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Biomedical subjects

K Makino

Publications and source records attributed to K Makino.

At least 19 recordsLinked to original sources
PubMed1992

Purification of serine hydroxymethyltransferase from Bacillus stearothermophilus with ion-exchange high-performance liquid chromatography.

The gene of serine hydroxymethyltransferase (SHMT) of a thermophilic bacterium Bacillus stearothermophilus was expressed in Escherichia coli, and SHMT was successfully purified from the crude extract of E. coli in two steps while maintaining the enzymatic activity. The purification steps involved ammonium sulphate precipitation followed by high-performance liquid chromatographic separation using the anion-exchange column Fractogel EMD DEAE-650(S). In addition to the DEAE column, three other types of anion- and cation-exchange columns were also studied for their ability to separate SHMT, and the performance of the four columns were compared.

Ammonium Sulfate↗
PubMed1992

Hydroxyl radical formation by UV-irradiated epidermal cells.

To elucidate the mechanism of sunlight-induced skin damage, guinea pigs were exposed to UV light (280-320 nm, UV B, 4 J/cm2) and a homogenate of the epidermis was examined by means of the thiobarbituric acid (TBA) test. Three hours after the exposure, TBA-malondialdehyde adducts had increased while glutathione reductase activity had decreased, indicating lipid peroxidation. To detect the initial species, spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to a suspension of illuminated epidermal cells (0.5 J/cm2). An ESR signal obtained only with irradiation comprised a 1:2:2:1 quartet [a(N)= a(beta H) = 1.49 mT] attributable to a spin adduct of hydroxyl radicals. These results suggest that sunlight exposure of skin may lead to hydroxyl radical generation and simultaneous lipid peroxidation.

Animals↗
PubMed1992

Attenuation of immunologic reactivity of lipoprotein(a) by thiols and cysteine-containing compounds. Structural implications.

Samples of human plasma having lipoprotein(a) (Lp[a]) protein levels between 5 and 15 mg/dl and a single apolipoprotein(a) (apo[a]) isoform were incubated in vitro at pH 7.7 with various concentrations (1-20 mM) of N-acetylcysteine, homocysteine, 2-mercaptoethanol (2ME), and dithiothreitol (DTT) for 1 hour at 37 degrees C under a nitrogen atmosphere. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblot analyses using a polyclonal antibody specific for apo(a) showed a progressive decrease in apo(a) immunoreactivity as a function of reductant concentration. This decrease of apo(a) immunoreactivity was corroborated by enzyme-linked immunosorbent assay (ELISA) using anti-apo(a) as the capture antibody and either anti-apo B or anti-apo(a) as the developing antibody. In turn, there was no significant decrease in the immunoreactivity of apo B-100, as assessed by ELISA using anti-apo B as both the capture and the detecting antibody. In the case of high concentrations of DTT the plasma samples had to be diluted to prevent gel formation on addition of the reductant. A progressive drop in immunoreactivity as a function of reagent concentration was also observed in pure preparations of Lp(a) incubated with the reducing agents at pH 7.7. At equivalent stoichiometries the changes were more marked than those observed with whole plasma, suggesting a quenching effect by the plasma proteins on the activity of the reductants. The changes in immunoreactivity were attended by dissociation of apo(a) from Lp(a) as assessed by Western blotting. This dissociation, which we interpret as the result of cleavage of the interchain disulfide bond(s), was complete at 5 mM DTT and 100 mM 2ME.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcysteine↗
PubMed1992

Pediatric brain stem infarction caused by a basilar and vertebral artery occlusion: case report.

Basilar and right vertebral artery occlusion, which caused a brain stem infarction, occurred in an 11-year-old boy. There have been nine previous cases of basilar artery occlusion with steno-occlusive lesion in the vertebral artery. It is suspected that dissection of the vertebral artery at the atlantoaxial level and a gradual progression of arterial dissection to the basilar artery were the major causes of this infarction.

Brain Stem↗
PubMed1992

Multiple endocrine neoplasia type 2A.

