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Biomedical subjects

M Nishijima

Publications and source records attributed to M Nishijima.

At least 109 records · Page 6Linked to original sources
PubMed1997

Korormicin, a novel antibiotic specifically active against marine gram-negative bacteria, produced by a marine bacterium.

A novel antibiotic named korormicin was isolated from the marine bacterium, Pseudoalteromonas sp. F-420. This strain was isolated from the surface of a macro alga Halimeda sp. collected from Palau (the Republic of Belau). The planar structure of korormicin was determined by the result of 2D NMR studies and mass spectral data. Korormicin had specific inhibitory activity against marine Gram-negative bacteria, but was inactive against terrestrial microorganisms.

Anti-Bacterial Agents↗
PubMed1996

Immunochemical identification of the pssA gene product as phosphatidylserine synthase I of Chinese hamster ovary cells.

We have previously shown that a Chinese hamster ovary (CHO) cell mutant defective in phosphatidylserine synthase I recovers the enzyme activity on transfection with a pssA cDNA clone isolated from the parental CHO-K1. The resultant transfectant, CDT-1, exhibited about 20-fold higher specific activity of the enzyme in the membrane fraction than CHO-K1 cells. Polyclonal antibodies against two peptides of the predicted pssA product cross-reacted with a membrane protein having an apparent molecular mass of 42 kDa, which was overproduced in CDT-1 cells. By immunoprecipitation with the antibody, phosphatidylserine synthase I activity as well as the 42-kDa protein was eliminated from solubilized membrane proteins of CDT-1 cells. Both the enzyme activity and the 42-kDa protein of CHO-K1 cells were enriched in the mitochondria-associated membrane fraction and the microsome fraction, but neither was enriched in the mitochondria fraction or the cytosol fraction. These results suggest that the pssA gene encodes phosphatidylserine synthase I.

Animals↗
PubMed1996

Post-translational processing of the phosphatidylserine decarboxylase gene product in Chinese hamster ovary cells.

We have isolated a full-length cDNA clone of the Chinese hamster ovary (CHO) pssC gene, which encodes mitochondrial phosphatidylserine decarboxylase. The cDNA clone is capable of increasing phosphatidylserine decarboxylase activity to 11-fold in CHO-K1 cells. The pssC gene product predicted from the cDNA sequence is composed of 409 amino acid residues. In an in vitro translation system coupled with in vitro transcription, the cDNA clone directs the formation of a protein with an apparent molecular mass of 46 kDa. In CHO-K1 cells, the cDNA clone leads to the production of two major peptides with apparent molecular masses of 38 and 34 kDa, as determined by Western blotting with an antibody raised against a recombinant pssC protein. When CHO-K1 cells transfected with the cDNA clone are labelled with [35S]methionine for a short period, proteins immunoprecipitated with the antibody lack radioactive 38 and 34 kDa peptides, but contain two radioactive peptides with apparent molecular masses of 46 and 42 kDa instead. The pssC gene product predicted from the cDNA sequence has, near its C-terminus, a unique Leu-Gly-Ser-Thr sequence which is known as a processing site for Escherichia coli phosphatidylserine decarboxylase. A mutant pssC cDNA clone, in which Ser378 in the conserved sequence is replaced by Ala, leads to overproduction of 46, 42 and 38 kDa peptides, but not a 34 kDa peptide. This mutant clone is incapable of increasing phosphatidylserine decarboxylase activity, in contrast to the wild-type clone. These results indicate that the processing at the Leu-Gly-Ser-Thr sequence is essential for formation of the active enzyme. Thus, the pssC gene product is converted into mature phosphatidylserine decarboxylase through multiple steps of post-translational processing.

Amino Acid Sequence↗
PubMed1996

Acute pathologic features with angiographic correlates of the nearly or completely occluded lesions of the cervical internal carotid artery.

BACKGROUND: The true pathologic process of nearly or completely occluded lesions of the cervical internal carotid artery (ICA) has not been studied sufficiently. This information is important in determining the critical indications for endarterectomy. METHODS: Acute pathologic features of these advanced occlusive lesions of the ICA were studied in 40 patients who underwent emergency carotid endarterectomy. Gross morphologic and histopathologic features of these occlusive lesions were examined, and the relationship between the clinical information and the pathologic characteristics was investigated. RESULTS: Thirty-seven lesions had histologic features of advanced atherosclerosis complicated by fresh intraplaque hemorrhages with or without transintimal extension. Thinwalled neovessels were thought to be an important etiologic factor in producing intraplaque hemorrhage. The remaining three lesions without these changes had strangulated embolic material at the occluded portion. A good correlation between these pathologic features and angiographic findings was found. CONCLUSION: The presented results clearly indicate that intraplaque hemorrhage is the most important factor in producing and determining the acute pathologic features of symptomatic and advanced atheromatous occlusive ICA lesions.

