because of pneumonia with grade IV neutropenia. The overall response included partial responses (PR) 18%, no change (NC) 55%, progressive disease (PR) 11% and the median survival from the start of outpatient chemotherapy was 384 days. The monthly average cost of medical care per inpatient was more than three times as high as that of outpatients. Cisplatin-free chemotherapy for advanced lung cancer should be given as outpatient treatment not only to maintain the quality of life of patients, but also to restrain the total cost of medical care and to use hospital beds efficiently.

Adenocarcinoma↗
PubMed2001

Recurrent giant longitudinal duodenal ulcer with massive hemorrhage in a Helicobacter pylori-negative patient.

A 67-year-old man, in whom a linear ulcer running from the duodenal bulb to the descending part had been noted 3 years previously, was admitted to our hospital because of abdominal pain and melena. Duodenoscopy revealed a bleeding giant longitudinal ulcer, which was more extensive than before. Tests for Helicobacter pylori (Hp) were negative. The ulcer was cured by endoscopic hemostasis and repeated blood transfusions. Attention must be paid to Hp-negative post-bulbar duodenal ulcers because of the frequent complications including hemorrhage.

Aged↗
PubMed2001

[Exchange transfusions in sepsis after the pediatric open heart surgery].

We experienced 2 cases of septic children after open heart surgery. Both of them recovered by using exchange blood transfusion technique. We use irradiated and dialysed fresh blood for exchange blood transfusion. After this procedure, they recovered from sepsis, as the datas improving, white blood cell reduced from 19,700 +/- 3,710 to 8,200 +/- 2,360, CRP reduced from 5.46 +/- 1.65 to 1.89 +/- 0.70, T-Bil reduced from 7.61 +/- 2.66 to 3.02 +/- 0.89, and BUN reduced from 525.92 +/- 6.64 to 19.76 +/- 5.34. Furthermore, blood pressure and urine volume were stable between exchange blood transfusion, although after open heart surgery. Therefore this procedure has benefits for the compromised, septic patients, performed open heart surgery, because of its stability of the circulating circumstances. And using the irradiated and dialysed fresh blood provides stable condition eventhough under high dose catecholamine use.

Anti-Bacterial Agents↗
PubMed2001

Chlamydia pneumoniae infection and accelerated development of coronary artery disease in patients with chronic renal failure.

AIMS: This study examined the relationship between Chlamydia pneumoniae (C. pneumoniae) infection and the accelerated development of coronary artery disease (CAD) in patients with chronic renal failure (CRF). METHODS: Two-hundred and fourteen patients undergoing coronary angiography, including 67 controls and 147 patients with CAD (97 without CRF and 50 with CRF), were enrolled in this study. Anti-C. pneumoniae specific IgG and IgA antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: Coronary artery disease (expressed as CAD score) was more severe in patients with than without CRF (14.9 +/- 6.0 vs. 11.3 +/- 6.0, p < 0.01). Seropositive rates of IgG and IgA antibodies against C. pneumoniae were higher in all CAD patients than in the controls (76.2% vs. 44.8%, p < 0.001 for IgG; 59.9% vs. 40.3%, p < 0.01 for IgA). In both CAD subgroups, IgG seropositive rates were similarly elevated (82.0% and 73.2% vs. 44.8% for control, p < 0.001, respectively), whereas those of IgA were significantly elevated only in CAD with CRF (68.0% vs. 55.7% for control, p < 0.01). The mean antibody index of IgG was elevated in all CAD patients compared with the controls (1.9 +/- 1.0 vs. 1.3 +/- 0.9, p < 0.0001), but that of IgA was not (1.5 +/- 1.0 vs. 1.2 +/- 0.9). Levels of IgG were elevated in all patients with CAD compared with the control (2.4 +/- 1.1 and 1.8 +/- 1.0 vs. 1.3 +/- 0.9, p < 0.001 and p < 0.001, respectively), whereas those of IgA were elevated only in CAD with CRF (1.8 +/- 1.1 vs. 1.2 +/- 0.9, p < 0.05). Stepwise logistic regression analysis revealed that the elevated IgG antibody index was an independent risk factor for CAD regardless of CRF (odds ratios 1.9, 1.8, and 2.3), whereas the IgA index was a risk factor only in CAD with CRF (odds ratio 1.7). CONCLUSIONS: Chlamydia pneumoniae infection may be related to the accelerated CAD in patients with CRF, which was specifically suggested by an elevated IgA level. In other words, the prevalence of active C. pneumoniae infection is higher in patients with CAD and CRF than that in those with CAD without CRF.