A 40-year-old woman was admitted with complaints of headache, palpitation and diaphoresis. She had undergone right hemithyroidectomy 12 years previously. Histological reexamination of the operative specimen revealed a medullary thyroid carcinoma. Abdominal ultrasonography, CT scan and angiography showed bilateral adrenal tumors. Serum catecholamine levels in both adrenal veins were high. Based on these data, bilateral adrenalectomy was performed. Histological examination confirmed the diagnosis of pheochromocytomas. After operation, serum calcitonin and urinary noradrenaline levels were still high. Further examination by 131I-metaiodobenzylguanidine (MIBG) scintigraphy is planned.

Adrenal Gland Neoplasms↗
PubMed1992

Essential oil phenyl propanoids. Useful as .OH scavengers?

In order to search for radical scavengers which could be used as raw materials for cosmetics, phenyl propanoids (eugenol, isoeugenol, dehydrodieugenol, dehydrodieugenol B and coniferyl aldehyde) were examined for their hydroxyl radical (.OH) scavenging ability. A Fenton system was used to produce .OH. In order to see scavenging by these phenyl propanoids, competition reactions between a spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and these phenyl propanoids for .OH were studied. The relative yield of the spin adduct of .OH (DMPO-OH) was measured by electron spin resonance spectroscopy. The approximate rate constants of the reactions between these phenyl propanoids and .OH estimated by measuring the reduced height of the ESR signals of DMPO-OH were found to be at least in the order of 10(9) M-1 s-1 (diffusion-controlled). Also, using the TBA tests, the reactions between .OH and several compounds reactive with .OH were investigated in the presence of the phenyl propanoids and it was found that the phenyl propanoids compete with such reactive compounds for .OH. These results indicate that these phenyl propanoids can be used as antioxidants for skin damage perhaps caused by .OH generated by UV-light.

Animals↗
PubMed1992

Interaction of antisense DNA with nucleic acids/proteins.

In order to study interaction of various types of labeled antisense DNAs were prepared. Fluorescein and 2,2,6,6-tetramethypiperidine-N-oxyl were the label molecules, which were introduced to 5'-end of oligonucleotides and their analogs. Interactions of labeled antisense DNAs with nucleic acids or proteins such as HSA, HIG and TF, were studied by UV, fluorescence depolarization spectroscopy, and ESR spectroscopy. Hybrid formation of antisense DNAs with oligonucleotides in solution could be monitored by the increase in fluorescence anisotropy (r) and by intensity change in ESR spectra. When phosphorothioate type antisense molecules anchoring fluorescein (F-OPT) were mixed with proteins, r drastically increased, whereas ODN slightly increased. These results suggest that OPTs have much more affinity for proteins than ODNs.

Blood Proteins↗
PubMed1992

Syntheses and properties of fluorescent labeled oligonucleotides containing deoxyethenoadenosine at 5' end.

The fluorescent labeled oligodeoxyribonucleotides which contain deoxyethenoadenosione (d epsilon A) at their 5' end were prepared by treating CPG bound oligonucleotides with 5'-DMTr-deoxyethenoadenosine-3'-H-phosphonate. The hybrid formation of d epsilon A-oligonucleotide with its complementary DNA was studied by fluorescence spectroscopy. The fluorescence of d epsilon A in a single strand was largely quenched by stacking interaction with the base at 3' position. When d epsilon A-oligonucleotides hybridized with their complementary strands, relative fluorescence quantum yields (Qrel) against d epsilon A changed in specific manners. These results suggest that d epsilon A-oligonucleotides are applicable to study the local structure of DNA in solution.

Base Sequence↗
PubMed1992

Separation and characterization of diastereoisomeric oligonucleotide.

For developing the antisense method, two types of oligonucleotides suitable for antisense molecules were explored for their essential properties. One is oligonucleoside phosphorothioate, and all their possible R/S diastereoisomers were separated and purified by reversed phase liquid chromatography. Isolated diastereoisomers have been investigated for the correlation between their configuration and hybridization manner. Separation, R/S characterization and spectroscopical properties of these oligonucleotides will be discussed.