Acute Disease↗
PubMed1996

Separation of carnitine enantiomers as the 9-anthroylnitrile derivatives and high-performance liquid chromatographic analysis on an ovomucoid-conjugated column.

9-Anthroylnitrile was used as an achiral reagent for the derivatization of carnitine. The reagent forms UV-absorbing derivatives with the hydroxyl groups of carnitine enantiomers under very mild conditions. The derivatives were separated by high-performance liquid chromatography on an ovomucoid-conjugated column with a mobile phase of acetonitrile-20 mM KH2PO4 (adjusted to pH 4.5 with phosphoric acid) (17:83, v/v). The separation factor (alpha) and resolution (Rs) of the enantiomers were 1.44 and 5.05, respectively. The calibration plots indicated good linearity over a sample concentration ranging from 0.2 to 1.0 mg ml-1, and the detection limit at 254 nm was 0.05 mg ml-1 for each carnitine enantiomer. The reproducibility in the analysis of 1 mg ml-1 of each enantiomer was within 2.0%. The method was applied successfully to the determination of carnitine enantiomers in pharmaceutical preparations.

Anthracenes↗
PubMed1996

Cloning, expression and characterization of plasma platelet-activating factor-acetylhydrolase from guinea pig.

In a previous study, we purified PAF-acetylhydrolase, which converts PAF to an inactive metabolite, lysoPAF, from peritoneal fluid of guinea pigs subjected to experimental endotoxin shock and found that this purified enzyme had similar biochemical properties to the plasma enzyme [Karasawa, K., Yato, M., Setaka, M., and Nojima, S. (1994) J. Biochem. 116, 374-379]. In this study, we isolated a homogeneous enzyme preparation from guinea pig plasma using a similar procedure. The molecular mass of this purified enzyme, as determined by SDS-PAGE was 58-63 kDa, larger than that (43 kDa) of the human enzyme. To elucidate the molecular structure of this enzyme and clarify its relationships with PAF-acetylhydrolases of other species, we isolated and sequenced a cDNA encoding this enzyme. Its cDNA contains an open reading frame encoding 436 amino acids and its predicted molecular mass (49 kDa) is lower than that of the native enzyme, suggesting that guinea pig plasma PAF-acetylhydrolase, unlike the human enzyme, is modified post-translationally, perhaps by glycosylation.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1996

[Stability of phenyl salicylate in alcoholic-aqueous solution].

The stability and degradation pathways of phenyl salicylate (PS) in 50 v/v% aqueous ethanol were investigated over the pH range of 3.2-8.4. The experiments were performed at three different temperatures (5, 23 and 50 degrees C) for four months by the use of high performance liquid chromatography. The degradation of PS was observed as a pseudo first-order kinetics not only in the alkaline region but in the acidic region and shown to proceed via transesterification (k1) and hydrolysis (k2) processes. The transesteified product, ethyl salicylate (ES), further underwent hydrolysis (k3) (k1 > k2 > k3). On the basis of kinetic studies, it was found that the degradation rate of PS decreased with decreasing pH and temperature. The half-lives of PS at pH 6.3 were 6.6 d (50 degrees C), 178 d (23 degrees C) and 2934 d (5 degrees C), respectively, and PS was stable at below ca. pH 4. On the other hand, PS in 100% ethanol also underwent the breakdown to ES by k1 process and its half-lives were 2.5 d (50 degrees C), 31.5 d (23 degrees C) and 257 d (5 degrees C), respectively. The present results is useful for the integrity of pharmaceutical formulations and delivery profiles.

Chromatography, High Pressure Liquid↗
PubMed1996

Immunochemical characterization of alkaline-soluble polysaccharide, P-1, from the kernels of Prunus mume Sieb. et Zucc.