Aged↗
PubMed2001

[A case of advanced gastric cancer producing alpha fetoprotein with multiple liver metastases responding to TS-1 after TAE].

We report a case of advanced gastric cancer producing Alpha Fetoprotein (AFP) with multiple liver metastases in which TS-1 is effective. Prognosis of gastric cancer producing AFP is well known to poor. A 74-year-old female was admitted complaining of anemia. She was diagnosed as having advanced gastric cancer with multiple liver metastases producing AFP by endoscopy, computed tomography and angiography. Her serum AFP level was 17,666 ng/ml and her serum CEA level was 5-2 ng/ml. After transarterial embolization (TAE), her family rejected her operation because it would not be curative. So, she was treated with TS-1, 40 mg, administered orally every day, followed by 14 days rest, as the first course. The next was TS-1, 80 mg orally administered for 6 courses. Her serum AFP level was down from 17,666 ng/ml to 94 ng/ml after 6 courses of TS-1. CT revealed that liver metastases did not change and endoscopy showed the primary lesion has diminished. Our report is the first to demonstrate that TS-1 is effective for patients with advanced gastric cancer producing AFP with multiple liver metastases.

Adenocarcinoma↗
PubMed2000

Immunoreactivity for glutamic acid decarboxylase and N-methyl-D-aspartate receptors of intracellularly labeled respiratory neurons in the cat.

In adult cats, immunofluorescence images of glutamic acid decarboxylase (GAD) and N-methyl-D-aspartate (NMDA) receptors were achieved in the ventral respiratory group (VRG) neurons, which had been individually identified by in vivo intracellular recording and labeling with neurobiotin. Among augmenting inspiratory (aug-I), postinspiratory (post-I), and augmenting expiratory (aug-E) neurons labeled, GAD-immunoreactivity was demonstrated only in those neurons that were not antidromically activated (NAA) by stimulation of the vagus nerve and the C2-C3 spinal cord. Substantial immunoreactivity for NMDA receptors was presented in virtually all types of neurons, but lesser reactivity in aug-E bulbospinal neurons. These results suggest that the aug-I, post-I, and aug-E types of NAA neurons are gamma-aminobutyric acid (GABA)ergic and that NMDA receptors distribute in lesser degree in aug-E bulbospinal neurons than in other types of VRG neurons.

Animals↗
PubMed2000

Virus-mediated transduction of apolipoprotein E (ApoE)-sendai develops lipoprotein glomerulopathy in ApoE-deficient mice.

Lipoprotein glomerulopathy (LPG) is a unique renal disease characterized by thrombus-like substances in markedly dilated glomerular capillaries, dysbetalipoproteinemia, and elevated plasma concentrations of apoE. Recent studies identified several apoE mutations in patients with LPG, including apoE2(R145P) Sendai (apoE-Sendai). Virus-mediated transduction of apoE-Sendai in apoE-deficient hypercholesterolemic mice resulted in insufficient correction of hypercholesterolemia and a marked and temporal induction of plasma triglyceride levels. In vitro binding studies showed that apoE-Sendai has a reduced affinity for the low density lipoprotein receptor, suggesting that dysbetalipoproteinemia in LPG is caused by the apoE mutation. Furthermore, histological examination revealed marked intraglomerular depositions of apoE-containing lipoproteins in mice injected with apoE-Sendai virus. These LPG-like depositions were detected 6 days after virus injection and were sustained for at least 60 days. Our results demonstrated that apoE-Sendai is an etiological cause of LPG.