Chromatography, High Pressure Liquid↗
PubMed1992

Effects of base damages on DNA replication--mechanism of preferential purine nucleotide insertion opposite abasic site in template DNA.

DNA polymerase preferentially inserts purine nucleotides opposite non-instructive lesions such as abasic sites during DNA replication. In order to elucidate the mechanism of the preferential insertion, a DNA template containing a model abasic site and primers containing 4 different nucleotides (A,G,C,T) at primer terminus were synthesized. The stability of the primer terminus nucleotide placed opposite the abasic site was evaluated on the basis of its sensitivity to 3'-5' exonuclease associated with DNA polymerase.

DNA↗
PubMed1992

NMR studies on solution structure of single-stranded oligonucleotides causing line broadening.

Unusual line broadening of 1H-NMR lines attributable to the proton (8H) of guanine residues was observed for all tetradeoxyoligonucleotides tested here which have a specific base sequence of dGXXG (X = A or T). For the same samples, line broadening was also obtained in the 31P-NMR spectra. These broadened signals did not become sharp up to 60 degrees C. This unusual spectral phenomenon has been attributed by 2D-NMR and differential NOE to the compact solution structure of the oligonucleotides.

Magnetic Resonance Spectroscopy↗
PubMed1992

Sequence-specific DNA recognition by basic peptides.

A chiral template with C2 symmetry has been used for modeling a dimeric interface of DNA binding protein. An oligopeptide derived from the basic region of MyoD, a recently described "helix-loop-helix" class of DNA binding protein, has been tethered to the template. Among the four models which differ in chirality and polarity with respect to the arrangement of two subunits, only one dimer model with right-handed and C-terminus to C-terminus arrangement of the peptide subunits binds DNA containing native MyoD binding sequence.

DNA↗
PubMed1992

Cytotoxic drug and cytotoxic drug/G-CSF mobilization of peripheral blood stem cells and their use for autografting.

We analysed 99 courses of leukapheresis after the use of cytotoxic drugs or cytotoxic drugs plus G-CSF (cytotoxic/G-CSF) to mobilize peripheral blood stem cells (PBSC) in 68 patients with hematologic or solid malignancies. Mean yields of granulocyte-macrophage progenitor cells (CFU-GM) with cytotoxic/G-CSF mobilization were significantly higher than those with cytotoxic mobilization (18.6 vs 8.40 x 10(4)/kg). The optimal timing of collection was different between these two mobilizations; the mean number of days to a peak level of circulating CFU-GM after cytotoxic/G-CSF mobilization was less than that after cytotoxic mobilization (24.2 vs 27.7 days). The leukocyte level on the day of peak CFU-GM was significantly higher in cytotoxic/G-CSF mobilization than that in cytotoxic mobilization (mean 12.8 vs 2.7 x 10(9)/l), whereas the platelet level was not different (mean 132 vs 125 x 10(9)/l). Increasing patient age was not a major adverse factor for PBSC collection. Synchronous recovery of both leukocytes and platelets was critical for achieving a high CFU-GM yield in these two mobilizations. Following PBSC autotransplantation, the rate of trilineage hematologic reconstitution showed a significant correlation with the infused dose of CFU-GM, whether they were collected with cytotoxic or cytotoxic/G-CSF mobilization. These results suggest that G-CSF can expand the PBSC pool and that CFU-GM yield after cytotoxic/G-CSF mobilization may predict trilineage hemopoietic reconstitution after ABSCT, as well as cytotoxic mobilization.

Adolescent↗
PubMed1992

Monomer-dimer equilibrium of nitroso-aromatic spin trap 3,5-dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), in aqueous solution.