Polyclonal antibodies against P-1, a pectic polysaccharide fraction extracted with 0.5 M NaOH from the kernels of Prunus mume and consisted of arabino-galacturonan, and I-3, the partial acid (0.1 M trifluoroacetic acid) hydrolysate of P-1, were prepared in Japanese white rabbits. Competitive ELISA experiments strongly suggested that anti P-1 and anti I-3 antibodies were different but P-1 and I-3 cross-reacted with each other to recognize a partly similar epitope structure. The reactivities of polysaccharide fractions from the raw flesh of P. mume, and the kernels of apricot and peach extracted with either water or sodium hydroxide were examined using both antisera by the indirect competitive ELISA method. The polysaccharide fractions extracted with sodium hydroxide solutions had the reactivities but not those extracted with cold and hot water. These facts suggested that the similar structure of polysaccharides to P-1 was present in the flesh of P. mume and the kernels of apricot and peach. However, neither pectin of apple nor citrus had reactivity with each antiserum. P-1 would be different in chemical structure from a commercially available pectin, a water-soluble polysaccharide from apple and citrus.

Animals↗
PubMed1996

Architecture of alkaline-soluble and bioactive polysaccharide from the kernels of Prunus mume Sieb. et Zucc. assessed by anti P-1 antibody.

P-1 was partially hydrolyzed with 0.01, 0.05, and 0.1 M trifluoroacetic acid (TFA), successively, and the dialyzable (E-1, E-2, and E-3) and non-dialyzable (I-1, I-2, and I-3) fractions were prepared and analyzed chemically and immunochemically. Either I-1 or E-1 reacted with anti P-1 serum as strongly as P-1 and were mitogenic. The cross-reactivity of I-2 and I-3 was less than I-1 with anti P-1 serum. However, they were as mitogenic as I-1. The cross-reactivity of E-2 and E-3 to anti P-1 serum was also very weak, and they were not mitogenic. The E-1 fraction had a similar sugar composition to I-1 and P-1. E-2 was a monosaccharide, all of Ara, and would be from the linkage of furanosyl residues in P-1. The composition of E-3 was free from Ara and the structure of E-3 was similar to that of I-3. E-3 would be considered to be deleted arabinofuranose from E-1. These results suggest that the mitogenic activity measured by the alkaline phosphatase assay is a property of the core part, I-3, but that P-1 contains several epitopes other than the core part by the immunochemical analysis.

Animals↗
PubMed1996

Fetal circulatory responses during maternal bleeding.

The purpose of this study was to investigate the fetal circulatory responses during maternal hemorrhage. Five pregnant goats with fetuses with a mean gestational age of 132 +/- 2 days were used. The maternal blood was withdrawn at 350 ml/h for 2 hours (e.g. 700 ml, 11.9 ml/kg maternal weight) and reinfused at the same speed. During maternal bleeding, maternal arterial pressure (MAP) gradually decreased. As a result of this maternal hypotension, fetal arterial pO2 and pH decreased, and PCO2 increased. After the reinfusion, fetal pO2 recovered but pH and PCO2 did not recover. Fetal arterial pressure (FAP) increased and heart rate (FHR) decreased during maternal bleeding and returned to the control level, after the reinfusion. Fetal arginine vasopressin (AVP) concentration increased to 401.2 +/- 318.5 pg/ml at the maximum bleeding. There were significant positive correlation between AVP concentration and FAP, and negative correlation between AVP and FHR during maternal bleeding. Therefore, we concluded that 700 ml maternal bleeding for 2 hours resulted the decrease in fetal pH, pO2, and FHR, and increase in PCO2, FAP, and AVP concentration. Fetal pH, PCO2, and AVP did not return to the control level in spite of reinfusion.

Animals↗
PubMed1996

Elevated plasma basic fibroblast growth factor in brain tumor patients.

We attempted to determine whether the plasma concentration of basic fibroblast growth factor (bFGF) was elevated in brain tumor patients. The plasma concentration of bFGF was measured in 55 brain tumor patients and 17 normal subjects by enzyme immunoassay. Upper limit of plasma bFGF in the normal subjects was 1.6 pg/ml. Elevated plasma bFGF levels were observed in 28 patients including 13 of 17 glioma patients, eight of 19 benign tumor patients, and seven of 19 malignant tumor patients. Twelve of 14 malignant glioma patients had elevated plasma bFGF levels. There was a good correlation (r = 0.42, p < 0.05) between the elevated plasma bFGF level and the tumor volume. Further studies are needed to determine whether the plasma bFGF level is a clinically useful diagnostic and prognostic marker for patients with brain tumors.

Adult↗
PubMed1996

Halymecins, new antimicroalgal substances produced by fungi isolated from marine algae.

Novel antimicroalgal substances halymecins A (1), B (2) and C (3) were isolated from the fermentation broth of a Fusarium sp. and halymecins D (4) and E (5) from an Acremonium sp. The structures of these halymecins, Fig. 1, were determined based on extensive 2D NMR studies as well as mass spectral data. These chemical structures are conjugates of di- and trihydroxydecanoic acid. Halymecin A showed antimicroalgal activity against Skeletonema costatum.