Adenoviridae↗
PubMed2000

Purification and characterization of UDP-glucose: hydroxycoumarin 7-O-glucosyltransferase, with broad substrate specificity from tobacco cultured cells.

The enzyme UDP-glucose: hydroxycoumarin 7-O-glucosyltransferase (CGTase), which catalyzes the formation of scopolin from scopoletin, was purified approximately 1200-fold from a culture of 2,4-D-treated tobacco cells (Nicotiana tabacum L. cv. Bright Yellow T-13) with a yield of 7%. Purification to apparent homogeneity, as judged by SDS-PAGE, was achieved by sequential anion-exchange chromatography, hydroxyapatite chromatography, gel filtration, a second round of anion-exchange chromatography, and affinity chromatography on UDP-glucuronic acid agarose. The purified enzyme had a pH optimum of 7.5, an isoelectric point (pI) of 5.0, and a molecular mass of 49 kDa. The enzyme did not require metal cofactors for activity. Its activity was inhibited by Zn(2+), Co(2+) and Cu(2+) ions, as well as by SH-blocking reagents. The K(m) values for UDP-glucose, scopoletin and esculetin were 43, 150 and 25 µM, respectively. A study of the initial rate of the reaction suggested that the reaction proceeded via a sequential mechanism. The purified enzyme preferred hydroxycoumarins as substrates but also exhibited significant activity with flavonoids. A database search using the amino terminus amino acid sequence of CGTase revealed strong homology to the amino acid sequences of other glucosyltransferases in plants.

Journal Article↗
PubMed2000

A monolayer complex of Cu2(OH)3C12H25SO4 directly precipitated from an aqueous SDS solution.

A layered complex with the chemical composition of Cu2(OH)3C12H25OSO3 was obtained through direct precipitation from a sodium dodecyl sulfate micellar solution of Cu(II) at a nearly neutral condition (pH approximately equals 6.8). From the XRD, 13C CPMAS NMR, and the spin probe ESR observations, a modified botallackite structure with a monolayer alkyl phase was proposed for the complex. Magnetic susceptibility measurements for the complex showed that there exist at least two exchange couplings: one is positive, and its magnitude is larger than that of the other, which is negative (J approximately equals -8 K). Although the cupric ions of the complex are paramagnetic, most of those are ESR silent and only the ESR signals from defects could be observed even at 298 K. A spin clustering model has been employed to explain the magnetic properties of the complex.

Journal Article↗
PubMed2000

Apolipoprotein-mediated cellular cholesterol/phospholipid efflux and plasma high density lipoprotein level in mice.

Helical apolipoprotein(apo)s generate pre-beta-high density lipoprotein (HDL) by removing cellular cholesterol and phospholipid upon the interaction with cells. To investigate its physiological relevance, we studied the effect of an in vitro inhibitor of this reaction, probucol, in mice on the cell-apo interaction and plasma HDL levels. Plasma HDL severely dropped in a few days with probucol-containing chow while low density protein decreased more mildly over a few weeks. The peritoneal macrophages were assayed for apoA-I binding, apoA-I-mediated release of cellular cholesterol and phospholipid and the reduction by apoA-I of the ACAT-available intracellular cholesterol pool. All of these parameters were strongly suppressed in the probucol-fed mice. In contrast, the mRNA levels of the potential regulatory proteins of the HDL level such as apoA-I, apoE, LCAT, PLTP, SRB1 and ABC1 did not change with probucol. The fractional clearance rate of plasma HDL-cholesteryl ester was uninfluenced by probucol, but that of the HDL-apoprotein was slightly increased. No measurable CETP activity was detected either in the control or probucol-fed mice plasma. The change in these functional parameters is consistent with that observed in the Tangier disease patients. We thus concluded that generation of HDL by apo-cell interaction is a major source of plasma HDL in mice.

Animals↗