3,5-Dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), which is widely used as a spin trap in biological systems, was allowed to form the monomer-dimer equilibrium in aqueous solution, and its equilibrium constant (Kc) was determined by NMR measurement and visible spectrum analysis. The Kc values obtained from the two different methods were virtually identical and evaluated as 1.3 x 10(-3) mol dm-3 at 25 degrees C. Further, the molar extinction coefficient of DBNBS monomer (epsilon 760) was determined to be 34 dm3mol-1cm-1. The present results indicate that only a minor portion (ca. 20%) of dissolved DBNBS (10 mmol dm-3) is practically capable of spin trapping under the conditions most widely used in biological studies.

Benzenesulfonates↗
PubMed1992

Comparison of 2,5,5-trimethyl-1-pyrroline-N-oxide (M3PO) and 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO) with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin traps.

2,5,5-Trimethyl-1-pyrroline-N-oxide (M3PO) and 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO) were examined for their potential as spin traps used in biological samples, and the results obtained for M3PO and M4PO were compared with those of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) reported previously. The rate constants for the reactions of M3PO and M4PO with hydroxyl radicals were in the same order of that constant of DMPO. The hyperfine splitting constants of M4PO spin adducts were as informative as those of DMPO adducts. In the presence of ferric ions, M3PO and M4PO formed 2-hydroxy-2,5,5-dimethyl-1-pyrrolidinyloxy (M3PO-OH) and 2-hydroxy-3,3,5,5-tetramethyl-1-pyrrolidinyloxyl (M4PO-OH), respectively, by the nucleophilic addition of a water molecule, as we have already reported for DMPO. M4PO-OH was subjected to oxidation by ferric ions with a rate much slower than that for DMPO-OH, while M3PO-OH was not. The results indicate that M4PO is a spin trap suitable for biological applications and that nitrones having a methyl group at C2 represent improved spin traps.

Cyclic N-Oxides↗
PubMed1992

[Dissecting aneurysm of the posterior inferior cerebellar artery; a case report].

A case of a dissecting aneurysm of the left posterior inferior cerebellar artery caused by giant cell angiitis is presented. A 22-year-old woman was admitted on August 30, 1990, with sudden onset of severe occipital headache and vomiting. Neurological examination on admission only showed severe meningismus. CT scan demonstrated subarachnoid hemorrhage and a small hematoma in the 4th ventricle. A left vertebral angiogram demonstrated that the left posterior inferior cerebellar artery was occluded at the lateral medullary segment. We diagnosed subarachnoid hemorrhage from a dissecting aneurysm. On the day following admission, the patient underwent a left suboccipital craniectomy. The posterior inferior cerebellar artery was enlarged for a distance of about 8 mm and there was typical purplish-red appearance in the dissecting aneurysm. This aneurysm was excised after trapping. The histological diagnosis was primary localized giant cell angiitis without systemic involvement. The etiology of the intracranial dissecting aneurysm is obscure, but this report suggests that cerebral angiitis can be considered as an important factor.

Adult↗
PubMed1992

[A case of extracerebral cavernous hemangioma in the middle fossa].

Authors reported an autopsy case of extracerebral cavernous hemangioma in the middle fossa and discussed the effect of irradiation therapy on it. A 72-year-old woman was admitted due to progressive deterioration of consciousness and the right hemiparesis. CT scan revealed a slightly high density mass, which was markedly heterogeneously enhanced with contrast media, in the left middle cranial fossa. Angiogram with prolonged injection demonstrated a faint tumor stain. Craniectomy and partial temporal lobectomy for decompression were performed, but the tumor could not be removed due to uncontrollable hemorrhage. Her level of consciousness further deteriorated, and in addition heart failure developed. And finally she became vegetative in spite of effective irradiation therapy of 46Gy. CT scan taken three months and seven years after the irradiation showed marked regression of the tumor. After the vegetative state for 8 years, the patient died of acute pancreatitis, and autopsy was performed. The cavernous hemangioma with markedly proliferated interstitial connective tissue and thrombosed vessels was verified by microscopical examination. Although the treatment was not successful in this patient, we confirmed that irradiation is useful in the management of the extra-axial cavernous hemangioma in the middle fossa as a pre- or postoperative adjunct therapy.

Aged↗