Acremonium↗
PubMed1996

[Comparison of fetal circulatory responses during maternal bleeding and fetal bleeding].

The purpose of this study was to compare the fetal circulatory responses during maternal hemorrhage and fetal hemorrhage. Four pregnant goats, gestational age 131 +/- 7 days for the fetal hemorrhage and 5 goats, 132 +/- 2 days (term 145 days) for the maternal hemorrhage were used. The amounts of hemorrhage were 700ml per 2 hours for the maternal hemorrhage and 40ml per 2 hours for the fetal hemorrhage. Although fetal arterial pH decreased during both hemorrhages, fetal arterial pO2 increased during the fetal hemorrhage and decreased in the maternal hemorrhage. The fetal arginine vasopressin concentration and plasma renin activity increased during both hemorrhages, but the rates of change in the hormone concentrations were higher during the fetal hemorrhage. The fetal aldosterone concentration decreased during maternal hemorrhage but increased during fetal hemorrhage. FAP increased and FHR decreased during maternal hemorrhage. FAP and FHR were significantly correlated to the AVP concentration. These relationships were not found during fetal hemorrhage. We therefore concluded that fetal responses were completely different in pO2, FAP and FHR during the maternal and fetal hemorrhages.

Aldosterone↗
PubMed1996

[Phase II study of paclitaxel (BMS-181339) in patients with ovarian cancer by 3-hour intravenous infusion].

A phase II study of Paclitaxel in patients with ovarian cancer by 3-hour intravenous infusion was undertaken by a cooperative study group of 30 institutes. Of 66 cases enrolled, 57 cases were evaluable for efficacy, and 63 cases were evaluable for safety. In spite of the fact that all cases for efficacy evaluation were previously treated with chemotherapy including platinum-based drugs, 2 cases of complete response (CR) and 15 cases of partial response (PR) were observed, with a response rate of 29.8% (The 95% confidence interval of response rate was 18.4-43.4%). Paclitaxel also showed 28.2% (11/39) response rate in patients refractory to treatment by platinum-based drugs. Histologically, the response rates were 28.9% (11/38) in serous adenocarcinoma, 40.0% (2/5) in clear cell adenocarcinoma and 25.0% (1/4) in mucinous adenocarcinoma. As the major laboratory abnormalities, leukopenia, neutropenia and decrease in hemoglobin were observed with incidence rates of 98.4% (62/63), 95.2% (59/62) and 85.7% (54/63), respectively. However, these abnormalities were clinically manageable by either withdrawal of medication, administration of antibiotics, G-CSF or metachysis etc. In addition, thrombocytopenia, elevation in GOT and GPT were seen with moderate incidence. Peripheral neuropathy was a major adverse symptom with an incidence of 79.4% (50/63), followed by alopecia, myalgia, arthralgia and fever. However, the majority of these adverse reactions were less than grade 3. From these findings, we confirmed that 3-hour intravenous infusion of Paclitaxel was a clinically useful chemotherapeutic agent in patients with ovarian cancer.

Adult↗
PubMed1996

[Significance of fetal arterial oxygen saturation (SpO2) monitoring].

The significance of fetal arterial oxygen saturation (SpO2) monitoring and its relationship with FHR patterns were studied. Continuous fetal SpO2 was obtained by infrared pulse oximetry (Nellcor N-400) in 76 cases. After amniotomy, a reflectance fetal oximetry sensor (Nellcor FS-10) was placed onto the fetal cheek. The relationship between SpO2 and FHR pattern was then studied and the following results were obtained. 1. Mean recording time was 218 min. and satisfactory records were obtained during 75% of that time. 2. Whenever the FHR was reassuring, the range of SpO2 was stable within 40-80%. 3. Variations in SpO2 values were noted during decelerative patterns. When the FHR was not reassuring, the SpO2 value tended to be lower than 40%. A more acidotic tendency was found in cases where SpO2 was below 40% prior to delivery (umbilical arterial pH 7.135 +/- 0.100 vs 7.282 +/- 0.047, p < 0.005). 4. In cases of fetal arrhythmia (congenital complete heart block 3, supra ventricular tachycardia 1), SpO2 monitoring seemed to be an effective tool for fetal surveillance during labor. Fetal SpO2 measurement seemed to be an alternative to scalp blood sampling and is especially effective in cases with a nonreassuring or uninterpretable FHR pattern such as fetal arrhythmia.

Arrhythmias, Cardiac↗